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Case Study

In order to reduce replacement costs and failures, a mid-size Mid-Atlantic utility engaged Xylem for help developing a machine learning approach to building a focused and cost-effective pipeline renewal strategy.

A mid-sized Mid-Atlantic utility with a reputation for taking a proactive and focused approach to continuously improving service reliability to their 270,000 customers was facing all too common situation. More than 1,000 miles of water mains across their system, with an average age of about 50 years. This had led to an increase in water main breaks, and so they started seeking innovative strategies that would improve service reliability while minimizing repair and replacement costs.

THE CHALLENGE

With water main breaks increasing, the customers served by the utility were challenged with unpredictable service outages and costly repairs as well as highly disruptive road closures. They desired to take a more proactive approach to prevent main breaks and improve their customer level of service (LoS) by focusing on the pipes that needed the greatest attention.

Previous experience in working with Xylem to manage their PCCP (prestressed concrete cylinder pipe) inventory led the utility to seek out a better replacement prioritization strategy than traditional techniques such as age and break history.

What solutions did Xylem and the utility come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

Project Highlights

Will help the utility lower their annual costs related to pipeline replacement from $90 million to just $20 million while achieving a dramatic four-fold reduction in failures.

Developed a plan to reduce customer outages and improve service reliability, while cutting replacement spending by over 70% compared to other prioritization methods.

Developed a real-time, field mobile tracking application to improve break record accuracy that reduces labor time required to update their Computerized maintenance management system (CMMS) and their geographic information system (GIS), as well as improve the output of the AI model

Services Provided

• Pipeline failure and risk analysis
• Mobile field data collection application
• Data integration with the utility’s existing systems

Case Study

In order to maximize their existing capital assets, reducing overflows and optimizing overall operation efficiency, the Metropolitan Sewer District of Greater Cincinnati (MSD) engaged Xylem in utilizing BLU-X, a drainage network optimization solution that uses a real-time decision support system consisting of smart sensors and actuators that track conveyance capacity.

Cincinnati’s sewers discharge an average of 11.5 billion gallons of combined sewage every year into the Ohio River and its tributary streams within Cincinnati’s urban watershed.

In 2002, the EPA entered into a federal consent decree with MSD, mandating the elimination of sanitary sewer overflows and significant mitigation of combined sewer overflows into receiving waterways. Engineers estimated the cost to mitigate the sewer overflows at $3.1 billion, an unacceptable capital expense to pass along to MSD’s customers.

THE CHALLENGE

Recognizing the generally inadequate stormwater management capabilities of their existing combined sewer system, MSD prepared a comprehensive wet weather improvement plan. MSD recognized that full sewer separation and deep tunnel construction are massive capital investments that have a very low return on investment because they create only episodic benefits during peak flow events and are single-use assets with little additional community wealth creation.

Instead, MSD’s objective was to maximize existing capital assets — such as sewer interceptors, storage and treatment facilities, and pump-stations — to reduce overflows and gain system-wide benefits through advanced control logic that will optimally operate MSD’s urban watershed.

What solutions did Xylem and MSD come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

Project Highlights

Overflow volumes reduced by 247 million gallons annually

More than a 90% reduction in cost compared to initial capital work estimated at $38 million

CSO mitigation achieved at a price of less than$0.01/gallon

Services Provided

• BLU-X real-time decision support system (RT-DSS) to manage storage and conveyance
• RT-DSS integrated into MSD’s existing SCADA and IT networks
• All sensor data presented on one unified platform

Case Study

In order to get a better understanding of the infiltration and inflow into their newly separated sanitary sewers, Grand Rapids engaged Xylem in utilizing BLU-X, a real-time decision support system consisting of smart sensors and actuators that track conveyance capacity.

Grand Rapids, MI is a community that has garnered accolades in the clean water industry for taking significant proactive steps to improve its sewer system. In the early 1990s, “River City” took the initiative to invest in transforming its collection system from a combined sewer system to separate storm and sanitary sewers. By moving from a single pipe for both stormwater and wastewater conveyance to separate pipes, the City avoided the introduction of sewage into its waterways, reducing overflows and subsequent pollution into the landmark Grand River that flows to Lake Michigan 40 miles downstream.

THE CHALLENGE

After nearly 25 years, Grand Rapids finished retrofitting its combined sewer overflow system to a separate sanitary and stormwater system, completing its long-term control plan (LTCP) in 2015. But now, the City needed to get a better understanding of the infiltration and inflow into these newly separated sanitary sewers to ensure compliance with a mandate from the Michigan Department of Environmental Quality (DEQ). This mandate allowed them zero overflow events of any kind, except as part of a wet weather event of a magnitude in excess of a 24-hour, 25-year storm.

For compliance purposes, the City needed analytic data to certify performance and understand how the system behaved during a wide variety of wet and dry weather conditions. While gathering this information, the City was also presented with a hydraulic report stating that areas of the community were experiencing excessive surcharging and flooding. They suspected otherwise, but needed proof to answer regulators, as mitigation to eliminate the surcharging and flooding was estimated to cost much as $1 billion; a capital expense the city could ill afford.

What solutions did Xylem and Grand Rapids come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

Project Highlights

Data demonstrated that the infiltration and inflow problem could be solved for $30-50 million as opposed to the original $1 billion estimate

Real-time decision support system brought in to help the Environmental Services Department for the sanitary system separation

City has expanded the sensor network to more parts of the system

Services Provided

• BLU-X real-time decision support system (RT-DSS) deployed to help characterize infiltration and inflow performance on sanitary lines
• All sensor data presented on one unified platform
• Integration into Grand Rapids’s existing IT networks

Utilities can save their communities substantial amounts of money, reduce the need for unaffordable rate increases or financing arrangements, and improve the environmental sustainability of their operations – all while maintaining and enhancing system control.

Around the world, critical valves are in poor repair, or even inoperable. When critical valves fail, managers have effectively lost control of their system, increasing vulnerability to water main breaks or any other system hazard. Once valves have failed, utilities have traditionally sought to replace them, often at great cost, both in terms of time and expense.

But what if there were another way? It turns out there is a far more economical, less risky, and more sustainable option: preventative maintenance, repair, and rehabilitation. High performing utilities are turning away from the wasteful practice of replacing valves that can be restored to full function, instead engaging experts in asset renewal to extend the life of those assets at a substantially lower cost.

This white paper will highlight:

  • identifying the true cost of large valve replacements
  • understanding the cost savings of a repair vs replace strategy
  • the benefits of performing routine critical valve assessments
  • what to look for in a valve assessment partner

With advancements in technology and a willingness to develop proactive pipeline integrity programs, utilities can successfully reduce failures, mitigate risk, reduce capital expenditures, and increase confidence in the overall operation of their force mains.

New standards of best practice for force main management involve a variety of methods and technologies to provide data and information with which to make decisions. Utilities can now often perform a detailed condition assessment while the force main remains in service.

There is no “one-size-fits-all” way of assessing force mains. Any approach should be tailored to risk tolerance, material, diameter and past failure history. Savvy utility managers are turning to programs that reduce damage to assets, prioritize investment to minimize community impact of asset failure, and reduce the consequence of failure by enabling system control.

This white paper will highlight:

  • how to develop a risk-based program
  • the most common modes of failure for force mains
  • how to define which of the three approaches to proactively assessing force mains best fits your goals and risk-tolerance
  • how utilities are finding success using these approaches to: prevent failures, reduce capital expenditures, mitigate risk, optimize budget allocation, and increase confidence and level of service.

Case Study

In order to proactively address the ongoing challenge of apparent water loss and make intelligent decisions regarding rates and capital expenditures, Clayton County Water Authority (CCWA) engaged Xylem to evaluate their entire metering operation.

As one of Georgia’s smallest counties in terms of land size area (only 143 square miles), Clayton County’s location near the top of a regional watershed means it has little area to gather precipitation into streams and rivers. With limited water supplies available in its own catchment area, CCWA is increasingly recognized as an industry leader for proactive water management approaches. Recently CCWA demonstrated this proactive mindset by instituting a program that would harness the power of data analytics to achieve benefits such as increased revenue, better customer care and wiser capital spending — all by targeting an invisible source of system leakage: apparent water loss.

THE CHALLENGE

Located in a state with some of the strictest efficiency and water conservation regulations in the country and a growing population, CCWA has been addressing water loss across its entire system. Apparent water loss (defined as water that is consumed, but not properly measured, accounted for or paid for) is a significant source of revenue leakage for many utilities. On average, about 5 percent of retail water is not registered at the meter, or unbilled for, representing approximately 2 percent of a utility’s top-line revenue.

In looking for an innovative solution to address these issues, CCWA was open to exploring new solutions using intelligent monitoring and management tools that allow them to undertake a prioritized, economically-justified meter replacement program. They refused to follow the status quo of random or time-based meter replacement and instead were driven to identify customer metering accuracies, quantify the apparent water loss and improve operational efficiencies — all without raising rates.

What solutions did Xylem and Clayton County Water Authority come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

Project Highlights

Over $1 million of recoverable revenue identified through meter inaccuracies over a four-year period

Identified average revenue loss of $6 (residential) to $67 (non-residential) per meter per year

Meter under-registration identified as largest contributor to apparent water loss

Realized short-term gains possible by concentrating on non-residential meters

Services Provided

• Intelligent meter management
• Apparent water loss management
• Lost revenue recovery

Case Study

The Champlain Water District utilized a variety of methods, including high-resolution inline leak and air pocket inspection, transient pressure monitoring (TPM), and a structural design check to ensure a critical transmission pipe’s design was sufficient for current operational conditions.

Champlain Water District (CWD) is an award-winning regional municipal organization that supplies drinking water to 12 municipal water systems in Vermont. As the largest water supplier in the state, CWD serves approximately 75,000 residential, commercial and industrial users. CWD draws water from Lake Champlain, and three high-value water transmission mains supply water to the user municipalities. When evidence of corrosion-related breaks was revealed in nearby distribution mains, CWD became concerned that a critical metallic water main in their system could be next.

THE CHALLENGE

After conducting their own risk prioritization plan, Joe Duncan, Chief Engineer for CWD, and his team kept with the proactive mindset and began a transmission main asset management program.

While the transmission system is relatively “young” and had no real break history, visual feedback from crews showed distribution mains in the vicinity of the transmission mains were experiencing corrosion-related breaks and in some instances looking like “Swiss cheese”. Due to the high importance of the transmission pipeline, CWD wanted to understand its condition and forestall potential corrosion issues.

What solutions did Xylem and Champlain Water District come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

VIDEO CASE STUDY

Project Highlights

Design check confirmed that the pipe design was sufficient for current loading

Acoustic monitoring identified no leaks or gas pockets

Transient monitoring revealed no harmful pressure surges

Anticipated repair funding was re-allocated to other capital work projects

Project Details

Solutions
SmartBall acoustic leak detection
Transient pressure monitoring
Strucutral analysis
Pipe Material
Ductile Iron (DIP)
Inspection Length
1.8 miles (2.9 km)
Diameter
24 inches (600mm)
Transmission Type
Water

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Whitepaper:
Metallic Pipeline Condition Assessment

Case Study

The Town of Flower Mound, Texas (Town), worked closely with Pure Technologies to conduct a leak and gas pocket detection survey of approximately 1.91 miles of potable water mains, which included nearly 1.4 miles of metallic pipelines. The Town is home to 70,000 residents and manages both the water and sewer utilities within Flower Mound.

THE CHALLENGE

In 2001 the Town suffered an uncontrolled leak and lost pressure to a third of their system for a two-day period due to a valve that could not be located. This led to an asset management program, and through this program, the 3.5 mile potable water main was identified in 2015 as a main due for inspection.

Inspecting metallic pipelines has been a challenge for utilities because historically there have been few assessment solutions available. Utilities often used indirect methods of assuming the condition of the pipeline or replaced based on age and consequence of failure, not on the actual condition of the infrastructure. The Town enlisted the help of Pure Technologies to provide a comprehensive condition assessment of key sections of their steel, ductile iron and BWP pipes in order to make balanced and accurate decisions and improve the reliability of service within the system.

How was Pure Technologies able to help the town of Flower Mound address this challenge? Find out and explore the results we achieved together by downloading the full case study below.

VIDEO CASE STUDY

Project Highlights

17 sections with defects identified

1 leak found

1 air pocked identified

1 undocumented outlet located

1 defect validated and replaced

Project Details

Services
PipeDiver® electromagnetic inspection

Sahara® acoustic leak and gas pocket detection & visual inspection

Structural design review

Transient pressure monitoring

Timing
September 2015 – December 2015
Pipe Material
Steel, Ductile Iron, Bar Wrapped
Inspection Length
3.5 miles (5.6 kilometers)
Diameter
20-30 inches
Transmission Type
Water

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Whitepaper:
Metallic Pipeline Condition Assessment

Case Study

In order to avoid the cost associated with large valve replacement, the city of Grand Rapids engaged Xylem to assess the true condition of 20 large valves and determine if they could be rehabilitated or repaired instead.

The City of Grand Rapids is the second largest water system in Michigan and delivers clean drinking water to the Grand Rapids area using Lake Michigan as its water source. The Grand Rapids Water System operates about 1,250 miles of pipelines, 31,000 system valves, and over 1,300 large system valves (16 inches and larger). Over the last few years, the operation and maintenance of the large valves had declined due to focus being placed on other critical priorities. Without a consistent exercise routine for critical valves, the utility found that many of these valves were inoperable and, as a result, began to seek funding for valve replacements.

THE CHALLENGE

Grand Rapids was aware of a long segment of transmission line that could not be isolated due to inoperable valves. To regain control of the line, the City replaced five large valves at an average cost of $125,000 per valve, each taking an average of one week to replace. This amount of work and cost was a wake-up call that compelled Grand Rapids to find alternate methods of rehabilitating their valve assets.

Xylem’s experience has shown that on average, 60 percent of valves in a water system are operable, meaning that 40 percent are either inoperable, not locatable, or in the wrong position. Statistically, this meant that with 1,300 valves in Grand Rapids’ system, around 500 of them could have some sort of issue. With limited information on which ones required attention and a limited capital budget for asset replacement, the City would need a more focused approach help them make repair or remediation decisions.

What solutions did Xylem and Grand Rapids come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

Project Highlights

The City saved more than $800k by assessing and repairing infrastructure rather than replacing – a cost savings of over 90%

8 critical valves restored to full operability for less than the cost of replacing just one valve

60% of the assessed valves were working properly, allowing operational expenditures to be allocated elsewhere

Services Provided

• Valve assessment – assessed 20 large valves in the transmission system
• Valve repair – repaired and restored eight critical valves to full operability
• Valve rehabilitation – rehabilited one inoperable 36″ gate valve

Case Study

To manage remaining useful life of a critical metallic force main, City of Cape Girardeau deploys SmartBall® as screening tool for condition assessment to identify gas pockets and high likelihood areas of internal corrosion.

Desktop studies commonly incorporate data such a pipe material, class, age, and failure history to assist in preliminary condition assessment programs without someone necessarily ever seeing the pipeline. Utilities often use desktop data as an initial step to help shape a management strategy.

For a higher level of condition assessment data, the health of a pipeline can be determined by combining desktop studies with an inline SmartBall leak and gas pocket survey, leading to focused test pits in areas where gas pockets indicate potential internal corrosion, the most common cause of ductile iron force main failure.

As proof of concept, Pure Technologies used the free-flowing SmartBall platform as part of a recent DIP force main condition assessment for City of Cape Girardeau, Missouri.

Project Details

Services
SmartBall leak and gas pocket survey

Condition assessment aided by SmartBall gas pocket location

Field service verification

Ultrasonic Thickness (UT) Testing for structural evaluation

Remaining Useful Life (RUL) analysis

Pipe Material
Ductile Iron Pipe (DIP) HDPE
Inspection Length
3 miles (4.8 km)
Diameter
20-in (500mm) & 24-in (600mm)
Transmission Type
Wastewater

Project Highlights

3 miles total distance inspected

26 gas pockets detected

5 pipes excavated, visually inspected and wall thickness measurements obtained

RUL data determined failures may occur within 2 years where gas pockets detected and 15 to 30 years where gas pockets were not present

THE CHALLENGE

The City of Cape Girardeau (Cape G) proactively manages 550 miles of water and wastewater pipelines for a population of nearly 40,000.

In January 2017, Cape G retained the services of Pure Technologies to field verify and further assess the condition of the Riverfront Force Main, a three-mile pipeline comprised of 20 and 24-inch ductile iron pipe (DIP), with a few replacement sections of HDPE.

Cape G had experienced a failure on Riverfront Force Main on the Memorial Day weekend of 2016. As the force main is relatively new (installed in 2000) and runs along the Mississippi River, the condition assessment of the non-redundant main was critical for the City.

What solutions did Pure Technologies and Cape G come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

pipe_diver

On Thursday May 17, thought-leaders, leading utilities, and other industry experts, came together for Xylem’s Modernizing Water Infrastructure Workshop in Laurel, MD. Like Infrastructure Week, the event served as a platform for innovators to connect, discuss, and inspire water industry professionals to solve the problems associated with managing water infrastructure. If you were unable to attend, here are some of the highlights of the day.

From Manure To Modern

The morning session focused on utilities, and began with a keynote presentation from industry visionary, George Hawkins, who provided an energetic analogy on how the manure crisis of the 1800s compares to our current water crisis. While the common person only saw the problem of horse manure, the engineers of the 1800s saw the potential for change and created the car, which eliminated the problem while increasing productivity and reducing costs. That’s what we, as an industry, need to focus on as we modernize water infrastructure — seeing the potential for greatness and improvement through innovation.

Hawkins went on to discuss how we report efficiency. If everything is measured in a productivity approach, seeking additional funding becomes easier. Money has gone farther than ever before in the water infrastructure industry because of the advancements in technology that allow us to work more efficiently and accurately. People are prepared to invest in something that matters to them, especially when they understand that the current monies are going further, and you can prove it. Listen to part of Hawkins’ presentation:

100 Years of Continuous Improvement

Following Hawkins’ passionate keynote address, we heard from Glen Diaz, Division Manager of Water/Wastewater Systems Assessment at WSSC. As WSSC (Washington Suburban Sanitary Commission) celebrates their 100-year anniversary, Diaz reflected on the advancements in technology through the years.

Even in the past 10 years, things have greatly improved in the water industry. Diaz cited the 66” water main break in Bethesda, MD in 2008 and how current technology can aid in preventing future incidents. Diaz went on to discuss how most PCCP failures are due to broken wires and how noisy pipes are typically problem pipes.

However, now, WSSC workers receive mobile alerts, through the implementation of Pure Technologies AFO system, as soon as wire breaks occur so they can address any cause for concern. This system has already helped WSSC avert 20 failure events to date, a $21 million dollar savings on the conservative side! See Diaz’s presentation here:

With Challenge, Comes Major Opportunity

After hearing from WSSC, we heard from Jody Caldwell, Asset Management Director for Great Lakes Water Authority (GLWA), on building an asset management program from the (under) ground up.

Caldwell began with an overview of some of the organizational challenges GLWA is experiencing being a relatively new utility. He talked about the process GLWA went through putting together a 10-year strategic roadmap focused on continuous improvement to overcome the challenges and build a utility for the future. Caldwell went on to discuss GLWA’s pipeline risk management strategy, which uses a quantitative, risk-based analysis to drive decisions. This tiered approach allows them to easily calculate their risk return on investment and ultimately, become a best-in-class pipeline management system. Catch the end of Caldwell’s presentation, as well as the Q&A session.

Extreme Preparation for Extreme Weather

After a brief networking break, there was a roundtable discussion that focused on how leading utilities dealt with the extreme weather conditions this past January. The roundtable featured (from left to right) Joseph Mantua, Deputy General Manager Operations at WSSC; Carlos A. Espinosa, Chief of the Office Of Asset Management at Baltimore City Department of Public Works; and Buddy Morgan, General Manager at Montgomery Water Works (Alabama). Who said the South doesn’t experience cold weather.

The discussion began with the question, “Were there particular pipe materials you found to be problematic during the extreme winter, and if so, what were they?” For the City of Montgomery, AL, cast iron mains had the most problems. Baltimore City was no different, reporting that 98% of the water main breaks were in cast iron pipes, the majority of which were 12” or smaller. WSSC confirmed the cast iron trend, with the majority of breaks occurring in 6 or 8 inch diameter pipes.

In order to prepare for next winter, the utilities agreed for the need to ensure that all their equipment is in working order ahead of time, and have conversations with their crews and contractors to make sure they’re prepared to respond, and recognize the need for additional support services and how to best utilize them. Additionally, the panel agreed that social media played a crucial role in real-time communications with customers, aiding them in being proactive with the media, and helping to communicate status updates. Watch the beginning portion of the roundtable discussion:

The discussion moved on to how to keep employees engaged during extreme weather conditions. Aside from the generous overtime benefits, WSSC brought hot meals to workers, while Alabama Water Works limited hours per week to 65 with 24 hours off before coming back. They also held celebratory cookouts once the weather warmed up.

Be Best-In-Class

After lunch, the afternoon sessions focused on technologies and management best practices. Pure’s very own Mike Higgins, Senior Vice President, Americas, talked about buried infrastructure philosophies utilities can use to manage their most valuable assets. Mike kicked-off his presentation by sharing statistics from the 2017 Infrastructure Report Card from the American Society of Civil Engineers (ASCE).

Following these eye-opening numbers, Higgins shared his insights on success for professionals in the water industry.
Key questions utilities need to answer include:

  • Why do you want to assess your pipeline?
  • What are the goals for your project or program?

 

Typically, the answers should focus on one or more of the following areas:

1) Averting pipeline failure
2) Reducing pipeline risk
3) Extending the life of an asset
4) Increasing sustainability
5) Optimizing CAPEX/TOTEX (capital/total expenditure)

Higgins then shared his secret recipe for the 10 key ingredients to be a best-in-class utility:
1) Focus on operations excellence
2) Coordinate with all key stakeholders
3) Perform necessary Public Relations
4) Create a clearly defined team across departments and disciplines
5) Always aspire towards total pipeline management
6) Prepare for emergencies, they will occur
7) Be opportunistic
8) Continue to innovate
9) Understand limitations of innovative approaches
10) Keep your boots on the ground (maximize the amount of inspected pipe)
 
He concluded his presentation talking about the importance of monitoring key performance indicators (KPIs) and keeping senior leadership engaged. Watch Higgins’ presentation:

The 4th Industrial Revolution

Richard Loeffler IV, Client Solutions Architect at Emnet, then reminded us that the number one criteria for where cities locate is the access to water. Loeffler also stated that we are in the midst of a 4th industrial revolution—IoT (Internet of Things) is changing the way we live, work, and play, and is transforming the fundamental economic cost structure of water and related civic works.

He used the example of South Bend, IN, to illustrate just how effective IoT and RTDSS (real-time decision support systems) can be. Ultimately, it’s all about environmental stewardship — it’s not just about saving money, but about doing the right thing for the world that we live in. View Loeffler’s presentation:

Smart Water

Following Loeffler’s informative presentation, Bridget Berardinelli, VP Product Management And Continuous Improvement for Xylem, stated how smart meters and applying analytics can help utilities generate real results. Berardinelli began by explaining how Sensus develops advanced technology solutions that enable the intelligent use of critical resources.

She covered Advanced Metering Infrastructure (AMI) and explained how to leverage it in order to increase operational efficiencies and improve scalability and flexibility. By delivering machine learning and analytics using a programmatic approach, Sensus is able to inform operational interventions that transform how water utilities operate. View her presentation:

Our Newest Solution

Concluding Berardinelli’s presentation, we heard from Pure Technologies Area Regional Manager, Susan Donnally, on how to manage large diameter water transmission mains. She began her presentation with a discussion on pipeline risk prioritization, stating that using data to drive decisions is a quintessential part of moving towards a proactive asset management approach. She then dove into why pipes fail; noting that age alone is a poor indicator of pipe condition. While there is no singular technology that can identify all of the indicators of pipe deterioration, a holistic, risk-based approach can help.

Donnally then moved on to highlight some of Pure’s latest technology innovations:

  • SmartBall® – in addition to leak and gas pocket detection, the tool now provides mapping, which combines data collected during an inspection with known, aboveground locations and pipeline drawings to create a field-generated GIS map of a pipeline.
  • PipeDiver® – Pure’s free-swimming condition assessment tool is now available with video and can easily correlate the data you’re getting from electromagnetics with actual footage.

 

Additionally, Donnally had a huge reveal! She introduced Pure’s newest PipeDiver solution, the PipeDiver UltraTM (currently in the beta testing phase with a couple of clients), which features high-resolution wall condition information for metallic pipes, such as cast iron, ductile iron, and steel, and is as easy to deploy as the existing PipeDiver. Watch her presentation:

You’re Not Going to Start with Perfection

Vice President of PureAnalytics, Travis Wagner, gave the final presentation of the day on managing distribution systems.

He truly engaged the audience by asking attendees to raise their hands if:

  • They saw a need or value in a pipeline renewal program
  • They agreed that a 10-20% efficiency in renewal programs is OK
  • They thought customer affordability was an issue
  • They had trouble with retirements and recruiting

 
Not surprisingly, most hands were raised! From there, Wagner went on to urge everyone to update their approach.

Utilities need to start asking themselves the following questions:

  • What is the current state of my assets?
  • What is my required level of service?
  • Which assets are critical to sustained performance?
  • What are my best O&M and CIP investment strategies?
  • What is my best long-term funding strategy?

 
Wagner concluded this portion of the presentation with a quote that all utilities should follow: “You’re not going to start with perfection, the goal is to build toward becoming better.”

Next, Wagner moved on to discuss risk management, consequence probability analysis, data collection, and risk mitigation. It was truly an eye-opening presentation:

The day concluded with demonstrations of all the latest technology available to utilities, including a 108” PipeDiver, SoundPrint® AFO system, Sensus meters, Visenti software demos, not to mention some great networking.

Want to learn more about our Modernizing Water Infrastructure Workshop? Check out #H2018Workshop on Facebook, LinkedIn, and Twitter.

 

Airfield location meant inspection scheduling was booked five months in advance.

Water main inspection to manage the critical assets for the Vancouver International Airport takes months of proactive planning, safety and scheduling.

In the management of a major international airport like Vancouver International Airport (YVR), Vancouver Airport Authority (VAA) operation officials inevitably face a number of unique challenges. Compounding the challenges is the fact that the airport runs as a mini-municipality because of its size and island location within the jurisdiction of the City of Richmond.

When carrying out a water main inspection in an airfield location, strict rules apply to how you operate in that area. A well-executed inspection requires a dedication to planning, safety, and scheduling.

Being an airfield location, a lot of detailed planning went into managing this South Runway Watermain Inspection. We stuck to the schedule, met all milestones, and were extremely pleased with the execution of the safety plan, which was critical in this restricted environment.” Stephen Little, Technical Specialist-Mechanical, Vancouver International Airport.

The water line provides an important service to South Terminal and leased buildings.

Project background

Canada’s second busiest airport, YVR, served 24.2 million passengers in 2017. Last year, VAA engaged Pure Technologies to perform a Sahara® leak and air pocket detection inspection on the South Runway Watermain (SRW). Built in 1966, the SRW is a 350mm water main constructed of asbestos cement that runs from the Airport Field Bulk Water Meter to the South Domestic Terminal for approximately 870m (2850 ft.).

The water line provides an important service to both the South Terminal and leased airport buildings, which include a busy McDonald’s, the Floatplane Terminal, Flying Beaver Bar & Grill and multiple aircraft maintenance facilities. The line also runs along the main airfield, and across some taxiing areas, driving home the point that failure is not an option.

The airport receives water from the City of Richmond, which was also keenly interested in the inspection planning, technology and the outcome.

A multi-purpose inspection

The main purpose of the survey was to assess the condition of the main to identify and accurately locate any leaks or air pockets using the acoustic capabilities of the Sahara leak detection tool. VAA wanted a visual take on the inside of the pipe using the video capabilities of the tool’s CCTV camera. In addition, VAA also wanted to map the bends in the line and take GPS coordinates at select points to update alignment plans.

Another important purpose of the inspection was to eliminate water loss at the airport, a goal initiated by management as part of a proactive environmental program to conserve water. Management wanted to locate areas of potential water loss in their system to help achieve their water reduction targets of 30 percent by 2020.

YVR receives water from the City of Richmond via several bulk meter locations. From here, VAA distributes the water throughout Sea Island. The presence of leaks would have an adverse effect on the airport reaching its water reduction targets.

Tethered Sahara tool is propelled by the product flow and features inline video to observe internal pipe conditions.

Sahara leak detection platform selected

Pure recommended the Sahara leak detection platform for its ability to provide same-day results, and to locate small leaks with sub-meter accuracy. The tethered tool is propelled by a small parachute inflated by the product flow.

The Sahara platform also features inline video that allows operators to observe internal pipe conditions, and in many instances, identify the type of leak and other details helpful for planning a repair before excavating.

 Although this first project was limited in scope and budget, because of the criticality of the line, both Pure and VAA put extra care and planning into efforts to ensure a relatively effortless access and retrieval of the condition assessment tool.

The City of Richmond assisted by removing their aging water meter and installing the flange supplied by the Sahara team for the launch of the tool. The City of Richmond then took the inspection opportunity to upgrade the old meter to a newer ultrasonic model.

Airfield location meant maintaining inspection schedule was critical  

As the line was located in the airfield, maintaining the inspection schedule was critical. Security escorts were required at all times for non-YVR employees, which meant scheduling for the project was booked nearly five months in advance.

As well, the inspection was a multi-jurisdictional project, as the pipeline was owned by both the City of Richmond and VAA, requiring close collaboration between all parties. Pure inserted the tool via the City of Richmond’s water meter (in the airfield) and inspected the downstream water main (owned by VAA).

“The South Runway Watermain inspection project was a good opportunity to trial and gain better understanding of the inspection technology. It also allowed us to get a level of comfort in order to identify other areas where we can apply it,” said Little. “Our comfort how well the inspection went is an incentive for us to explore more non-destructive inspection methods.”

The adaptable design of the Sahara tool allowed for a horizontal insertion at the water meter chamber. (Vertical insertion is the more common method for inserting the tool.)

Inspection results

The adaptable design of the Sahara tool allowed for a horizontal insertion (vertical is more common insertion method) at the water meter chamber and the inspection was completed under live conditions without disruption to service, using the water meter bypass and downstream fire hydrants.

In a single day, the Sahara crew inserted the tethered tool through the water meter chamber, inspected approximately 870 meters (2850 feet) and determined the pipeline alignment with all bends and 100-meter intervals marked. In conjunction with the inspection, VAA and the City of Richmond were able to upgrade the old water meter to an ultrasonic unit, a bonus to the inspection goals.

In the end, zero (0) leaks and zero (0) air pockets were identified during the inspection, and CCTV showed some small tuberculation on the metallic bends. Although VAA recognized no immediate concerns, the Airport Authority now knows the correct updated line location and the overall condition of their assets.

Overall, a great success for a pilot project.

 

Inspection required divers to retrieve PipeDiver tool from piping outlet located 40 feet beneath the Atlantic Ocean.

For the Township of Ocean Sewerage Authority, proper planning, quick thinking and late night tool modifications keep critical pipeline inspection on track and on schedule.

As every utility manager knows, a critical pipeline inspection can be temporarily derailed for unanticipated reasons. Especially when the assumed pipeline turns out to be composed of a completely different material, with a smaller than expected internal diameter, all of which could affect the condition assessment methods.

If you’re the manager under a time-critical deadline, you face pressure to resolve the issue and successfully move the inspection forward.

Fortunately, with proper planning, quick thinking and an experienced mobilization team in place, an unforeseen challenge like this can turn into an opportunity to gain a better understanding on the state of your linear assets.

Pipeline broken up into 4,000 foot and 2,000 sections by a drop manhole.

Project background

In November 2016, Pure Technologies (Pure) was contracted by Hazen and Sawyer (Hazen), consultant to the Township of Ocean Sewerage Authority (TOSA) in Oakhurst, New Jersey, to conduct a non-destructive evaluation of TOSA’s 36-inch diameter Ocean Outfall Pipeline constructed between 1966 and 1968. The pipeline was (supposedly) a 1.1 mile steel pipe that carries treated effluent to diffuser piping located 40 feet beneath the Atlantic Ocean.

TOSA had sought Hazen’s assistance in exploring ways to help them better understand the wall loss condition of their outfall pipeline in order to evaluate the need for repairs and or reconstruction options using the inspection data.

Prepping the PipeDiver tool for the electromagnetic inspection.

Understanding the pipe material determines inspection methods

In addition, the line is broken up into 4,000 foot and 2,000 foot sections by a drop manhole. According to profile assumptions, the Ocean Outfall Pipeline was thought to be steel. Understanding the pipe material is an important step in the selection and justification of condition assessment methods.

Based on the assumed steel material, Pure recommended the free-swimming PipeDiver® tool to deliver electromagnetic technology for the inspection method. The PipeDiver tool is equipped with Pure’s proven electromagnetic technology, which can be used on metallic pipe materials such as steel and ductile iron to detect cylinder corrosion. Electromagnetic sensors also provide the location and an estimate of the area and depth affected.

“This assessment using the latest in-pipe inspection technology, provided TOSA significant value in cost savings and avoided unnecessary public disruption, all while providing a better understanding of their infrastructure for the long-term management of their ocean outfall. With this understanding comes peace of mind in knowing that the most economical and effective in-kind replacement will be implemented to ensure long-term reliability of this vital asset.” William S. Gettings, P.E., MBA, BCEE, Senior Associate and NJ Office Manager Hazen and Sawyer

Two models of the free-swimming PipeDiver tool were assembled to inspect the various pipe materials, one for steel, the other for PCCP.

As a precaution, two models of PipeDiver tool assembled

Different PipeDiver tools are used for assessment of different pipe material. The optimized 24-detector PipeDiver tool uses electromagnetic technology to locate and identify steel pipes that have indications of wall loss, while the 6-detector PipeDiver tool is designed to identify PCCP pipes that have indications of broken wire wraps, the leading indicator of problematic pipe.

While it was known that the 2,000-foot (Section A) was made of steel pipe, there was no definitive information on the 4,000-foot (Section B) of pipeline material. In response, two models of the PipeDiver tool (a 24-detector tool for steel and a six-detector tool for PCCP were brought on site, assembled and balanced).

The metallic PipeDiver was run through Section B, where data determined that the section was not steel pipe, but rather PCCP, with a small section of cast iron pipe.

That was good call.

Getting the PipeDiver tool ready for the first insertion.

Sections of pipeline 3 inches smaller than anticipated

During the planning stage, it was thought that the pipeline had a 36-inch internal diameter. However, it became apparent after seeing some highly anomalous data sets from the 24-detector PipeDiver tool that the internal diameter was at least 3 inches smaller, which was confirmed at both the inlet and outlet by direct measurement using onsite divers.

This necessitated some late night heroics from Pure’s analysis group, research and development and on-site staff to modify the neutrally buoyant tool to fit into the smaller pipeline.

From here, the inspections went off without a hitch.

In the end, multiple PipeDiver runs were performed over the five-day inspection. On Section A of the steel pipeline, three pipes displayed anomalies indicating wall loss from 30 percent to 50 percent. One pipe contained a single location of wall loss, while two pipes had multiple locations of wall loss.

Analysis of the PCCP data obtained during the inspection determined that one pipe section in Section B displayed an electromagnetic anomaly consistent with five broken wire wraps, and one anomalous signal shift that could be caused by an undocumented feature or a change in pipe property.

A beautiful way to end a successful inspection.

TOSA has a better understanding of their linear assets

Pure worked closely with Hazen and TNJ Marine, Inc. throughout the inspection.  It was recommended that a portion of Section A undergo replacement due to pipe sections with anomalous electromagnetic signals, apparent pipe wall degradation and visible wall loss anomalies. In addition, where five wire breaks were found, it was recommended that a 16-foot length of 36-inch PCCP including plated access port within a sealed access manhole be replaced. Finally, it was recommended Section B undergo re-inspection within the next five years to monitor existing damage and re-evaluate the pipe section with anomalous signal.

All in all, a successful inspection despite the many challenges.

A leak represents not only water loss, but can indicate the potential for pipeline failure.

How proactive utilities are taking the gamble out of finding leaks in order to mitigate failure risk

It takes a lot more than luck and traditional acoustic correlation methods to locate a suspected leak on large critical mains. Not all leaks are obvious, and some leaks can seep for years without visibly surfacing, putting utilities at risk for catastrophic failure.

That is why a proactive leak detection strategy plays such an important role in any asset management program. It allows utilities to obtain the general condition of their mains, since a leak not only represents a real water loss, but can also indicate the potential for pipeline failure.

Recently two water operators — The City of Vancouver, B.C. and The City of Norman, Texas— took measures to mitigate failure risks by implementing a leak detection program for their transmission networks. The utilities deployed various inline leak detection technologies, dependent on such factors as pipe diameter, material, access point availability, and operational constraints.

Acoustic intensity of anomaly and actual leak located

Left: Acoustic intensity of anomaly.   Right: Actual leak located

Inline technologies for leak detection

Inline leak detection technologies use non-destructive methods in which acoustic sensors are inserted into a pressurized pipeline. The “hissing” sound or vibration resulting from a leak in a pipe transmits an acoustic signal collected by the sensor when passing the leak site. The amplitude and frequency of the sound depends on the pipe material and internal pressure, and is easy to distinguish from other pipeline sounds.

Pure Technologies has developed two inline leak detection platforms for large-diameter pipelines of all materials: Sahara® (with a tethered sensor) and SmartBall® (a free-swimming tool).  Both tools are equipped with a sensitive acoustic sensor that can locate very small leaks (as small as 0.1 l/min) with high location accuracy.

SmartBall inside a pipe

The SmartBall tool can be launched while the main remains in operation, limiting disruption to service.

SmartBall leak detection technology

The SmartBall platform is an innovative technique to identify leaks and gas pockets in large-diameter pipelines while the line remains in service, minimizing disruption. The free-swimming ball contains a sophisticated leak detection circuitry and is released untethered into the water flow often through an air valve or hydrant (any 100mm opening). The SmartBall follows the water flow and is tracked by surface mounted sensors as it rolls through the pipe making a continuous recording of the acoustic activity in the pipeline. At a downstream location, the ball rolls into the retrieval device and is extracted from the pipe. The data is then evaluated to report the presence of leaks and gas pockets.

Since the SmartBall is propelled by the water flow, it can be used to survey the subject main for long distances (battery life up to 20 hours) in one deployment. As a result, modifications to the main are significantly reduced.

The tethered Sahara platform provides acoustic data on the presences of leaks and gas pockets and has the ability to map the pipeline alignment.

Tethered Sahara inspection platform

Utilities have long relied on the Sahara leak detection platform for speed, accuracy and real-time results.

The tethered platform identifies leaks and gas pockets by providing acoustic data on the presence of leaks for distances up to 1,800 meters (6,000 feet). The tool also has the ability for mapping the pipeline alignment, and is equipped with CCTV, adding an assessment.

The tool can be inserted into an active pipeline, through almost any tap two (2) inches and greater. As the Sahara tool enters the pipe, the flow velocity of the water inflates a small parachute, which pulls the tool through the pipe, with the probe lighting the way, highlighting any visual defects in the pipeline.

If the Sahara tool encounters any acoustic events – such as a leak – the operator can stop the tool at the exact point of the leak. At the same time, an above ground operator locates the sensor, marking the exact leak location within plus or minus 0.5 meters (18 inches). This enables users to know in real time where leaks are located.

The SmartBall tool was successfully retrieved with the acoustic data intact.

City of Vancouver SmartBall inspection

In March 2016, the City of Vancouver retained the services of Pure Technologies to perform a condition assessment of the Powell-Clark Feeder Main. The pipeline is comprised of concrete cylinder pipe (PCCP/BWP), ranging from 750 to 900m in diameter, installed in 1986-87.

In addition to providing an earlier PipeDiver® electromagnetic inspection to identify broken prestressing wire wraps on the main, Pure Technologies also performed a SmartBall inspection to identify and locate leaks and pockets of trapped gas along the line.

The SmartBall tool was inserted into the pipeline through a flange access and acoustic data was collected and recorded as the tool traversed the pipeline. At a distance of 5.8 kilometers, (470 meters from the end of the inspection run), the tool stopped, which was confirmed by the live tracking software. By analyzing data from the earlier PipeDiver EM inspection, Pure determined that unknown debris likely lodged the SmartBall tool.

The City excavated and modified a tap to allow Pure to access the pipeline with a submersible ROV (equipped with a camera) to retrieve the SmartBall tool and examine the debris, which turned out to be an old tool cart. The cart and SmartBall tool were extracted, and the data considered valid.

Analysis indicated three (3) anomalies characteristic of leaks and zero (0) pockets of trapped gas. Two (2) instances of entrained air were identified as migratory acoustic anomalies, and flagged for future inspection, as they may develop new pockets of trapped air.

When combined with the results from the EM inspection, the condition data will be used as part of the City of Vancouver’s asset management initiative and allow for proactive measures in the management of their infrastructure.

Sahara inspection for City of Norman, Texas 

In December 2016, Pure Technologies performed a leak detection survey on the 30-inch Robinson Street Replacement Water Main (RSRWM) for McKee Utility Contractors (McKee).  The RSRWM is owned and operated by the City of Norman, Oklahoma.

McKee suspected a leak on the pipeline, as the RSRWM was failing to hold pressure during the 150 psi hydrostatic pressure test.  As a result, McKee requested that Pure Technologies inspect 4,248 feet of the RSRWM and pinpoint any leaks in the inspected section.

The Sahara platform was selected for its ability to provide same-day results, and to accurately locate small leaks with sub-meter accuracy. The tethered tool is propelled by a small parachute inflated by the product flow, requiring a flow velocity as little as one foot per second to progress through a water main.

Because the pipeline was not yet in service, the flow was generated with a city connection pushing water into the main, and a 12-inch blow-off spewing it out. The Sahara audio-visual (AV) sensor was deployed to the endpoint using the flow velocity provided by the blow-off.

After the leak was located and marked above ground, McKee quickly excavated around the butterfly valve, tightened the bolts and eliminated the leak on the same day.

Two leaks detected, located and repaired

As a result of the survey, 4,294 feet of the RSRWM was inspected, with two leaks located.

Leak 1 was located 1000 feet from the first insertion. Video from the Sahara tool showed that the leak was located on the mechanical joint securing the inline butterfly valve to the pipeline. The Sahara team located the leak, and marked it above ground and McKee was able to start excavating immediately. After quickly excavating the butterfly valve, McKee was able to tighten the bolts on the BFV, eliminating the leak the same day as the excavation.

A second leak was located, marked above ground, excavated, and repaired the same way as the first. After repairing the two leaks found, the line passed pressure test.

While metallic rising mains have been historically difficult to manage, a risk-based approach increases confidence in the condition of the pipeline.

Nothing grabs headline news like the failure of a rising main, which can be extremely damaging to the environment and harmful to a utility’s reputation.

Historically, wastewater rising mains have been difficult to manage, especially those made with ferrous materials, where the failure method is slow when compared to concrete pressure pipe. As well, sewer rising mains have special operational challenges that don’t apply to gravity sewer mains as they typically cannot be taken out of service for inspection, and due to the presence of solids in the fluid, rising mains represent a far more abrasive environment than potable systems such that assessment methods for water mains may not be applicable.

The presence of pockets increases the potential of corrosion in metallic pipes.

Gas pockets are of significant concern in rising mains.

The primary failure mechanism of ferrous rising mains is due to internal corrosion. Gas pockets are of significant concern in rising mains, as concentrations of hydrogen sulfide gas within wastewater can be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall. This may cause corrosion and eventual breakdown of the pipe’s wall.

Therefore, a first step in assessing rising main condition should be the identification of gas pocket locations within the pipeline.

Pure Technologies has performed an analysis of rising mains inspected using acoustic based technologies in order to better characterize the frequency and location of gas pockets. Based on the analysis, it was found that 72% of gas pockets were not at known high points or air release valves, therefore, the most precise way to identify gas pockets within a rising main is through the implementation of inline acoustic inspection technologies.

The collection of gas pocket locations alone will not indicate the condition of the pipeline, but instead identifies locations where an increase in corrosion potential is observed. To ascertain the true condition of a pressure pipe, higher resolution electromagnetic technologies are required. These technologies measure pipe wall thickness in ferrous materials and broken wire or bar wraps in concrete pressure pipe.

Once the condition data is collected, advanced analytics can be applied to estimate the pipeline’s remaining useful life.

“Previous analyses involved straight-line assumptions – comparing the pipe wall thickness at installation against what it is today. However this doesn’t give an accurate picture of how pipes degrade…by using statistical modeling we can develop a more predictable degradation rate based off of over 14,000 miles of inspection data Pure has collected over the past 30+ years.”

Jennifer Steffens, Market Sector Leader, Water and Wastewater, Pure Technologies

Jennifer Steffens, Market Sector Leader, Water and Wastewater, Pure Technologies

Desktop studies are not always reliable.

While often the first thought is to replace the aging wastewater assets based on factors such as age and failure history, this option makes neither logical nor financial sense. With so many miles of buried pipelines and such limited capital budgets, utilities don’t have hundreds of millions to spend on replacing pipelines which still have remaining useful life.

At Pure Technologies, we believe there is a better way. A more feasible approach to ensuring the safe operation of rising mains is to undertake a risk-based approach to manage their operation. A risk-based approach will provide decision intelligence on which assets require rehabilitation or replacement to extend their useful life. Or which assets can be left alone.

Our approach is to help utilities evaluate the current state of their buried infrastructure and provide them with high confidence condition and operating data.   We then couple this with our years of extensive experience and project history (more than 12,000 kilometers of pressure pipe assessment) to provide utilities with actionable information, which allows them to make informed decisions as to the management of these critical assets.

Value of a risk-based approach to manage rising mains.

Utilities that embrace a risk-based approach to manage their rising main inventory have found that on average they can safely manage their rising mains for roughly 5 to 15 percent of the replacement cost. This pragmatic approach focuses on providing real condition data through assessment, which can be used to selectively renew isolated areas of damaged pipe in lieu of capital replacement.

Four steps to a risk-based approach.

At Pure, we recommend a risk-based approach to manage wastewater rising mains by focusing on four main areas:

  • Preliminary Risk Analysis
  • Internal Corrosion Potential Surveys using Inline Acoustics
  • Pipe Wall Assessment using Advanced Technologies
  • Condition Data Analysis and Advanced Risk Assessment

Most common reasons for pipeline failure.

Preliminary analysis.

Preliminary analysis includes collecting the right data to develop a prioritized plan for assessment, including the selection of appropriate technologies. To help make preliminary decisions, Pure collects all available information to understand the history of the pipeline and the likely failure modes. The data analysis will provide an understanding of the construction and context of the pipeline. Data of interest typically includes pipe characteristics, installation factors, environmental and performance-related data, operational data, and failure data.

Acoustic-based SmartBall® tool locates leaks and gas pockets

Acoustic-based SmartBall® tool used to locate leaks and gas pockets.

Sahara is an inline tethered tool that can locate leaks and gas pockets.

Internal corrosion potential survey.

An internal corrosion potential survey uses inline tools to locate gas pockets that can increase the potential for corrosion and eventual breakdown of the pipe wall. Pure Technologies typically deploys its acoustic-based SmartBall® leak and gas detection tool, as well as its tethered Sahara® leak and gas pocket detection platform to locate gas pockets in pressurized lines of all materials.

Pipe wall assessment.

While the presence of gas pockets may indicate areas of potential concern, it will not give a quantifiable answer as to the structural life of the pipe.

Pipe wall assessment is completed using a variety of technology solutions to identify defects and deterioration of the pipe wall in a variety of pipe materials. For pipe wall assessment of metallic rising mains, common internal electromagnetic technologies include the PipeWalker® and PureRobotics® platforms, as well as the free-swimming 24-detector PipeDiver® assessment tool, developed to identify electromagnetic anomalies indicating pipe wall loss.

PipeDiver® assessment tool, identifies electromagnetic anomalies indicating pipe wall loss.

Condition assessment analysis.

Condition data analysis and risk assessment evaluates how to safely renew or extend the life of rising mains. The risk evaluation considers not only the probability of failure (condition) of the rising main based on inspection data, but also the consequence of failure in order to make sound engineering decisions.

Understanding the risk of the pipeline is an important step in selecting and justifying the appropriate condition assessment methods. As the risk of the asset increases, the value of using high-resolution comprehensive assessment techniques increases. Higher resolution data results in more confident decision making, and would justify and prioritize the application of assessment techniques.

Diagnostic analytics helps utilities move risk assessment forward.

In the past, inspections were done, the data analysed, and the results passed on to the utility. Pure Technologies now offers a more holistic program of diagnostic analytics. This includes analysis of what caused the corrosion problem within the pipe wall, what the impact the corrosion has on the life of the pipeline, and a prescriptive analysis of how it needs to be repaired or rehabilitated.

The next step gathering momentum? Predictive analysis to elongate service life.

Spokane is touted as one of the most beautiful and future-forward cities in North America.

Replacement programs for risky aging mains are often far more complicated and expensive than anticipated. 

While it may seem like the simplest solution for a utility, replacement programs for risky aging mains are often far more complicated and expensive than anticipated. Seldom is the original estimate close to the final price tag.

As the City of Spokane (City) recently found out, high risk is often driven by a lack of data or poor data. Moreover, age rarely correlates with condition. According to the American Society of Engineers, 96 percent of underground pipe is good condition. Of the remaining 4 percent, only one percent has significant damage that warrants replacement. The challenge is to determine the location of the individual damaged assets.

The City of Spokane recognized this fact going into a condition assessment program for two of their critical aging transmission mains, the 24-inch Manito Transmission Main and the 18/24/30-inch 57Th Avenue Transmission Main, which run through residential and commercial areas, and a historic park. Together, the pipelines service two of the City’s pressure zones, which have a combined annual demand of approximately 21 percent of water to the City’s entire water system.

The mains in question were constructed of steel in the 1960s. For this material, the failure modes are most often related to corrosion, corrosion combined with cyclic loading, manufacturing or construction/third party damage.

The mains assessed were constructed of steel in the 1960s

The mains assessed were constructed of steel in the 1960s.

First step: gathering condition assessment data.

The first step in understanding a pipeline is to evaluate the design of the pipeline under actual internal pressures, external loading and current design standards. Managing these critical assets takes a confident management strategy, which includes gathering condition assessment data and evaluating the results using advanced engineering analytics.

As the scope of the proposed assessment was broad, the City retained the services of Pure Technologies (Pure) to deploy a multitude of technologies to determine the condition of the mains.

24-Detector PipeDiver tool

A 24-detector PipeDiver tool was deployed for an electromagnetic wall thickness evaluation.

Recommended internal inspections consisted of SmartBall® acoustic leak detection and PipeDiver® electromagnetic wall thickness evaluation and video recordings. At the same time, Pure used transient pressure monitoring to determine hydraulic loading conditions of the pipelines.

In addition, Pure performed external observations using Pulsed Eddy Current (PEC) and Ultrasonic Thickness (UT) Gauging technologies during excavations of the 57Th Avenue Transmission Main.

Pure also conducted a structural analysis to determine the wall thickness required if the pipelines were designed today under actual internal pressures and external loading. Pure also performed three-dimensional finite element analysis (FEA) performance curves to determine the combination of corrosion depth and length would exceed the Yield Limit of the steel.

Finally, Pure also performed remaining useful life (RUL) analysis of the 57th Avenue Transmission Main to predict wall loss degradation rates and recommend re-inspection intervals, as part of its decision intelligence solutions.

Challenges included nighttime work with traffic control and rain.

Indefatigable crews faced night-time work with traffic control, relentless rain and sloppy conditions.

Project challenges included non-existent lay sheets. 

The project was not without challenges, starting with poor data — an outdated plan and profile drawings and non-existent lay sheets.  For the inspection, crews also faced a survey route with no existing features for tool insertion and extraction, two inline 24-inch butterfly valves, nighttime work with traffic control, and rain. Lots of rain.

While no one could anticipate all the challenges during the planning stage, the engineering experience of the project teams and collaborative dialogue between Pure and the City ensured a working solution for most unforeseen events, with contingencies in place.

Testing the PipeDiver through a butterfly valve

To ensure a smooth execution, the City provided a similar 24-inch butterfly valve to test the PipeDiver passage.

As mentioned, lots of pre-inspection discussion occurred to minimize risk of the free-flowing 24-detector PipeDiver tool getting stuck at the butterfly valves (BFVs). The City was prepared to dewater the line if necessary. To mitigate additional risk, the City provided a pool in their garage to setup and test the inspection equipment. They also provided a similar 24-inch BFV to test the PipeDiver passage.

All the advance planning paid off. The inspection occurred over 10 days and was executed flawlessly, in spite of the damp weather conditions.

Damaged pipe

Pipe damaged from suspected backhoe bucket teeth during previous excavation.

Two pipes excavated to validate inspection results.

For the Manito Transmission Main, 202 pipes were inspected, with zero leaks and zero electromagnetic anomalies detected.

For the 57th Avenue Transmission Main, Pure inspected 282 pipes. Analysis indicated one (1) leak and three (3) pipes with electromagnetic anomalies. Taken as a whole, analysis indicated 99.4 percent of pipes with no corrosion and 0.6 percent of pipes with anomalies indicative of corrosion.

Based on the EM report, two (2) pipes were excavated to validate results and provide data for a Remaining Useful Life analysis. A third pipe was reported to have corrosion anomalies but was not excavated because of its location the middle of a busy intersection.

Upon excavation, the pipe’s coating was observed to be damaged, which appeared to be caused by bucket teeth from a backhoe during a previous excavation to repair the dresser joint. One of the damaged areas matched the location of the reported EM anomaly perfectly and Pulsed Eddy Current measured 17% wall loss while PipeDiver reported 20%. No wall loss was found at the other areas of damaged coating. The City applied a mastic coating to all areas of damaged coating before burying the pipe.

Excavated pipe

Two pipes were excavated to validate results.

Both pipelines originally scheduled for replacement at expected cost of $7 million.

The City of Spokane originally scheduled both pipelines to be replaced at an expected cost of $7 million dollars. After inspection project expenses, the remaining funds can now be applied to other capital projects, which makes this a good news story.

Moreover, with the analysis in, and the repairs made, the City of Spokane now has confident information to plan and move forward with periodic inspections.

 

 

Tethered inline inspection tool helps European city determine condition of steel pipeline unused for more than 4 decades.

Bilbao is an industrial port city in northern Spain, surrounded by famous green mountains. The metropolis, where more than a million people live, is also famous for the Guggenheim Museum Bilbao, the curvy, titanium-clad building that sparked a downtown revitalization when it opened in 1997.

Recently the city’s utility, Bilbao Bizkaia Water Consortium (BBWC), sparked interest in a possible revitalization program for a segment of its pipeline infrastructure that it had inherited. This involved the inspection of an older steel pipeline that had remained non-operational for more than 40 years.

In July 2017, Pipeline Infrastructure, consultant to Bilbao Bizkaia Water Consortium, decided to conduct a non-destructive evaluation of the utility’s Venta-Alta-Ollargan-Etxebarri Pipeline that had been unused since the 1970s. The utility wanted to use Pure Technologies’ tethered Sahara® acoustic platform for a leak and air pocket inspection to determine the current condition of the pipe wall.

Although not planned initially, owing to the effortless inspection of the Venta-Alta-Ollargan-Etxebarri Pipeline, the crews mobilized for an additional Sahara inspection at the Venta Alta Treatment plant, and the following day, a survey on 600 meters of a 500mm diameter reinforced concrete pipeline located in Portugalete. This pipeline traverses under the Bilbao River near the famous Vizcaya suspension bridge.

“We were pleased with the overall Sahara inspections, and all teams collaborated closely to inform us of the tool’s progress. Now that we know the current state of the pipelines, we can optimize our budgets to make better asset management decisions.”

Ángela Ríos Somavilla, Consorcio Aguas de Bilbao Bizkaia

Sahara inspection

Crews setting up to install the Sahara tool and then track its progress.

About the Venta-Alta-Ollargan-Etxebarri pipeline.

Once a critical main within the city’s linear network, the Venta-Alta-Ollargan-Etxebarri pipeline had been decommissioned for more than four decades. Constructed of steel, with an interior epoxy coating, the 1200mm diameter pipeline is more 3,000 meters in length.

The Bilbao Bizkaia Water Consortium sought assistance to assess the condition of the pipeline to determine the possibility of its operation again to deliver surplus water during the storm season for use in the generation of electric power at a nearby Hydro plant.

Due to the age of pipeline, and the fact that it was non-operational for over 40 years, BBWC was interested in locating any possible leaks in order to plan a defensible course of action.

Based on the inspection results, BBWC would then determine if it was necessary to design a new pipeline or opt for continuous rehabilitation. The other option, if feasible, would be to repair any defects in a timely manner to ensure the proper operation and safety of the pipeline, all the while making informed capital decisions.

A lot was at stake, which was why the inspection was so critical to BBWC.

Sahara is an inline tethered tool used to locate leaks and gas pockets without disruption to service.

Tethered Sahara technology accurately locates leaks with sub-meter accuracy.

To ascertain the condition of the line, BBWC selected the Sahara leak detection platform  for the inspection, conducted over three days with seven insertion points along the affected pipeline. Sahara is an inline tethered tool that can assess pipelines 152mm and larger, without any disruption to service.

Propelled by a small parachute inflated by the product flow, the tool requires a flow velocity as little as 0.3 m per second to progress through a water main. From a single insertion, the tool can travel more than one kilometer if flow, pressure and pipeline layout allow it.

Because the sensor tool is tethered, an operator can stop and reverse the tool to investigate acoustic events such as leaks, gas pockets and visual anomalies. At the same time, an above-ground operator locates the sensor above ground.

Much of the pipeline traverses an urban environment.

Pipeline commissioned exclusively for inspection.

The mothballed Venta-Alta-Ollargan-Etxebarri pipeline was commissioned exclusively for the inspection, which took 3-4 hours to fill and bring up to pressurize again. BBWC initiated a flow rate of 650 l/s and 700 l/s in order to obtain a flow velocity of approximately 0.6 m/s. enough to propel the Sahara sensor. Pressure varied between 1.2 and 2 bars.

As mentioned, owing to the early completion of the Venta-Alta-Ollargan-Etxebarri inspection, crews then mobilized to perform two additional surveys, one day at the Venta Alta treatment plant and the following day on the reinforced concrete pipeline than runs under the Bilbao River.

During the entire five-day survey, the Sahara mobilization crews kept in constant contact with BBWC, accurately communicating the inspection time, depending on the length of each of the pipe sections, number of fittings, access difficulty, etc. in order to the limit the supply and avoid the unnecessary waste of water.

While the crews faced some challenges, overall all three inspections were successful, and went off without a major hitch.

Inspection results prove that for most pipelines, age does not matter.

Analysis of the acoustic data identified no new leaks along the 2800 meters of inspected Venta-Alta-Ollargan-Etxebarri pipeline. For a pipeline decommissioned for over 40 years, the line is in surprisingly remarkable condition.

Three leaks were identified on the reinforced concrete pipeline, all located under the river. Knowing the current state of the pipelines, Bilbao Bizkaia Water Consortium can now make informed capital decisions on whether to repair or rehabilitate the lines. Knowledge is power.

 

For this Vancouver Island community, tight deadlines, plug valves, and a rising tide were among the challenges faced during this condition assessment project.

Sometimes the catalyst for a pipeline inspection can come from an unexpected source. In this instance, the story began when it was noticed that a sewer pipe was exposed from erosion during low tide along the beach. That observation set the wheels in motion for an eventual inspection of a critical force main that services approximately 41,000 residents in both the Town of Comox and the City of Courtenay on the eastern coast of Vancouver Island.

The pipeline was installed in the early 1980s, and consists of an 8.75 km large-diameter force main that connects the City of Courtenay, Town of Comox and K’ómoks First Nation Community to the Comox Valley Water Pollution Control Centre (CVWPCC). This includes a five-kilometer portion buried in an “intertidal” foreshore section (area between high and low tide).

Over time, a section of beach eroded and exposed the line to coastal wave action (high tide hides the pipe). The Comox Valley Regional District (CVRD) took steps to restore the beach section where pipeline had been exposed, and began developing plans to relocate the exposed force main off the foreshore.

Island community concerned about pipeline risk of failure.

Sensitive location and potential environmental consequences strike nerve with community.

A new concept was developed that would utilize a portion of the existing force main within the foreshore but remove from service the exposed force main. Due to its sensitive location and the environmental consequences of a potential failure, the CVRD elected to complete a highly specialized pipe condition assessment on the entire length of the line to better understand the remaining service life and condition of the force main. As a result, the project timeline was tight, as CVRD needed imminent results to proceed with corrective action immediately should it be required.

The assessment challenges began from the get-go.

The inspected portion of the pipeline was built of two different pipe materials (PCCP and BWP) and three different pipe diameters (450-, 750- and 820-mm). As well, the critical line could not be taken out of service. The CVRD consultant, Associated Engineering, assisted in developing the request for proposal (RFP) process used to select Pure Technologies (Pure) to conduct the condition assessment, which included an electromagnetic inspection, structural curves, leak and gas pocket detection, and transient pressure monitoring.

Pure proposed the acoustic-based SmartBall® tool for the leak and gas pocket detection, and its free-swimming PipeDiver® inspection platform for the electromagnetic inspection of the line.

“This project had a lot of challenges, especially since the asset was so critical to the region. However Pure was able to help us understand the true condition of the line without requiring a shutdown of the critical force main, and has given us defensible information to make informed decisions in the future.”

Kris La Rose, Senior Manager Water/ Wastewater Services, Comox Valley Regional District

Pipeline alignment follows along the Vancouver Island coast.

Transient pressure monitoring used to understand surge pressures within the line.

First, transient pressure monitors were installed at the Courtney Pump Station (CPS). For more than 4 weeks, the recorded pressure data was used to understand the operational and surge pressures within the force main and their impact on the structural integrity of the pipeline.

SmartBall® technology detects and locates acoustic signature related to leaks and gas pockets.

While transient pressure data was collecting, Pure deployed its proprietary SmartBall technology, a multi-sensor tool used to detect and locate the acoustic signature related to leaks and gas pockets in pressurized pipelines.

The tool has the ability to inspect long distances in a single run, and while the SmartBall is deployed, the pipeline remains in service, limiting disruption to customers.

PipeDiver tool collects electromagnetic data regarding the pipe wall.

PipeDiver® electromagnetic technology designed to assess PCCP, BWP and metallic pipes.

In addition to utilizing the SmartBall tool, Pure chose to deploy the PipeDiver platform, a free-swimming condition assessment tool that collects electromagnetic data regarding the pipe wall, and operates while the pipeline remains in service, an important factor for the force main inspection. The tool travels with the product flow and utilizes flexible petals to navigate plug valves, tees and bends in the pipeline.

Crews had to retrieve the PipeDiver tool within a short 20-minute time window.

Tight time-frame for tool insertion and retrieval of sensor data.

Due to the criticality of the line, and a small capacity wet well at the CPS, the inspection teams had a very short time window (20 minutes) to insert the inspection tools. The small capacity wet well also meant that boosting flows was limited – if pumped too hard, the wet well would draw down and empty, and if pumped too slow, the PipeDiver tool could get lodged at the inline plug valves. (Low flow rate is not a significant problem for the SmartBall tool.) The solution was to first use the SmartBall inspection tool to test the flows in order to optimize the inspection approach for the PipeDiver run.

While the low flow rate slowed the SmartBall inspection, a forecast of rain moved up the PipeDiver run a day ahead in order to take advantage of extra flows that could be provided by the wet weather. The tool also had to navigate a series of 90-degree bends and a plug valve with a small port width in the pump station pipe.

Tracking the tools along the beach was fraught with potential for problems. Inspection crews needed to monitor the tidal forecasts in order to access the tracking sensors during the tide ebb, which meant a short window to retrieve the sensor data.

In spite of the challenges and risk, the dynamic four-day inspection proved successful, and went off without a hitch. The Pure Technologies crew and CVRD operators worked very well together, and their collaborative efforts ensured that this important project was successfully completed.

Damp weather didn’t dampen the inspection ingenuity of the team.

Data analysis indicated no electromagnetic distress on inspected pipes.

Based on the inspection data, Pure analysts identified zero (0) leaks, one (1) acoustic anomaly associated with trapped gas, five (5) acoustic anomalies characteristic of transient gas and two (2) acoustic anomalies associated with entrained gas. In particular, gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

The results also showed no indication of electromagnetic distress on the inspected pipes, which was good news, in spite of the corrosive salt water environment.

Overall, the CVRD was pleased with the inspection results, as they were able to understand the condition of the pipeline and make an informed decision for capital improvements. The project demonstrates how the region uses actionable data to effectively manage their finances and risk, while continuing to provide the community with a safe and reliable delivery of wastewater.

 

Case Study

Hutt City’s main outfall pipeline (MOP) is one of its most critical assets, taking treated wastewater from the Seaview treatment plant to the outfall at Pencarrow Head. The MOP is 18 kilometres long and has an average flow is about 550 litres per second. It was commissioned in 1962 and has an expected life of about 60 years.

Project Details

Services
Assess and Address®Technology Driven Pipeline Solutions
Electromagnetic Inspection
SmartBall® Leak and Gas Pocket Detection
3D Finite Element Analysis and Structural Modelling
Timing
2007- ongoing
Pipe Material
PCCP
Inspection Length
18 km (11 miles)
Diameter
1295mm (50-inch)
Transmission Type
Treated Wastewater

Project Highlights

EM inspection showed 354 of 4,662 pipe sections with some distress

92% of Hutt City’s main outfall pipeline had no deterioration at all

Hutt City was able to extend the life of the critical asset through proactive pipeline management

Challenge

Monitoring the condition of underground assets is a major challenge; much of the New Zealand’s infrastructure was constructed more than 60 years ago and is beginning to reach the end of its design life. While councils search for solutions to manage infrastructure, there is increasing public pressure to minimise rates and improve environmental performance.

Over time, Hutt City’s MOP has showed signs of deterioration, culminating with one pipe section failing catastrophically during normal operation. While replacing the ageing MOP is one solution, it is very difficult and expensive to complete. While the main has a replacement value of $60 million, the costs associated with replacement would likely be much higher due to the logistical challenges associated with constructing a new main.

Solution

In May 2013, Hutt City Council and Hutt Valley Water Services contracted MWH Global to assess the possibility of repairing or replacing of the MOP. In order to complete a comprehensive condition assessment of the main, MWH contracted Pure Technologies, a Calgary-based company.

In order to fully understand the condition of an asset, it is important to use a variety of solutions that identify different aspects of deterioration. This approach is called Assess and Address®, which focuses on identifying and locating isolated areas of distress along a pipeline for renewal. Through this approach, Hutt City can avoid replacing the entire MOP – which is challenging and costly – while increasing its reliability and extending its useful life. Pure used multiple solutions for to assess the MOP for leaks, gas pockets, and structural deterioration. The SmartBall® tool was used to identify leaks and pockets of trapped gas, as well as validate the results of the electromagnetic (EM) inspection. The tool is a free-swimming and measures the acoustic activity associated with leaks and gas pockets in pressurized pipelines.

To identify structural deterioration, electromagnetic technology was used on the PipeRider platform in the dewatered pipeline. Once calibrated above the ground using spare pipe sections – with one of the pipes having some wires exposed and cut for the calibration – the bike was disassembled and placed in one end of the pipeline. The inspection was completed by generating an eddy current and measuring the signal as it conducts through the reinforcing steel within the concrete pipe wall as the tool traverses the pipeline. In Prestressed Concrete Pipe (PCP), the reinforcing steel wires are the main structural component. As these wires begin to deteriorate, specific pipe sections become structurally weaker and are more likely to fail.

Upon completion of the inspection, Pure performed 3D Finite Element Analysis and Structural Modelling on specific sections of the MOP. This process determines how the specific pipe material will perform under different operating conditions, which will guide Hutt City on how to safely operate its main to prevent pipe failures.

This analysis also provides an estimated remaining useful life for the asset, which aids in the development of re-inspection and replacement planning.  

Results

By managing the MOP in favour of replacement, Hutt City was able to determine that one of its most critical assets had remaining useful life. This prevented a very expensive and challenging replacement project, allowed for the deferral and redeployment of capital to other projects.

The data collected and subsequent structural analysis provided an understanding of the condition of the pipe’s main structural component while being non-destructive to the pipe itself. In total, 8 percent of pipe sections had some level of deterioration (354 of 4,622), meaning a complete replacement was unnecessary and the asset has remaining useful life.

By managing its critical infrastructure, Hutt City demonstrated its commitment to providing safe, reliable and sustainable service while ensuring that capital works budget is efficiently and responsibly allocated.

It’s fantastic we’re able to use this world-class technology in our city and benefit from the advanced results it can give us to help plan for the future.

Bruce Sherlock

General Manager, Hutt Valley Water Services

Case Study

In March 2014, Pure Technologies completed a successful leak detection survey on behalf of Mancomunidad Comarca de Pamplona (MCP). The inspected pipeline is part of the MCP’s water supply network, was constructed 20 years ago, and traverses from Olaz – El Cano Pump Station to the Gorraiz Reservoir for 2.4 kilometers.

The main’s purpose is to keep water supply to the town of Egües, which features a hotel and golf course. The pipeline has an operating pressure of 12 bar and is pump operated with 50 litres per second during winter months and 100 litres per second during summer season because of increased demand. The inspection was performed in two runs to proactively address water loss on the transmission main.

Project Details

Services
SmartBall® Leak and Gas Pocket Detection
Timing
March 2014
Pipe Material
Ductile Iron
Inspection Length
2.4 km (1.5 miles)
Diameter
400mm (16-inch)
Transmission Type
Water

Project Highlights

SmartBall® leak detection located 4 leaks in 1.49 miles (2.4 kms) of inspection

3 of 4 leaks have been verified and repaired by MCP

Leaks as small as 1 litre per minute identified by SmartBall technology

Challenge
MCP is very dedicated to controlling water loss and completing regular leak detection; they have a permanent internal group with the unique mandate of finding leaks. Typically, they use an advanced SCADA system to identify an area with a leak and then experienced technicians use geophones to establish the exact location of the leak. Using this procedure, MCP has reached a Non-Revenue Water (NRW) level of roughly 10 percent of in their entire network. However, the Impulsión de Gorraiz had a known leak that could not be pinpointed precisely. MCP knew its elevation coordinates but couldn’t identify its exact location using traditional methods.

Solution
With a philosophy of continuous improvement, MCP used Pure’s services to perform a leak detection survey with SmartBall. To supplement its internal leak detection team and SCADA system, MCP wanted to test the validity of an inline leak detection tool and locate the known leak on this pipeline. MCP places equal importance on identifying large leaks and small leaks.

While large leaks leak at a much higher rate, identifying them only eliminates a leak at the tail end of its life. In terms of reducing NRW, locating small leaks may actually represent the best opportunity for long-term water loss reduction. Catching a leak while it is very small prevents the decades of sustained water loss that would occur as it grows into a large leak. While large leaks are important to locate, using technology that can find small leaks on large-diameter pipelines can prevent the development of large leaks and play a vital role in the safe management of a pipeline network.

MCP used SmartBall® leak detection for the inspections. The tool is a free-swimming leak detection platform that operates while the pipeline remains in service. It is capable of completing long inspections in a single deployment and is equipped with an acoustic sensor that identifies acoustic anomalies associated with leaks; the acoustic signature is then analyzed to determine if it is a leak, air pocket, or an external noise.

To track the tool as it traverses the pipeline, SmartBall receivers (SBR) are placed strategically throughout the planned inspection route. As the tool traverses, it makes a sound that is recorded by the receivers to determine its position on the pipeline; this system allows leak locations to be estimated typically within 1.5- meters (6-feet) of the actual leak location.

Due to a 12 bar pressure at the pump station, a new high pressure insertion cap was designed and fabricated to assist with insertion procedure together with a pulley system that allowed the SmartBall insertion claw to be pushed into the pipeline. In order to ensure the highest level of accuracy, additional SBR points were mounted to track the tool closely and a mobile SBR unit was also used. At the reservoir, a small-diameter net was used to retrieve the tool after the inspection was completed.

Results
Upon completion of the inspection, data analysis revealed four acoustic anomalies resembling leaks despite MCP expecting only one leak along the main. Using updated client estimates and the SmartBall tool’s joint detection feature, Pure identified the exact location of three of the four leaks with an accuracy of less than 0.5 meters, including the known leak. The fourth leak verification has been deferred by MCP until a later date. The close location accuracy was confirmed after MCP excavated the leak locations for repair. In addition to the accuracy, the inspection was also successful in identifying small leaks. The leaks confirmed through excavation were as small as ~0.1 liters per minute.

Based on the inspection, MCP was very satisfied with the technology and information that will be used for future management of their network.

In North America, the material and size of pipes that make up water and sewer networks range widely. Because these pipeline systems are so complex, it requires a strategic approach based on risk and real data for effective long-term management.

Worker inspecting pipe

Historically, however, it has been challenging to gather real data that can shape defensive capital decisions for an entire system. The assessment of metallic pipelines — which make up most water and pressurized sewer networks — differs from prestressed concrete cylinder pipes (PCCP), both in terms of failure modes and in the fact that metallic pipe materials are featured in both transmission and distribution networks.

While PCCP assessment and management have been successfully used by utilities for years, effective assessment solutions for ferrous pipe have only recently been commercialized.

In 2011, Pure Technologies began an initiative to help close the gap in metallic pipe assessment technologies, and focus attention on gathering honest feedback from proactive utilities on what solutions are needed to effectively manage metallic pipe.

Seven years later, Pure Technologies reports that notable progress has been made with the development and advancement of assessment technologies for metallic pipeline networks.

Team of workers with a metallic pipe

Many proactive utilities involved in guiding Pure’s research efforts

Proactive utilities have been involved in the metallic pipe initiative, and instrumental in the development of new inspection tools for metallic pipe, both by providing feedback that helps guide research and development, and by providing opportunities that allow solution testing in live operating conditions. As a result of these efforts, there has been significant improvements to the technologies available to utilities for assessing the condition of metallic pipelines in both transmission and distribution networks.

For large-diameter transmission mains, there is a well-developed business case for assessing these mains as they approach the end of their useful life. These pipelines typically carry a high replacement cost and are higher risk — due primarily to their size and criticality — making it important for utilities to fully understand the condition of the asset.

Armed with real condition data, utilities can make a defensible renewal or replacement decision about the pipeline. Based on well over 14,000 miles of data, Pure Technologies has found that only a small percentage of pipes are in need of immediate renewal.

Small diameter metallic pipe leak

Case for using inline tools for small diameter pipelines

In distribution networks, however, the case for condition assessment is more challenging as smaller pipelines can sometimes be replaced cost-effectively. Despite this, the process for making a replacement decision should be based, whenever possible, on risk and real data.

With the EPA suggesting that between 70 and 90 percent of pipes being replaced have remaining useful life, the case is even stronger for collecting condition data to drive the decision making to help utilities spend their replacement dollars more efficiently and avoid replacing pipe with remaining useful life.

In some instances with smaller diameter pipes, it is often cost-efficient to use inline tools to gather detailed screening data on a pipe-by-pipe basis to determine if replacement is necessary.

A new approach to metallic pipeline management

While there is no silver bullet technology for assessing metallic pipelines, Pure has developed a flexible, risk-based approach to help utilities better understand their infrastructure, gather actionable data and prioritize both short and long-term management efforts.

Over the past few years, Pure has worked along proactive utilities to develop its data-driven Assess and Address® approach, which focuses on four main areas:

  • Understand
  • Assess
  • Address
  • Manage

Through the implementation of programs across North America, Pure has found that the majority of pipelines 16 inches and above can be cost-effectively managed for between 5 and 15 percent of the replacement cost.

Starting an effective pipeline management program

The first step of any pipeline management program is understanding the system-wide risk along with the benefits and limitations of assessment solutions. This allows for the development of a defensible management strategy that can be implemented to maintain and extend the life of the assets.

Many technologies now exist to provide a snapshot of a pipeline condition at various levels of confidence. It is therefore prudent for utilities to approach technology selection and subsequent analysis based on the risk of each pipeline.

A more thorough risk assessment involves estimating the Consequence of Failure (CoF) and the Likelihood of Failure (Lof) of each pipeline based on internal knowledge, operational history and pipeline characteristics. This initial risk assessment determines which areas of the system require further assessment to acquire real condition data and provides the utility with the necessary information to make an informed technology selection.

By using risk to guide management strategies, owners can ensure they are implementing the right approach, at the right time, with the lowest financial impact. The goal of a management program should always be o focus resources on managing the asset while safely getting the most service life out of the pipeline.

Sinkhole in a street

Reducing the Consequence of Failure

Reducing CoF comes down to improving emergency events through field operations efficiency. Studies have shown that the time to shut down a pipeline had more impact on the consequence of failure than the diameter of the pipeline.

Utilities can reduce CoF — and in turn risk — by gaining a better control on their system, which can be achieved two ways:

  • 1. Adding valves and redundancy in the system
  • 2. Knowing the location, condition and operability of control points

For example, if a pipe fails and utility operations staff are unable to locate valves — or the valves are inoperable when they are located — it will take longer to isolate a pipe failure. This will result in greater damage, more water loss and longer outages and repair times as a result of the failure. Implementing a proactive program for control assets that focus on providing better data for field staff reduces CoF by decreasing emergency response time.

Reducing the Likelihood of Failure through condition assessment

Many factors influence the likelihood that a pipeline will fail. Metallic pipelines, specifically, have a variety of failure modes and require a wide array of technologies to accurately assess their condition. Until recently, technologies for metallic pipe assessment have been unavailable or limited in their viability.

As a result, lower risk metallic mains have historically been prioritized for replacement using age, material and break history, while higher risk mains have sometimes been assessed with test pits along the length of the pipeline. After test pitting, statistical methods are used to extrapolate the condition of the test pit locations along the entire pipe length.

Through the development of metallic assessment solutions, condition data shows that pipe distress is often random and localized, meaning that an area of distress identified during the test pit method may inaccurately identify the entire pipeline as distressed, conversely, identify the entire length of pipeline as in good condition.

The development of reliable inline condition assessment tools provides owners with pipe-by-pipe data that gives a more complete picture of the actual condition of the pipeline. This allows for a more targeted management of small sections of pipe instead of generalizing the condition of an entire pipe length. It also allows for the collection of real data to drive pipeline renewal, which allows for more defensible capital decision making.

Case Study

The Netherlands faces unique challenges with their underground pipe networks due to their proximity to numerous dykes that regulate water levels.

Because pipe failures can lead to drastic consequences for Dutch infrastructure, Waternet undertook a leak detection program for three major pipelines that pass various critical infrastructure including dykes, motorways and airport runways.

Extensive testing was done by officials and Pure Technologies prior to the inspection to ensure the technology could offer a comprehensive leak assessment of the pipeline’s condition.

Project Details

Services
SmartBall® leak and gas pocket inspection
Timing
2013-2014
Pipe Material
PCCP
Inspection Length
195 km (121 miles)
Diameter
1200mm-1500mm (48-60 inch)
Transmission Type
Water

Project Highlights

195kms

of pipelines inspected

3

leaks located

3

leaks verified

Risk mitigated on critical pipeline
Challenge
Most of the Netherlands is situated under sea level, and a large system of dykes protects the land from rising water, while also connecting villages and cities. Water pipelines are often laid in close proximity to the dykes, meaning burst pipes would have devastating e­ffects on the road infrastructure and the surrounding communities.

Today, the aging dyke system is eroding the pipelines foundation causing stress and increasing the likelihood of failures. As a result of several incidents with failing or leaking pipelines in the vicinity of dykes, their owners issued a decree that required water utilities to prove the integrity of its buried assets. Waternet, the regional public water authority for Amsterdam, identified several pipelines of particular concern where a small leak from a pipeline could impact dyke integrity and a risk analysis discovered areas of pipe weakness. Based on these results, authorities determined that further testing in the form of inline leak detection should be performed.

Before embarking on inline leak detection, local officials required several rounds of extensive testing of the proposed technology to demonstrate e­ffectiveness in detecting and locating small leaks in the pipeline. In addition, since the scope of inspection included approximately 180 km of concrete pipelines, the leak detection technology had to demonstrate the ability to inspect long sections of pipe for the project to be most e­ffective.

Solution
Waternet partnered with Pure Technologies to perform inline inspections on three separate pipelines.

The SmartBall® leak detection tool was chosen to assess the integrity of the pipelines and to find leaks along the length of the pipe. The SmartBall tool is a free-flowing leak detection platform that operates while the pipeline remains in service. It is capable of completing long inspections in a single deployment and is equipped with an acoustic sensor that identifies acoustic anomalies associated with leaks and air pockets.

Typically inserted through an existing valve, it travels with the water flow recording the acoustic environment within the line. The SmartBall tool is then removed by either deploying a net at a predetermined extraction point or at another discharge point of the pipeline. The data is stored on the device and analyzed upon completion of the inspection. It is able to travel through long sections of pipe gathering approximately 18 hours of data, making it the ideal solution for the long pipelines of the Waternet leak detection program.

Calibration tests were done to conform to the strict requirements implemented by the dyke owners who wanted clear indications on the lower leak detection limit specific to the composition of the pipe. A calibration stack was developed and extensive tests were performed, simulating leaks to create a calibration curve for various leak sizes. The tests proved SmartBall could detect the leaks smaller than the threshold set by the dyke owners.

Results
Pure Technologies performed SmartBall inspections for Waternet along the WRK pipelines. These pipelines run mainly through rural farmland but also cross through critical dyke systems.

The first portion of the inspection began in 2013 when 146 kilometres of pipeline was broken into eight lengthy inspections. In 2014 the remaining 49 kilometres were inspected. Three leaks were found and verified during the inspection of the entire 195 kilometres of pipeline.

Pure Technologies worked closely with Waternet to fulfill the comprehensive requirements of the leak detection program required by the utility. The importance the dyke system to the protection of the country’s infrastructure and communities mean the integrity of the pipelines must be maintained. The inline leak detection program gave Waternet the necessary information to fulfill their commitment to the dyke owners, and help extend the life of these critical pipelines.

Case Study

This preeminent steel producer is a North American leader in advanced steel manufacturing technology. Typical to most steel processing plants, this mill uses recirculated water for a broad variety of purposes, including cooling the blast furnaces, quenching slag, and drawing heat from the overall hot plant environment.

Project Details

Services
PureRobotics® electromagnetic condition assessment
PureRobotics® HD-CCTV inspection
Risk assessment and prioritization
Single day mobilization and inspection
Timing
2015
Pipe Material
Lined Cylinder and Embedded Cylinder Pipe (Types of PCCP)
Inspection Length
0.68 miles
Diameter
48-inch & 54-inch
Transmission Type
Recirculating Water

Project Highlights

0.68 miles (1.09kms) total distance inspected

117 pipes inspected

31 pipes with broken wire wraps

25 repaired and replaced pipes

Challenge

The lines used for recirculating water play a critical role in the operation of a steel plant. When the mill scheduled a brief operational shutdown, they wanted to quickly understand the true condition on a section of their return and supply lines in order assess and prioritize risk and rehabilitate any problem pipes.

On June 2015, the steel mill engaged Pure Technologies Ltd. (Pure) to conduct a non-destructive evaluation of the prestressed concrete cylinder pipe (PCCP) sections in the 48 inch Recirculating Water Return (RWR) and the 54-inch Recirculating Water Supply (RWS) Lines.

The inspected portion of RWR Line is composed of single wrap lined cylinder pipe (LCP). The inspected portion of RWS Line is composed mainly of single wrap embedded cylinder pipe (ECP) without shorting and a short section of single wrap LCP. The pipes were manufactured in 1981.

Pure Technologies previously inspected the 48-inch RWR Line in July 2009 and January 2010 and the 54- inch RWS Line in January 2010. To facilitate a direct comparison between past and current inspection results, the data from the 2010 inspection was reviewed to ensure data analysis continuity.

Solution

The purpose of the single day inspection was to locate and identify pipes that have broken prestressing wire wraps, using Pure’s electromagnetic inspection technology. An electromagnetic inspection provides a non-destructive method of evaluating the baseline condition of the prestressing wire, the structural component that provides the pipe’s strength.

Since the line was dewatered, the survey requirements would also include a visual inspection, which led Pure to recommend the tethered PureRobotics platform, as it is equipped with a high definition CCTV camera to deliver a live video stream from inside the pipe.

The robotic transporter is designed to carry a variety of sensors and tools and can travel a total of 2.9 kilometers from a single point of access. With the new generation of robot, the speed is doubled to 85 feet per minute, which greatly improves efficiency in the field, a huge benefit during time-critical shutdowns.

The inspection went off without a hitch, as crews from the plant had earlier prepped all access points. Pure simply set up a tripod with a chain fall, and lowered the tethered robot through a manhole into the pipe to begin the inspection journey.

Results

Overall, the survey was a low effort, little disruption inspection, conducted in less than a day.

The inspection covered a cumulative distance of 0.68 miles and spanned a total of 177 pipes.

Of these pipes, 25 are replacement pipes or have been previously repaired using carbon fibre.

Analysis of the data obtained during the inspection determined that out of the remaining 152 pipes, 8 pipes in the 48- inch RWR Line and 23 pipes in the 54-inch RWS Line displayed electromagnetic anomalies consistent with prestressing wire damage, ranging from 5 to 40 broken wire wraps.

With the actionable information delivered by Pure, the mill was able to learn about the current condition of their critical assets, and strategize rehabilitation and repair initiatives that meet the goals of their production. In the end, effective asset management using the latest tools and strategies helps reduce costs through targeted spending.

Case Study

The Milwaukee Metropolitan Sewerage District (MMSD) takes a proactive approach to water management initiatives, as evidenced in the condition assessment of the Franklin-Muskego Force Main.

Ownership of the pipeline is shared between the City of Muskego and MMSD, the government agency that provides water management services for about 1.1 million people in 28 communities in the Greater Milwaukee Area.

In 2015, Pure Technologies (Pure) worked closely with MMSD to perform a detailed condition assessment of the approximately 25-year old ductile iron pipeline. The purpose of the assessment was to identify the structural condition of the metallic force main, and included pressure monitoring, a SmartBall® leak and gas pocket detection survey, and a PipeDiver® electromagnetic inspection of the pipeline.

Project Details

Services
SmartBall® Leak and Gas Pocket Detection
PipeDiver® Electromagnetic Inspection
Transient Pressure Monitoring
Structural Engineering
Timing
2015
Pipe Material
Ductile Iron
Inspection Length
2.9 miles (4.7 kms)
Diameter
20-30 inches (500-750mm)
Transmission Type
Wastewater

Project Highlights

Inspection identified 13 pipe sections with electromagnetic anomalies

Defects ranged from 20-55% wall loss

Transient pressure monitoring indicated pipeline operating within design capacity

Challenge
The Franklin-Muskego Force Main carries wastewater along approximately 3 miles of 24-inch and 30-inch ductile iron pipe (DIP). One of the challenges in assessing DIP is determining if the pipe has undergone any wall thickness loss due to internal or external corrosion, which are the primary causes of failure. DIP in water service with a cement mortar lining generally has fewer internal corrosion failure rates, unless damaged during handling and installation, or later as a result of 3rd party damage. This is not the case when DIP is used in a force main, where internal corrosion is the primary cause of failure.

Gas pockets are of significant concern as concentrations of hydrogen sulfide gas within wastewater may cause corrosion and eventual breakdown of the pipe’s exposed surface. In a force main, identifying internal areas with potential corrosion is challenging, as traditional gravity pipeline inspection techniques are often not applicable to in-service pressurized pipelines.

One method for assessing gas pockets is to locate air release valves (ARVs) or other high points along the alignment and conduct test pit investigations in those areas. While this is a valid method for locating potential gas pocket locations, additional gas pockets may occur due to differential settlement, improper installation or non-functioning ARVs. Desktop surveys may not identify and locate all gas pockets along a pipeline, which is why Pure recommends other more precise survey methods.

Solution
To evaluate the condition of the Franklin-Muskego force main, Pure recommended in-line condition assessment. This included inspecting for the presence of gas pockets, using electromagnetics for assessing the condition of the pipe wall and structural engineering to evaluate the significance of defects found.

In October 2015 Pure performed a SmartBall leak and gas pocket detection survey and a PipeDiver electromagnetic inspection of the Franklin-Muskego Force Main. The SmartBall platform is a free-swimming tool that uses acoustics to detect leaks and gas pockets while the pipeline remains in full service. Pure’s flexible, free-swimming PipeDiver tool collects electromagnetic (EM) data that is used to measure the relative wall thickness of the cylinder – the main structural component of the pipeline. With electromagnetics onboard, PipeDiver can identify localized areas of wall loss in the cylinder of the pipe, and broken bar wraps in BWP, all while the pipeline remains in service.

Results
The results of the C150 design check showed that the pipe’s nominal wall thickness is sufficient for current loading conditions. Transient pressure monitoring indicated that over the period of monitoring, the pipeline operated within its design capacity.

Through the PipeDiver inspection, 13 pipes were found to have a total of 16 electromagnetic anomalies consistent with localized wall loss, ranging between 20 percent to 55 percent wall loss. At the time of writing, MMSD was making plans to excavate and repair one pipe section with three areas of pipe loss ranging from 35 percent to 55 percent wall loss. The results of the condition assessment indicate that the Franklin-Muskego Force Main is in good condition.

While the assessment recognized several areas with an increased likelihood of failure, overall the data was good, and coupled with Pure’s engineering recommendations, gave all stakeholders confidence in the health of pipeline for the near foreseeable future.

Case Study

Following a water main break in 2009 that resulted in the loss of 15 million gallons of treated water, LWC began a Transmission Assessment Program, using various assessment technologies from Pure Technologies.

Project Details

Services
PureRobotics® electromagnetics (EM) condition assessment

PureRobotics HD-CCTV inspection

Inertial measurement unit for GIS component

Risk prioritization

Timing
2015
Pipe Material
PCCP
Inspection Length
3.4 miles (5.5 kms)
Diameter
24-30 inches (610-760mm)
Transmission Type
Water

Project Highlights

EM data identified 17 anomalies warranting further investigation

HD-CCTV identified longitudinal cracks consistent with overloading

One (1) pipe section found to display anomalous EM signals associated with broken wire wraps and wall cylinder loss

Challenge
In the summer of 2015, LWC deployed PureRobotics to assess 3.4 miles of 24 to 30-inch transmission mains in its network. With 4,100 miles of pipeline to maintain, (200 miles of it transmission main) LWC focused its condition assessment on its transmission main system – pipes that would cause the greatest amount of damage in the case of failure. The loss of non-revenue water, either chronically in small amounts or from a catastrophic failure, can result in massive costs to a water utility.

By prioritizing the risk levels associated with their transmission main system, LWC has created an ongoing inspection program to keep a watchful eye on the health of their pipelines. The program utilizes a number of Pure Technologies assessment tools to find active leaks as well as potential future threats.

Solution
In May of 2015, PureRobotics was deployed on the Cross County Header, Ray Lane Easement Pipeline, and Bardstown Road Pipelines. The latest generation robotic crawler is designed to carry sensors and tools up to 1.8 miles (2.9 kilometers) through potable water or wastewater at a speed of 85 feet per minute. For LWC, PureRobotics used CCTV to provide a comprehensive high-definition visual inspection.

The robotic crawler was also outfitted with specialized tools to conduct an electromagnetic assessment on the condition of the pipeline and inertial measurement unit (IMU) for the GIS component. The Inertial Measurement Unit (IMU) deployed with PureRobotics uses a series of Fiber Optic Gyroscopes (FOGs) and accelerometers to track depth, lateral and horizontal movements from a known GPS reference point. The output is a GIS spatial map of the pipeline which depicts elevation changes as well as notable features of interest encountered during the inspection.

Pure’s electromagnetic assessment uses transformer coupling to detect anomalous regions in the pipe cylinder and prestressing wires. This data is correlated with odometer readings from the PureRobotics umbilical tether as well as HD recorded CCTV and IMU to attempt to locate areas of distress in the pipeline.

Results
High definition CCTV inspection results showed a number of longitudinal cracks consistent with overloading. These types of mortar cracks may eventually lead to corrosion of the steel cylinder or prestressing wire and eventually a failure of the pipe.

One pipe section in the Ray Lane Easement pipeline was found to display anomalous electromagnetic signals showing a significant number of broken prestressing wire wrap breaks as well as cylinder wall loss. This was correlated with visual data, showing spalling and exposed steel at the invert of the pipe. LWC intends to investigate this issue at a later date.

Visual assessment also showed a number of pipe sections with spalling. Pure recommended continued monitoring at these locations during future inspections. Electromagnetic assessment also found 11 pipes with anomalous signals not consistent with wire breaks. Investigation performed on one of these anomalous pipes showed a non-standard metal sleeve used in manufacturing. From this information, it was determined that the remaining 10 anomalous pipes could be left in service.

As one of the first utilities to deploy the third generation PureRobotics platform, LWC now has defensible data to move forward with its ongoing rehabilitation program.

Case Study

The City of Calgary provides water and wastewater services for more than 1 million people in the Greater Calgary area. For many municipalities, accurate and regular condition assessment of large-diameter pressure pipelines has become more important in recent years as these assets continue to age and risk of failure increases.

In Calgary, three critical feedermains (14th Street/North Hillhurst, John Laurie and Top Hill) are each constructed of different materials: lined cylinder pipe (LCP), prestressed concrete cylinder pipe (PCCP) and bar wrapped pipe (BWP). The pipes range from 750mm (30-inch) to 900mm (35- inch) in diameter.

Project Details

Services
PureRobotics® electromagnetic condition assessment

PureRobotics® HD-CCTV inspection

Risk Prioritization

Timing
2015
Pipe Material
PCCP, LCP, BWP
Inspection Length
4.74 km (2.9 miles)
Diameter
750mm-900mm (29-35 inch)
Transmission Type
Water

Project Highlights

Condition assessment on 2.92 miles (4.7 kms) of feedermain pipes

Data identified 8 pipes with electromagnetic anomalies consistent with broken pressing wire wraps

HD-CTTV identified 3 pipes with damaged internal mortar and exposed cylinder

Challenge
In an annual condition assessment program, The City inspects its PCCP, BWP and LCP for deterioration. By identifying isolated pipe sections with deterioration, the City is able to make selective repairs in favor of full-scale replacement, which comes at a high cost and may replace sections with significant remaining useful life.

In data collected from more than 14,000 miles of pressure pipe condition assessment, Pure Technologies has found that only a small percentage of pipes (less than 5 percent) are in need of repair and therefore have years of service left. Condition assessment data also suggests that pipe distress is localized, and significant ROI can be achieved by locating and addressing isolated problems through structural inspection.

Solution
To inspect the three feedermains, the City deployed PureRobotics®, a tethered robotic system that delivers live video, and is equipped with electromagnetic technology that can be configured to inspect a variety of pipelines and materials with different operational conditions.

In BWP, the technology identifies and locates broken bars and areas of corrosion on the steel cylinder, which are the main indication this type of pipe will eventually fail. Although BWP looks similar to PCCP in cross section, the design and materials are significantly different.

PCCP is a concrete pipe that remains under compression because of the prestressing wires, with the thin-gauge steel cylinder acting as a water membrane. With BWP, the cylinder plays a much larger role in the structural integrity of the pipe. BWP is essentially designed as a steel pipe with mild steel used to manufacture the steel cylinder and steel bars. PCCP utilizes mild steel for the cylinder, but high strength steel is utilized for the wire, which is wrapped under high tension. As a result, the bar in BWP and wire in PCCP respond differently to environmental conditions that facilitate corrosion.

The high strength steel wire in PCCP is smaller in diameter and wrapped under higher tension, therefore corrosion makes it quite vulnerable to breakage. The mild steel bars in BWP are thicker in diameter and wrapped under less tension, therefore corrosion takes significantly longer to lead to breakage. The type of failure is also much different; PCCP tends to fail suddenly with a large dispersion of energy. This type of failure is less likely in BWP where failures are similar to steel pipe with long periods of leakage occurring prior to rupture. Because of the differences in make-up, BWP and PCCP are inspected using unique methods to determine their structural condition.

Results
Of the 694 pipes cumulatively inspected over the 4.74 kilometers, eight (8) pipes were identified with electromagnetic anomalies consistent with broken prestressing wraps. Additionally, two (2) pipes were found with an anomalous signal not characteristic of broken bar wraps that can be attributed to a change in the pipe cylinder.

Evaluation of the John Laurie Boulevard Feedermain concluded that one (1) pipe was identified to have an anomalous signal likely caused by a non-uniform cylinder. Images obtained from the robot indicated this pipe has damaged internal mortar and exposed cylinder. Additionally, two (2) pipes on this feedermain were identified to have damaged internal mortar and exposed cylinder, but did not contain anomalous signals.

The City of Calgary was pleased with the results, and through condition assessment, has been able to identify and address individual distressed pipe sections on otherwise serviceable feedermains. This has allowed the City to avoid potential ruptures, while increasing service reliability and useful life of the feedermains.

For utilities with large-diameter networks, waiting for failures to occur before repairing or replacing highly critical mains is not an option.

Massive pressured water lleak on a street

With a large amount of buried water infrastructure reaching the end of its service life, operators have every incentive to take a proactive approach to asset management.

Nowhere is this more critical than in busy urban centres. The fallout from an unexpected failure can have major societal costs, and greatly diminish public confidence in the utility.

Asset management begins with condition assessment

Successful asset management begins with condition assessment, the point at which problems and challenges are understood and shaped into definitive plans from both an operational and financial perspective.

To proactively address their pipeline conditions, operators today have access to variety of tools, technologies and engineering analysis that allow for a comprehensive condition assessment of large-diameter pressure pipes, for both water and wastewater systems.

“Unfortunately there is no ‘silver bullet’ with regard to condition assessment technologies,” said Mike Wrigglesworth, Senior Vice President of Pure Technologies. “Each pipeline is unique, and no single technology is the fix for all situations. A combination of factors, from pipe material to soil conditions, operational challenges, age, installation and third party factors will all play a role in the likelihood of failure. Combined with the consequence of failure, a risk-based approach can then be used to select the best condition assessment tool or technologies.”

Matching assessment technology with the pipeline conditions and project goals

While operators can now deploy a number of data-based tools and techniques to assess pipeline conditions, each technology also comes with varying degrees of limitation. For instance, while magnetic flux leakage (MFL) tools provide the highest resolution data for steel pipe, MFL is of limited value for concrete pipe.

Medium resolution techniques such as electromagnetics can identify localized areas of wall loss on metallic pipes such as ductile iron and steel, but not on cast iron pipe as cylinder thickness is often too thick and material properties vary considerably, negatively affecting results. In both cases, it is often prudent to deploy leak detection technologies, as studies show joint defects lead to leaks, and leaks are precursors to failure.

“Often the best solution is to use different but complementary technologies to collect robust condition data that is then evaluated using engineering analysis against a comprehensive risk of failure versus a consequence of failure analysis.”

Sahara® Leak and Gas Pocket Detection

Pure’s proprietary Sahara® inspection platform is a tethered, multi-sensor tool that can identify acoustic-based leaks, gas pockets and visual anomalies in real time, with no disruption to service.

The Sahara tool features a small parachute that uses the product flow to draw the sensor through the pipeline while being controlled from the surface.

SmartBall® Leak and Gas Pocket Detection

SmartBall® is a multi-sensor tool used to identify a variety of conditions in pressurized pipelines. The tool is easy to deploy through existing pipeline features, and travels untethered with the product flow, collecting information.

The tool’s highly sensitive acoustic sensor can locate small leaks and gas pockets, with typical location accuracy within 6 feet (1.8 m).

PipeDiver® Condition Assessment

PipeDiver® is a free-swimming condition assessment tool that operates while the pipeline remains in service.

Originally designed for use in PCCP, the tool has electromagnetic sensors to identify and locate broken prestressing wire wraps. For metallic pipelines, the optimized PipeDiver has the ability to pinpoint localized areas of wall loss.

The tool is also able to deliver video images from inside the pipe.

PipeWalker™ Condition Assessment

The PipeWalker tool provides a viable option for pipeline condition assessment in situations where the pipe is dewatered or where the option to dewater is available.

The tool is equipped with electromagnetic sensors for detecting wire wrap breaks on PCCP pipes and for detecting corrosion on metallic pipes.

PureRobotics® Pipeline Inspection

PureRobotics® is a depth-rated robotic pipeline inspection system that can be configured to inspect pipe applications 24-inches and larger.

Tethered by a high-strength fiber optic cable, the crawler is capable of performing multi-sensor inspections in dewatered pipes or while submerged in depressurized pipes.

The crawler features HD digital CCTV, and can be equipped with electromagnetic sensors, Inertial Mapping, 3-D LIDAR, LASER, SONAR and other tools upon request.

Matching the level of resolution to the risk of the line

While there are a variety of approaches available for assessing a pipeline’s condition, much of an operator’s effort must go into matching the level of resolution of the approach to the overall risk of the line.

The idea is to put the highest resolution technologies on the most critical lines. In the end, the goal of deploying a particular technology (or complementary technologies) is to identify and locate the areas that need rehabilitation or repair as opposed to wholesale replacement of those lines.

Armed with the right information, operators can determine remaining useful life, and confidently move forward to prioritize and target capital spending, while avoiding failures.

Case Study

In early 2015, Pure Technologies (Pure) conducted a condition assessment of Pipeline No. 1 owned and operated by The City of Tacoma (Tacoma Water), as part of their proactive asset management program. Pipeline No. 1 is a critical link in Tacoma’s transmission system, conveying up to 72 MGD of potable water over a 26-mile stretch to the McMillin Reservoir. Tacoma Water provides water service to more than 300,000 residents throughout Pierce and King Counties in Washington.

While the critical pipeline has had previous condition assessment and repairs on targeted sections, the goal of the latest survey was to provide Tacoma Water with detailed assessment information to determine future repair, rehabilitation and re-inspection strategies.

Project Details

Services
PureEM™ manned electromagnetic inspection

Handheld ultrasonic thickness testing

Structural engineering analysis using 3-dimensional nonlinear finite element analysis (FEA)

Remaining useful life projections using Monte Carlo simulation

Timing
48 Hours
Pipe Material
Welded Steel
Inspection Length
917 feet (279 meters)
Diameter
48-52 inches
Transmission Type
Water

Project Highlights

Survey covered 917 feet and spanned 125 pipes

12 pipes identified with electromagnetic anomalies

Defects identified ranged from 15 to 35 percent wall loss

Inspection deployed 48-detector electromagnetic tool

Challenge

By the end of 2013, Tacoma had repaired approximately 15 leaks at 3 locations along the section of Pipeline No. 1 located near Boise Creek. In order to investigate this section of pipeline further, Tacoma decided to excavate the pipe in select locations to observe the condition of the pipeline.

Several areas with minor pitting were identified during the investigation. Due to the critical nature of this pipeline, Tacoma decided to take further action on the main and considered a replacement project.  However, before proceeding, Tacoma wanted to validate the need to replace this section of pipe.

As a result, a comprehensive condition assessment of the main was performed to confirm its condition before initiating an expensive and disruptive replacement project. Owing to the criticality of the line, Pure had only 48 hours to conduct the non-destructive condition assessment, using its proprietary electromagnetic technology (PureEM™) on just over 900 feet of pipe.

Solution

Assessing the condition of metallic pipelines is a challenging task best performed using a combination of assessment methodologies, engineering science and experiential judgment. Pure’s PureEM electromagnetic tool was used to evaluate the condition of the pipe wall and identify localized areas of wall loss. The significance of the results were evaluated through structural engineering, and long-term recommendations were made based on statistical modeling and remaining useful life projections.

As the pipeline could only be taken out of service for 48 hours, this required careful planning and extensive tool preparation. The PureEM tool was inserted through an existing manhole access and assembled in the pipe. During the inspection, technicians gathered electromagnetic data, numbered the pipe, and took detailed notes on the internal visual condition of the pipe. UT thickness measurements were also collected on the pipe in several areas.

A pre-inspection calibration of the PureEM tool allowed for more precise quantification of the defect identified through the EM inspection. This involved destructive testing on an above-ground 52-inch welded steel pipe of similar vintage to calibrate the EM signal changes for this particular type of pipe.

Following the inspections, Pure’s structural engineers used finite element modeling to evaluate the significance of the defect identified. Finally, a Monte-Carlo simulation was employed to estimate the pipe’s remaining useful life.

Results

Analysis of the electromagnetic data obtained during the inspection determined that of the 125 pipes surveyed, 12 pipes had electromagnetic anomalies consistent with wall loss ranging from 15 percent to 35 percent.

The results of the structural analysis indicate that the internal stresses in the subject pipeline are very low compared to the structural capacity of the pipe. None of the detected anomalies are at or near a point of concern, and the pipeline can be operated without immediate rehabilitation.

With the remaining useful life estimated at the pipeline operating without significant risk of structural failure in the next 30 to 50 years, Tacoma Water now has data-driven confidence in the short and long-term management of Pipeline No. 1.

As a result of Pure’s Assess and Address® approach, the City of Tacoma avoided near-term replacement of the main, which was estimated between US$2 to 3 million.

Quote

“With the remaining useful life estimated at the pipeline operating without significant risk of structural failure in the next 30 to 50 years, Tacoma Water now has data-driven confidence in the short and long-term management of Pipeline No. 1.  As a result of Pure’s Assess and Address® approach, the City of Tacoma avoided near-term replacement of the main, which was estimated between US$2 to 3 million.”

Case Study

K-water, the national bulk water utility in South Korea, supplies water across the country to smaller cities and controls everything from collection, treatment and pumping to maintenance, inspection and rehabilitation of the nation-wide pipeline system.

In addition to supplying treated water to these small cities, many have contracted K-water to manage and maintain their distribution systems as they battle the challenges of aging infrastructure. Beginning in 2011, K-water has used Sahara® Leak Detection to address non-revenue water and collect condition information about its metallic pipelines.

Project Details

Services
Sahara® Leak Detection
NRW reduction program
Baseline condition assessment
Timing
2012-ongoing
Pipe Material
Steel, Cast Iron, Ductile Iron
Diameter
6-inch (150mm) to 90-inch (2300mm)
Transmission Type
Water

Project Highlights

22 leaks located in 25 miles (40.23 kms) of inspection

Pinhole leaks identified within 5 cm of actual location

Estimated 350,400 m3 of water saved per year in Tongyeong City

Challenge

In 2009, K-water was searching for a large-diame­ter leak detection tool for its critical trunk mains. While K-water has done an exemplary job of maintaining its nation-wide pipeline network, which totals about 5,000 kilometers and has a Non-Revenue Water (NRW) rate of about 2 per­cent, many of its client municipalities suffer from high levels of NRW as their infrastructure ages and begins to leak. K-water was also interested in a tool that would allow them to compare actual pipeline conditions with their extensive pipeline engineering knowledge, allowing for quality con­dition assessment and failure prevention. In 2011, K-water began a knowledge-transfer program with Pure Technologies to become independent operators of Sahara leak detection.

Solution

K-water has built up expert knowledge in pipe­line engineering, a database of information on their pipe materials and pipe failure methods, and has adopted the best condition assessment technologies in the market to help inspect their pipelines so that efficient, prioritized rehabilita­tion and replacement plans can be made.

One condition assessment tool K-water has adopted is the Sahara platform – a tethered system with acoustic leak detection and inline video. While many utilities around the world use this tool for large-diameter leak detection, K-wa­ter has adopted it in an innovative way, choosing to use it as a complete condition assessment tool to provide information on its pipelines and accu­rate location of leaks.

The tool is non-destructive and is pulled by the flow of water by a small drag chute. When the sensor is inserted into a tap, it remains tethered to the surface to allow for immediate checking of suspected leaks and gas pockets, internal pipe wall conditions and pipeline features by winching the sensor back and forth from the surface. The sensor is also tracked at ground level by a staff member, allowing for precise spot markings for excavations. Sahara also provides real-time inline video, which allows the operator to see live pipe conditions as the tool surveys for leaks and gas pockets.

Operating with a national mandate and several stakeholders, K-water faces a number of logistical challenges with its pipeline infrastructure.

One challenge is population density; South Korea is roughly 2 per cent of the size of Canada with almost double the population, meaning large, densely populated regions rely on K-water for consistent water service. A failure or service interruption to a critical trunk main could be disastrous K-water’s credibility with customers.

South Korea is also a very mountain­ous region, meaning pipelines supplying water throughout the country often pass through areas that are difficult to inspect using traditional methods. In addition to the landscape, many of K-water’s large diameter pipelines are buried deep in the ground, making excavation projects com­plex and expensive to complete.

By becoming certified Sahara tool operators, K-water staff can deploy the tool at their own descretion and are able to overcome these chal­lenges to complete inspections in difficult regions.

Results

Tongyeong City, South Korea, which has a high NRW and features 32-inch (800-mm) steel pipe, has been inspected twice; first as part of Pure’s Sahara training program and subsequently by K-water as an independent operator. The inspec­tions in Tongyeong City were extremely success­ful, locating 10 total leaks with high accuracy in 2.5 kilometers of inspection for an estimated sav­ings of 350,400 cubic meters of water per year.

During the training inspections, Pure and K-wa­ter were able to locate pinhole leaks as close as 5-cm above and below the actual leak location – meaning service disruption, excavation and repair times were minimal. In K-water’s subsequent inspection of the same pipeline in Tongyeong City, they were able to excavate and repair all three identified leaks in 5.5 hours each during the night (3 separate repairs), causing little disruption to customers.

In total, K-water has inspected 25 kilometers of pipeline and located 22 leaks of varying sizes. K-water has inspected both its own pipelines as well the regional pipelines that it operates and has covered pipes with diameters as small as 150-mm and as large as 2300-mm, with most pipe being either steel, ductile iron or cast iron pipe. K-water’s 2012 program will cover about 52 kilometers of pipeline for leaks and gas pockets

While the tool has been effective in locating leaks for K-water, its value as a complete condition assessment tool has also been helpful due to the unique challenges faced in South Korea. K-water has been able assess the state of its pipelines by combining the inline video data and its extensive engineering knowledge. By doing this, K-water has become a thought-leader in large-diameter pipeline management.

K-water has successfully applied the Sahara platform for condition assessment in its transmission mains and for leak detection in municipal trunk mains.

Se-Hwan Kim

General Manager, Water Supply Operation & Maintenance Department, K-water

Speak to One of Our Experts





Case Study

The Milwaukee Metropolitan Sewerage District (MMSD) takes a proactive approach to water management initiatives, as evidenced in the recent condition assessment of the Franklin-Muskego Force Main.

In 2015, Pure Technologies (Pure) worked closely with MMSD to perform a detailed condition assessment of the approximately 25-year old ductile iron pipeline. The purpose of the assessment was to identify the structural condition of the metallic force main, and included pressure monitoring, a SmartBall® leak and gas pocket detection survey, and a PipeDiver® electromagnetic inspection of the pipeline.

Project Details

Services
SmartBall® leak and gas pocket detection

PipeDiver® electromagnetic inspection

Pressure monitoring

Structural engineering

Timing
2015
Pipe Material
Ductile Iron
Inspection Length
2.9 miles
Diameter
20-inch to 30-inch
Transmission Type
Wastewater

Project Highlights

Condition assessment on

4.7km

of feedermain pipes

Data identified

8

pipes with electromagnetic anomalies consistent with broken pressing wire wraps

HD-CTTV identified

3

pipes with damaged internal mortar and exposed cylinder

Challenge

The Franklin-Muskego Force Main carries wastewater along approximately 3 miles of 24-inch and 30-inch ductile iron pipe (DIP).

One of the challenges in assessing DIP is determining if the pipe has undergone any wall thickness loss due to internal or external corrosion, which are the primary causes of failure. DIP in water service with a cement mortar lining generally has fewer internal corrosion failure rates, unless damaged during handling and installation, or later as a result of 3rd party damage.

This is not the case when DIP is used in a force main, where internal corrosion is the primary cause of failure. Gas pockets are of significant concern as concentrations of hydrogen sulfide gas within wastewater may cause corrosion and eventual breakdown of the pipe’s exposed surface.

In a force main, identifying internal areas with potential corrosion is challenging, as traditional gravity pipeline inspection techniques are often not applicable to in-service pressurized pipelines.

One method for assessing gas pockets is to locate air release valves (ARVs) or other high points along the alignment and conduct test pit investigations in those areas. While this is a valid method for locating potential gas pocket locations, additional gas pockets may occur due to differential settlement, improper installation or non-functioning ARVs.

Desktop surveys may not identify and locate all gas pockets along a pipeline, which is why Pure recommends other more precise survey methods.

Solution

To evaluate the condition of the Franklin-Muskego force main, Pure recommended in-line condition assessment. This included inspecting for the presence of gas pockets, using electromagnetics for assessing the condition of the pipe wall and structural engineering to evaluate the significance of defects found.

In October 2015 Pure performed a SmartBall leak and gas pocket detection survey and a PipeDiver electromagnetic inspection of the Franklin-Muskego Force Main.

The SmartBall platform is a free-swimming tool that uses acoustics to detect leaks and gas pockets while the pipeline remains in full service.

Pure’s flexible, free-swimming PipeDiver tool collects electromagnetic (EM) data that is used to measure the relative wall thickness of the cylinder – the main structural component of the pipeline. With PureEM® onboard, PipeDiver can identify localized areas of wall loss in the cylinder of the pipe, and broken bar wraps in BWP, all while the pipeline remains in service.

Results

The results of the C150 design check showed that the pipe’s nominal wall thickness is sufficient for current loading conditions. Transient pressure monitoring indicated that over the period of monitoring, the pipeline operated within its design capacity.

Through the PipeDiver inspection, 13 pipes were found to have a total of 16 electromagnetic anomalies consistent with localized wall loss, ranging between 20 percent to 55 percent wall loss. At the time of writing, MMSD was making plans to excavate and repair one pipe section with three areas of pipe loss ranging from 35 percent to 55 percent wall loss.

The results of the condition assessment indicate that the Franklin-Muskego Force Main is in good condition.

While the assessment recognized several areas with an increased likelihood of failure, overall the data was good, and coupled with Pure’s engineering recommendations, gave all stakeholders confidence in the health of pipeline for the near foreseeable future.

Case Study

The Foothill Municipal Water District (FMWD) serves approximately 86,000 people through its member agencies located in the foothills of the San Gabriel Mountains, bordered between the City of Pasadena and the City of Glendale. In March 2013, Pure Technologies (Pure) successfully completed in La Canada Flintridge, a 2.2-mile internal inspection and condition assessment of a 24-inch mortar-lined steel force main to identify broad areas of wall loss.

Project Details

Services
PureRobotics™ electromagnetic condition assessment inspection

PureRobotics HD-CCTV inspection

Structural assessment

Engineering services

Risk prioritization

Timing
2013
Pipe Material
Mortar-lined Steel
Inspection Length
2.2 miles (3.55 km)
Diameter
24-inch (610-mm)
Transmission Type
Water

Project Highlights

EM data identified 17 anomalies warranting further investigation

FMWD selected 2 locations to perform test pitting

Results revealed minimal wall loss and continued operation of water main

Challenge

For utilities like FMWD, which has no redundancy in its system, finding a reliable inspection method that provides condition data for the entire length of a steel pipeline is an important aspect of its condition assessment program.

As well, as part of the condition assessment, a structural evaluation was performed to determine whether the force main design satisfies AWWA M11 “Steel Pipe – A Guide for Design and Installation, fourth edition” standards. The results of this evaluation has helped FMWD determine where to focus more detailed inspections in order to make detailed rehabilitation decisions for this force main.

Solution

To complete the inspection, FMWD used PureRobotics electromagnetic condition assessment equipped with electromagnetic technology and high-definition closed circuit television (HD-CCTV). The platform is a non-destructive, in-line assessment tool that provides screening level wall thickness data in the circumferential and axial directions of metallic pipelines.

The robotics tool used was assembled inside the pipeline and controlled remotely by operators on ground level. This allowed FMWD to maximize the HD-CCTV function as internal features could be closely inspected with the camera. By opting for an inline assessment in favor of traditional metallic inspection methods, FMWD has a baseline condition of the entire 2.2-mile water main.

Results

After reviewing the electromagnetic data, Pure Technologies was able to identify 17 electromagnetic anomalies that warrant additional investigation. Using the resulting information, the top 10 anomalies were ranked based on the strength, area and repeatability of signal loss and visually using HD-CCTV.

FMWD selected two locations to perform test pitting to obtain higher resolution data needed to evaluate rehabilitation or repair needs and determine the remaining useful life of the water main.

Results of the two test pits revealed minimal wall loss and resulted in the continued operation of the steel water main with no rehabilitation required. Ranking the anomalies based on size allowed the prioritization of further inspection based on sound and defensible engineering judgment.

Risk prioritization is an important facet of any condition assessment program because it allows the most urgent needs to be addressed first. By proactively managing its pipeline assets, FMWD is able to continue to deliver quality water to its member agencies in a cost-efficient manner to meet their projected demands.

Case Study

Evides Watercompany was open to exploring new ways to reduce risks and extend the service life of their buried infrastructure. In particular, Evides wanted to assess the condition of its TL2.60 pipeline, a cement-lined 800mm (31.5 inch) steel pipe, with 2.8 kilometers (1.7 miles) of the inspected pipeline running along an important highway connecting Rotterdam to The Hague.

To assist in the condition assessment, Evides elected to deploy the 24-sensor PipeDiver®, an innovative tool from Pure Technologies designed to assess and address large-diameter metallic pipelines.

Project Details

Services
SmartBall® leak detection

PipeDiver® condition assessment

Timing
2016
Pipe Material
Steel
Inspection Length
2.84 km (1.7 miles)
Diameter
800mm (31.5-inch)
Transmission Type
Water

Project Highlights

 

Four (4)
pipes identified with anomalies

60% wall loss
on one pipe section identified by EM data

Zero (0)
leaks detected

 

HD-CTTV identified
estimated savings due to inspection: 1.1M Euros

 

Challenge
Prior to inspection, Evides created a series of predetermined defects made on a specific pipe segment in a research environment. The objective was to validate the tool against a range of known defects in a pipe with the same characteristics as the pipe inspected. During this process, all defects within the stated sensitivity were detected by the 24D PipeDiver tool at the precise location, providing confidence for the upcoming live inspection.

PipeDiver is a flexible, free-swimming condition assessment tool for pressurized water and wastewater pipelines. The video-equipped tool is ideal for critical pipelines that cannot be removed from service due to a lack of redundancy or operational constraints.

Solution
While PipeDiver has traditionally been deployed on prestressed concrete pipe to identify and locate broken prestressing wire wraps, the 24-detector PipeDiver has been specifically developed for metallic pipelines. For the Evides inspection, the PipeDiver tool with 24 electromagnetic sensors was used to locate and identify steel pipes with anomalies associated with corrosion or reduced wall thickness.

This Evides inspection marked the first condition assessment of metallic pipe using the 24D PipeDiver in Europe, an exercise that confirmed the validity of the tool’s sensor technology and validate once more the effectiveness of the platform to inspect pipelines.

The insertions went off without a hitch, and the PipeDiver sailed through the pipeline obstacle course with ease, gathering EM data along the route.

Results
Of the approximately 237 pipe sections inspected during the real inspection, four pipes were identified with anomalies indicative of cylinder wall loss, ranging between 30 percent and 60 percent. The wall loss defects ranged from 10.8 to 37.7 cubic centimeters (0.64 to 2.30 cubic inches).

After the inspection, three out of the four locations were dug-up to verify the reported defects, using non-destructive ultrasonic techniques. On each of the locations, the defects were found, and the actual material loss was in the range of the reported material loss.

Overall, the results proved the worth of PipeDiver as an advanced condition assessment tool able to deliver precise, actionable data on metallic pipes. The exercise showed the PipeDiver tool as a cost-effective solution versus methods that have operational constraints or require a shutdown or dewatering, or in this case, taken out of service. Evides estimated capital savings of 1.1M Euros as a result of the inspection and repairs.

Quote

“PipeDiver proved to be a suitable tool for one of our most important inspection needs: Corrosion of cement-lined steel pipes. We are especially glad the tool was able to pass a butterfly valve, and to be inserted and extracted through 600mm manholes, as this greatly improves operability and cost effectiveness.”

–Bart Bergmans, Project Manager, Infrastructure Asset Management, Evides Watercompany

Case Study

Daphne is located along the eastern shore of Mobile Bay, an area served by Daphne Utilities, which provides water, wastewater, and natural gas services to approximately 25,000 residents.

In 1985 the City purchased the Lake Forest Utility, and in doing so, Daphne Utilities took over their existing wastewater treatment plant, which was built in the 1970s.  The facility discharges through the Daphne Outfall, a 6,000-foot, 18-inch ductile iron effluent pipeline that discharges treated wastewater into Mobile Bay. Although the main was critical to the City, little information about it was transferred when Daphne Utilities acquired the facility.  Daphne Utilities later officially named the facility the Water Reclamation Facility.

Project Details

Services
Mapping deliverable

Pipeline alignment

Sahara® leak and gas pocket detection

Timing
One (1) day
Pipe Material
Ductile Iron
Inspection Length
1000 feet (304 meters)
Diameter
18-Inch (457mm)
Transmission Type
Treated Wastewater

Project Highlights

Pipeline assessment hampered by

non-existent plans

Obstacles in pipeline path include

urban development and wildlife sanctuary

Zero (0) leaks

eight (8) gas pockets detected

One (1) day

mobilization
1000ft inspected

Challenge
For many years after Daphne Utilities took over the Water Reclamation Facility the outfall line operated as a gravity discharge line. As the population grew and flows to the plant increased, Daphne Utilities installed pumps to occasionally increase the volume of treated wastewater passing through the discharge line. As development expanded, the situation progressed from a time when the pumps occasionally ran, to the point where the pumps ran almost continuously.

Gravity main transformed into a force main

Now, a pipe designed as a gravity main had transformed into a force main, pumping under pressure at all times, with its location and condition unknown – and with no redundancy.

To proactively manage this critical asset, in June 2015, Daphne Utilities retained the services of Pure Technologies (Pure) for a one-day Sahara® leak and gas pocket detection inspection of the Daphne Outfall, with a mapping deliverable.

The primary purpose of the inspection was to determine the pipeline alignment, since you can’t maintain what you can’t locate.  Since the 18-inch outfall was built, the terrain had changed markedly.  The original shoreline had been extended by hundreds of feet to accommodate the construction of a major highway and several hotels and restaurants.
In fact, based on best guesses and poor drawings, Daphne Utilities suspected that a five-story Hampton Inn had been built on top of the 18-inch outfall!
In short, Daphne Utilities didn’t know the exact pipeline location or its operational conditions.

Solution
To ascertain the alignment and condition of the 18-inch outfall, Daphne Utilities engaged Pure Technologies for a single day inspection.  In addition to the challenge of not knowing the exact pipeline alignment, it also appeared that the pipeline traversed under a swamp sanctuary for hundreds of alligators and other wildlife, in an area known as “Gator Alley.”

To conduct the mapping and assessment survey, Pure recommended the Sahara leak and gas pocket detection platform. Sahara is an inline tethered tool that can assess pipelines 6 inches and larger, without any disruption to service.

Because the sensor tool is tethered, an operator can stop and reverse the tool to investigate acoustic events such as leaks, gas pockets and visual anomalies. At the same time, an above-ground operator locates the sensor above ground, marking the exact location of the pipeline at any point along the pipe with sub-meter accuracy.

The mapping capability of Sahara allows utility owners to determine the exact location of their pipeline at any point, as well as the location of any leaks or gas pockets.

Results
Analysis of the acoustic data identified zero (0) leaks and eight (8) air pockets, which were impacting the efficiency of the line, as gas pockets occupy space within the already maxed-out pipeline. During the inspection, the alignment of the pipeline was determined and recorded from the treatment plant to the edge of the marsh where Mobile Bay starts, confirming the pipeline does indeed pass underneath the Hampton Inn.

In a single day, the Sahara crew determined flow velocity, inserted the tethered tool, inspected 1,000 feet, determined the pipeline alignment, and confirmed its location and the location of 8 gas pockets. As a result, Daphne now knows they have gas pockets and they now know the line location in order to execute a plan to deal with the gas pockets.

Not bad for a day’s work.

Case Study

Metropolitana Milanese (MM) manages the integrated water services for the City of Milan, which has more than 2,295 kilometers (1,430 miles) of pipeline in their network.  MM identified a critical transmission main as a priority for inspection, and proactively assessed a nine kilometer section using the SmartBall inline leak detection tool.  The Assiana Linate Transmission Main was selected as a high value main due to its location in the heart of Milan. A rupture would prove to be costly and disruptive to the city, and Metropolitana Milanese had no prior condition information on the main’s integrity.

Project Details

Services
SmartBall® Inline Leak Detection
Timing
2015
Pipe Material
Steel
Inspection Length
9 kilometers (5.5 miles)
Diameter
1200mm (48-inch)
Transmission Type
Water

Project Highlights

23
leaks in 9km identified by SmartBall® inspection

Inspection identified high concentration of leaks in specific zones

Program costs expected to be repaid in 3 years from water savings

Challenge

Assessing the condition of buried infrastructure can be challenging and difficult to predict. Traditional belief dictates the condition of the pipe is directly associated with its age, however extensive field work shows this is not always the case. One-hundred year old pipes can be dug up in like-new condition, and newer pipes can show extensive damage due to operational, environmental, and installation factors. While the Assiano Linate Transmission main, a 1200mm steel transmission main situated in the heart of Milan, was installed in 1982 and therefore is not particularly old, its important nature to the network made it a priority for assessment. Reducing Non-Revenue Water (NRW) is a major concern for municipalities and a proactive approach to pipeline inspection is critical to managing investments.

Solution

Metropolitana Milanese proactively assessed a nine kilometer section of the Assiano Linate Transmission main using the SmartBall leak detection tool. This technology was chosen to allow the transmission main to remain in operation during the inspection, a critical requirement due to the networks served by the main.

The tool is a free-flowing leak detection platform that operates while the pipeline remains in service. It is capable of completing long inspections in a single deployment and is equipped with an acoustic sensor that identifies acoustic anomalies associated with leaks and air pockets. The acoustic signature is then analyzed to determine if it is a leak, air pocket, or an external noise.

Identifying leaks small or large contributes to maintaining the condition of a transmission main. In metallic pipe materials, a catastrophic failure is often preceded by a period of leakage, so identifying and repairing leaks can help to reduce water main failures, as well as reduce Non-Revenue Water loss not detected in water balances.

Results

The SmartBall inspection identified 23 large leaks within 9 kilometers of pipeline inspected. One area of high leak concentration detected 8 leaks in a short 240 meter section. Although Metropolitana Milanese chose a low resolution tool for their assessment program, the concentrated location of the leaks resulted in an accurate condition assessment by finding the weak link in the transmission main.

While many leaks were detected during the inspection, because the overall flow of the main is high, the leakage was undetectable with traditional metering equipment. However, the potential savings from the leak detection program are significant enough to have a positive impact on the city’s Non-Revenue Water Program, and its finances.  Although the production cost of water is relatively low, the expected savings in water loss from repairing the leaks will pay back the costs of the project in approximately three years, including the cost of repair to the damaged section.

Furthermore, the results indicated that limited portions of the main have damage while most of the pipeline appears to be in relatively good condition. This gives a targeted area for repairs without the need to dig up large sections of the pipeline – a costly and time-consuming process.

By determining the specific locations of leaks on the Assiano Linate Transmission Main, Metropolitana Milanese will be able to reduce its NRW and has gained a better understanding of the overall condition of the pipeline. This will aid in future capital planning and will also provide a valuable study into determining the external factors that might be causing the leakage.

Focused repair works for the leaks will allow the utility to extend the life of the pipeline and reduce water loss, thus improving the overall service to its customers. The final data from the inspection will be presented in an innovative asset management overview to Metropolitana Milanese.

Quote

“SmartBall has been a cost-effective solution to assess the condition of a very critical pipe in our network without causing any negative impact in our daily operations.”

–Metropolitana Milanese

Case Study

The City of Montreal supplies drinking water and wastewater services to a population of nearly 1.9 million people. Starting in 2007, Pure Technologies (Pure) began working with the City’s potable water transmission division on a pipeline assessment program that included electromagnetic (PureEM) inspection and acoustic monitoring.

In 2015, as part of a pre-emptive program to reduce loss of non-revenue water and understand the condition of their pipes, the City partnered with Pure to conduct an ongoing, three-year leak detection survey on a series of critical pipes within its potable water network located mostly in the downtown core.

Project Details

Services
Sahara® leak detection

CCTV visual inspection

Timing
2015-Ongoing
Pipe Material
BWP, Steel, Cast Iron, PCCP
Inspection Length
28.9 km (18.5 m)
Diameter
500mm – 1200mm (20-inch – 48-inch)
Transmission Type
Water

Project Highlights

20.8 miles (33.5 kms) inspected to date

46 insertions completed

24 leaks identified

9 leaks identified as feature leaks

Challenge
The City recognized the value of detecting leaks, however small, to prevent these from developing into greater problems. While leaks occur most frequently on small-diameter distributions mains, leaks and ruptures on trunk mains are a much bigger concern for utility operators due to the relatively higher consequence of failure.

In addition to physical losses of water caused by a series of small leaks, the escaping water can eventually erode the surrounding soil making the area more prone to washouts or sinkholes, a major headache especially in densely populated areas. Leaking water can eventually find its way to the surface, or into sewers, overburdening the system. Unplanned excavations to repair unforeseen leaks can also erode consumer confidence in a public utility.

Solution
For its multi-year leak detection program, the City requested Pure to deploy its highly reliable and precise Sahara® acoustic video inspection on 46 kilometers of pipelines chiefly in the downtown core. The pipeline sections consist of PCCP, BWP, cast iron and steel.

The Sahara platform comes with a variety of sensor tools to perform the inspection. This includes an acoustic sensor to perform leak and gas pocket detection, and high-resolution video camera to assess internal pipe conditions.

Because the Sahara tool is drawn by product flow via a small drag chute, and is tethered to a data acquisition unit on the surface, it gives the operator close control to confirm suspected leaks, gas pockets and other visual anomalies. The tool can visually confirm pipe irregularities, continuously recording, allowing for both real-time and post-processing analysis.

For the Montreal project, the purpose of the Sahara inspection was to assess the condition of the pipeline by identifying and locating leaks, pockets of trapped gas and to identify larger visual anomalies utilizing Closed Circuit Television (CCTV) footage collected during the inspection. The data would help shape the rehabilitation urgency and timing.

 

Results
To date, Sahara has had 46 insertions and a total of 33.5 kilometers (20.8 m) have been assessed. Analysis of the data identified 24 leaks and zero (0) gas pockets in the pipeline sections inspected. The Sahara sensor was tracked above ground using the Sahara Locator® device to track the Sahara tool and locate any potential leaks or anomalies found.

 The assessment is proving its worth from a verification viewpoint, and the leaks have been either repaired or addressed for prioritization. The current program is scheduled for completion by 2017.

With its pre-emptive leak detection program, the City is Montreal is a great example of a smart water manager taking proactive efforts at keeping its network in healthy shape.

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Case Study

In 2015, Utilities Kingston retained the services of Pure Technologies to perform a condition assessment on the Dalton Avenue (North End) Pump Station Force Mains.

At approximately 35 years, each asset was entering a critical stage of its life-cycle. The purpose of the assessment was to identify the structural condition of the 450mm and 600mm force mains, both of which are approximately 1,550 meters long and follow a parallel route.

The assessment included transient pressure monitoring, a SmartBall® leak and gas pocket detection survey, and a PipeDiver® electromagnetic inspection of the pipeline.

Project Details

Services
SmartBall® leak and gas pocket detection
PipeDiver® electromagnetic inspection
Transient pressure monitoring
Risk of failure evaluation
Timing
2015
Pipe Material
Ductile Iron, Steel, Reinforced Concrete
Inspection Length
3.05 kilometers (1.9 miles)
Diameter
450mm to 600mm (18 inch to 24 inch)
Transmission Type
Wastewater

Project Highlights

 

3.05 kms cumulative distance of survey

 

1 acoustic anomaly associated with transient gas (SmartBall inspection)

55 pipes with EM anomalies characteristic of localized wall loss (PipeDiver inspection)

 

Zero leaks detected

 

Challenge

The older of the two force mains is 450mm (18-inch) in diameter, constructed of ductile iron built in the late 1950s, and had failed several times over its lifetime. The newer of the two force mains is 600mm (24-inch) in diameter, built from reinforced concrete (RCP) and steel, with two sections of suspected metallic pipe, which was not confirmed in the profile drawings.

As the pipe material specifics were still unknown at the time of the inspection, Pure Technologies elected to conduct a PipeDiver run to accommodate both possible types of pipe material – assumed by all to be bar wrapped pipe (BWP) and prestressed concrete cylinder pipe (PCCP).

Historically, it has proven challenging to assess the condition of pressurized mains that carry sewage, especially those made with ferrous material. Metallic force mains have special operational challenges that don’t apply to gravity sewer systems, and due to the presence of solids in the flow, force mains represent a far more abrasive environment than potable water systems.

Gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall. This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Solution

Transient pressure monitors were installed on the header of each force main and for nearly five weeks the recorded pressure data was used to understand the operational and surge pressures within the force mains and their impact on the structural integrity of the pipelines.

Utilities Kingston began the initial force main condition assessment by deploying SmartBall technology, a free-flowing multi-sensor tool used to detect and locate the acoustic sounds related to leaks and gas pockets in pressurized pipelines. The tool has the ability to inspect long distances in one run, and requires only two access points, one for insertion and one for extraction. SmartBall is an effective condition assessment tool for force mains, which don’t typically feature butterfly valves, allowing the SmartBall to roll through the line quite easily, collecting acoustical data.

Following the SmartBall run, UK deployed the free-swimming PipeDiver assessment tool, which travels with the product flow, and utilizes flexible petals to navigate butterfly valves, tees and bends in the pipeline. Originally designed for use in pressurized concrete cylinder pipes (PCCP), the tool has specialized electromagnetic sensors (PureEM) to identify and locate broken prestressing wire wraps, (one of the main structural components and failure modes of a prestressed concrete pipe).

Historically, technologies available to assess the condition of metallic pipe have been limited. This led Pure TEchnologies to develop the specialized PipeDiver for metallic pipes, equipped with advanced electromagnetic technology to identify broken bars in bar wrapped pipe, and localized areas of wall loss in BWP, steel and ductile iron.

Results

In the end, one (1) acoustic anomaly characteristic of transient gas on the 450mm force main was identified with data collected during the SmartBall inspection. No acoustic anomalies were identified within the 600mm force main during the SmartBall inspection.

Of the 650 pipes inspected with the PipeDiver tool, a total of 55 pipes in the 450mm Dalton Avenue Pump Station force main had electromagnetic anomalies characteristic of localized wall loss. These results represent a high percentage of distress along the length of the pipeline and indicate a high risk of failure.

Recommendations included an extended period of transient pressure monitoring as the maximum pressures recorded exceed the 600mm RCP design limitations. Utilities Kingston should also review the pressure reducing valves at the pump station and investigate the operating procedures to determine the cause of the transient pressures.

The fact-finding data collected from both the inspections and transient pressure monitoring gave Utilities Kingston a better understanding of their real, not assumed assets. The results, which included a DIP risk of failure analysis, were used to complete a structural evaluation of the force mains, and have provided Utilities Kingston with actionable information regarding any necessary repairs or rehabilitation.

Since 2007, utilities all over the world have been using the SmartBall® pipeline inspection platform to save millions of dollars in water loss and to fix leaks before they turn into larger problems.


Developed by Pure Technologies (Pure), the tool is trusted by utilities for two main reasons. One is for condition assessment purposes, and the other is for reducing non-revenue water. From a condition assessment perspective, SmartBall® is a proactive tool that can be used as part of a larger holistic approach to help identify problem areas that require repairs before they turn into bigger issues, and also to help utilities prioritize capital spending.

SmartBall inside a pipe.

Detect and locate acoustic sounds related to leaks and gas pockets

The primary purpose of the SmartBall tool is to detect and locate the acoustic sounds related to leaks and gas pockets.

“Unlike traditional correlators, the SmartBall sensors travel inline along the pipe, inspecting every inch of the water main to detect potential problems such as leaks and gas pockets. Based on thousands of miles of experience, the SmartBall tool has found three to four times more leaks than trunk main correlators, which are traditionally used in smaller diameter pipes, and are less effective for transmission mains and larger diameter pipes.”

Cam White

Business Line Manager, SmartBall

Deployed for long runs in one inspection for water and wastewater pipelines

What makes the SmartBall tool so remarkable is its ability to get into and out of pipelines very easily, and to be deployed for long runs in one inspection for both water and wastewater pipelines. The tool requires only two access points – one for insertion and one for extraction.

For insertion, the foam-shelled SmartBall tool is placed into a claw, compressed, and then lowered into the line through a 4-inch (100mm) or larger tap, all while the line is pressurized. Throughout the survey, Pure’s inspection team constantly monitors the SmartBall’s position as it traverses the pipeline collecting data.

  • An acoustic sensor listens for leaks and gas pockets.
  • An accelerometer and gyroscope measure the SmartBall’s movement, which can later be used for pipeline mapping.
  • A magnetometer measures the magnetic field coming off the pipe wall, data that can be used to find joints and other pipeline features.
SmartBall extraction process

Multiple insertion and extraction options available

There are many alternative options available to get the SmartBall in and out of a pipeline. Having multiple options reduces the money and effort required by utilities to support the inspection.

Once the inspection is complete, the data is extracted from the ball and sent to Pure’s data analysts where they will identify leaks and gas pockets.

As utility owners know, it can be expensive to excavate, and what SmartBall tool does is provide information that’s accurate, so clients can dig up the pipeline and find the leak the first time.

Rideau Canal, Ottawa

For the City of Ottawa, the SmartBall tool is used to locate “leak-where-predicted”

The “leak-where-predicted” scenario recently happened with the City of Ottawa when Pure deployed its SmartBall inspection platform to locate leaks and pockets of trapped gas along a critical transmission main, as part of a long-term condition assessment program for the municipality.

The Baseline Road Water Transmission Main is a high priority 1220mm (48-inch) diameter pipeline comprised of lined cylinder pipe (LCP).

For the City of Ottawa project, five (5) surface-mounted acoustic sensors were placed along the pipeline to track the SmartBall tool during the inspection. The SmartBall device was inserted into the pipeline through a 100mm drain near a hospital. Acoustic and sensor data was collected and recorded as the SmartBall tool traversed the pipeline for more than three kilometers.

From the survey results, Pure detected one (1) acoustic anomaly characteristic of a leak and zero (0) anomalies consistent with pockets of trapped gas.

The “leak-where-predicted” scenario recently happened with the City of Ottawa when Pure deployed its SmartBall inspection platform to locate leaks and pockets of trapped gas along a critical transmission main, as part of a long-term condition assessment program for the municipality.

The Baseline Road Water Transmission Main is a high priority 1220mm (48-inch) diameter pipeline comprised of lined cylinder pipe (LCP).

For the City of Ottawa project, five (5) surface-mounted acoustic sensors were placed along the pipeline to track the SmartBall tool during the inspection. The SmartBall device was inserted into the pipeline through a 100mm drain near a hospital. Acoustic and sensor data was collected and recorded as the SmartBall tool traversed the pipeline for more than three kilometers.

From the survey results, Pure detected one (1) acoustic anomaly characteristic of a leak and zero (0) anomalies consistent with pockets of trapped gas.

SmartBall inside a pipe and working zone map

Ground microphones fail, SmartBall tool succeeds

Although Pure was confident in the SmartBall leak detection data, sometimes it’s worth a try to verify an anomaly with a complimentary technology. In this instance, ground microphones, regarded as a conventional a leak detection tool, were deployed to try and detect leak sounds. Although the suspect area was marked, neither Pure nor the client could pick up leak-related sounds from the ground microphone.

Even though the leak was not picked up by the ground microphone, Pure was confident that the acoustic signature from the SmartBall was caused by a leak, based on more than 15 years of experience identifying leaks. That confidence and experience proved right, and when the suspected area was excavated, the leak was located within a meter of where the data analyst calculated the leak to be.

The results gave the City of Ottawa actionable data regarding the condition of their pipeline, and the City was able to fix the leak reducing non-revenue water loss and any potentially costly damage caused by the leak. It’s a great example of a proactive utility taking efforts to improve the reliability of its services.

Lyon City Square

With a population of nearly 500,000, Lyon is the third largest city in France, a vibrant metropolis known for its modern Confluence district as well as Renaissance palaces and Roman ruins that date back more than 2,000 years.

While Lyon’s historic architecture has aged well, the same cannot be said for its buried infrastructure. In June of 2016, Suez retained the services of Pure Technologies (Pure) to perform a SmartBall® inspection of two critical water mains, the Grigny Water Main and Les Halles Water Main, both located near Lyon. The inspections, conducted over two days, were part of a long-term condition assessment program for the city.

As an industrial services and solutions company specialising in securing and recovering resources, Suez provides its customers (local authorities, industry and consumers) with concrete solutions to address new resource management challenges.

Pipelines constructed of ductile iron and cast iron

The Grigny Water Main is a 500mm (20-inch) cast iron pipeline that transfers Water from the Grigny Pump Station to Saint Romain en Gier. The SmartBall inspection started at a previously installed 150mm (6-inch) tap and ended at a previously installed 150mm tap in Saint Romain en Gier, and covered a distance of approximately 8.6 kilometers (5.3 miles).

The following day Pure deployed a second SmartBall inspection, this time on the Les Halles Water Main, a 400mm (16-inch) ductile iron pipeline that transfers water from Les Halles to Saint Laurent D Chamousset. The purpose of the inspection was to locate and identify leaks and pockets of trapped gas along the 2.9 kilometer (1.8 mile) section of pipeline.

SmartBall under a gas pocket inside a water pipe

SmartBall® tool chosen for ease of use and sensitivity to gas pockets and small leaks

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and its ability to inspect long distances in a single deployment. The free-swimming, acoustic-based SmartBall tool is inserted into the pipeline flow, and after traversing the inspection length, the tool is captured and extracted at a point downstream.

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

For this project, 13 surface-mounted acoustic sensors (SMS) were placed along the Grigny pipeline to track the SmartBall tool during the inspection. For the Les Halles inspection, five (5) SMS were used to track the tool. SmartBall receivers were connected to the sensors on the pipeline at locations to track the tool during inspection.

An extraction net was used to extract the SmartBall tool once it traversed the entire length of both pipelines, and the data was evaluated by Pure analysts to identify acoustic anomalies associated with leaks and pockets of trapped gas.

Screen with Data Analysis

SmartBall survey detects two leaks and zero (0) gas pockets

The acoustic data recorded by the SmartBall tool was analyzed and cross-referenced with the position data from each SmartBall Receiver (SBR) to determine a location for each acoustic anomaly.

From the results conducted on the Grigny Water Main, Pure detected a total of two (2) acoustic anomalies characteristic of leaks and zero (0) anomalies consistent with pockets of trapped gas. Pure analysts classified one leak as a small leak, and a second as a large leak.

For the survey of the Les Halles Water Main, Pure detected zero (0) anomalies characteristic of leaks and zero (0) acoustic anomalies characteristic of pockets of trapped gas.

The results gave Suez actionable data regarding the condition of the pipelines, and the confidence to move forward on fixing the leaks. It’s a great example of a water authority taking proactive efforts at keeping its network in healthy shape.

SmartBall with case and insertion tools

What keeps a water utility manager up at night? Getting a phone call from a distraught resident about an unplanned (and unwanted!) ornamental pond developing in the cul-de-sac.

On an already soggy, wet day in early November 2016, water began filling a cul-de-sac in an affluent neighbourhood in the City of Southlake, Texas. To contain surface flooding, Southlake water authorities took immediate remedial action by sequentially shutting down each water line in the area in an attempt to isolate the leak.

“As for using the Sahara tool to find the leak, upon saw cutting the street and excavating, Pure Technologies hit the bullseye yet again for Southlake.” Kyle Flanagan

Water Department Supervisor, City of Southlake

In addition, the City used external listening devices to try and locate the leak – the external listening devices indicated that some kind of leak was present, but the City was unable to pinpoint the location. In the end, the City had to shut down the 42-inch Caylor bar-wrapped potable water main, a low-pressure gravity main passing through the area. This was done to confirm that the 42-inch Caylor Main was leaking.

Sure enough, once the 42-inch Caylor Main was shut down, the water stopped surfacing. When the City reopened the main, the water did not resume surfacing. Despite the inconclusive evidence, the City remained convinced that the 42-inch main was the leak source.

Workers with horses in a field

Soggy ground, horse pasture and and muddy conditions hamper inspection

With uncertainty remaining, the City of Southlake called in Pure Technologies to assist in identifying and locating the leak. Unfortunately, the bad luck continued, as heavy rains and muddy conditions hampered Pure and its mobilization truck from access to the pipeline right-of-way. Even crews from Southlake got stuck when they tried drive the pipeline right-of-way.

One possible additional access point was available through a private owner’s horse pasture, but low-hanging power lines created a safety hazard that would prevent crews from accessing the site by that route.

Disappointed, the crews demobilized to wait for better weather or a better access point.

Sahara device

Sahara® platform selected for speed, accuracy and on-the-spot results

The next day Southlake identified another access point 1,000 feet further upstream, and prepared it for the Sahara inspection.

The Sahara leak detection platform was selected for its ability to provide same day results, and to accurately locate small leaks with sub-meter accuracy. The tethered tool is propelled by a small parachute inflated by the product flow, requiring a flow velocity as little as one foot per second to progress through a water main.

Because the Sahara inline tool is tethered, an operator has complete control, and can closely examine events of interest such as leaks, gas pockets and visual anomalies in real time.

The tool can detect up to four times as many leaks as correlators because the acoustic sensor is brought right to the leak. The Sahara platform also features inline video that allows operators to observe internal pipe conditions, and many times identify the type of leak – indicating if the leak is on a joint, in the pipe barrel, at a feature, and other details helpful for planning a repair before excavating.

Pipe inner surface

Second attempt to find the leak

For the assembled crews, pressure escalated to quickly find the leak location.

Once the Pure mobilization crew set up the installation equipment and inserted the Sahara sensor, the pressure gauge indicated only 36 PSI, not the best scenario for leak detection. Furthermore, the inspection was heading uphill toward the area of interest, and could expect even lower pressure nearer to the suspected leak location area due to loss of head pressure as the pipe ascended the slope.

Further complicating matters, the pipe wall thickness was determined to be about 4 inches, and leak paths that pass through 4 inches of concrete and mortar can often include sharp bends that can muffle leak signatures.

From the insertion point, Sahara inspected a total of 2,400 feet, passing through the cul-de-sac area at around 1,600 feet from insertion.

Sahara platform inside a pipe filled with water

A slow pullback of the tethered Sahara tool to recheck areas of interest

During deployment, review of acoustic data noted a few areas of interest, but nothing definitive. The inspection continued past these areas of interest in the hopes of finding something more conclusive.  When nothing was found, the Pure crew began a slow pullback of the tethered Sahara tool to recheck the areas of interest.

One of the benefits of a tethered tool is that two inspection passes can be conducted on the same section on the same day.

Of the possible leak areas, one acoustic anomaly seemed promising, and that spot was marked above ground.

Since Pure could not get a consistent peak location, and since the audio lacked many classic leak characteristics, it was flagged as an anomaly on site. After review of the acoustic signature off site using advanced sound enhancing software, Pure Technologies was able to resolve the signature as a leak, and reported it as a leak to the City of Southlake.

Because this suspected leak did not, even in post analysis, present with all the elements of a leak signature, and because it lacked a distinctive peak location, Pure Technologies recommended that the City of Southlake check a 7-foot length of the pipe, all the way around the pipe.

Worker digging to reveal the leak

Surprise, surprise, 4 leaks verified

As directed, Southlake crews excavated the indicated areas and found not one but four leaks. The presence of four leaks in close proximity to one another, all at low pressure, explained the difficulty of finding a leak peak.

The four leaks located ranged from pencil-sized to quarter-sized. The sloppy mortar job over an access plate into the 42-inch Caylor Main was just good enough to help muffle the leaks, but not good enough to protect the cylinder from corrosion and eventual leakage.

Small leak before being fixed

In the end, despite difficulties of inspecting small leaks in a low-pressure environment, the inspection was deemed a success, and Southlake was extremely pleased with the accurate results.

Thanks to collaboration between crews from Southlake and Pure, the mystery leak was solved. The inline tethered Sahara tool came through again.

Big City Landscape View

Rand Water is the largest bulk water utility in Africa and one of the largest in the world, providing bulk potable water to more than 23 million people in Gauteng, parts of Mpumalanga, the Free State and North West – an area that stretches over 31,000 square kilometres. Rand Water’s distribution network includes over 3,300 kilometres of large-diameter pipelines.

In 2015 Rand Water embarked on the largest proactive bulk water pipeline condition assessment  investigation ever in South Africa. An important part of the assessment includes inline non-disruptive leak detection inspections covering just over 2,200 kilometers of Rand Water’s bulk pipeline network.

SmartBall in a case with the laptop used to control it.

SmartBall leak detection platform used for most inspections

The free-swimming SmartBall™ leak detection system is utilized to perform the majority of these inspections. The multi-sensor tool is used to detect and locate the acoustic signature related to leaks and gas pockets in pressurized pipelines. While the SmartBall is deployed, the pipeline remains in service, limiting disruption to customers.

Unlike traditional listening tools like correlators, which have limited success on large diameter pipes, the free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls, it can inspect every inch of the main to detect leaks and gas pockets.

Big pipes

High pressure, high flow pipelines can make insertion and extraction difficult

Due to the vast transfer distances and varying topography within the supply area, the Rand Water system is characterized by pipelines operating under extreme pressures (higher than 16 bar [232 psi] and up to 40 bar [580 psi]) and high flow velocities (higher than 2 m/s), historically beyond safe operating limits of the standard SmartBall insertion and extraction equipment.

This rendered some of the pipelines unsuitable for inspection unless a solution could be found to safely insert and extract SmartBall from a high pressure/high flow pipeline.

Worker inspecting pipe

Pure works with SSIS PIpeline Services to help solve this unique challenge

Pure Technologies embraces research and development (R&D), with a strong design focus on continuously developing new inspection technologies and improve existing systems. SSIS Pipeline Services, which represents Pure Technologies in SA, challenged the Pure R&D team to find a solution for this unique high pressure Rand Water problem.

From this challenge, the Titan system was born.

Introducing Titan insertion and extraction system

Following extensive R&D and pre-delivery testing, the first-of-its-kind enlarged Titan insertion and extraction system was delivered to South Africa in May 2016. The system included a retrofitted high pressure LDEN (Large Diameter Extraction Net) kit capable for use in pressure environments up to 40 bar (600 PSI) and higher.

Workers with high pressure pipes

SSIS staff underwent shop training at the hands of one of the mechanical design engineers from Pure, followed by hands-on training on a number of high pressure, high velocity Rand Water pipelines.

To date, the Titan system has been used safely and successfully on pipelines up to 2900mm in diameter, operating at 2.5 m/s and at pressures up to 18 bar (261 psi). The system’s highest recorded operating pressure was at 23 bar (333 psi) on a 900mm diameter pipeline with 1.5 m/s flow.

Testing the waters, pushing the limits

The Titan system now enables SSIS to safely perform SmartBall leak and gas pocket inspections on high pressure pipelines previously off limits.

The latest successful test illustrates the SSIS commitment to the local water industry through innovation and dedicated support from Pure Technologies. It again proves that no problem is too big to solve, and every challenge can be overcome through dedicated teamwork and cutting-edge innovation.

Worker joining two pieces of pipe

Using risk-based data analysis and innovative renewal strategies, two US water systems show how utilities can avoid full pipeline replacement, reduce service interruptions, and save money.

As this informative Opflow article discusses, by more precisely understanding the condition of buried infrastructure, water utilities can more effectively focus resources to prolong safety and increase reliability.

Authors: Randy Moore, Travis Wagner, Nathan Faber, Robert Stanley, Buzz Pishkur, Jessie Allen

Gateway of The North City of North Bay

On one hand, it may seem like a waste of capital dollars if you perform a pipeline condition assessment and the final analysis turns up no leaks. Alternatively, you can also look at the no-leak report as a good news validation story, especially when using the information to help establish an asset management plan.

Such was the case for a city of 51,000 situated between the shores of lovely Lake Nipissing and Trout Lake in Northern Ontario.

In September 2016, the  City of North Bay (City) retained the services of Pure Technologies (Pure) to perform a two-phase condition assessment on the Marshall Avenue Force Main (MAFM). The MAFM is a critical 508mm (20-inch) asbestos cement pipeline that services approximately half the city, and transfers wastewater from the Marshal Avenue Pump Station to the North Bay Sewage Treatment Plant.

Aerial picture with sewer map

The City was interested in exploring technologies to help them better understand the actual condition of their force main in order to implement a comprehensive asset management program using the inspection data.

To assist in the assessment, Pure Technologies elected to first conduct transient pressure monitoring, followed by a SmartBall® inspection to acoustically identify and locate leaks and pockets of trapped gas along the pipeline.

Transient pressure monitoring helps understand structural integrity of the pipeline

First, transient pressure monitors were installed at the pump station discharge header. For approximately six weeks, the recorded pressure data was used to understand the operational and surge pressures within the force main and their impact on the structural integrity of the pipeline.

When pipe wall degradation is combined with surge pressures, the likelihood of pipe failure can be significantly increased.  Evaluation of the pump station operation, such as pump start-up mode, typical and peak flows, operating and surge pressures, and surge protection, can provide important information on the stress.

SmartBall with its controls and tools

SmartBall tool provides acoustic signature related leaks and gas pockets

While transient pressure data was collecting, Pure deployed its proprietary SmartBall technology, a multi-sensor tool used to detect and locate the acoustic signature related to leaks and gas pockets in pressurized pipelines. The tool has the ability to inspect long distances in a single run, and while the SmartBall is deployed, the pipeline remains in service, limiting disruption to customers.

Unlike traditional listening tools like correlators, which have limited success on large diameter pipes, the free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls inside the pipe, it can inspect every inch of the main to detect leaks and gas pockets.

From insertion to extraction, the SmartBall inspection took a little over four hours, with no unexpected events as anticipated during the planning stage.

SmartBall functionality chart

Results lead to effective management of finances and risk

Based on the inspection data, Pure analysts reported zero (0) anomalies characteristic of leaks, and 13 acoustic anomalies characteristic of pockets of trapped gas, mostly around air valves.  In particular, gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall. This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Gas pockets combined with pressure transients can have significant impact on the pipeline, as vacuum conditions may be created. This can cause cavitation at the gas pocket as the transient gas passes, increasing stress on the pipe wall and therefore increasing the risk of failure if the structural capacity has been compromised.

City considering adding more air valves to help expel collecting gas

Based on a hydraulic evaluation of the pipeline, structural fatigue was not a concern, although test pits were recommended to determine asbestos cement thickness and gas pocket mitigation using swabs also recommended. In the near term, the City is considering adding more air valves to the pipeline to help expel collecting gas.

Overall, the City of North Bay was pleased with the project results, as they were able to understand the overall condition of the pipeline and make an informed decision for capital improvements of the Marshall Avenue Force Main. The project demonstrates how the City uses actionable data to effectively manage their finances and risk, while continuing to provide the community with a safe and reliable delivery of wastewater.

Massive pressured water leak

According to AWWA’s 2016 Benchmarking Survey, the average water and wastewater utility has seven breaks per 100 miles of piping every year. Tip-top systems experience just four breaks in that distance, while those at the bottom have 18.

While it’s interesting to note the difference in break rates, it’s unfair to compare one utility to another, as a multitude of factors come into play as to why pipelines can deteriorate to state of failure. Countless sources of stress both inside and outside a pipe related to geographical location, soil-pipe type interactions, age, and construction are among factors that can take their toll on the pipe’s condition.

Worker inspecting pipe

For utilities, the one constant across the spectrum is the acknowledgment that simply replacing pipeline assets is cost prohibitive, and that advanced condition assessment services like those provided by Pure Technologies (Pure) can help utilities confidently make informed decisions that significantly reduce capital and operating costs.

Single-episode blowouts garner all the attention

While single-episode blowouts are quite rare, these tend to garner most media attention, and cause the most obvious blowbacks to the pipeline operator. What the public doesn’t usually notice are the pinhole leaks, hairline cracks, corrosion and leaking gaskets that tend to occur first.

Most catastrophic failures are caused by a sudden unexpected stress such as a water hammer acting on an existing weak point in the pipe. There is a widely held belief that the failure process is a simple one, where a pipe corrodes to the point at which it can no longer withstand the applied internal and external forces, resulting in a main break. However, research has shown that the failure process is more complex than expected.

Corrosion plays a significant role in water main failures, but soil-pipe interactions, manufacturing techniques and human error are also important factors. Failures also take place in multiple stages rather than in a single episode. Early damage not only weakens portions of the pipe, it also allows water to escape, causing corrosion and washing out of the supporting soil.

Broken water pipe on a street

Age alone does not indicate high-risk pipes

Pipes at highest risk are typically constructed using dated materials or methods, running through an area with heavy vehicle traffic. Urban centers typically represent significant loss potential from damage caused by water main breaks as a result of high-density buildings, underground infrastructure, important traffic thoroughfares, and economic loss potential of power, gas, water utilities and legal cases.

The net result is that age alone cannot be relied on as an indicator of a high-risk pipe.

Broken pipe

Types of pipe material and typical cause of failure

Prestressed concrete cylinder pipe (PCCP) has a unique failure mechanism: high strength steel pre-stressing wires that provide strength to the pipe can become distressed and reduce the structural integrity of the pipe. Broken wires can be caused by physical damage to the pipe, corrosion, or hydrogen embrittlement.

Areas of broken wires may be accompanied by leaks, especially in pipelines smaller than 48 inches in diameter, where the internal steel cylinder corrodes at the same rate as the wires or where water escaping through the joint encourages corrosion. Leakage has been proven to be a key indicator of structural condition in lined cylinder pipe, a type of PCCP in which the prestressing wires are placed directly on the steel cylinder. These types of leaks can create voids around the pipe and introduce added stress at an existing weak point.

Cast iron pipes corrode, become brittle and are prone to cracking. Many older North American cities have cast iron pipes that were installed in the 1800s, prior to the existence of pipeline standards, when methods of construction were non-uniform and advanced quality control programs did not exist. Consequently, many pipelines were installed using what are considered poor construction practices by today’s standards.

Ductile iron pipes have failure mechanisms similar to those of cast iron pipes; however they become less brittle and consequently degrade at a slower rate. These pipes may be capable of supporting large leaks for longer periods of time without failing immediately.

Plastic and polyvinyl chloride (PVC) pipes are less prone to corrosion and less brittle than iron pipes. Failures in these pipes are often traced to leaking joints where the escaping water creates voids around the pipeline, causing unplanned stresses on the pipe.

Steel pipes primarily fail due to loss of integrity at welds, and external corrosion causing severe pitting and weakening the pipe wall. Both losses of joint integrity and through-wall corrosion pits lead to leakage long before failure. Older steel pipes in aggressive environments are capable of sustaining massive levels of leakage for decades before failing.

Workers digging with mechanical shovel

Making ongoing condition assessment part of proactive asset management

While pipe material and typical pipe stresses are factors that can contribute to a state of pipe failure, it remains impossible to compare one pipeline to another, and to make generalized statements about remaining service life, especially based on age and depreciation. Instead, it pays to conduct ongoing condition assessment, and then to use that risk-driven asset data collection to reduce the likelihood of replacing pipe that can safely and effectively serve communities for several more years.

Mackay City Coast

Justification of an ongoing condition assessment program can, at times, be difficult for water utilities. However, successful inspections that deliver actionable outcomes on how to manage aging assets make this justification much easier.

Certainly that was the case for Mackay Regional Council (MRC) when it engaged the services of Pure Technologies to conduct a variety of condition assessment inspections on their critical mains in order to improve their understanding of these aging assets.

For MRC, the goal of the 3-year Condition Assessment Program is to undertake and then analyze the results from the preliminary inspections, followed by a commitment to explore secondary condition assessments, where warranted.

Mackay satellital image with mains map

About Mackay Regional Council

Mackay Regional Council is a small but progressive water utility that serves a population of nearly 124,000 on the eastern coast of North Queensland, Australia. The utility has a total of 2,150 km of water and wastewater mains in its network. MRC is proactive in its approach to water management, and takes pride in the development of its industry-leading condition assessment program, initiating the first leg of the program with Pure mid-2016.

SmartBall with case and insertion tools

First SmartBall inspection on two sewer rising mains

In June 2016, MRC retained the services of Pure to perform a SmartBall® inspection of the Coles Road Sewer Rising Main (SRM), also known as force main. The Coles Road SRM is an asbestos cement (AC) and ductile iron (DI) pipeline that transfers wastewater from the Coles Road Sewer Pump Station (SPS) to the Mount Basset Sewer Rising Main. The purpose of the SmartBall inspection was to identify leaks and pockets of trapped gas along the pipeline.

Pure recommended the SmartBall tool for its relative ease of insertion and extraction of in-service pipelines, and its ability to inspect long distances in a single deployment. The tool’s acoustic sensor can detect ‘pinhole’ sized leaks and gas pockets within a location accuracy of plus or minus 1.8 m (6 feet), a critical factor in urban environments where excavations can be costly and disruptive to the public.

After the review of data integrity and backup from the Coles Road site, the crew moved to the Beaconsfield SRM, where a further SmartBall inspection was completed. The inspection went as smoothly as the first, and all data was confirmed for quality.

This technology has assisted us in assessing the operational and potential structural integrity of some hard to access buried mains of high failure consequence without significant service outage or worker safety in a way not previously utilised.  It certainly lifts us out of the purely reactive mode toward the proactive assessment of buried infrastructure in terms of service delivery risk management and maintenance/renewal planning…”

MRC Project Leader

Second SmartBall inspection on a sewer rising main and raw water main

During the next phase of the project, Pure conducted a preliminary condition assessment of two more critical mains, the Mount Basset SRM and the following day, on Marwood Bore Raw Water Main. Pure always utilizes separate inspection sets for potable and wastewater to eliminate any risk of contamination.

SmartBall extraction

Second SmartBall inspection on a sewer rising main and raw water main

Results of the preliminary condition assessment were utilised to identify whether a secondary condition assessment is required.

Historically, it has proven challenging to assess the condition of pressurized mains that carry sewage, especially those made with ferrous material. Sewer rising mains have special operational challenges that don’t apply to gravity sewer systems, and due to the presence of solids in the flow, sewer rising mains represent a far more abrasive environment than potable water systems.

Gas pockets are of significant concern in rising sewer mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Utilizing Sahara™ platform with CCTV

For the third phase of the Program, MRC engaged Pure for a condition assessment of the Gordon Street Water Main. In order to inspect this critical main, Pure conducted three (3) separate insertions using the Sahara inspection platform. The Sahara system uses an innovative tethered platform to conduct non-destructive inline leak and gas pocket detection, and an internal visual inspection via closed circuit television (CCTV), without disruption to service. This allows for real-time reporting of acoustic anomalies detected in the pressurized lines.

The inspection occurred over a period of two nights to minimize traffic disruption. The targeted portion of the main consists of cast iron (CI) and asbestos cement (AC) pipe in three diameters.

“We are still to progress fully into this mode of operation, however this technology appears to provide us a firm foundation to step off from…”

Don Pidsley

Working during the night

Collected data gives MRC actionable information on necessity for secondary assessments

All in all, the data collected to date has given MRC a better understanding of their critical assets. By undertaking a preliminary condition assessment approach, MRC now has actionable information regarding the necessity of future secondary assessments.

Based on preliminary results, minimal disruption and collaborative cooperation between the mobilization teams, MRC has inquired about additional inspections under their in their industry-leading condition assessment program.

Workers meeting in a parking

Some pipeline inspections are more daunting than others, as Daphne Utilities recently found out. Not only was the planned condition assessment on a critical pipeline hampered by non-existent plans, there were also obstacles in the pipeline path that included urban development atop the pipe and an alligator-infested swamp.

In the end, to map and assess their pipeline, Daphne Utilities opted for the Sahara® leak and gas pocket detection platform, which includes the ability to determine pipeline alignment with sub-meter accuracy.  With the Sahara platform, Daphne Utilities could not only determine the exact pipeline location, but also assess its operation and condition.

Daphne’s Story

Affectionately known as the “Jubilee City”, Daphne was incorporated in 1953 and due to its location, serves as a suburb of Mobile, Alabama. Daphne is located along the eastern shore of Mobile Bay, an area served by Daphne Utilities, which provides water, wastewater, and natural gas services to approximately 25,000 residents.

In 1985 the City purchased the Lake Forest Utility, and in doing so, Daphne Utilities took over their existing wastewater treatment plant, which was built in the 1970s.  The facility discharges through the Daphne Outfall, a 6,000-foot, 18-inch ductile iron effluent pipeline that discharges treated wastewater into Mobile Bay. Although the main was critical to the City, little information about it was transferred when Daphne Utilities acquired the facility.  Daphne Utilities later officially named the facility the Water Reclamation Facility.

For many years after Daphne Utilities took over the Water Reclamation Facility the outfall line operated as a gravity discharge line. As the population grew and flows to the plant increased, Daphne Utilities installed pumps to occasionally increase the volume of treated wastewater passing through the discharge line. As development expanded, the situation progressed from a time when the pumps occasionally ran, to the point where the pumps ran almost continuously.

Satellite view with sewer location

Over the years the gravity main transformed into a force main

Now, a pipe designed as a gravity main had transformed into a force main, pumping under pressure at all times, with its location and condition unknown – and with no redundancy.

To proactively manage this critical asset, Daphne Utilities retained the services of Pure Technologies for a one-day Sahara® leak and gas pocket detection inspection of the Daphne Outfall, with a mapping deliverable.

The primary purpose of the inspection was to determine the pipeline alignment, since you can’t maintain what you can’t locate.  Since the 18-inch outfall was built, the terrain had changed markedly.  The original shoreline had been extended by hundreds of feet to accommodate the construction of a major highway and several hotels and restaurants.

In fact, based on best guesses and poor drawings, Daphne Utilities suspected that a five-story Hampton Inn had been built on top of the 18-inch outfall!

In short, Daphne Utilities didn’t know the exact pipeline location or its operational conditions.

Bridges over a river

Section of the outfall traverses area known as “Gator Alley”

To ascertain the alignment and condition of the 18-inch outfall, Daphne Utilities engaged Pure Technologies for a single day inspection. In addition to the challenge of not knowing the exact pipeline alignment, it also appeared that the pipeline traversed under a swamp sanctuary for hundreds of alligators and other wildlife, in an area known as “Gator Alley.”

Due to the location that the line traverses, extra safety precautions were needed for the inspection crews. Project planning included the deployment of an alligator watchman to watch specifically for a notorious 14-foot alligator known to inhabit the area in the vicinity of the 18-inch outfall.

Sahara inspection technology chosen for accuracy at pinpointing leaks and gas pockets

To conduct the mapping and assessment survey, Pure recommended the Sahara leak and gas pocket detection platform. Sahara is an inline tethered tool that can assess pipelines 6 inches and larger, without any disruption to service.

Because the sensor tool is tethered, an operator can stop and reverse the tool to investigate acoustic events such as leaks, gas pockets and visual anomalies. At the same time, an above-ground operator locates the sensor above ground, marking the exact location of the pipeline at any point along the pipe with sub-meter accuracy.

The mapping capability of Sahara allows utility owners to determine the exact location of their pipeline at any point, as well as the location of any leaks or gas pockets.

Results give Daphne jubilant confidence moving forward

Analysis of the acoustic data identified zero (0) leaks and eight (8) air pockets, which were impacting the efficiency of the line, as gas pockets occupy space within the already maxed-out pipeline. During the inspection, the alignment of the pipeline was determined and recorded from the treatment plant to the edge of the marsh where Mobile Bay starts, confirming the pipeline does indeed pass underneath the Hampton Inn.

Not bad for a day’s work

In a single day, the Sahara crew determined flow velocity, inserted the tethered tool, inspected 1,000 feet, determined the pipeline alignment, and confirmed its location and the location of 8 gas pockets.  As a result, Daphne now knows they have gas pockets and they now know the line location in order to execute a plan to deal with the gas pockets.

As for dealing with alligators, that’s unnecessary now.

Alligator watching to the cammera
Staff members behind an open pipe

When you’re a regional water authority with a sound way to identify problems with your aging water pipeline before the problems get bigger, it’s cause for a celebration, highlighted with speeches, live demonstrations and cake included in the ceremony.

In late November 2016, a delegation of government officials, special guests and educators gathered in London, Ontario Canada  to celebrate the successful funding, installation and commissioning of a 60 km (37 miles) Acoustic Fiber Optic (AFO) system installed on the Lake Huron Water System’s water transmission pipeline.

Map with pipeline location

Pipeline draws water from near Grand Bend to terminal reservoir north of London

The pipeline, which supplies drinking water to more than 500,000 people in southwestern Ontario, draws water from the Lake Huron water treatment plant near Grand Bend to the terminal reservoir just north of London. Constructed of 1200mm (48-inch) prestressed concrete cylinder pipe (PCCP), the Lake Huron-to-London pipeline has ruptured four times, most recently in 2012.

To mitigate the chance of a future catastrophic failure on such a critical line, the water authority for the Lake Huron Primary Water Supply System collaborated with Pure Technologies (Pure) to install an acoustic-based monitoring system, designed to ensure the success of the Region’s long-term comprehensive pipeline management program.

The $7.5 million upgrade to the Lake Huron-to London water line is part of $179.1 million in water safety infrastructure investments across Southwestern Ontario.

SoundPrint® AFO Fiber Optic wire

SoundPrint Acoustic Fiber Optic technology tracks and records pipeline deterioration

Pure’s SoundPrint Acoustic Fiber Optic (AFO) monitoring technology is an industry-leading system that that listens, identifies and locates pipeline deterioration in real time. Once installed on a pipeline, the SoundPrint AFO system remotely detects the acoustic signature of wire breaks or “pings” in prestressed concrete cylinder pipe, and records their specific pipe location. If break activity increases, utility staff are alerted and can intervene on the deteriorating pipe in advance of failure.

Under the new system, “We will get an email to say a section of pipe has a break, and they even give us the map location of where it happens,”

John Walker

Operations Manager, Lake Huron and Elgin Area Primary Water Supply

The AFO system remotely detects the acoustic signature of breaks in the pipeline structural reinforcement and records the specific pipe location of the deterioration, alerting operating staff who can intervene in advance of a catastrophic failure of this regionally significant water transmission pipeline.

“A snapping wire or two won’t sound an alarm bell,” says Heather Edwards, project manager at Pure. “But when our monitoring team listens and identifies a large number of pings from wires breaking in a concentrated location, that’s when we focus attention on the acoustic anomalies to determine whether remedial action needs to take place.”

By managing their pipelines with innovative technologies, utilities can save millions of dollars

The project was special for Pure as it showcased the innovative SountPrint AFO technology upon which the company was founded more than 20 years ago.

“We love partnering with forward-thinking utilities like London Region to save money by using innovative technologies like the AFO system,” said Mike Wrigglesworth, senior vice-president of Pure Technologies, who spoke at the ceremony. “Instead of budgeting for an expensive replacement program or dealing with disruptive bursts, London Region has saved millions of dollars by actually managing their pipeline.”

Pure surpasses 700 miles (1,100 km) AFO monitoring milestone

Globally, Pure has surpassed 700 miles (1,100 km) of active AFO monitoring. Currently within North America and China, Pure monitors 56 mains from a combined total of 17 clients, including London Region. Pure’s active AFO system has recorded more than 43,600 wire breaks from its managed roster of pipelines located in North America and China alone.

With the installation of AFO technology in place, the London Region utility ensures active management of their most valuable buried assets, for the life of the asset.

That’s a comforting thought, well worth celebrating.

In preparing for its water future, the Region of Peel (Peel) adopts a unique assessment strategy for a newly constructed potable water transmission main that extends deep underground through the heart of Peel Region. The effort is paying off, with Peel decision makers gaining a better understanding of this pipeline as it comes into service.

Working on a new potable water transmission main

Peel Water & Wastewater services approximately 1.3 million residents and 88,000 businesses in Brampton, Caledon and Mississauga. The Hanlan Water Project is the largest water pipeline capital initiative ever undertaken by Peel, with a cost of approximately $500 million. The completed transmission and sub-transmission mains included in the Hanlan Water Project will serve Peel’s growth projections for the next two decades.

The project includes 15 km of 2400mm (96-inch) PCCP water transmission main. Construction began in 2011 and is scheduled for completion by 2017. The project is split into three contracts and construction includes both tunnelling and open-cut methods.

Outside and inside a tunnel

Some pipeline sections tunneled in excavated depths of 50 meters

The project is unique from the point of view that the majority of the pipeline will be built under existing infrastructure, with some sections of pipeline tunnelled in excavated depths up to 50 meters (150 feet).

Peel has encouraged the use of technology and innovation throughout this project and has included innovative assessment strategies by Pure Technologies prior to pipeline commissioning. Baseline condition assessment and real-time monitoring technologies have offered value, and peace of mind to Peel managers and decision makers involved with this project.

SoundPrint® acoustic fiber optic (AFO) inside a pipe

Acoustic monitoring versus electromagnetic inspection technology

Pure’s baseline condition assessment includes visual inspection, 3D inertial mapping, electromagnetic (EM) inspection where applicable and SoundPrint® acoustic fiber optic (AFO) monitoring the pipeline during hydrostatic pressure testing of the pipeline. The project includes a continuous monitoring solution once the pipeline is commissioned into service, expected in 2017.

AFO monitoring is an innovative monitoring technology for identifying wire breaks in PCCP pipes. Unlike EM, which identifies the number of wire breaks that exist at a point in time, acoustic monitoring identifies the number of wire breaks that occur during the monitoring period, effectively identifying the location of active deterioration for the lifespan of the asset.

By ‘listening’ for wire breaks, pipes that are approaching failure can be identified and rehabilitated. With the installation of AFO technology at the time of construction, Peel ensures active management of their most valuable buried assets, for the life of the asset.

“A snapping wire or two won’t sound an alarm bell,” says Adam Koebel on behalf of the Data Analysis Group at Pure. “But when our monitoring team notices a large number of pings from the wires breaking in a concentrated location, that’s when we focus attention on the acoustic anomalies to determine whether remedial action needs to take place.”

The project was split into 3 contracts with varying scope per contract

The 15 km of 2400mm PCCP project was split into 3 contracts with different general contractors, and complimentary scope per contract.

Pipeline construction along a road

The acoustic monitoring covered a distance of 1,138 meters and spanned a total of 132 pipe sticks. Analysis of the data recorded during the pipeline monitoring found two (2) acoustic anomalies consistent with wire wrap breaks, which amounts to a negligible amount of change or distress. Pure conducted a second (post pressure test) EM scan to confirm the AFO testing and determine the presence of pipe wall distress.

Contract 1 (underway) includes visual inspection and mapping

Pure’s involvement in Contract 1 began in 2016, with a visual and sounding inspection of 5.87 km of the 2400m PCCP pipeline and included identifying potential joint defects and other signs of distress, as well as verifying lay schedule from within the pipe. AFO monitoring will let Peel and their contractor know if any distress occurred during hydrostatic testing.

Contract 3 is on schedule to wrap-up in 2017, while Contract 4 scope of work will include final disinfection and commissioning of the new feedermain.

Once a baseline condition has been established, the AFO system will allow Peel to track the deterioration rate and identify at-risk pipes before they fail.

For Peel, acoustic fiber optic monitoring is like preventative medicine, and as a safeguard, it’s proven to work.

Fiber optic
City of Baltimore

Over the past decade, the City of Baltimore has seen vast improvements in control point operability and system sustainability of its water distribution assets. The report card is looking better each year.

The Baltimore City Department of Public Works shoulders a big responsibility. The Department provides 265 million gallons of water daily to 1.8 million people in the greater Baltimore region, and maintains 3,400 miles of water mains, 19,000 fire hydrants and more than 64,000 pipeline valves.

For more than ten years, Wachs Water Services has partnered with Baltimore and surrounding counties to deliver GIS data, coax non-functioning valves and hydrants back to operational life and reduce the probability of failure. The ongoing program is a showcase for Wachs Water Services to demonstrate how its unique approach, field experience and mechanical advantage could give Baltimore new confidence in managing their water distribution assets.

Broken water mains propel utility to investigate distribution system

Many of Baltimore’s water distribution system assets are decades old, with some pipes dating back 100 years and more. Since 2000, large-diameter pipeline failures were occurring more frequently, resulting in extreme flooding in some urban areas. Emergency response was often delayed because of difficult to locate or non-operational valves.

The water utility decided it was time to locate, assess and repair or replace the critical pipeline valves within their distribution system. They turned to the industry leader in valve management solutions, Wachs Water Services, a division of Pure Technologies.

WachsWater Workers

Valve management delivers operational intelligence to mitigate risk

Collaborating closely with field crews from Baltimore Public Works, Wachs Water Services technicians immediately went to work to locate and test the thousands of pipeline valves and water assets within the distribution system.

Valve management involves integrating field-verified valve status details into the GIS system, the vital “operational intelligence” utilities need in mitigating operational risk, and accelerating emergency response to major pipeline failures.

After physically locating each valve, Wachs Water Services field technicians recorded the valves’ precise GPS position, operational and service history, and current functional status into Baltimore GIS (geographical information systems) and CMMS (computerized maintenance management systems), ensuring the vital asset information could be easily accessed during an emergency response.

Damaged or questionable valves were expertly serviced, replaced or updated to verify compliance with industry specifications, and Baltimore field crews were trained to deal with operating valves to respond to an array of emergency situations.

Damaged valve

Valve training pays dividends sooner than expected

The emergency valve training paid dividends much sooner than expected. In September 2009, a 72-inch PCCP water main suffered a catastrophic failure near a busy Baltimore street intersection, flooding the area with 175,000 gallons per minute. Field crews from Baltimore Public Works, Wachs Water Services and emergency service workers converged on the scene as water submerged residential areas and threatened 6,000 homes.

Working closely with Baltimore Public Works, Wachs Water Services provided detailed maps and plans for shutting down the broken pipeline main, including information on all valves involved, and the specific pattern to execute the shutdown in a manageable way.

The utility knew exactly what crews to deploy, where to deploy them, and what they needed when they arrived on location, successfully shutting down all pipelines feeding the ruptured main in a fraction of the time.

Baltimore proves its commitment to municipal water stewardship

Tremendous progress has been made by Baltimore City and surrounding counties, and they have set industry benchmarks for control point operability and system sustainability. In the ongoing program, more than 64,000 valves and 22,000 fire hydrants have been GPS-located and mapped over more than 2,000 miles of mains.

The City has earned high marks, not only for its diligence, but also for its commitment to municipal water stewardship.

Tech analysing data

It was a perfect day for an inspection.

Under a crisp blue sky, in the polders along a major motorway near Rotterdam, more than 40 water professionals from The Netherlands, Australia and the UK gathered to witness a unique project undertaken by the water utility Evides Watercompany.

The purpose of the project was to showcase the 24-sensor PipeDiver®, an innovative tool from Pure Technologies designed to assess and address large-diameter metallic pipelines.

As the second-largest water utility in the Netherlands, Evides was open to exploring new ways to reduce risks and extend the service life of their buried infrastructure.

Workers looking up

“Our first reaction is positive. PipeDiver proved to be a suitable tool for one of our most important inspection needs: corrosion of cement lined steel pipes. We are especially glad the tool was able to pass a butterfly valve, and to be inserted and extracted through 600mm manholes, as this greatly improves operability and cost effectiveness. Bart Bergmans

Project Manager, Infrastructure Asset Management, Evides Watercompany.

Inspected large-diameter steel pipeline runs along critical highway

The Evides TL2.60 pipeline is a cement-lined 800mm (31.5 inch) steel pipe, with 2.8 kilometers (1.7 miles) of the inspected pipeline running along an important highway connecting Rotterdam to The Hague. The transmission pipeline was selected for its criticality and some operational challenges that Evides wanted to address, including the presence of an inline butterfly valve that precluded other inspection tools from performing at this trial.

Prior to inspection, Evides created a series of predetermined defects made on a specific pipe segment in a research environment. The objective was to validate the tool against a range of known defects in a pipe with the same characteristics as the pipe inspected. During this process, all defects within the stated sensitivity were detected by PipeDiver at the precise location, providing confidence for the upcoming live inspection.

PipeDiver insertion

24-detector PipeDiver launches with eager anticipation and high expectation

All eyes were on the launch of Pure’s 24D PipeDiver tool, scheduled for the first of three identical runs, designed for data redundancy.

PipeDiver is a flexible, free-swimming condition assessment tool for pressurized water and wastewater pipelines. The video-equipped tool is ideal for critical pipelines that cannot be removed from service due to lack of redundancy or operational constraints.

Unlike more restrictive assessment tools, PipeDiver is a neutrally buoyant tool that flows with the product and easily navigates through most butterfly valves, tees and bends in the pipeline, delivering electromagnetic (EM) data for a variety of pipe type and materials.

24D PipeDiver tool developed for locating corrosion on metallic pipe

While the PipeDiver tool has traditionally been deployed on prestressed concrete pipe to identify and locate broken prestressing wire wraps, the 24-detector PipeDiver has been specifically developed for metallic pipelines. For the Evides inspection, the PipeDiver tool with 24 electromagnetic sensors was used to locate and identify steel pipes with anomalies associated with corrosion or reduced wall thickness.

“This inspection and related validations have shown that PipeDiver is able to deliver results that allow for well-founded replacement decision making of large-diameter, cement coated, steel pipelines.”

PipeDiver working inside a pipe

High definition camera records passage for all invitees to watch

Because the inspection exercise had so many invited utilities invested in the outcome, Evides provided inline cameras parked at both the butterfly valve and extraction point to record in real-time the passage of the PipeDiver. Thanks to the cameras, the world could watch.

The insertions went off without a hitch, and the PipeDiver sailed through the pipeline obstacle course with ease, gathering EM data along the route.

Results support long-term asset management decisions

Of the approximately 237 pipe sections inspected during the real inspection, four pipes were identified with anomalies indicative of cylinder wall loss.

After the inspection, three out of the four locations were dug-up to verify the reported defects, using non-destructive ultrasonic techniques. On each of the locations, defects were found, and the actual material loss was in the range reported by Pure Technologies.

Overall, the results proved the worth of PipeDiver as an advanced condition assessment tool able to deliver precise, actionable data on metallic pipes. The exercise showed the PipeDiver tool as a cost-effective solution versus methods that have operational constraints or require a shutdown or dewatering, or in this case, taken out of service.

This Evides inspection marked the first condition assessment of metallic pipe using the 24D PipeDiver in Europe, an exercise that confirmed the efficacy of the tool’s sensor technology and validated once more the effectiveness of the platform to inspect pipelines.

Using pipeline condition assessment platform like the PipeDiver tool can help utilities like Evides to support long-term asset management decisions on their underground infrastructure. The water world couldn’t agree more.

Workers from 14 utilities learning about new technology

14 global utilities in attendance

The PipeDiver project offered the opportunity for 14 of the most forward utilities from around the world to share experiences and learn about innovative technologies used to assess and address large-diameter metallic pipelines. The utilities included:

  • From Australia: Yarra Valley Water, Seq Water, Unity Water, Gold Coast Water, Water Corporation, Sun Water, SA Water
  • From the United Kingdom: Severn Trent Water, Anglian Water, Welsh Water
  • From the Netherlands: Waternet, Vitens, WML, PWN, Evides Watercompany
AWA State of the Water Industry Report

Since 2004 the American Water Works Association has been tracking issues and trends in the water industry. The Association continues to conduct this annual survey in order to identify significant challenges facing the water industry, as well as provide analysis to support water professionals as they develop and communicate strategies to address current and future issues.

In September 2015, emails were randomly sent to a general list of AWWA members and contacts inviting participation in the 2016 study.

A few of the major highlights from the 2016 report

AWWA received 1,468 completed surveys during the survey period, which serves as a good barometer on the state of the industry.

  • The current health of the industry (i.e., soundness) as rated by all respondents was 4.5 on a scale of 1 to 7, the same score observed in 2015; this score has fallen into a range of 4.5 to 4.9 since the survey began in 2004.
  • Looking forward five years, the soundness of the water industry was expected to decline to 4.4 (also on a scale of 1 to 7), which is the same score observed in 2015; this score has fallen into a range of 4.4 to 5.0 since the survey’s inception.
  • Some 30% of utility personnel reported their utilities are currently struggling to cover the full cost of providing services, including R&R and expansion needs, through customer rates and fees, and this jumps to 38% when respondents considered the full cost of service in the future. Notably, 11% of respondents felt that their utilities were currently not at all able to cover the full cost of providing service.

 

Top five most important issues facing the water industry

  1. Renewal & replacement (R&R) of aging water and wastewater infrastructure
  2. Financing for capital improvements
  3. Public understanding of the value of water systems and services
  4. Long-term water supply availability
  5. Public understanding of the value of water resources

 A note on gender: 77% of the 2016 SOTWI respondents were male, but the gender gap diminishes as age decreases; the greatest gender imbalance occurred for those 65 and older (only 3% women), but this imbalance decreased almost linearly as the age category decreased until parity is reached for those 25 years old and younger (i.e., 50% female/50% male ratio).

 

  • Some 30% of utility personnel reported their utilities are currently struggling to cover the full cost of providing services, including R&R and expansion needs, through customer rates and fees, and this jumps to 38% when respondents considered the full cost of service in the future. Notably, 11% of respondents felt that their utilities were currently unable to cover the full cost of providing service.
  • The most important issue in the area of infrastructure R&R was “establishing and following a financial policy for capital reinvestment,” with 42% of respondents rating this a critical issue. Other important R&R issues included prioritizing R&R needs, justifying R&R programs to ratepayers, and justifying R&R programs to oversight bodies such as boards and councils.
  • Interesting change: 56% of respondents reported that their utilities’ access to capital was as good or better than at any time in the last five years, up from 53% in 2015 and 46% in 2014; only 10% reported that their utilities’ access to capital was “as bad or worse than at any time in the last five years”, down from 11% in 2015 and 17% in 2014.
  • 38% of utility respondents reported declining total water sales while 31% of respondents reported their total water sales were flat or little changed in the last 10 years; similar results were observed on a per-account basis. Taken altogether, this means that a large majority of utilities could potentially face issues associated with low or declining water demand if these trends continue while the costs for water services increase.
  • When utility personnel were asked how their utilities are responding to cost recovery needs in the face of changing water sales and consumption patterns, the most reported response was shifting more of the cost recovery from consumption-based fees to fixed fees within the rate structure. Other commonly reported strategies included changes in growth-related fees and shifting the rate design to an increasing block-rate structure. Only 8% of the respondents indicated no changes were needed at their utilities.

 

To view the entire report, make yourself comfortable, pour yourself a coffee, and download the document from the AWWA site, which you can access below.

Download full PDF

24-Detector PipeDiver tool

Advanced PipeDiver tool developed for condition assessment of metallic pipes.

Pure Technologies (Pure) never says no to an engineering challenge. If a client has a particular pipeline assessment or monitoring challenge to overcome in order to make a rehabilitation decision, we’ll do whatever it takes to help our clients solve the problem.

Pure Technologies embraces research and development (R&D), with a strong dedication to continually develop new technologies and improve upon existing inspection systems. This attitude of taking a winning platform and making it better was demonstrated again with the introduction of the optimized PipeDiver, an advanced, multi-sensor tool developed specifically for the condition assessment of metallic pipes within pressurized pipe networks.

PipeDiver inspection tool operates while the pipeline remains in service

As a technology platform, PipeDiver is a versatile, free-swimming condition assessment tool that operates while the pipeline remains in service, often providing an easier and less costly alternative than inspection methods that require a shut-down or dewatering.

Two men working with a PipeDiver device

The PipeDiver platform is ideal for critical, large-diameter lines that cannot be removed from service due to operational constraints or lack of redundancy. The PipeDiver tool requires only a 12-inch access, and can be deployed on pipelines that range from 16 inches up to 120 inches.

The tool can be deployed, collect information on pipeline condition and extracted in a single mobilization.

As the PipeDiver platform can be equipped with a closed circuit television (CCTV) camera, the tool is able to record and deliver video images from the inside of the pipeline (quality depends on water clarity).

PipeDiver Cammera working

Tool able to navigate most butterfly valves, tees and pipeline bends

To begin an inspection, the tool is balanced to be neutrally bouyant and inserted into a pressurized or depressurized pipeline through a tap connection, or an existing access point. The tool travels with the product flow, and utililzes flexible petals to navigate butterfly valves, tees and bends in the pipeline.

Originally designed for use in pressurized concrete cylinder pipes (PCCP), the tool has specialized electromagnetic sensors (PureEM) to identify and locate broken prestressing wire wraps, (one of the main structural components and failure modes of a prestressed concrete pipe).

Historically, technologies available to assess the condition of metallic pipe have been full diameter tools (“Smart Pigs”) unable to traverse most water or wastewater pressure pipelines due to inline valve restrictions and limited access for insertion and retrevial of a full diameter tool. These challenges led Pure’s R&D to develop the specialized PipeDiver for metallic pipes, equipped with advanced electromagnetic technology to identify localized areas of wall loss.

The PipeDiver electromagnetic (EM) technology can also be used in bar wrap pipelines to identify broken bars and steel cylinder damage, the two main structural components bar wrap pipe.

PipeDiver device inside a pool of water

Utilities Kingston welcomes PipeDiver to assess its metallic pipeline

Since its introduction, the optimized PipeDiver platform has been deployed for various projects in Europe, Canada and the U.S.

This year Utilities Kingston agreed to pilot the new technology as part of a comprehensive condition assessment on its Dalton Avenue (North End) Pump Station Force Mains. The pipelines are both approximately 1,550 meters long and follow a parallel route for approximately 1 kilometer.

The older of the two force mains is 450 mm (18-inch) in diameter, constructed of ductile iron built in the late 1950s, and had failed several times over its lifetime. The newer of the two force mains is 600 mm (24-inch) in diameter, built from an unspecified concrete pipe from the early 1960s. As the pipe material specifics were still unknown at the time of the inspection, the Pure elected to conduct a PipeDiver run to accommodate both possible types of pipe material – assumed by all to be bar wrapped pipe (BWP) and prestressed concrete cylinder pipe (PCCP).

Force main defects can vary from one pipe material to another

During a forensics exercise on the 600 mm force main using earlier PipeDiver technology, it was revealed that the actual pipe material included 102 suspected metallic pipes, which were not identified as such in the original plan and profile drawings.

This included ductile ironsteel and unexpectedly, reinforced concrete pipe (RCP), which is not usually used in pressurized environments. Electromagnetic inspection of the RCP can only reveal anomalies on the circumferential cage and not the longitudinal bars.

Inserting the PipeDiver device through an inspection hole

Optimized PipeDiver tool deployed in wastewater

Pure deployed its optimized PipeDiver tool to conduct a quality analysis of the 450 mm pipe. The purpose of the inspection was to locate and identify steel and ductile iron pipes that have indications of wall loss.

This marked the first condition assessment of metallic pipe using the optimized PipeDiver in wastewater, an exercise that confirmed the validity of the tool’s sensor technology.

Results lead to actionable information regarding rehabilitation

Of the 650 pipes inspected with the PipeDiver tool, a total of 55 pipes in the 450 mm Dalton Avenue Pump Station Force Main had electromagnetic anomalies characteristic of localized wall loss.

The data collected gave Utilities Kingston a better understanding of their real, not assumed assets. The results, which included a DIP risk of failure analysis, were used to complete a structural evaluation of the force mains, and have provided UK with actionable information regarding any necessary repairs or rehabilitation.

PipeDrive device revision after the inspection has finished
City of Vancouver from the air

With its Pacific Ocean entranceway and towering backdrop of snow-dusted mountains, it’s no wonder the City of Vancouver ranks among the most laid-back, beautiful cities in Canada, and indeed, the world. Water is in its blood.

This spring the coastal seaport city retained the services of Pure Technologies (Pure) to perform a condition assessment and risk analysis of the Powell-Clark Feeder Main, part of the city’s water system that daily delivers 360-million liters of high-quality water throughout the city. During the course of the assessment, the inspection team had to deal with unexpected challenges, but in true West Coast spirit, collaboration between the inspection teams led to success.

Over five days in March 2016, Pure performed an electromagnetic inspection of the subject pipeline utilizing its free-swimming PipeDiver® platform, and an acoustic inspection using its free-flowing SmartBall® inspection tool. Pure also monitored this feeder main using a Transient Pressure Monitor for three months prior to the previous two inspections.

PipeDiver device

PipeDiver inspection identifies electromagnetic anomalies

The Powell Street Feeder Main is comprised of prestressed concrete cylinder pipe (PCCP), ranging from 750 to 900-mm in diameter. The Clark Drive Feeder Main consists of 750-mm of bar wrapped pipe (BWP).

The PipeDiver electromagnetic inspection covered a cumulative distance of 4.57 kilometers and spanned 676 pipes. Unlike more restrictive assessment tools, PipeDiver is a flexible, free-swimming tool that flows with the product and is able to easily navigate through most butterfly valves, apertures and bends in the pipeline, delivering electromagnetic (EM) data for a variety of pipe type and materials.

EM technology provides prestressing wire-break estimates on each individual section of PCCP, which is the best indicator that this type of pipe will fail. This allows for one deteriorated pipe to be identified within an entire pipeline that is in good condition overall, and also provides the baseline condition on all pipes in the inspected distance.

Analysis of the data obtained during the inspection determined that one (1) pipe (less than one percent of the pipeline) in the 750 mm Powell-Clark Feeder Main displayed electromagnetic anomalies consistent with 30 broken prestressing wire wraps. This is well below the average distress rate observed by Pure Technologies in PCCP pipelines, which is 3.8 percent of pipes in structural distress.
SmartBall with case and insertion tools

SmartBall inspection tool used to locate leaks and gas pockets

In addition to the EM inspection, Pure also performed a SmartBall inspection to identify and locate leaks and pockets of trapped gas along the pipeline.

Unlike traditional external listening tools with limited success on large diameter pipes, free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls, it can inspect every inch of a water main to detect leaks and gas pockets.

The SmartBall tool was inserted into the pipeline through a flange access and acoustic and sensor data was collected and recorded as the tool traversed the pipeline. At a distance of 5.8 kilometers, (only 470 meters from the end of the inspection run), the tool stopped tracking.

Crews from the City and Pure put their heads together to solve the problem.

ROV camera shows a tool cart inside the pipe

Collective thinking clears the debris and all is well

By analyzing data from the earlier PipeDiver inspection, Pure determined that unknown debris likely lodged the SmartBall tool.

The City excavated and modified a tap to allow Pure to access the pipeline with a submersible ROV (equipped with a camera) to retrieve the SmartBall tool and examine the debris, which turned out to be an old forgotten tool cart. The cart and SmartBall tool were extracted, the data was evaluated and considered valid, and all was good.

From the SmartBall data, Pure Technologies detected three (3) anomalies characteristic of leaks and zero (0) acoustic anomalies characteristic of pockets of trapped gas.

While no gas pockets were identified during this inspection, two (2) instances of entrained air were identified as migratory acoustic anomalies, and flagged for future inspection, as they may develop new pockets of trapped gas.

Validated results help the City manage its infrastructure

In spite of the cart debris blocking the SmartBall tool during the last few meters of its long inspection journey, the data collected during the pipeline assessment was analyzed as valid.

When combined with the results from the PipeDiver EM inspection, the condition data will be used as part of the City of Vancouver’s asset management initiative and allow for proactive measures in the assessment and management of their infrastructure.

West Palm Beach Aerial View

The City of West Palm Beach (WPB) makes a concerted effort to engage its citizens.

As one of the three largest cities in South Florida, WPB is a vibrant, growing waterfront community with a population of more than 100,000. Since 1974, WPB has experienced exponential growth in its population and correspondingly, in its wastewater management needs. During this time, WPB has continuously upgraded its pumping and treatment processes based on advances in regulations and technology.

In the evolution of its force main strategy, WPB has undertaken a variety of initiatives to manage its network to reflect the needs of its community. This ties into an overall strategy by dealing with rehabilitation needs proactively to prevent costly system failures while planning the rehabilitation and assessment of an entire system over the long term.

West Palm Beach bucks the trend to replace based on age of system

Historically, management of a force main network has been based on the general age of the system without specific information of the system in relation to its normal and extreme weather operation.

Bucking this trend, WPB takes an enlightened view to the management of its wastewater network, with age of the system not an automatic reason to replace or rehabilitate. While complete replacement would be ideal, the cost associated with full scale replacement is unfeasible. Ratepayers demand fiscal responsibility and are reluctant to sign over blank cheques to their utilities.

As a testament to its proactive stance, WPB has completed the first phase of a condition assessment, design and rehabilitation program of its force main network, which includes a nearly six-mile section of pipeline that conveys wastewater from Lift Station 22 to the East Central Regional Water Reclamation Facility (ECRWRF). Comprised of 42-inch and 48-inch lined cylinder pipe (LCP) and 48-inch embedded cylinder pipe (ECP), this force main, constructed in 1974, is considered the most critical piece of underground infrastructure for the City’s wastewater system.

Staff working at insertion site

In 2007, WPB conducted acoustic monitoring of the ECRWRF Force Main to determine what areas were deteriorating, but the results proved inconclusive.

In 2015, with the evolution of condition assessment techniques, WPB retained Pure Technologies to conduct a follow-up inspection using pressure monitoring and non-destructive inline assessment technologies.

For WPB, the process included examination of the ECRWRF pipeline from a wide variety of parameters. For example, manufacturing standards from the original force main design were structurally analyzed in contrast to current design standards.

The program examined current operational and maintenance practices, monitored air release valves and looked at pressure profiles based on the multiple pumping station connections to the force main. By deploying acoustic and electromagnetic technologies from Pure Technologies, WPB identified high priority areas based on gas pockets and structural stress along the force main route. WPB combined this information with rehabilitation and replacement strategies to define the second phase of the management process.

SmartBall® inside a pipe

First inspection: SmartBall® acoustic leak and gas detection

In February, Pure used its SmartBall inspection platform to conduct acoustic leak and gas pocket detection on the line. Unlike traditional external listening tools with limited success on large-diameter pipes, free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls, it can inspect every inch of the main to detect leaks and gas pockets.

The SmartBall tool was inserted into the pipeline through a hot tap and acoustic data was collected and recorded as the tool traversed the pipeline, where it was later retrieved at a bypass grit chamber.

PipeDiver® electromagnetic inspection

Next: PipeDiver® electromagnetic inspection

Subsequently, Pure deployed its free-swimming PipeDiver platform to perform an electromagnetic (EM) inspection to locate broken prestressing wire wraps in the LCP/ECP pipe. Unlike more restrictive assessment tools, PipeDiver is a flexible, free-swimming tool that flows with the product and is able to easily navigate through most butterfly valves, apertures and bends in the pipeline, delivering electromagnetic (EM) data for a variety of pipe type and materials.

EM technology provides prestressing wire-break estimates on each individual section of PCCP, which is the best indicator that this type of pipe will fail. This allows for one deteriorated pipe to be identified within an entire pipeline that is in good condition overall, and also provides the baseline condition on all pipes in the inspected distance.

Results guide the success of the program

During the SmartBall inspection, zero (0) leaks were detected, while 23 recordings were indicative of entrained gas and gas slugs.  Of the 1,682 pipes inspected by the PipeDiver tool, approximately 10 percent of pipes displayed electromagnetic anomalies consistent with broken prestressing wire wraps.

Overall, the condition assessment found the majority of the pipe to be in good condition. Pressure monitoring identified intermittent pressure surges within the design standards of the force main. However, this effort elevated the City’s awareness of the relationships between pressure management and the structural integrity of the pipeline.

Based on the completed assessment, the City implemented a two-year project delivery timeline for extending the service life of the force main for another 40 to 50 years.  The schedule included a comprehensive community outreach program that has residents onboard with the phased-in design and construction approach.

SmartBall extraction and retrieval

Tarrant Regional Water District (TRWD) and Pure Technologies U.S. (Pure) have a long history of working together to keep the water transmission mains in the Dallas-Fort Worth (DFW) area in good operating condition.

The partnership began 17 years ago with mutual development of electromagnetic technology to inspect prestressed concrete cylinder pipe (PCCP). One of Pure’s first electromagnetic inspection prototypes was developed (with funding assistance from American Water Works Research Foundation [now Water Research Foundation (WRF)], commercialized (with assistance from TRWD) and first pulled through TRWD’s pipeline on a little red wagon!

Inspection Prototype

TRWD is one of the largest raw water suppliers in DFW with large-diameter pipelines that transport water from the East Texas Cedar Creek and Richland-Chambers Reservoirs. TRWD provides water to almost two million people and spans an 11-county area in North Texas.

Electromagnetic Inspector

Electromagnetic technology platforms recognized around the world

Since 1999, TRWD has utilized Pure’s advanced inspection and condition assessment services to evaluate than 240 miles of PCCP. Over the years, TRWD has deployed a variety of inspection platforms to determine the condition of their critical supply lines. This includes PipeDiver®, a free-swimming electromagnetic inspection technology, Sahara®, an acoustic leak and gas pocket detection tool, and a manned electromagnetic tool equipped with PureEM® to collect full circumferential data of the pipe wall.

The condition assessment data is compiled with a Geographic Information System (GIS) deliverable, which provides TRWD with detailed information that is used to implement a targeted pipeline repair and replacement strategy.

TRWD utilizes Pure Technologies’ cost-effective Assess and Address® approach to target specific pipes for repair or replacement that are near the end of their service life, as opposed to replacing entire sections of pipe in good condition. In addition, this proactive approach allows TRWD to document significant savings over a complete pipeline replacement strategy.

Since 2000, a total of 271 pipes have been replaced during planned maintenance based on the results from Pure inspections.  As a result, TRWD has noticed a dramatic decline in failures since the late 90s doing a risk-based prioritization and replacement/rehab program, in addition to implementing cathodic protection, pressure transient surge reduction measures, and pipeline protection measures from external loads.

TRWD is extremely proactive when it comes to understanding their pipeline infrastructure. They take pride in their ability to locate and repair leaks, and repair or replace damaged pipes during routine maintenance schedules – rather than in emergency situations.

Tech inspecting a pipe with a tool

In order to reduce the costs of tracking and gain market share, pig tracking vendors will often cut a few corners by reducing the number of hours spent on training or lowering training expectations for its field technicians. By reducing the quality of tracking, tracking providers are then able to offer more competitive pricing.

Although this can be an effective cost cutting technique, reducing tracking quality can cause significant risk during an ILI run. In most cases, pig trackers will experience nothing out of the ordinary and will spend the entire run simply driving from site to site. But, when an unexpected event – such as a speed increase –  suddenly occurs, the quality of tracking becomes crucial.

Cartoon truck and mountains

Legacy tracking methods use a standard geophone to identify a pig passage and locating a pig using these methods requires training and experience. If the field technician has not received enough training, they can easily miss the pig passage or falsely report that the pig has passed with only a geophone to back up their word. This lack of experience can make small incidents worse than they need to be

Remote Tracking Eliminates Guess Work

During an unexpected event, legacy pig tracking can result in a guessing game – there is no definitive information on the whereabouts of a pig. However, using remote tracking eliminates guess work and provides a real-time update of a pig’s position.

Remote tracking uses AGMs equipped with multiple sensors combined with remote tracking units (RTUs). The ability to track remotely allows several pigs to be tracked simultaneously by a single technician at a central location.  If something unexpected occurs, the remote tracker has a significant amount of available information to help solve the problem, unlike conventional method. To learn more about remote pig tracking and how remote tracking works, download the pig tracking white paper below.

Download full PDF

With the deteriorating state of many aging water mains found in cities across North America, urbanites are frequently witnessing unexpected plumes of water erupt as man-made geysers in their own metropolitan backyards.

While natural geysers are awe inspiring, urban geysers are much less so, due to their destruction to property, roads and the environment. Because an uninterrupted water flow is the lifeblood of every well-managed city, getting an early warning on the weak spots within the water network translates into smart municipal business, and can help prevent catastrophic blowouts down the road.

No company understands this reality better than Pure Technologies (Pure), developers behind Acoustic Fiber Optic (AFO) technology that monitors the structural health of PCCP transmission mains. Pure’s near real time AFO technology is now embraced by a growing number of pipeline operators across North America and Asia.

Map of pipeline operators across North America and Asia using AFO technology.

Reasons why water mains crack, leak and burst

Many utilties operate water mains made from prestressed concrete cylinder pipe (PCCP). This pipe consists of a concrete core, a thin steel cylinder, high tensile prestressing wire and a mortar coating. When the mortar cracks, water seeps in and corrodes the reinforcing wire.  As the wire breaks, it creates a weak spot, and as internal water overwhelms the core, the wire gives way and the pipe can burst, often with a geyser-like force.

Pure’s AFO technology monitors in near real time, the structural integrity of prestressed pipe by recording the “pings” or number of wire breaks in each main section.

“A snapping wire or two won’t break the camel’s back enough to sound an alarm bell,” says Adam Koebel on behalf of the Data Analysis Group at Pure. “But when our monitoring teamnotices a large number of pings from the wires breaking in a concentrated location, that’s when we focus attention on the acoustic anomalies to determine whether remedial action needs to take place.”

Koebel stresses that while it may take weeks, months or even years, eventually one extra straw will break the camel’s back and for a pipeline, that last additional cracking wire has the potential to turn a small leak into a large problem.

“Once a baseline condition has been established through electromagnetic inspection, the AFO system allows us to track the deterioration rate and identify at-risk pipes before these fail. It’s preventative medicine, and as a safeguard, it’s proven to work. The fiber never lies,” adds Koebel.

Pure AFO developed to replace limitations of hydrophone array technology

Prior to Pure’s deployment of its first acoustic fiber optic system in 2007, transmission mains were chiefly monitored using cumbersome hydrophone array technology.

This older sonic technology has limitations, especially since the system’s success depends on an array of submerged microphones embedded in the cable, all in functioning order, spaced from 100 to 200 feet apart. That’s the downside – the equipment failure rate is high in a permanent immersion environment, and each hydrophone array has a monitoring distance limited to less than eight kilometers (five miles) of pipeline.

Comparatively, AFO technology is reliable at recording breaking (pinging) wire wraps, since the entire cable is acoustically sensitive from the start of the data acquisition unit to the end of the fiber. An AFO system can monitor 20 kilometers (12 miles) with a single system and 40 kilometers (24 miles) with a dual system. Moreover, Pure’s AFO system can be installed and function whether the mains are dewatered or in service.

Tech working inside a pipe

 

Big boom theory helps promote AFO technology and PCCP management

To address the limitations of hydrophone array technology, Pure’s research and development team set out to develop a better way to improve the accuracy and reliability of pipeline monitoring.  The elusive research effort took seven years, and after consulting with leaders in the field of digital signal processing and acoustic sensing, Pure developed its own proprietary acoustic technology for PCCP environments.

“Based on the operating expense and limitations of hydrophone arrays, selling our new AFO solution was relatively easy,” says Peter Paulson, co-founder of Pure and one of the researchers behind the development of the innovative AFO technology.

According to Paulson, Pure proved the efficacy of their monitoring system during an early test run for pipeline clients.

“At the time, we had set up a demo pipeline operation on our grounds, and in a distant tent we gathered clients around to listen in around a computer screen. One of our test engineers then cut a single prestressed wire from the pipeline located a block away. Because we had amplified the sound print, the immediate resounding “boom” startled the attendees into recognizing that our AFO technology really does work. We built our reputation from there.”

The rest is acoustic fiber optic history. AFO technology is now regarded as the leading standard of PCCP monitoring.

Pure surpasses 1,120 km AFO monitoring milestone

Pure has surpassed 1,120 kilometers (700 miles) globally of active AFO monitoring. Currently within North America and China, Pure is monitoring 56 mains from a combined total of 17 clients. Pure’s active AFO system has recorded more than 43,600 wire breaks from its managed roster of pipelines located in North America and China alone.

For every AFO system, the pipeline data is streamed to a Pure data analyis team who analyze the acoustic information. Any and all wire breaks captured by the AFO system are reported within one business day to the client. If any problem is detected and confirmed, the client is notified and they can then proactively manage their pipeline by choosing how to intervene before serious damage occurs.

Koebel likens AFO data management to road repairs. “Better to repair a pothole than tear up the entire street to find the problem,” he says. “In essence, that’s the value we bring to the table. If clients don’t hear from us that means they’ve got good pipes.”

Georgia Road Sign

Unlike many large, well-funded municipalities, smaller mid-sized communities often lack the financial resources to conduct proactive inspections on their buried infrastructure. Generally it’s a common situation prevalent across much of the United States.

For this reason, when several medium-sized Georgia communities were provided state funding for an inspection and condition assessment on critical sections of their water pipelines, they jumped at the opportunity to have actionable information about their actual pipeline condition.

A baseline condition inspection helps operators make defensible decisions

The Georgia Environmental Finance Authority (GEFA) facilitates programs that conserve and protect Georgia’s energy, land and water resources. In this instance, GEFA provided technical assistance funding for seven mid-sized communities to perform condition assessment on large diameter lines, which for these communities, ranged from 8-inch polyvinyl chloride (PVC) to 24-inch ductile iron pipes.

Pure Technologies was retained to perform condition assessment work for seven (7) Georgia communities, which included Marietta Board of Lights and Water, Paulding County, Haralson County, City of Dublin, City of Valdosta, Spalding County, and Coweta County—whose populations ranged from 10,000 to 100,000.

For the most part, Pure performed a SmartBall® leak and gas pocket inspection and Transient Pressure Monitoring with Fatigue Analysis on the potable water pipelines for the subject communities.

In addition, Pure was also retained to deploy a SmartBall® Pipe Wall Assessment (PWA) on the ductile iron mains for the City of Valdosta Utilities Department and the Marietta Board of Lights and Water.

PWA data

SmartBall PWA technology is used to evaluate metallic pipelines by detecting and measuring the changing levels of the magnetic field, which is related to the stress in the pipe wall. As a screening tool, PWA technology provides an indication of pipe sections exhibiting higher levels of stress, which can be used as a first stage of pipeline condition assessment to help make informed decisions on higher resolution investigations, inspection, data collection and subsequent management or rehabilitation.

SmartBall tool chosen for its ease of use and sensitivity to small leaks

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and ability to inspect long distances in one deployment. The free-swimming, acoustic-based SmartBall tool is inserted into the flow of a pipeline, traverses the pipeline, and is captured and extracted at a point downstream.

SmartBall inside a pipe with a net

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

Deploying the SmartBall tool allowed each inspection to take place while the mains remained in service, a benefit much appreciated by the communities.

“This was an excellent opportunity to offer mid-sized communities in Georgia with a non-destructive internal inspection of critical pipes within areas where traditional methods may not able to collect this important information. Pure provided very professional service to work with the Utilities and help develop a specific plan to acquire this valuable data.”

Larry Lewison, NRW Analyst, Consultant

Inspection not without its challenges

In general, for most of these smaller communities, condition assessment was a novel concept, which meant lots of communication between Pure and the utilities. Mid-sized utilities, understandably, are often hamstrung by a lack of as-built drawings, geographic information systems (GIS) or other connection and appurtenances information on their pipeline network.

In the end, based on Pure’s many years of inline inspection experience and expertise, obstacles were overcome and the overall inspection program was a positive learning experience for all.

Results from cumulative 11.7 miles of inspection

Immediately after each inspection, the data was downloaded from the SmartBall tool, verified for quality and sent to Pure Technologies for review by the analysis team.

Based on the acoustic results of all the SmartBall inspections, three (3) true leaks and zero (0) acoustic anomalies characteristic of gas pockets were found on a cumulative distance of 11.73 miles of pipe inspected. For the city of Valdosta, which included a PWA inspection, Pure identified 30 specific pipes as having anomalies indicative of stress. For the Marietta Board of Lights and Water, Pure detected 61 stress anomalies along the pipe wall. This indicates a 22 percent anomaly rate, which is average compared to historical data on similar pipelines.

In addition, Pure also performed fatigue analysis for all PVC pipes, and no immediate concerns were noted.

The results indicate that the assessed mains are generally in serviceable condition, and gave the Georgia communities confidence in the overall health their systems, with no need for immediate rehabilitation, except for the three leaks that warranted attention. This process allows the communities to develop a sustainable long-term strategy for managing their critical buried assets.

Insertion and extraction sites

Utilities have limited asset management funding at their disposal and yet waiting for failures to happen before repairing or replacing critical water mains is simply not a cost-effective option.

Cities need a working water infrastructure. It’s that simple. The solution, though, has tended to be a lot more complicated. The majority of urban water infrastructures are old and reaching the end of their usage expectancy. In addition, most are buried deep beneath the very cities they service and system-wide pipeline replacement is far too costly. Yet, if those large-diameter pressurized pipelines unexpectedly fail, the consequences can be catastrophic, to the city and the people living there. It can also shake the public’s confidence in the utility, harming its reputation in the process.

The fact is, not all old pipe is bad pipe. The Water Research Foundation Report found that age is not a primary factor for pipe failure. Many buried pipes, well over 100 years old, can still be considered in “like new” condition. Through extensive research and data from more than 14,000 milesof pressure pipeline inspection, we have found that less than 1% of pipes are damaged enough to need immediate repair. And that’s good news for cash-strapped, resource-short pipeline operators.

Unfortunately, there is no “one technology fits all” solution to this problem, which is why the choice of assessment tools is critical. The smartest choice is to deploy different but complimentary technologies that can collect the robust condition data required to evaluate which pipes need repair or replacement and which should be left alone. This pipe-by-pipe approach helps utilities make informed decisions based on assessment results, which in turn can reduce capital costs by as much as 90 percent.

Pure Technologies’ Assess and Address® approach is not only logical, scalable and cost effective, it also provides the highest return on investment.

Beginning with Pure’s risk-based assessment method followed by the deployment of complimentary technologies – like SoundPrint® – we work together with utilities to help facilitate pro-active, cost effective renewal and enduring pipeline management strategies that help keep our cities up and running for years to come.

Hanging rock with a sheep above

Don’t Get Stuck Between a Rock and a Hard Place

City of Ottawa Skyline

When your inspection task is to survey a critical pipeline for leaks, nothing is more satisfying than trusting your technology to predict the leak location and then standing by as the client excavates the area to find a flow of water within one meter of exactly where you said it would be.

The above-described “leak-where-predicted” recently happened with the City of Ottawa, when Pure Technologies (Pure) deployed its SmartBall® inspection platform to locate leaks along a critical transmission main, as part of a long-term condition assessment program for the municipality. Over the past five years, Pure has used its suite of platform tools, including Sahara®PipeDiver®, and PureRobotics®, as well as the free-swimming SmartBall device, for deployment on the City’s ongoing Drinking Water Transmission Main Condition Assessment Program.

Transmission main comprised of 1220mm (48-inch) lined cylinder pipe

The City’s potable water distribution system consists of 3,728 km of both local water mains and large-diameter transmission mains that move large volumes of water throughout the capital. The City has approximately 230 kms of transmission mains ranging in diameter from 600mm to 1980mm, (24-inch to 78-inch) subdivided into 96 segments for the purpose of a risk-based prioritization.

For the subject project, the City of Ottawa retained the services of Pure to perform a SmartBall tool inspection to identify and locate leaks and pockets of trapped gas along the Baseline Road Water Transmission Main, a high priority pipeline. The 1220mm (48-inch) diameter pipeline is comprised of Lined Cylinder Pipe (LCP) mostly constructed in the 1970s.

Pipe leaking

SmartBall tool chosen for its ease of use and sensitivity to small leaks

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and ability to inspect long distances in one deployment. The free-swimming, acoustic-based SmartBall assembly is inserted into the flow of a pipeline, traverses the pipeline, and is captured and extracted at a point downstream.

SmartBall extraction process

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

For the City of Ottawa project, five (5) surface-mounted acoustic sensors were placed along pipeline to track the SmartBall tool during the inspection. SmartBall receivers were connected to the sensors on the pipeline at the locations indicated to track the tool during inspection.

The SmartBall device was inserted into the pipeline through a 100mm drain near a hospital. Acoustic and sensor data was collected and recorded as the SmartBall tool traversed the pipeline for more than three kilometers. The SmartBall was then extracted from a reservoir using a Remotely Operated Underwater Vehicle and data was evaluated to identify acoustic anomalies associated with leaks and pockets of trapped gas.

Verification with ground microphones turned up unexpected results

From the survey results, Pure detected one (1) acoustic anomaly characteristic of a leak and zero (0) anomalies consistent with pockets of trapped gas.

Although Pure was confident in the SmartBall leak detection data, sometimes it’s worth a try to verify an anomaly with a complimentary technology. In this instance, ground microphones, regarded as a conventional a leak detection tool, were deployed to try and detect leak sounds. Although the suspect area was marked, neither Pure nor the client could pick up leak-related sounds from the ground microphone.

Even though the leak was not picked up by the ground microphone, Pure was confident that the acoustic signature from the SmartBall was caused by a leak, based on more than 15 years of experience identifying leaks. That confidence and experience proved right, and when the suspected area was excavated, the leak was located within a meter of where data analyst calculated the leak to be.

The results gave the City of Ottawa actionable data regarding the condition of their pipeline, and the City was able to fix the leak reducing non-revenue water loss and any potentially costly damage caused by the leak. It’s a great example of a proactive utility taking efforts to improve the reliability of its services.

SmartBall extracted by Pure technicians
City of Montreal Skyline

The City of Montreal believes that the best medicine is preventative medicine, especially as it applies to its water network.

Montreal has an impressive water system that supplies drinking water to a population of nearly 1.9 million people. Since 2002, the historic city, the second largest metropolis in Canada, began a long-term major rehabilitation of its extensive network of water main (770 kilometers) and distribution pipes (4,600 kilometers).

In 2015, as part of a pre-emptive program to reduce loss of non-revenue water, the City partnered with Pure Technologies (Pure) to conduct an ongoing, three-year leak detection survey on a series of critical pipes within its network, several of which are located in the downtown core.

Inserting tools through inspection hole in a street

Stopping small leaks from developing into major breaks

The City recognized the value of detecting leaks, however small, to prevent these from developing into greater problems. Compared to a major pipe rupture, which can cause catastrophic damage and incur immediate excavation and costly repairs, small leaks are less obvious at first, and can seep underground for some time without obvious detection.

In addition to physical losses of water caused by a series of small leaks, the escaping non-revenue water can eventually erode the surrounding soil making the area more prone to washouts or sinkholes, a major headache especially in densely populated areas. Unplanned excavations to repair unforeseen leaks can also erode consumer confidence in a public utility.

Leak detection strategy includes Sahara acoustic video inspection

For its multi-year leak detection program, the City requested Pure to deploy its highly reliable and precise Sahara® acoustic video inspection on 46 kilometers of pipelines chiefly in the downtown core. The pipeline sections consist of bar wrappedsteel and cast iron pipe.

The Sahara platform is modular, and can be configured with a variety of sensor tools to perform the condition assessment. This includes an acoustic sensor to perform leak and gas pocket detection, a high-resolution video camera to assess internal pipe conditions, and an electromagnetic sensor to identify stress in the pipe wall.

Because the Sahara tool is drawn by product flow via a small drag chute, and is tethered to a data acquisition unit on the surface, it gives the operator close control to confirm suspected leaks, gas pockets and other pipeline anomalies. The tool can visually confirm pipe irregularities, continuously recording, allowing for both real-time and post-processing analysis.

Workers during Sahara device insertion

 

Data used to shape urgency and timing of rehabilitation efforts

For the Montreal project, the purpose of the Sahara inspection was to assess the condition of the pipeline by identifying and locating leaks, pockets of trapped gas and to identify larger visual anomalies utilizing Closed Circuit Television (CCTV) footage collected during the inspection. The data would help shape the rehabilitation urgency and timing.

To date, a total of 13.2 kilometers have been assessed. Analysis of the data identified eight (8) leaks and zero (0) gas pockets in the pipeline sections inspected. The Sahara sensor was tracked above ground using the Sahara Locator device to pinpoint in real time the location of any potential leaks or anomalies.

The leak detection program has not been without challenges. Valve operations were needed to achieve required pressure flows, and mobilization had to be based on hours of demand, and inspections conducted during those hours.  A number of tight chamber clearances meant the creation of new insertions taps, and because of the urban environment, markings had to be precise, and crews had to deal with traffic issues.

Despite challenges, the assessment is proving its worth from a verification viewpoint, and the leaks have been either repaired or addressed for prioritization. The current program is scheduled for completion by 2017.

With its pre-emptive leak detection program, the City is Montreal is a great example of a smart water manager taking proactive efforts at keeping its network in healthy shape.

City of Milwaukee Skyline

Milwaukee is a water hub, and not just because of its location along the shores of Lake Michigan, which holds 4.3 percent of the world’s supply of fresh drinking water. The City also boasts of global leadership in water technology, having won a U.S. Water Prize for innovative watershed-based approaches toward water sustainability.

The City takes a proactive approach to water management initiatives, as evidenced in the recent condition assessment of the Franklin-Muskego Force Main. Ownership of the pipeline is shared between the City of Muskego and the Milwaukee Metropolitan Sewerage District (MMSD), the government agency that provides water management services for about 1.1 million people in 28 communities in the Greater Milwaukee Area.

Metallic valves

MMSD and Muskego request detailed structural assessment on metallic force main

In 2015, Pure Technologies (Pure) was contracted to perform a detailed condition assessment of the approximately 25-year old pipeline. The purpose of the assessment was to identify the structural condition of the metallic force main, and included pressure monitoring, a SmartBall® leak and gas pocket detection survey, a PipeDiver® electromagnetic inspection, and structural evaluations of the pipeline.

Notably, the latest investigation used electromagnetic technology delivered on the 24-sensor mini PipeDiver platform to validate inspections conducted the previous year along the same lines.

Ductile iron pipe is a challenging material to assess

The Franklin-Muskego Force Main carries wastewater along approximately 1.6 miles of 24-inch and 1.3 miles of 30-inch ductile iron pipe (DIP). A small section of 20-inch DIP force main was also included in the survey.

One of the challenges in assessing DIP is determining if the pipe has undergone any loss of wall thickness due to internal or external corrosion, which are the primary causes of failure. DIP in water service with a cement mortar lining generally has fewer internal corrosion failure rates, unless damaged during handling and installation, or later as a result of 3rd party damage.

This is not the case when DIP is used in a force main, where internal corrosion is the primary cause of failure. Gas pockets are of significant concern as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Gravity mains vs pressurized mains

In a force main, identifying internal areas with potential corrosion is challenging, as traditional gravity pipeline inspection techniques are often not applicable to in-service pressurized pipelines.

One method for assessing gas pockets is to locate air release valves (ARVs) or other high points along the alignment and provide pipe wall assessment in those areas. While this is a valid method for locating potential gas pocket locations, additional gas pockets may occur due to differential settlement, improper installation or non-functioning ARVs.

Therefore, these desktop surveys may not identify and locate all gas pockets along a pipeline, which is why Pure recommends other more precise survey methods.

SmartBall with case and insertion tools

SmartBall inspection summary

In June 2014 and October 2015 Pure performed a SmartBall leak and gas pocket detection survey of the Franklin-Muskego Force Main. Acoustic and sensor data was collected and recorded as the free-flowing SmartBall device traversed the pipeline.

During the 2014 survey, Pure detected zero (0) anomalies characteristic of leaks and one (1) anomaly that characterized a fully developed gas pocket.  During the 2015 survey, the SmartBall tool detected zero (0) anomalies characteristic of leaks and four (4) acoustic anomalies characteristic of fully developed gas pockets on the force main.

PipeDiver tool. insertion

24-sensor PipeDiver electromagnetic inspection

In 2014 Pure conducted a PipeDiver electromagnetic inspection, followed by a re-inspection in 2015, utilizing the new, 24-sensor electromagnetic PipeDiver tool. The technology ascertains a magnetic signature for each pipe section to identify anomalies that are produced by areas of corrosion or reduced wall thickness.

During the 2015 electromagnetic inspection using the mini PipeDiver, 13 pipes were found to have a total of 16 electromagnetic anomalies consistent with localized wall loss.

The electromagnetic inspection conducted in the 2015 inspection used an enhanced exciter coil allowing the electromagnetic field to return a more pronounced response. In addition to the enhanced exciter coil, the tool used in the 2015 inspection had a total of 24 receiving sensors, improving the ability of the tool to identify defects.

Confident conclusions

The results of the condition assessment indicate that the Franklin-Muskego Force Main is generally in serviceable condition, which was confirmed after an excavated pipe established a true baseline condition.

While the assessment recognized several areas with an increased likelihood of failure, overall the data was good, and coupled with Pure’s engineering recommendations, gave all stakeholders confidence in the health of pipeline for the near foreseeable future.

Longboat Key Aerial View

When much of your critical sewer pipeline lies buried under a bay of shimmering ocean water, the challenges required to assess its condition may seem daunting. That task faced the Town of Longboat Key, an affluent retirement community located on the barrier island of the same name off the west coast of Florida.

Sensitive to environmental, health and safety issues, the Town has been concerned about their 20-inch ductile iron pipe (DIP) force main installed in 1973. Inspections have been conducted in 1996, 2007 and 2011 with ultrasonic and visual methodologies for assessment.

Aside from being the only wastewater discharge from the island, approximately two miles of the four-mile pipeline runs under the Sarasota Bay before heading to the mainland, where it discharges into the Manatee County Southwest Water Reclamation Facility. The Town designated this force main as a priority pipeline due to the high consequence of failure, and is proactively managing this asset.

With talks of constructing a redundant pipeline, an island resident inquired about the condition of the existing force main and so the Town’s familiar engineering consultant, Greeley and Hansen, contracted Pure Technologies (Pure) as part of the comprehensive condition assessment project.

One of the challenges in assessing DIP is determining if the pipe has undergone any loss of wall thickness due to internal or external corrosion, which are the primary causes of failure.

SmartBall with case and insertion tools

SmartBall® platform provides a variety of condition data in a single deployment

To maximize the amount of actionable information to be gleaned from the force main project, Pure proposed leak and gas pocket detection services coupled with a pipe wall assessment (PWA) utilizing the SmartBall technology platform.

SmartBall is a multi-sensor inspection platform that provides utilities with a variety of pipeline condition data in a single deployment. Because the tool doesn’t disrupt service, it integrates easily into a management strategy to help pipeline owners reduce water loss, screen their network for problem areas and gain a better understanding of the condition of their assets.

SmartBall PWA technology is a screening tool that provides an indication of pipe wall stress on metallic pipes. The technology can be used as a first stage of pipeline condition assessment to help make informed decisions to focus higher resolution investigations, inspections, data collection and subsequent management of the pipeline.

SmartBall was also used to locate leaks and gas pockets in the line. Pipeline leaks are of concern for all pipe materials as they are often found to be the precursor of major failures. A pipeline failure can begin with weakening of the joint or barrel that may include a small leak.

In wastewater pipelines, identifying gas pockets is an important part of safely managing the asset, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Project challenges include underwater tracking throughout inspection

From inception, the biggest challenge was tracking the SmartBall over the 12,000-feet (2.27 miles) subaqueous portion of the pipeline. The Town was very concerned about sedimentation in that section under the bay, and insisted on Pure tracking the SmartBall PWA sensor tool throughout the inspection.

To accommodate the Town’s tracking request, 11 surface-mounted acoustic sensors (SMS) were placed along the pipeline to track the progress of the SmartBall tool during the inspection. SmartBall receivers (SBRs) were connected to the sensors on the pipeline to track the tool during the inspection based on information and drawings supplied by the Town.

Monitoring data collected during inspection

Results from acoustic and electromagnetic anomalies

From the data collected and analyzed, SmartBall detected zero (0) acoustic anomalies characteristic of leaks and zero (0) gas pockets during the inspection. This indicated no leaks within the detection limits of the detection technology.

At the same time, of the 1,133 identified pipe segments, 95 (8.4 percent) showed signals not attributed to known features.  The anomalies identified from the SmartBall PWA analysis included one large anomaly, 18 medium-sized anomalies and 76 small -sized anomalies. The electomagnetic signals associated with 28 of the 76 small anomalies appeared to be similar or repeatable, leading to the likelihood that a manufactured difference in pipe design exists between these 28 pipe sections.

More accurate GIS data revealed

Based on the PWA results, Pure recommended choosing a diversity of pit locations and assessing these with external verification techniques (e.g. high resolution magnetic flux leakage, pulsed eddy current, ultrasonic thickness testing, etc.) to further evaluate the probability of pipeline failure.

As well, Greely and Hansen (and the Town) now have a better handle on the spatial data of the system (GIS) and by statistically analyzing the data, can now develop pipe management strategies for the short-term management and long-term renewal strategies for the force main. By its proactive approach to asset management, the Town sets itself apart as a great example of how a community can plan for its long-term infrastructure needs.

Amsterdam, Holland

Would you take on a new pipeline inspection challenge, even if you knew it would land you in hot water?

Recently Pure Technologies (Pure) was able to chalk up success by adding one more type of pipeline to its inspection resumé. In this instance it was a district heating pipeline owned and operated by Eneco, one of the largest producers and suppliers of natural gas, electricity and heat, serving more than two million business and residential customers in the Netherlands.

District heating make sustainable sense

The concept of heat pipelines makes a lot of environmental sense. Throughout northern Europe, many municipalities and power generators have built closed systems of vacuum-insulated pipelines that circulate hot water from power plants and incinerators, sometimes above 100°C, through radiators in houses, businesses and other structures. This is an efficient method of heating buildings, and boasts a 98 percent heat retention rate during transmission.

SmartBall with case and insertion tools

Pure performs SmartBall leak and gas pocket detection survey

Recently Eneco contracted Pure to perform a comprehensive SmartBall® leak and gas pocket detection survey of the Centrale Merwedekanaal to WOS District Heating System. This is a 500 mm steel pipeline within a 700 mm steel pipeline of which a vacuum is created in the annular space to insulate the hot water. The survey purpose was to locate leaks and pockets of trapped gas present in the pipeline at the time of inspection.

The subject pipeline, originally installed in 1985, was suspected of having a leak, owning to an observation of water present in the annular space. As mentioned, the heating system pipeline consists of an inner 500 mm steel pipeline and an outer 700 mm steel pipeline, with a vacuum maintained in-between. The lines, constructed both above ground and below ground, incorporate numerous 90 degree bends and u-shapes, to allow for expansion and contraction as the product temperature changes.

Tracking with a laptop connected to the SmartBall

During the project, Pure inspected approximately 2.6 kilometers of the pipeline, with the goal to locate the leak(s) causing the water loss.

For the survey, Pure proposed the SmartBall leak and gas pocket detection system, a free-swimming, acoustic-based technology that detects anomalous acoustic activity associated with leaks or gas pockets in pressurized pipelines.

While other leak detection techniques such as noise loggers and correlators may identify a single leak or gas pocket between each sensor, they cannot accurately locate the limits of an anomaly nor identify multiple anomalies. In this specific case, the use of noise loggers is hindered by isolation. The SmartBall tool travels directly past each acoustic anomaly of interest on the inner pipe and thus significant advantages are recognized.

Unique challenges to overcome

The standard procedure for tracking the SmartBall tool depends on positioning acoustic sensors on the outside of the inspected pipe and listening to the device as it passes.

Since the line is so well insulated from heat loss, it is also well insulated against sound transfer, which meant it unlikely for good tracking on any sensor mounted to the outer 700 mm pipe. Additionally, Eneco was understandably averse to compromising the integrity of the vacuum seal of the line, and therefore did not wish to expose the 500 mm pipe to mount sensors.

In the absence of external tracking means, other reference points in the data are critical for accurately locating anomalies within the pipeline.  SmartBall contains gyroscopes that can measure bends in the pipeline that it traverses, and as there were many aforementioned 90 degree bends, these were clearly seen in the data.  The bends in the Eneco pipeline made for great geospatial reference points and therefore allowed for locating anomalies with relatively high confidence.

Pipeline over the surface

SmartBall tool deployed to survey district heating pipeline

The acoustic data recorded by the SmartBall tool was analyzed and cross-referenced with the position data. From the data collected and analyzed, the SmartBall device detected five (5) possible weaknesses, which were clearly visible in the data. Zero (0) gas pockets were detected.

The results give Eneco actionable data regarding the condition of their pipeline, and despite challenges, the assessment is proving its worth. It’s a great example of a proactive utility taking efforts to maximize its capital expenditures.

City of Belmont Skyline

To help budget over the next 20 years, the City of Belmont (City) wanted to proactively understand and assess their force mains through a comprehensive condition assessment. Located in the San Francisco Bay area, Belmont serves 26,000 residents and maintains more than 90 miles of sewer mains comprising of 85 miles of gravity mains and 5 miles of force mains, of varying size and material.

To address its goal, the City contracted Pure Technologies (Pure) to deploy a wide range of both proprietary and third-party technologies and techniques to achieve a holistic assessment. The risk associated with a failure was significant, owing to a lack of redundancy, difficulty and cost of bypassing flow and potential for severe consequences to public health and the environment.

Pure provided inspection and condition assessment services on eight of the City’s force mains. The project scope included GAP analysis, condition assessmentengineering analysis, and necessary repair or replacement recommendations to establish a long-term management plan for Belmont’s force main inventory.

Variety of solutions and technologies used to assess inventory

A number of solutions and technologies were used to assess Belmont’s force mains. Phase one involved a GAP analysis, performed by interviewing operations staff and reviewing historic information, GIS maps, and drawings.

Phase two included an assessment of the eight force mains through the use of various technologies, including SmartBall® leak and gas pocket detection, SmartBall Pipe Wall Assessment (PWA), soil corrosion survey, hydrogen sulfide monitoring, transient pressure monitoring, and hydraulic evaluation.

SmartBall with extraction tool and controls

SmartBall leak detection is a free-flowing tool used to locate leaks and gas pockets in pressurized pipelines. The tool is equipped with a highly sensitive acoustic sensor that is able to locate “pinhole” sized leaks. Pipeline leaks are of concern for force mains as these emit illegal discharges to the environment and are often found to be a precursor of major failures. In metallic pipes, gas pockets are of significant concern, as hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Pipe wall assessment (PWA) is a screening technology for assessing the condition of metallic pipelines by identifying pipe sections with increased levels of stress. SmartBall gas pocket and leak detection services were used for the 8-12-inch diameter mains.

Transient pressure monitoring and hydraulic evaluation used on the smaller mains

Transient pressure monitoring and hydraulic evaluation was used to evaluate the smaller 6-inch force mains. Hydraulic pressure transients occur in pipelines when steady-state-conditions of the system change due to pressure or flow disturbances. It is important to conduct transient pressure monitoring and hydraulic evaluation because damage from pressure transients can include cracking of mortar coating or lining, crack propagation, movement at joints, and structural fatigue.

During the condition assessment, Pure evaluated the likelihood and consequence of failure criteria and developed a scoring system, placing each force main in one of three categories: low risk, moderate risk, or high risk.

Satellite image with location map

For phase three, Pure conducted a life cycle and financial analysis, outlining the potential life and replacement/repair costs for each force main. By comparing results identified in each assessment phase, the City of Belmont can now move forward and create both a short-term and long-term rehabilitation plan.

“Through innovative technology, comprehensive data gathering and analysis, Pure Technologies helped us to assess condition of our large force mains within budget constraints, to help us plan our future capital improvement program…”

Each main evaluated with an overall risk rating

The GAP analysis included a review of all the information given to Pure at the beginning of the project and included historic information, GIS, and some drawings. During this phase, many of the parameters such as pipe length and material were found to differ from what was originally thought through the process of internal inspections and external excavations.

Pure conducted the SmartBall leak and gas pocket detection survey on four force mains and found 21 unique anomalies. The SmartBall PWA discovered seven indications of stress on the two metallic pipelines.  Hydraulic analysis of all eight force mains revealed that several force mains have a nominal increased potential for failure due to significant pressure swings and a large quantity of pumping cycles. Hydrogen sulfide monitoring was performed on six force mains to quantify the potential for internal corrosion caused by hydrogen gas.

Once all tests were completed, each force main was evaluated by its likelihood of failure and consequence of failure, and then given an overall risk rating.

Assessment includes life cycle and financial analysis

By determining overall risk for each force main, Pure was able to complete a life cycle and financial analysis and provide Belmont with the best data available to make long-term decisions on managing their assets. Each force main was given an estimate of its remaining life as well as a financial comparison of different management option costs. The financial comparison took capital replacement costs into account with Pure’s Assess & Address™ approach in both the best case and worst case scenarios. In both instances, the management options showed costs significantly lower than a full capital replacement option.

Using both the data and short and long-term recommendations provided by Pure, Belmont is now fully equipped to make the best possible decision and budget accordingly over the next 20 years, while continuing to address and mitigate risk.

The most common form of pipeline integrity used by oil and gas pipeline owners is inline inspection (ILI). Inspection pigs are widely used to clean pipelines, as well as identify areas of damage along the pipe wall to ensure the safe delivery of energy products.

Historically, once a pig is deployed in a pipeline, a technician confirms the tool’s arrival time at various tracking locations throughout the planned inspection distance. Once the tool has passed each location, it is out of sight until it reaches the next tracking point. However, recent technological advancements in tracking technology now allow for pigs to be tracked remotely throughout an entire ILI run.

Remote tracking combines the use of above ground markers (AGMs) and Remote Tracking Units (RTUs) that are deployed before an ILI run is scheduled to take place and are used to track the pig from a central location. When a pig approaches a tracking site, the RTU and AGM are activated to track the tool, which eliminates the need to have a field technician to be on site.

Consistent Live Tracking

PureHM has developed a web-based software called LiveMap that tracks a pig throughout the entire ILI run. LiveMap provides real-time updates via email or SMS with the pig’s location, speed, and estimated time of arrival to ensure that there is better visibility for stakeholders during a project. This advanced technology mitigates the risk of unexpected challenges in an ILI run, such as a stuck pig or speed excursion.

Live tracking offers more control throughout an inspection, and can help prevent costly incidents such as lost pigs by providing accurate information on a pig’s location. A lost pig can interrupt or stop product flow in a pipeline, and can lead to pipeline damage and unforeseen service disruptions.

LiveMap drawing

During an ILI run, the time and speed information collected each time the pig passes the AGM is updated and presented in LiveMap. In traditional legacy tracking runs, this is completed and reported by the field tracker, while in remote tracking runs this is completed automatically with a defensible record of the passage.

To learn more about remote tracking, download PureHM’s pig tracking white paper.

Download full PDF

Kingston Pipe Material Map

Internal measurement map indicates various pipe materials detected during the conditon assessment of the Dalton Avenue force mains in Kingston.

The familiar adage, “never assume anything” certainly applies to the water and wastewater pipeline industry. The message was brought home to Utilities Kingston (UK) early this year when the utility was surprised to find unexpected pipe material on sections of pipe during a condition assessment on its Dalton Avenue (North End) Pump Station force mains.

Conducting a condition assessment on a pipeline can pose a particular challenge if the pipe material is unknown, as each pipe type exhibits specific characteristics that affect its structural integrity. Despite the challenge, UK managed to move forward thanks to assistance from Pure Technologies, bringing its inspection, risk assessment and engineering analysis services, along with its comprehensive suite of technologies to survey the pipeline for leaks, gas pockets and wire breaks.

Utilities Kingston is unique in Ontario, combining water, wastewater, gas and electrical services, and a broadband fibre optics provider under one company.  UK’s engineering and public works departments provide potable water and wastewater collection and treatment to 36,000 customers.  The utility owns and operates approximately 550 kilometres of water mains and 500 kilometres of sewer mains to service the local population of nearly 125,000.

With an average age of 35 years, each of their pipeline assets is entering a critical stage in its life-cycle.

The subject pipeline had experienced a failure and as a result, the utility was interested in exploring technologies to help them implement a comprehensive asset management program for their pipelines.

Condition assessment includes various screening technologies

UK retained Pure to perform a condition assessment inspection, consisting of a SmartBall® leak detection survey, a PipeDiver® electromagnetic inspection and a transient pressure monitoring on the Dalton Avenue Sewage Pump 450-millimeter and 600-millimeter force mains. The two sewage force mains are both approximately 1,550 meters long and follow a parallel route for approximately 1 kilometer.

The older of the two force mains is 450-mm (18-inch) in diameter, constructed of ductile iron, was built in the late 1950s, and had failed several times over its lifetime. The newer of the two force mains is 600-mm (24-inch) in diameter was an unspecified concrete pipe from the early 1960s. As the pipe material specifics were still unknown at the time of the inspection, Pure elected to conduct a free-swimming PipeDiver electromagnetic run to accommodate both possible types of pipe material – assumed by all to be bar wrapped pipe (BWP) and prestressed concrete cylinder pipe (PCCP). The PipeDiver inspection platform uses electromagnetic (EM) sensors to evaluate the existing condition of the pre-stressing wires. EM inspections collect a magnetic signature for each pipe section to identify anomalies that indicate zones of wire break damage. The presence of wire breaks in concrete pressure pipe is often a sign of impending failure.

Pure’s SmartBall tool was deployed on both pipes, checking for leaks and gas pockets.

PipeDiver on a street

Force main defects can vary from one pipe material to another

During a forensics exercise on the 600-mm force main using 12-detector PipeDiver technology, it was revealed that rather than BWP or PCCP, the actual pipe material included reinforced concrete pipe (RCP), which is not usually used in pressurized environments. Electromagnetic inspection of the RCP can only reveal anomalies on the circumferential cage and not the longitudinal bars.

Furthermore, the inspection identified 102 suspected metallic pipes, which were not identified as such in the original plan and profile drawings.

PipeDiver tool before insertion

Prepping the PipeDiver tool before insertion.

Pure first: metallic pipe condition assessment using mini PipeDiver tool in wastewater

Pure deployed its electromagnetic 24-detector mini PipeDiver tool to conduct a condition assessment of the 450-mm pipe. The purpose of the enhanced electromagnetic inspection is to locate and identify steel and ductile iron pipes that have indications of wall loss.

This marked the first condition assessment of metallic pipe using the 24-detector mini PipeDiver tool in wastewater, an exercise that confirmed the validity of the tool’s sensor technology.

Results lead to actionable information regarding rehabilitation

In the end, one (1) acoustic anomaly characteristic of transient gas on the 450-mm forcemain was identified during the analysis of the data collected during the SmartBall tool inspections.

No anomalies resembling leaks were identified within the 600-mm force main.

Of the 650 pipes inspected, a total of 55 pipes in the 450-mm Dalton Avenue Pump Station force main had electromagnetic anomalies characteristic of localized wall loss (DIP). These results represent a high percentage of distress along the length of the pipeline and indicate a high risk of failure.

The data collected from both the inspections and transit pressure monitoring gave Utilities Kingston a better understanding of their real, not assumed assets. The results were used to complete a structural evaluation of the force mains, and have provided UK with actionable information regarding any necessary repairs or rehabilitation.

Team Members of Pure and UK

Members of the Pure and UK team pose after a long day of inspection.

Lisboa Map

SIMAS Oeiras e Amadora distributes drinking water to 350,000 customers in the Lisbon region of Portugal.

Drinking water systems degrade over time, with the useful life of the pipe and component parts often lasting for decades. Of course, age is only part of the equation. The deterioration of any particular pipeline depends on a multitude of factors, including pipe material and class. To complicate matters, factors such as soil environment, chemical properties of the water, climate changes, and operational particulars can all contribute to weakened pipes.

All that said, when a suspected leak develops in a pressured main after only five years in operation, it’s important to locate and repair the leak and determine what operational, environmental or installation factors led to the failure.

That was the situation faced by Intermunicipal Service Oeiras and Amadora, a water management company responsible for the distribution of drinking water for the municipalities of Amadora and Oeiras in the Lisbon region of Portugal. SIMAS Oeiras e Amadora distributes water to more than 350,000 customers who have come to rely on the public company for their water services.

The F. Passarinhos-Atalaia duct is a pressurized pipeline that supplies water to one of eight reservoirs operated by SIMAS Oeiras e Amadora in the municipality of Amadora. Installed in 2007, the large 600 mm (24-inch) transmission main, made from ductile iron material, delivers drinking water to approximately 31 percent of Amadora’s residents, making it a critical part of the municipality’s buried infrastructure.

Pressure drop indicated possibility of critical leak

In 2012, SIMAS Oeiras e Amadora detected a noticeable pressure drop in the system, indicating the possibility of a critical leak, the predecessor of a potential rupture that could negatively impact the environment and significantly disrupt day-to-day life in the community.

When traditional leak detection methods—geophones and acoustic correlators­ were unable to detect the location and size of the leak, SIMAS Oeiras e Amadora called on its contractor to perform a leak detection survey using the innovative SmartBall tool from Pure Technologies (Pure).  Because of the criticality of the line, the survey was conducted while the pipeline remained in operation.

Since 2007 utilities all over the world have been using Pure’s SmartBall pipeline inspection technology to save millions of dollars in water loss and prevented water main breaks.

SmartBall inside a pipe

Pure’s SmartBall tool can be launched while the main remains in operation.

SmartBall tool launched without disrupting service

Pure’s patented SmartBall tool is an aluminum-core, foam-shell ball packed with several different sensors that can be launched into a water main without any disruption to client service.

Unlike traditional external listening tools that have limited success on large diameter pipes, SmartBall is the industry’s only free-flowing multi-sensor technology that provides the highest degree of accuracy, since as the ball rolls, it can inspect every inch of a water main to detect potential problems such as leaks and gas pockets. Its highly sensitive acoustic sensors can locate ‘pinhole’ leaks and gas pockets within a location accuracy of 1.8 meters.

The SmartBall was inserted into the pipeline through a 6” gate valve and the journey took two hours and 49 minutes. One small leak was detected, 863 meters from the insertion site. This leak was repaired and allowed SIMAS Oeiras e Amadora to recover costs associated the loss of non-revenue water, had it remained undetected.

Assess assets from inside the pipe rather than from external clues

Leak detection is a necessary step to reduce water loss and prevent major water main breaks. The benefits of leak detection are obvious in increased revenues, lower risk of contamination, lower liability due to a reduction of main breaks, and increased public trust.

Although the SmartBall tool detected just one leak, the inspection gave SIMAS Oeiras e Amadora the capacity to assess assets from inside the pipe rather than drawing conclusions from indirect, external clues. If leaks are discovered early, operators can take necessary action to makes repairs before they become a major problem.

This process allows progressive operators like SIMAS Oeiras e Amadora to develop a sustainable long-term strategy for managing their critical buried assets.

Amsterdam, Holland

Would you take on a new pipeline inspection challenge, even if you knew it would land you in hot water?

Recently Pure Technologies (Pure) was able to chalk up success by adding one more type of pipeline to its inspection resumé. In this instance it was a district heating pipeline owned and operated by Eneco, one of the largest producers and suppliers of natural gas, electricity and heat, serving more than two million business and residential customers in the Netherlands.

District heating make sustainable sense

The concept of heat pipelines makes a lot of environmental sense. Throughout northern Europe, many municipalities and power generators have built closed systems of vacuum-insulated pipelines that circulate hot water from power plants and incinerators, sometimes above 100°C, through radiators in houses, businesses and other structures. This is an efficient method of heating buildings, and boasts a 98 percent heat retention rate during transmission.

SmartBall with case and insertion tools

Pure performs SmartBall leak and gas pocket detection survey

Recently Eneco contracted Pure to perform a comprehensive SmartBall® leak and gas pocket detection survey of the Centrale Merwedekanaal to WOS District Heating System. This is a 500 mm steel pipeline within a 700 mm steel pipeline of which a vacuum is created in the annular space to insulate the hot water. The survey purpose was to locate leaks and pockets of trapped gas present in the pipeline at the time of inspection.

The subject pipeline, originally installed in 1985, was suspected of having a leak, owning to an observation of water present in the annular space. As mentioned, the heating system pipeline consists of an inner 500 mm steel pipeline and an outer 700 mm steel pipeline, with a vacuum maintained in-between. The lines, constructed both above ground and below ground, incorporate numerous 90 degree bends and u-shapes, to allow for expansion and contraction as the product temperature changes.

Tracking with a laptop connected to the SmartBall

During the project, Pure inspected approximately 2.6 kilometers of the pipeline, with the goal to locate the leak(s) causing the water loss.

For the survey, Pure proposed the SmartBall leak and gas pocket detection system, a free-swimming, acoustic-based technology that detects anomalous acoustic activity associated with leaks or gas pockets in pressurized pipelines.

While other leak detection techniques such as noise loggers and correlators may identify a single leak or gas pocket between each sensor, they cannot accurately locate the limits of an anomaly nor identify multiple anomalies. In this specific case, the use of noise loggers is hindered by isolation. The SmartBall tool travels directly past each acoustic anomaly of interest on the inner pipe and thus significant advantages are recognized.

Unique challenges to overcome

The standard procedure for tracking the SmartBall tool depends on positioning acoustic sensors on the outside of the inspected pipe and listening to the device as it passes. Since the line is so well insulated from heat loss, it is also well insulated against sound transfer, which meant it unlikely for good tracking on any sensor mounted to the outer 700 mm pipe. Additionally, Eneco was understandably averse to compromising the integrity of the vacuum seal of the line, and therefore did not wish to expose the 500 mm pipe to mount sensors. In the absence of external tracking means, other reference points in the data are critical for accurately locating anomalies within the pipeline.  SmartBall contains gyroscopes that can measure bends in the pipeline that it traverses, and as there were many aforementioned 90 degree bends, these were clearly seen in the data.  The bends in the Eneco pipeline made for great geospatial reference points and therefore allowed for locating anomalies with relatively high confidence.

Pipeline over the surface

SmartBall tool deployed to survey district heating pipeline

The acoustic data recorded by the SmartBall tool was analyzed and cross-referenced with the position data. From the data collected and analyzed, the SmartBall device detected five (5) possible weaknesses, which were clearly visible in the data. Zero (0) gas pockets were detected. The results give Eneco actionable data regarding the condition of their pipeline, and despite challenges, the assessment is proving its worth. It’s a great example of a proactive utility taking efforts to maximize its capital expenditures.

Historical pipe installation

An archived photo from installation of the pipeline five decades ago.

When your pipeline operates well for five decades, it’s easy to be lulled into a false sense of security about the condition of your buried assets. Out of sight, out of mind.

Then, in an instant, that mindset can change.

For Canadian River Municipal Water Authority (CRMWA), that wakeup call happened after dealing with two unexpected failures in quick succession earlier this year. The failure repercussions quickly introduced CRMWA to Pure Technologies, a leader in technologies for the inspection, monitoring and management of critical infrastructure.

CRMWA provides water to 11 member cities in the Texas Panhandle and South Plains region, near the cities of Amarillo and Lubbock. The water authority, which serves more than 500,000 people, draws water from Lake Meredith through a 358-mile aqueduct system completed in 1966. Comprised of approximately 55 miles of non-cylinder prestressed concrete pipe (PCP) along with approximately 300 miles of reinforced concrete pipe (RCP) and bar wrapped concrete cylinder pipe (BWP), the main aqueduct can deliver up to 118 million gallons of water daily to the 11 member cities.

Digging out failed pipes

One of the pipe failures that caused a blowout.

December 30: First blowout ends flow to 9 cities

The first indication of a problem occurred with a pipe rupture on Dec. 30, 2015, which abruptly ended the flow of water to nine of CRMWA’s member cities, leaving the cities to use precious reserves or their own water.

With the initial failure of a 72-inch (1830-millimeter) diameter non cylinder prestressed concrete pipe (PCP), the water agency lost millions of gallons of water, forcing a temporary pipeline shutdown to make immediate repairs.

January 5: Soon after the first blowout was repaired, an adjacent pipe began leaking

Five days later, on Jan. 5, CRMWA completed repair number one, and started to refill the system when an adjacent pipe began leaking.

This new leak lead to an emergency mobilization from Pure at the request of CRMWA. Pure’s condition assessment technologies have helped clients prevent more than 2,300 failures worldwide, resulting in billions of dollars in savings, and hundreds of billions of gallons in water savings. Pure has also located more than 4,000 leaks on water mains using its leak detection technologies.

Broken concrete pipe exposing the internal anatomy

One of the EM anomalies verified and excavated for repairs.

January 5-6: Pure mobilized to begin a manned electromagnetic survey

The same day, a crew of three mobilized from Dallas to the failure site near Amarillo. The purpose was to conduct a non-destructive evaluation using Pure’s electromagnetic inspection technology on the pipe immediately adjacent to the damaged sections. Over the next two days, Pure scanned 8,822 feet with internal manned electromagnetics.

January 8: Based on expedited EM analysis, Pure informed CRMWA of two large anomalies in two pipes near the first failure.  Over the next two days CRMWA completed the second leak repair, and hoped for more time to conduct a third repair where Pure called a large electromagnetic anomaly.

January 11: After Pure demobilized from the job site, the client turned on the pipeline, and after flowing for 12 hours, a second failure occurred, in the area located where Pure’s EM analysis indicated a potential problem.

January 12-13: Over the next few days, Pure verified five electromagnetic anomalies in three pipes near the failure site while CRMWA completed additional repairs. Based on the verified results, CRMWA requested a total of approximately 47 miles of manned EM inspection, which was completed by mid-March.

“The electromagnetic inspection was well worth the cost. Now we know the condition of our pipelines. We know the locations of our problems. The scan revealed 16 pipes where corrosion had put the lines at risk for developing additional blowouts. Those have been repaired much more cheaply and quickly than the costs of fixing blowouts.”

Kent Satterwhite

General Manager, CRMWA

Preparing the pipeline paid off by finishing ahead of schedule

CRMWA worked around the clock leading up to the inspections to dewater and prepare the pipeline for the internal inspections. The hard work paid off well, with no holdups on the inspection progress. The excellent planning by CRMWA and Pure allowed the inspection to wrap up ahead of schedule. Once the internal inspection was completed, Pure was also able to perform a destructive calibration on a pipe section which CRMWA provided, which was helpful for the analysis of the data collected. CRMWA was also able to repair 16 pipes that were very close to failure as identified by the electromagnetic surveys.

Sometimes one unexpected pipeline problem can compel long term planning and action, as it did with CRMWA. The Water Authority now has a defined plan to assess the condition of their pipeline, giving them the confidence to move forward with greater assurance and peace-of-mind.

Man with fish inside pipe

After a long day,  Pure and CRMWA celebrated with a fish dinner, caught while draining the raw water line.

Fish inside a cooler
Biosand filters kits assembled

A representative from CAWST recently visited Pure’s Calgary office and told a large audience about its unique approach to teaching people in developing countries how to build biosand filters to provide clean water. In turn, Pure was able to use its peoplepower to help CAWST with the assembly of sand sieve kits for use in the filters. The protection of water resources is a core value shared by both Pure and CAWST.

CAWST, or the Centre for Affordable Water and Sanitation, is a Calgary-based charity and licensed engineering firm that provides technical training and consulting expertise in water and sanitation to the poor and underprivileged in developing nations. In its own words, CAWST “teaches people how to get safe drinking water, sanitation and hygiene in their own homes using simple, affordable technologies.”

The majority of CAWST’s tools are made locally using available materials, but the biosand filters require a specific type of sand. If end users don’t have the correct grade and consistency, the filter won’t work. CAWST generally supplies its users with sand sieve kits during its on-site training programs but, being a non-profit organization, often asks for volunteers to help assemble them ahead of time.

Enter Pure. At the meeting in November, Pure employees from several departments in Calgary gathered at lunch to listen to the presentation and then assemble 12 sand kits. The contribution helped reduce the assembly workload for CAWST and end users, and provided Pure team members with an opportunity to learn about the biosand filter. Pure employees also enjoyed a change of pace, an opportunity to interact with colleagues, and a great deal of fun.

Building sand kits
Houston and Oaklahoma

Sahara® technology is winning accolades from satisfied owners and operators of buried infrastructure the world over. In North America, two recent projects demonstrate the benefits of using this in-line tethered tool for critical leak detection surveys, especially when speed and accuracy are paramount.

Sahara Diagram

Sahara is the first tool designed for live inspection of large diameter mains, and one of the most accurate tools available for detecting and locating real-time leaks, gas pockets and structural defects in complex networks typically found in urban environments.

The tool is inserted via a valved appurtenance, and then moves through the pipeline using the flow of water and a small drag chute – all without interrupting service. Once the sensor tool is inserted, it remains tethered to the surface. This allows for real-time results and maximum control, as the tool can be winched back and forth to immediately confirm suspected leaks and other anomalies. The sensor is also tracked at ground level by a staff member, allowing for precise spot markings for excavations.

Oklahoma City welcomes Sahara leak detection survey on critical main

In March 2015, McKee Utility Contractors (McKee) retained Pure Technologies (Pure) to perform a quick-turnaround leak detection survey on a troublesome 72-inch Transmission Main (TM) in Oklahoma City. The critical TM, which is composed of prestressed concrete cylinder pipe (PCCP) and transmits potable water, is owned and operated by Oklahoma City Water Utilities (OCWU).

In this instance, OCWU suspected a leak along a low point of the line where surface water was noticed. A previous catastrophic failure on the line compelled the utility to call on the prime contractor McKee to dig, locate, and repair the leak.

Thwarted by two days of digging and not finding the leak, McKee called on Pure to assess approximately 4400 feet of pipe and to determine the location of the leak source and any gas pockets using Sahara leak detection technology.

Quick mobilization, short turnaround timing

The planning and execution took place in short order. McKee contacted Pure on Saturday, the project planned on Sunday and by Monday a field crew and equipment were mobilized to the site in Oklahoma City. On Tuesday, a single inspection was performed, and one (1) leak was detected 360 feet downstream from the Sahara insertion point. The leak was classified as a large leak based on the audible range.  The inspection continued for a total inspection distance of 546 feet.  No other leaks were detected at the time of inspection.

By the time Pure began extracting the Sahara tool, McKee had ordered a backhoe enroute, and by afternoon the pipe was excavated, the leak located, and the repairs were able to begin.

Shane McKee, president of McKee was extremely pleased with the accuracy of the Sahara technology and the fast turnaround from the Pure team.

“Based on the results I’ve seen, I’m never again digging up another pipe again without Pure and its technology to help guide the process.”

Shane Mckee

Shane Mckee, McKee Utility Contractors

Sahara Insertion Tool

Houston energy company deploys Sahara tool to quickly locate leak in chilled water line.

Large cities often operate central chilled water plants to cool water that is then sold to building owners for use in air conditioning.

In Houston, Enwave Houston delivers chilled water through 5.4 miles of pipe to air-condition 24 buildings, including Minute Maid Park, home of the Houston Astros. The 27,000 ton system uses ice storage technology to help keep central business district buildings comfortable in spite of summer`s high temperatures and humidity.

In December 2015, Pure was retained by Boyer Inc. to perform a Sahara inspection on Enwave`s 24-inch Chilled Water Supply pipeline (CWS) and also on their 24-inch Chilled Water Return pipeline (CWR). The purpose of the inspection was to locate a suspected leak on one of the dual lines that run parallel along the downtown core.

Data identified events associated with leaks and air pockets.

Boyer proposed two separate insertions during the planning phase. Pure completed both proposed insertions over a two-day period for a total of 795 feet of pipeline inspected. Acoustic data was collected and recorded during the inspections as the Sahara sensor traversed the main. The data was evaluated to identify events associated with leaks and pockets of trapped air.

During the inspections, one leak and zero air pockets were detected. The Sahara sensor was tracked above ground to track the sensor along each pipeline and verify the endpoint of each endpoint. The leak was located 144 feet downstream from the insertion point on the second day with sub-meter accuracy, allowing a pinpoint excavation to be made for repairs, minimizing disruption to downtown Houston traffic, and minimizing the contractor`s cost of excavation and road restoration.

When time and accuracy matter, utilities count on the Sahara platform.

The two case studies demonstrate the efficacy of the Sahara leak detection system. When time and pinpoint accuracy matter, the Sahara platform gets the job done right.

Wachs Water Services – Valve Restoration from Pure Technologies on Vimeo.

For large urban cities, one of the quickest ways to realize an investment return from their network of underground assets is to inventory the water distribution system and assess the overall condition of valves and fire hydrants.

This progressive major southeast U.S. city recognized the value of getting a comprehensive handle on the condition and usability of its aging control assets. The city, which operates a complex water network for nearly one million customers, recently completed a long-term asset management program for its valves and hydrants.

Wachs Water Services, in a joint venture with Brindley Pieters & Associates (WWS-BPA Joint Venture), recently completed the latest phase of this city’s Asset Assessment Program, providing the city with an immediate return on investment by maximizing usability of control assets. The water distribution system consists of approximately 59,000 valves and 24,000 fire hydrants.

Open Hydrant with water flowing

The program also ensured future savings through the development of a geographic information system (GIS) database that contains necessary water system transmission and distribution assets records and global positioning system (GIS) locations to meet water utility asset management and maintenance requirements. The program is projected to save the city a minimum of $77 million over the next ten years.

Estimated $77 million savings from increased control and enhanced management

The $77 million in savings, resulting from the increased control and enhanced management, will be realized even if the city makes no further investments in their system.  This represents three dollars ROI for every dollar invested.  With continued preventative maintenance and further enhancements to their GIS data program, the city could potentially save an additional $65 million over the same 10 year period.

“Every dollar that the utility has invested into this program delivers three dollars of tangible savings from quantifiable system operability improvements and consistent control…”

“Managing an aging water network requires a results-driven approach that achieves both immediate system improvements and long-term sustainability. Every dollar that the utility has invested into this program delivers three dollars of tangible savings from quantifiable system operability improvements and consistent control,” summarized Cliff Wilson, President of Wachs Water Services.

The Valve and Hydrant Asset Assessment Program met two objectives.  The first restored maximum usability to the distribution system, providing immediate system improvements.  The second developed a comprehensive and accurate GIS database, ensuring long-term sustainability.
Valve and Hydrant Asset Assessment

Good news: 95 percent of valves could be located, accessed, and operated within 15 minutes

WWS-BPA evaluated and digitized 82,412 total assets (59,020 valves and 23,392 hydrants).   This process revealed that the city had an initial valve usability of only 27.9 percent.  This low level of control asset usability drastically increased response time and the impact footprint, increasing disruption to customers, increasing traffic rerouting and delays, and increasing collateral damage.   Low usability increases overall costs.

The team rehabilitated over 50,000 assets, including 43,000 valves, most during the initial field assessment.   By the end of the program, 95 percent of valves could be located, accessed, and operated within 15 minutes.

Maximizing usability minimizes costs

City residents and utility crews immediately recognized the benefits.  Field teams can identify and locate assets quickly.  Traffic delays are avoided.  Insurance claims for residents and businesses decreased.   Pre-planned construction shutdowns are more efficient.

To develop the comprehensive GIS database, the WWS-BPA team collected and digitized more than 60 attributes per valve, and over 40 attributes per hydrant, including sub-meter GPS position.  The team digitized 3000 miles of the distribution network, connecting all the assets into an accurate, accessible, and maintainable information system.  The city’s operational crews now have an accurate picture of the system, with exact locations for the control assets along with their usability.  This information is used not only to respond to emergencies, but to manage and maintain the system’s high level of control.

Wachs Water Services is proud to be a part of this project that has set industry standards for large urban cities and demonstrated that efficiencies can be increased through restoration and information rather than replacement.

SmartBall on a net at the end of a pipe

For this leak detection survey, Pure’s innovative free-swimming acoustic tool gathered critical information about the aging pipeline assets of this historic Arabian city.

This large public utility supplies bulk water to this bustling, historic resort city located in the Arabian Penninsula region. The city’s infrastructure – above ground and below – has recently been modernized to keep up with growth and support the expanding tourist industry.

Recognizing that its underground infrastructure was reaching the end of its service life, the water utility called on Pure Technologies Abu Dhabi (Pure) and its local agent International Aramoon Company, to perform a series of SmartBall leak detection surveys on 150 kilometers (93 miles) of its ductile iron pipe (DIP) water network.

SmartBall gathers critical information about the city’s buried pipeline assets

Every pipeline is unique and comes with its own set of assessment challenges. When an operator has a strong understanding about the risk and operational conditions of their system, an appropriate and defensible inspection plan can be developed.

For this project, Pure introduced its proprietary SmartBall leak detection platform to identify and locate leaks and pockets of trapped gas along the water pipeline.

Pure began the SmartBall inspection project facing a number of challenges. For starters, due to limited access to historical drawings, the pipeline system and route was relatively unknown, with only a scanned copy of the schematic available for review.  Operational challenges included fluctuating flows within the pipeline, as well as a lack of access points for insertion and extraction.

To make matters more difficult, Pure faced issues related to the isolation of branches during the inspection.  The utility could not provide the option for a valve exercise prior to the trial “dummy” SmartBall run, which was decided on to eliminate the chances losing the real SmartBall.

Acoustic intensity of anomaly and actual leak located

 Left: Acoustic intensity of anomaly.   Right: Actual leak located

SmartBall acoustic tool collects data as it rolls through the pipeline

Pure began the project with an ocular visit attended by the client and a pipeline maintenance operator to understand the right of way and alignment of pipeline sections. The distances between pipeline features were measured using an odometer, while bend locations were assumed based on street references from the schematic drawing.

Since the pipeline was non-redundant and could not be shut down, insertion and extraction points were provided by hot tapping the pipeline.

Prior to the official SmartBall launch, Pure conducted a trial run with a dummy ball on each pipe section to eliminate the chance of losing the SmartBall on its journey. Both the dummy ball run and SmartBall inspection were deployed on the same day to reduce the possibilities of flow fluctuations.

As the free-swimming SmartBall tool rolls through the pipeline, it collects acoustic data. The acoustic sensor identifies the sound of water leaving the pipeline, or the sound of trapped air at the top of the pipeline, which can reduce water flow and increase strain on pumps.

Easy to deploy, SmartBall also makes it easy to screen the pipeline for leaks, which could indicate a structural problem that deserves further attention.

Assessment identifies 21 leaks on 68 kilometers of pipe

To date, the SmartBall tool has inspected more than 68 kilometers (29 miles) of pipe within the city’s network, with additional runs planned. The inspection resulted in the identification of 21 leaks of various sizes. Of the total, 14 leaks have been verified and repaired by the utility.

The investigation confirmed that with good condition assessment, asset life can be extended, while managing utility’s exposure to risk. This mindset sets a good example for other Arabian cities to follow in developing a sustainable long-term strategy for managing aging infrastructure.

Flower Mound Sign

Named for a prominent landmark mound with more than 175 species of wild flowers, the Town of Flower Mound is ranked as one of the ten best places to earn a living and raise a family in Texas.

To complement these natural and economic positives, the scenic Town of 70,000 is also known for its municipal water stewardship and proactive approach in maintaining the quality of its buried infrastructure. This includes 430 miles of water mains and 230 miles sewer pipes serving 22,000 residential and industrial connections.

As part of the ongoing program for condition assessment of its buried infrastructure, the Town recently retained the services of Pure Technologies U.S. Inc. (Pure) to conduct a Sahara® leak and gas pocket detection inspection of approximately 21,200 feet of the Potable Water Main (PWM), which connects the Pintail Pump Station to the Waketon Water Tower. Constructed in 1973, the critical section of 20-and 30-inch pipeline is comprised of bar-wrapped (AWWA C303)steel and ductile iron pipe.

“Most pipelines are designed for 50 to 75 years expectancy, and service life can vary depending on factors such as depth, soil conditions and pipe material,” said Randy Williams, Utility Services Manager of Flower Mound Public Works (FMPW) District. “Rather than waiting for breaks to happen, the Town strives to assess the condition of the assets before that happens.”

The Sahara inspection followed a structural assessment using a PipeDiver® inspection of this same pipeline conducted one month earlier and covered many of the identical pipeline sections. FMPW chose CCTV inline video and enhanced electromagnetic (EM) assessment to provide a comprehensive condition assessment.

PipeDiver platform carried to the insertion point

Pure’s free-flowing PipeDiver platform, which preceded the Sahara inspection along the same pipeline, is being carried to the insertion point.

Detecting small leaks with Sahara inspection platform

The Sahara® pipeline inspection platform is one of the most accurate tools available for leak detection, gas pocket detection, and locating structural defects in complex networks of large diameter water and wastewater pipes.

The tethered tool is capable of locating very small leaks typically within 1.5 feet (0.5 meters) of their actual location. The tool also features inline video that allows operators to observe internal in-service pipe conditions.

Added value: Flower Mound inspection included design and installation of taps

The insertion locations for the Sahara inspection were dictated by the previous PipeDiver inspection, which indicated a large number of bends and long distances to cover with less than ideal access.

In light of the limitations, and within a very short time frame, Pure took on the responsibility to manage the tapping process in-house, including the design, excavation and installation of the taps to insert and extract the Sahara tool from the pipes. Although this task was atypical of work normally provided, it is an example of the added value Pure can bring to a project.

Detected: one leak, one large gas pocket, plus improved GIS information

It’s still early in game, and the electromagnetic results have yet to be fully evaluated. Nonetheless, the Sahara inspection detected a leak on an undocumented offtake installed on pipe suspected to have been blanked off and buried, and now leaking.

In addition to pinpointing the leak and gas pocket, the condition assessment located an additional six undocumented outlets the Town was previously unaware of, leading Pure and FMPW to surmise that the outlets were installed and equipped with blind flanges for future expansion. Additionally, during this inspection, sections of pipeline alignment were discovered to be quite different than what FMPW expected.

FMPW now has a true comprehensive condition assessment of their pipeline that includes GIS quality mapping, video inspection and recording of the pipeline interior, leak and gas pocket identification and repair, and assessment of the structural integrity on a pipe-by-pipe basis — allowing for localized verification and repair. Overall, GIS information has been improved, with location and images of possible leaks, defects or anomalies.

“The proactive approach we’re taking allows us to predict water main breaks, which improves our reliability of service,” said Williams. “When you locate a defect, you can schedule a repair, notify people, and get it done at the right time of day, and at a schedule of our choosing. Everybody benefits.”

Randy Williams, Utility Services Manager of Flower Mound Public Works (FMPW) District, talks about the Utility’s approach to condition assessment.

City of Saskatoon

While pipeline management may seem unaffordable, understanding the condition and targeting repair provides an alternate approach to wholesale replacement and allows operators to accomplish the same de-risking effort with less money.

The City of Saskatoon operates more than 100 kilometers of water mains (400 mm diameter and larger) within the Water and Sewer Preservation Group.  The City has an extensive water main break database dating back to 1959, which assigns a condition rating to water main segments. These ratings are useful for evaluating small diameter local lines where the consequence of water outages are low, and a “run to failure” strategy is acceptable.

For large diameter transmission water mains, waiting for failures to occur before repairing or replacing highly critical mains is not an option. A proactive approach to condition assessment is needed.

“The benefits of accurate condition data can be significant,” says Stephen Wood, P. Eng. Water and Sewer Preservation Manager for the City.  “Allocating limited maintenance and replacement funds on the correct locations is crucial and this is impossible without good condition data. However, obtaining condition data on highly critical, non-redundant, pressurized water mains can also be costly. For this reason the City set out to determine where to focus its condition assessment efforts.”

First priority: where to start?

To help Saskatoon better understand its network and overcome its particular challenges, the City partnered with Pure Technologies to help answer the questions: where do we start in prioritizing our pipelines based on Risk, and what strategy should we implement moving forward?

Straight capital replacement is unaffordable. The City recognized the need to set up a risk framework in order to evaluate its highest priority pipelines first, rather than looking at a pipe based on when it was installed.

Pure proposed a data driven, risk-prioritized approach to managing the critical buried infrastructure. The City and Pure worked closely to develop a systematic approach with specific tasks to implement a pipeline risk prioritization plan.

1. Collect existing data and provide a “gap analysis”

Prior to the project, existing information was collected and reviewed as it related to the pipeline assets. Pure looked at maintenance records and compared existing information with what is necessary to develop the preliminary risk assessment and ultimately the condition assessment of each asset. This “gap analysis” provided a summary of the available information related to the pipelines as well as what is not currently available.

At the same time, additional pipeline attributes were gathered, including existing information on material, diameter, failure history, previous rehabilitation, hydraulics, soil sampling, etc.

Risk graphic and aerial map of water main conditions

(Left) Circle size represents the total pipe length under each risk category.
(Right) Aerial map of water main conditions by neighbourhood.

2. Define risk category and establish relevant risk factors

Pure adopted a logical approach to quantify risk as the product of likelihood of failure (LoF) index and consequence of failure (CoF) index. Relevant risk factors were selected after learning the historical pipeline behavior and data availability. Each factor was assessed by a score value between high (5) to low (1).

3. Compute the risk analysis

Based on the metrics of consequence of failure, likelihood of failure scoring and layered with risk mitigation factors, Pure performed a risk computation using PureNet in-house software to determine the highest risk pipes and recommend the inspection technology.

4. Calculate pipeline and neighbourhood risk

Pure had the ability to look at a single line and plot it into risk zones node to node, feature to feature, and within set neighbourhood parameters. The risk zones recognize that pipelines do not deteriorate on a uniform basis. By aggregating the data by neighbourhood, the risk prioritization can help decision makers plan and target regions, facilitate scheduling, maintenance and repairs, and better communicate with stakeholders.

5. Model budgetary needs for different management scenarios

Through the exercise, Pure gave the City a static risk picture to provide a baseline look at the system, as well as a plan to forecast risk and establish appropriate budgets for multiple management strategies.

Pure developed a 50-year pipe replacement plan that systematically replaces pipe based on risk priority up to the available budget in a given year.

“Allocating limited maintenance and replacement funds on the correct locations is crucial and this is impossible without good condition data.”

Replacement model versus condition assessment model

The replacement model offers limited coverage due to the high replacement costs from replacing entire pipe segments at a time. In comparison, the condition assessment model can achieve greater coverage for lower cost due to its unique methodology.

The condition assessment strategy is an approach where a program is developed that systematically inspects pipe based on risk priority and only addresses damage where needed. Under this program, pipelines are screened for repair or replacement depending on current condition of individual pipes. The provision of additional knowledge allows only the worst of the pipes to be addressed and avoids the premature repair or replacement of those pipes still in good condition.

What’s next?

“The results of the report give us a clear indication of the benefits of condition assessment along with a priority list for addressing our highest risk locations,” says Stephen Wood.  “The next step is to put the plan into action. We are currently working on developing a project for 2016 that will provide a condition assessment of approximately 2.5 kilometers of our highest risk water mains.”

Scottish Water takes innovative and responsible approaches to pipeline management. To assess the condition of its Newmore Raw Water Main, the water provider used PipeDiver™ inline inspection technology, the first use of the technology in Europe.

Scottish Water (SW) is the fourth largest water and wastewater provider in the United Kingdom (UK), serving more than 5 million customers in 2.4 million households. As one of the country’s largest businesses, with a £1 billion (US$1.54 billion) annual turnover, SW also acts as the wholesaler of water and wastewater services in the competitive market for business customers in Scotland.

A leader in the industry, SW has long undertaken innovative and responsible approaches to pipeline management. For its inventory of strategic infrastructure assets, the water operator is employing advanced techniques to build detailed criticality and integrity profiles. These profiles will be used to develop and maintain dynamic and fully detailed pipeline management plans.

Spray released from air valve and Pure crew readying PipeDiver for insertion

(Left) Pure and Scottish Water crew standing by as spray released from air valve. (Right) Pure crew readying PipeDiver for insertion to assess condition of Newmore Raw Water Main.

Inspection covered 14.6 kilometers (9.1 miles) and spanned 3,382 pipes

Scottish Water had long been working on conducting a risk-based condition assessment of its transmission main that delivers raw water from the Redburn to a reservoir feeding the Newmore water treatment plant, in the Inverness region of Scotland.

The purpose of the inspection was to locate and identify leaks and pipes with stress, using proprietary leak detection and electromagnetic technologies. The inspection covered 14.6 kilometers (9.1 miles) and spanned a total of 3,382 pipes composed of 685-millimeter (27-inch) and 762-millimeter (30-inch) pipe.

PipeDiver technology locates and quantifies stress

Pure Technologies, in partnership with WRc, began its initial screening assessment in March 2015 with SmartBall™ technology, a free-swimming leak and gas pocket detection tool used to record acoustic data on the pipeline. This data was evaluated to identify acoustic anomalies associated with leaks and pockets of trapped gas.

From the data, Pure identified 5 anomalies associated with leaks and no acoustic anomalies characteristic of pockets of trapped gas.

In August 2015, a few months after completing the leak detection survey, Pure mobilized its team to undertake a first within Europe – a structural condition assessment using PipeDiver™ technology, an inline tool used to locate and quantify distress.

The PipeDiver tool is free-swimming and comprised of three parts – a battery module, electromagnetic module and a tracking module. The electromagnetic sensors are located on each fin and collect a magnetic signature for each pipe section to identify anomalies that are produced by damage to the structural component for the integrity of the pipe.

Inspection results

The inspection determined 12 pipes with EM anomalies consistent with pipe distress damage.

To repair, replace or leave alone? That is the risk-based question

The PipeDiver inspection determined that 12 pipes in the Newmore Transmission Main displayed electromagnetic anomalies consistent with damage. Effective analysis of electromagnetic data first requires baseline knowledge of how the electromagnetic signal behaves when no damage is present. This baseline is then compared to the data signal received when damage occurs on the pipe. To understand how the data signal responds, Pure performed calibration scans on pipes similar to the inspected pipe, provided by Scottish Water.

While the electromagnetic technology provides data for structural deterioration, the challenge is to determine how much damage creates an unacceptable level of risk, thereby requiring intervention actions.

Pure has developed an innovative approach for pipeline management using structural models along with hydraulic evaluation data to deliver a Pipe Performance Curve used for the management of a pressure main. The decision-making tool plots stress versus pressure, and will allow SW to understand when a pipe is trending toward ultimate failure, which in turn will help in making defensible investment decisions.

Utilities Complete Condition Assessment Of Bar-Wrapped Pipe With Smartball®, Pipediver®, And Robotic Platform Tools

By the early 1940s, cast iron pipe was losing its historic cachet as the go-to material for new buried infrastructure. Cast iron’s replacement was bar-wrapped pipe (BWP), and it quickly gained acceptance as a reliable, durable and cost-effective pipe material for use in large-diameter transmission and sewer force mains.

Typically, BWP consists of a welded steel cylinder with reinforcing bars wrapped around the cylinder to provide strength. An internal concrete lining and external mortar coating provide corrosion protection to the steel components. The watertight membrane enables the composite pipe to withstand high internal pressures and the effects of external earth and traffic loads.

Until recently, BWP condition assessment proved difficult

Despite early adoption from many pipeline operators, the downside to BWP has been the difficulty to assess the pipe’s condition, where failures are often precipitated by deterioration of the reinforcing bars and long periods of leakage that often go undetected.

It’s now 70 years later, and the methods to assess the condition of bar wrapped pipe have only been recently developed and commercialized. On this forefront, Pure Technologies is recognized for its toolbox of condition assessment technologies that can identify broad areas of cylinder corrosion and bar breaks.

Two Texas cities join forces to assess shared BWP water supply line

In one specific case, the city of Irving and a partnering agency in North Texas joined together to initiate a condition assessment project of their shared water supply line, made up primarily of bar-wrapped pipe. Constructed in 1955, the 48-inch Jamison Water Transmission Main is a critical non-redundant pipeline that conveys potable water to a combined population of 400,000 residences within the Dallas Fort-Worth Metroplex.

The two agencies worked side by side to implement an Assess and Address™ pipeline inspection protocol to determine the condition of the pipeline and to increase the utilities’ reliability of water delivery.

The condition assessment utilized inline acoustic leak and air pocket detection, robotics with high definition CCTV and enhanced electromagnetic detection, transient pressure monitoring and non-linear Finite Element Analysis (FEA) of the steel cylinder corrosion and broken bar wraps.

The results concluded that 97 percent of the 583 pipes inspected had no detectable damage. Less than 3 percent of the total pipes inspected exhibited minor distress, of which 15 (2.5 percent) pipes exhibited thinner steel cylinder.

Through close collaboration, the two agencies were able to effectively manage a shared asset with the goal of preventing disruptive and expensive pipe failures. The information gained from the assessment will allow for the implementation of a cost-effective, long-term management plan to extend the life of the pipeline.

Trinity River Authority of Texas (TRA) evaluates 8.8 miles of critical BWP transmission main

In a second case involving BWP, Pure collaborated with Trinity River Authority on assessing the condition of a pipeline that is a critical link in the reliable delivery of drinking water to five cities within the Dallas-Fort-Worth Metroplex. The aging pipeline was scheduled for replacement due to previous failures and inability to be removed from service for repairs.

To understand the overall pipeline condition, TRA contracted Pure to inspect and evaluate the pipeline by conducting comprehensive hydraulic, leak detection and condition assessment on 8.8 miles of the 30-inch bar-wrapped pipe.

For the leak and air pocket assessment, TRA used the SmartBall® inspection tool, a non-destructive, free-swimming technology that measures the acoustic activity associated with leaks and gas pockets in pressurized pipelines. Regular leak detection inspections can help utilities identify leaks that may not be visible at the surface.

Increased reliability, reduced capital costs

For the structural inspection, TRA used PipeDiver®, a free-swimming electromagnetic tool that identifies bar breaks and broad areas of cylinder corrosion in BWP using PureEM technology while the line remains in service.

The inspection of the BWP identified 14 pipes with bar break damage and 72 pipes with electromagnetic anomalies resembling cylinder defects out of 1284 inspected pipes. By repairing specific pipe sections with deterioration, TRA was able to avoid replacing the entire pipeline at a high capital cost and continue providing reliable service to customers in the region.

Dallas Water Utilities Discovers Massive Hidden Sinkhole And Achieves Huge Savings Through Annual Leak Detection Program

The year began with the Lone Star state experiencing its fourth year of drought, compelling State Governor Greg Abbott to reissue an Emergency Disaster Proclamation in early May to deal with the declining aquifer levels and severe water shortages. Only a few weeks later, torrential rains flooded so much of the state that the Governor issued another Emergency Disaster Proclamation to prepare for the new crisis. Then, another long stretch of baking heat.

Weather extremes push water utilities to the limit

For most utilities, weather can play havoc with buried infrastructure. While drought can cause the dry brittle ground to shift and pipes to break, excessive rain can result in washouts, loss of bedding and risk for accelerated pipe failures.

In 2015, weather extremes in such a short period taxed water utilities across Texas. Despite the challenging environmental conditions, Dallas Water Utilities (DWU) moved forward to carry out its annual leak detection program. Over the years, DWU has focused its water loss reduction efforts on both its critical large-diameter transmission mains, which have the highest consequence of failure, and on its distribution systems.

Pipe leaking

Detection results include discovery of a large pipe leak near a major roadway

Staff inserting Sahara tool

Crews successfully used the Sahara® tool to locate 10 leaks in 16 miles of inspection.

DWU’s first condition assessment program using electromagnetics was completed in 2001, followed by the use of newer leak detection technologies in succeeding years. The program is now in its 14th year of operation, and DWU has become a showcase utility for proactive pipeline management, a fact recognized by the Texas Water Development Board.

DWU adds 16 miles to its leak detection program in 2015

DWU’s distribution system is one of the largest in the United States, being a regional provider, the utility delivers water service to 2.4 million customers within the Dallas and surrounding city limits. The major distribution system includes over 4,900 miles (7,800 km) of distribution and transmission mains.

DWU’s goal is to continually evaluate, upgrade and replace its water and wastewater assets in order to make its systems operate efficiently. DWU’s long-time partner in this infrastructure endeavour is Pure Technologies (Pure). This year Pure was contracted to perform leak and air pocket detection for 16 miles (25.7 kilometers) of water mains made of a variety of materials, including prestressed concrete cylinder pipe (PCCP), cast iron pipe (CIP) and ductile iron pipe (DIP).

DWU deploys inline detection tools

For inspection of its transmission mains, DWU has long used Sahara leak detection and inline closed circuit video (CCTV) provided by Pure. More recently, DWU has also used SmartBall® technology for longer inspections.

Sahara is the first tool designed for live inspection of large-diameter mains, and one of the most accurate tools available for detecting leaks, gas pockets and structural defects in complex networks typically found in urban environments.

The tool is pulled by the flow of water by a small drag chute while the line remains in service. When the sensor is inserted into a 2-inch tap, it remains tethered to the surface. This allows for real-time results and maximum control, as the tool can be winched back and forth to immediately confirm suspected leaks and other anomalies. The sensor is also tracked at ground level by a staff member, allowing for precise spot markings for excavations.

Detection results include discovery of massive sinkhole near major roadway

The 2015 inspections, conducted over 23 days, challenged the Pure and DWU crews as they faced an environment with temperatures soaring to 104°F (41°C) on many consecutive days.

In spite of the trying working conditions, the crews successfully used the Sahara tool to locate 10 leaks in 16 miles of inspection. This included the unexpected discovery of a very large leak in the barrel of a 12-inch ductile iron water main. DWU’s proactive repair prevented a collapse since the large leak was creating a cavernous sinkhole near a major roadway.

By locating and repairing the leak, which had been seeping water for an estimated year, DWU averted a potential catastrophic crisis and saved the utility at least 893,000 gallons of lost water per year, equivalent to filling 1353 Olympic-sized swimming pools.

Olympic-sized swimming pool

Large leak discovery saved DWU at least 893,000 gallons of lost water annually, equivalent to filling 1353 Olympic-sized pools.

Sahara and SmartBall inspections in Dallas have been extremely successful, locating 160 leaks in 209 miles. The estimated water savings from these leaks is about 4 MGD. For DWU, the reduction in failures has reduced loss claims and service interruptions, as well as reduced treatment and delivery costs.

Whatever the weather, DWU is moving forward.

The Usutu Water Scheme supplies raw water to a number of coal-fired power stations and towns in the Mpumalanga province of South Africa. The bulk water pipeline, completed in the late 1970s, consists of large diameter (DN1300 mm) pre-stressed concrete non-cylinder pipe (PCP) that links two mains for a total of 90 kilometers between the Rietspruit, Davel and Kriel Reservoirs.

Recognizing that the infrastructure might be reaching the end of its lifespan, the Department of Water and Sanitation (DWS) called on SSIS Pipeline Services, which represents Pure Technologies in South Africa, to conduct a comprehensive condition assessment of the pipelines.

Destructing the old to help evaluate the current pipe state

Due to a lack of records, DWS provided Pure with old removed pipes, as well as spare pipes that were destructively evaluated to determine the design specs and calibrate the electromagnetic signal to accurately detect wire breaks.

Every pipeline is unique, and if a utility has a strong understanding of the operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed, pipe by pipe. Pure came onboard bringing its inspection, risk assessment and engineering analysis services, along with its comprehensive suite of technologies to survey the pipeline for leaks, gas pockets and wire breaks.

Civil Engineering Cover June 2015

Pipediver Field crew operators insert the PipeDiver inspection tool into the pipeline.

Field crew operators insert the PipeDiver inspection tool

Pipediver Field crew operators insert the PipeDiver inspection tool into the pipeline.

Ostrich

Project begins with leak detection surveys

For DWS, Pure and SSIS began with leak and air pocket detection surveys, employing Pure’s proprietary SmartBall™ technology. As the free-swimming SmartBall tool rolls through the pipeline, it collects acoustic data. The acoustic sensor identifies the sound of water leaving the pipeline, or the sound of trapped air at the top of the pipeline, which can reduce the water flow and increase strain on the pumps.

Easy to deploy, the SmartBall tool is an excellent screening tool for PCP inspection programs by identifying leaks and air pockets in the main. These areas provide a preliminary look at the condition of the pipeline.

As a follow-up to the SmartBall survey, SSIS employed its Sahara® platform, a tethered tool with attached audio-video surveys to gain a better understanding of the leak locations along the pipeline. A total of ten leaks were detected and accurately located using SmartBall and Sahara.

PipeDiver™ electromagnetic survey evaluates the pre-stressing wires

Because the Usutu pipelines could not be taken out of service, crews inserted Pure’s revolutionary PipeDiver™ tool, which features collapsible fins that allows it to pass through sharp bends, diameter reductions and butterfly valves as it is carried by the flow of water.

The free-swimming PipeDiver inspection platform uses electromagnetic (EM) sensors to evaluate the existing condition of the pre-stressing wires. EM inspections collect a magnetic signature for each pipe section to identify anomalies that indicate zones of wire break damage. The presence of wire breaks in concrete pressure pipe is often a sign of impending failure. This inspection method is the best available technology to determine the baseline condition of the PCP mains.

While the PipeDiver survey was performed, the critical pipeline remained in operation. The entire 90 kilometers of pipeline was inspected in three runs, and the inspections found the majority of pipes to be in good condition.

Investigation replaces uncertainty with peace-of-mind risk assessment

In addition to using to the monitoring technologies described above, Pure also conducted a variety of other risk assessment and engineering analysis services for the project.

This included field verification data to compile a calibrated hydraulic model to mime the steady state and transient behaviour of the pipelines. The results showed that DWS’s current operating procedures worked well to control the flow and prevent pressure surges.

Pure Technologies also completed a finite element analysis (FEA) to quantify the structural ramifications of the broken pre-stressing wires detected by electromagnetic inspection. This analysis was used in tandem with the electromagnetic inspection results in the risk assessment.

DWS sets a good example for managing its transmission main assets

The project highlights the value of embracing a proactive pipeline condition assessment programme using best practices, expertise, and cutting-edge technology.

The investigation confirmed the asset life can be extended, while managing DWS’s exposure to risk and sets a good example for other South African utilities to follow in developing a sustainable long-term strategy for managing their asset

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A ruptured sewer pipe can attract a lot of unwanted attention, even when it happens on private property. Last year, hours before celebrities were to arrive at the Golden Globes Awards show at the Beverley Hills Hotel, a reputed sewer pipe burst, spewing a mess of wastewater on the red carpet, according to media reports. When large pipes fail, it’s usually breaking news. And when the failed pipeline is part of a pressurized wastewater force main network, repercussions to the environment and the public have the potential to be catastrophic, with fallout to a utility’s reputation. In Canada, pressurized force mains that carry sewage make up only about 7.5 percent of the typical wastewater system compared to gravity mains. Because sewer force mains tend to run constantly, and often operate without redundancy, there is little opportunity to assess the pipes. When problems arise, and a critical force main is out of commission, the entire wastewater system can stop, causing overflows or the need to implement costly bypass pumping. Worse still, pollution generated by a raw sewage leak can flood to the surface and into a watercourse. Clean-up costs can be staggering and environmental impacts can be devastating.

PureRobotics device

The PureRobotics platform can assess the structural integrity of force mains and provide inline video to observe internal pipe conditions.

Force mains have unique signs of impending failure

Internally, force mains have unique warning signs of failure. Because of the sewage flow, trapped gas pockets can allow concentrations of hydrogen sulfide gas to be released from solution and subsequently convert to sulfuric acid by bacteria on the pipe wall, leading to corrosion of the pipe wall. As the pipe wall corrodes internally, it becomes weaker and more likely to fail unexpectedly. While corrosion and defect failures on sewer pipelines are a fact of life for wastewater utilities, these failures do not occur systemically. As a result, knowing when to replace and when to preserve assets through close inspection is more critical than ever.

SmartBall with extraction tool and controls

Managing force mains proactively can help utilities prevent environmental regulation violations that are expensive to mitigate.

Addressing the high consequence of failure in wastewater pipes

Aging pipes, increasing costs of failures and high replacement costs represent significant challenges facing force main owners. As a result, utilities have come to rely on Pure Technologies for its suite of technologies that can identify the weak links. Selective rehabilitation of force mains maximizes the life of the asset, typically at 10-15 percent of replacement costs. Pure’s strategy employs a risk-management approach that looks at likelihood of failure (LOF) and consequence of failure (COF). LOF variables are related to the chance that a pipe could fail, and include: pipe age, material, operating conditions and soil conditions, among other things. COF variables may include the pipe size, its location, environmental and social consequences of a rupture, interruption to service and tarnished public reputations.

Low risk assessment

For low risk force mains, screening and desktop evaluations such as hydraulic analysis and pressure management within the system are often enough to manage the assets. As risk goes up, however, utilities should look at higher resolution technologies that offer more confidence for higher predictability.

Medium resolution assessment

The SmartBall® Pipe Wall Assessment (PWA) tool is Pure’s best technology for identifying leaks, gas pockets and wall stress locations in metallic sewer force mains. PWA technology looks at pipeline walls affected by loading and bedding conditions, as well as other factors that cause stress on the pipe, including structural damage caused by internal or external corrosion. As the free-swimming SmartBall tool rolls through the pipeline, it collects both acoustic and electromagnetic (EM) data. The acoustic sensor is used to identify the sound of wastewater leaving the pipeline, or more often, the sound of trapped gas at the top of the pipeline. Trapped gas within a force main may lead to internal corrosion and eventual breakdown of the pipe wall which is the primary cause of force main failures. In addition to the acoustic data, the SmartBall platform also collects EM data to identify areas of the pipe wall that are under stress. Areas of the pipe wall with damage will be under more stress than areas with limited or no damage. Stress on the pipe wall can also be caused by other factors such as excessive loading and hard bedding surrounding the pipe. Recent developments in SmartBall technology now allow for the combination of leak and gas pocket surveys with PWA surveys in a single deployment, providing a complete screening tool for force mains. Based on initial surveys using the SmartBall PWA tool, areas where gas pockets overlap with stress anomalies represent the largest area of concern of force main owners, as it indicates a high likelihood of corrosion.

High resolution assessment

In force mains with a higher risk, utilities should also consider assessment with a higher resolution tool in addition to a pre-screening survey that detects anomalous changes. For lines that cannot be taken out of service, Pure can deploy the PipeDiver tool, which uses electromagnetic sensors to detect areas of damage along the pipeline. The inline inspection system is an innovative, free-swimming condition assessment platform specially designed for in-service inspection of pressure pipelines. Configured with PureEM™ sensor arrays, the tool can be used with precision to identify wire breaks in PCCP and broad areas of cylinder corrosion in metallic pipe.

No one solution for every pipe or pipeline

While there is no silver bullet for assessing every pipeline, if a utility has a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows force main owners to develop a sustainable long-term strategy for managing their critical force main assets.

This notion came to life in a North American survey conducted in 2014 and published online this year in The American Water Works Association Journal on current sustainable infrastructure practices among water and wastewater utilities.

Authored by associate professor Amy Landis, the survey found that of the 125 American utilities that responded, less than half “failed to implement some form of sustainability practice, which ranged from renewable energy to infrastructure repair to demand management. Of the respondents, only 18 percent of utilities reported publishing a sustainability policy or vision.”

Surprising results in spite of critical importance

The results are rather surprising, considering that sustainable water infrastructure is critical to providing the American public with clean and safe water. The American Society of Civil Engineers (ASCE) gives drinking water and wastewater infrastructure a “D” grade, which puts the infrastructure in “poor and at risk” with most of the assets approaching end of service life, some reaching the age of 100 years old or more.

For combined water and wastewater utilities, the most common selected metric to evaluate sustainability practice was “water consumption and/or water delivery efficiency” at 63 percent. Coming in second for sustainable infrastructure practice was “employ trenchless pipe repair and/or rehabilitation.”

Old main

Buried assets are approaching end of service life, some reaching the age of 100 years old or more.

Helping water utilities embrace sustainability

The good news is that it is easier today for public water utilities to move forward on the path to social, environmental, and economic sustainability. Modern inline technologies and precise data analysis tools certainly help the effort.

For more than a decade, Pure Technologies has played a key role in helping progressive utilities follow through with actions to promote sustainable practices for their water and wastewater infrastructure.

Sustainable practices include helping pipeline owners optimize capital and remaining useful life as they seek to more efficiently manage their assets.

As a trusted global leader specializing in the assessment, monitoring and management of pressurized pipelines, Pure has completed structural condition assessment on more than 8,000 miles of critical water mains. This has helped utilities avoid critical pipeline failures that can be expensive to remediate and damaging to their reputation. In addition, Pure has located more than 4,000 leaks on mains using inline leak detection. Through these activities, billions of gallons have water have been saved through repaired leaks and avoided pipe failures.

Pipe Surface Inspection

By understanding the operational conditions in their system, utilities can develop a defensible plan for managing their infrastructure.

Capital savings can be invested back into the system

The numbers continue to impress. Based on Pure’s condition assessment data, we have found that 96 percent of pipe sections do not have any deterioration at all and are in “like new” condition, while less than 1 percent of pipe sections require immediate repair. This is comforting information to utilities with aging pipelines still in operation, as is the case with the remarkable cast iron water main buried in 1831 beneath what is now Greenwich Village.

By identifying and repairing isolated sections that require intervention followed by a long-term management strategy, a utility can realize major capital program savings over replacement or large-scale rehabilitation. On average, a utility owner can proactively manage a pipeline for 5 to 15 percent of the capital replacement cost. The money saved can be invested to fix and sustain other parts of the system.

The U.S. EPA and ASCE estimate the funding costs associated with buried infrastructure ranges from more than $200 billion to 1 trillion over the next 25 years. The numbers are staggering. Pure Technologies is helping utilities manage their buried infrastructure through its Assess and Address™ approach to pipeline management, and as result, has saved clients hundreds of millions of dollars in replacement costs.

Public pressure to do the right thing

With drought, climate change and water conservation now part of the daily conversation, the pressure is on for public utilities to incorporate sustainable practices into their planning. It’s the right thing to do, from an economic, environment and social standpoint.

By having a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows utilities to develop a sustainable long-term strategy for managing their infrastructure well into the next century.

Metallic pipes have a long history in distribution systems throughout North America, with cast iron and carbon steel making their debut in the early 1800s. In many states, pipelines deploying the early metal are still in service, including the cast iron water main buried in 1831 beneath what is now Greenwich Village.

Risk prioritization as a starting point

Before undertaking any metallic pipe inspection, a utility should first complete a risk prioritization of all their buried assets, factoring in a variety of consequence of failure (COF) and likelihood of failure (LOF) variables to determine the highest/lowest risk pipelines. A distribution pipe buried in a cornfield probably has a lower risk profile than a water main buried under a children’s hospital.

This first step in risk analysis is critical, and can help determine a prioritized strategy. The higher the risk, the more an operator requires reliable information for an action plan to replace, rehabilitate or inspect the pipes further to gather more precise data.

Using asset risk to guide the management strategies, an operator can feel confident about implementing the right approach, at the right time, with the lowest financial impact. Overall, this strategy ensures long-term service, reliability and safe operation.

Match the technology and inspection method with the risk

This initial process also allows operators to choose the most appropriate inspection method based on different pipe material and operational requirements, including lack of redundancy.

If the analysis ranks the mains as medium to high-risk pipes, it makes sense to utilize medium to high-resolution inspection technologies. High risk pipes are probably more expensive and more difficult to replace, and probably affect more people if taken out of service.

 

Medium Resolution Technology

Pipeline Inspection and Condition Assessment Services

PureEM™

PureEM technology represents a form of non-destructive testing that provides a snapshot of the pipeline`s condition by inducing electric currents/magnetic fields within the pipe to measure an electromagnetic response. By creating these fields, PureEM data identifies specific areas of the pipe wall with large EM anomalies. In the case of metallic pipes, these anomalies typically represent broad areas of corrosion.

Typically, metallic pipes are first assessed with a prescreening tool – including inline leak detection and pipe wall assessment – followed by PureEM testing, using one of three platform tools. This multi-tool approach provides the operator with a variety of condition information that can help inform renewal decisions.

With PureEM manned inspection tools, field technicians have the option enter the pipeline with a PureEM inspection tool (e.g. push cart, bicycle) and traverse the length of the pipeline, inspecting for damage. The tool can be used in dewatered water and wastewater pipelines.

Free-Swimming Pipeline Inspection

PipeDiver®

When configured with PureEM, the free-swimming PipeDiver tool is an effective medium resolution tool to assess areas of damage along a pipeline that is live or can’t be taken out of service due to a lack of redundancy or operational constraints. It is ideal for metallic pipes with a higher consequence of failure, since the tool operates while the pipeline remains in service.

PureRobotics™ – Pipeline Inspection

PureRobotics™

Pure`s long range, multi-sensor robotic inspection vehicles are capable of conducting PureEM inspections on steel and ductile iron pipes. The robotic vehicle can be used in depressurized and partially dewatered and wastewater pipelines.

No one solution for every pipeline

Every pipeline has a unique set of conditions, which is why there is no one silver bullet that works across the board.

However, if a utility has a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows operators to develop a sustainable long-term strategy for managing their critical buried assets.

To combat drought conditions, lawn care companies have come up with creative ways to maintain their business.

Change is in the air. One only needs to check the daily news to understand why climate change, drought and water infrastructure have become frequent buzzwords heard around the water cooler.

For residents of states that stretch from the Pacific Coast to across the southwestern United States, the summer of 2015 may go down in history as one of the driest seasons on record, with widespread restrictions on water usage.

This past spring California Governor Jerry Brown proclaimed mandatory water cutbacks for all residents. Calling this “perhaps the worst drought California has ever seen since records began being kept about 100 years ago,” the Governor ordered cities and towns to cut usage by as much as 36 percent.

With the stroke of a pen, the simple act of washing your car, watering your lawn or taking a shower instead of a bath has become a conscious decision. The repercussions of water restrictions are even changing kitchen habits for cooks, restaurants and food producers, and across the nation many water-thirsty crops are forcing consumers to pay higher prices at the grocery store.

Water supplies and delivery systems threatened

Population growth, drought and severe climate changes have resulted in declining reservoir and aquifer levels, threatening water supplies and delivery systems. The water level in Lake Mead, the largest drinking-water reservoir in the United States, has dropped so much that the city of Las Vegas agreed to spend US$800,000 to build a deeper 3-mile long intake pipe to address the problem for residents and visitors.

“We have to think differently,” said Michael Connor, the deputy secretary of the Interior Department. “It’s not enough just to conserve water. We have a lot of infrastructure, but a lot of it doesn’t work very well anymore. We need to undertake what amounts to a giant re-plumbing project across the West.”

Daunting challenges demand innovative solutions

Although there are no simple solutions, the crisis has given us ample opportunity to reconsider how we use water and what we can do to conserve, reuse and repair. And while proactive water conservation is a smart way for consumers to react, the crisis puts increased pressure on water utilities to better manage their resources and pipeline networks.

One of the biggest drivers for utilities is finding ways to reduce the loss of water from leaky pipes. According to the American Water Works Association, that loss can range between 14 to 18 percent, nationwide. When a state like California distributes an estimated 38 billion gallons a day, the savings potential is immense, from both a financial and resource standpoint.

 Pure Technologies works with water utilities to help manage their resources and pipeline networks

Cutting edge leak detection technologies help preserve water

Pure Technologies, a world leader in infrastructure management, has been helping utilities and water authorities manage the life cycle of their pipeline assets for more than a decade.

To date Pure has assessed, analyzed and monitored more than 8,700 miles of pressurized pipeline, everything from distribution and transmission mains  delivering drinking water to wastewater pipelines carrying raw sewage.

Through our technical platforms and engineering services, Pure’s condition assessment technologies have helped clients prevent more than 2,300 failures worldwide, resulting in billions of dollars in savings, not to mention hundreds of billions of gallons in water savings. Pure has also located more than 4,000 leaks on water mains using our leak detection technologies.

Not surprising, the real job is just beginning, as society becomes acutely more aware of water issues.

You can’t manage what you don’t measure

Globally, utilities have come to value Pure’s expertise in helping them to sustainably manage their water networks using inspection as the cornerstone to understanding what needs to be addressed.

Getting a firm handle on water loss means taking a holistic approach. Utilities can effectively reduce their real water losses by completing regular leak detection in their distribution network using traditional leak detection tools, like correlators, combined with a transmission main leak detection program using inline tools that can accurately locate high-loss leaks.

Service providers such as Wachs Water Services can also reduce water loss through a valve management program, which improves valve condition and location information for field staff. An effective valve program allows a utility to reduce their response time – and the associated water loss – when a pipe failure does occur.

Regular condition assessment of water mains can also identify pipes that are at risk of failure, and can effectively reduce failures that result in large water losses.

All this operational efficiency is going over well with stakeholders and a more informed public that appreciates sustainable efforts and has embraced singing shorter songs in the shower.

Water and sewer utilities across North America are facing a major funding gap related to their buried pipeline infrastructure. Based on current estimates, utilities do not have enough capital available to fix or replace their aging assets. In addition to the funding gap, utilities are under scrutiny because of increased incidences of pipeline failures that are disruptive to communities and expensive to mitigate.

This new reality has forced utilities to squeeze more remaining life out of existing assets, creating more demand for condition assessment programs that allow utilities to identify specific areas of damage and selectively repair pipelines in favor of full replacement.

Historically, condition assessment has been in the realm of a few specialized firms that respond to high profile pipeline failures; however, the industry has changed and condition assessment is becoming widely used and trusted. This approach has been adopted by many utilities that have successfully managed risk and extended the life of assets for a fraction of the cost of a replacement program.

According to a study by Pure Technologies, the majority of pipelines 16 inches and above can be cost-effectively managed for between 5 and 15 percent of the replacement cost. The study found that pipeline damage is typically not systematic across an entire pipeline, but is usually localized due to factors such as design, manufacturing, installation, environmental, operational or maintenance factors.

Equipped with this information, utilities can be assured that assessing the majority of their mains before replacement can reduce their infrastructure gap and extend the useful life of assets.

However, one question that often gets asked about condition assessment programs is how a utility should choose the right condition assessment solution.

The easiest way to solve this challenge is to employ a risk-based approach to condition assessment using a variety of tools that offer different resolutions.

Staff inserting tools

Defining Risk and Pipeline Priorities

Risk is a measure of the probability and consequence of uncertain future events, in this case, potential pipeline failure. A basic approach can be used to define risk even in complex systems; simply, risk is a product of Consequence of Failure and Likelihood of Failure (CoF x LoF).

Consequence of Failure (COF) refers to the damage a failure would cause based on factors like its location, the amount of users it supplies, and its size and operating pressure. Likelihood of Failure (LOF) refers to the probability of a failure occurring based on factors such as age, pipe material, soil conditions, operating pressure, failure history, among others.

Generally, the Consequence of Failure is well defined by the potential damage a pipeline failure would impose on the surrounding environment and is generally fairly static – or – once defined, it is unlikely going to change rapidly.

With this in mind the key to managing risk, or the possibility that a pipeline could fail, is in understanding the Likelihood of Failure. This can be achieved by quantifying the physical condition of the pipeline and understanding and quantifying the factors that affect the potential for deterioration of the assets.

Once risk is defined, the pipeline inventory can be prioritized which helps in the selection of condition assessment approaches and the application of the appropriate technologies. In general, high-risk pipelines warrant a detailed assessment while low risk pipelines can use lower resolution alternatives.

Using Risk to Select Condition Assessment Techniques

When selecting condition assessment techniques, qualifications and technical judgment should be used in lieu of price. High resolution tools come with a higher cost, but saving money on a low resolution condition assessment is not a responsible alternative for a high-risk main.

For example, the savings gained by selecting a low resolution technology for a large-diameter pipeline with a high CoF are often miniscule in comparison to the repair and capital programming decisions that result from the low resolution condition assessment data. If the data is inconclusive or inaccurate, a utility may unnecessarily invest millions in a capital replacement program that was not required, easily eliminating the savings achieved by selecting the less expensive condition assessment option.

Tech monitoring results

Additionally, the cost of a failure should be considered when selecting a lower-cost assessment for a critical pipeline. The average cost of a large-diameter pipe failure is between US $500,000 and $1.5 million; money saved on lower-resolution assessments can easily be negated by the cost of mitigating a single failure and the resulting reputational damage.

One method of selecting a technology is to compare uncertainty to risk. As mentioned earlier, risk is a measure of the probability and consequence of uncertain future events. When dealing with a high-risk asset, it is important that the solution allows the utility manager to minimize the uncertainty of the condition assessment. More importantly, it is crucial that the utility manager knows the condition of the asset to the best extent possible, particularly in areas where there is a high Consequence of Failure.

Pure Technologies has a suite of condition assessment tools with different resolutions. Our low resolution solutions can provide basic condition data on leaks, air pockets and areas of pipe wall stress that could represent damage. This is a valuable prescreening option for high-risk mains, or alternatively for lower risk mains, can be enough detail for a utility to manage the asset.

Pure’s medium and high resolution tools provide more comprehensive data for higher risk pipe. Our high resolution tools can provide detailed accuracy, for example, locating small pits on metallic pipe. The data collected from both medium and high resolution tools is often used by utilities to create rehabilitation plans for critical mains.

Regardless of the solution provider, it is important that utilities employ a balanced, risk-based approach to condition assessment that uses appropriate tools. The most important factor a utility owner can remember is that there is no silver bullet to assess an entire system.

Small leaks sink big ships – the same can be said for large-diameter pipes in utility networks. While large leaks or ruptures are seen as newsworthy stories accompanied by images of water flowing down the streets; smaller leaks can often be more devastating. Left undetected, they can add up over time, contributing significantly to Non-Revenue Water, and eventually, they too can lead to catastrophic pipeline failures.

Many utilities focus leak detection efforts on locating and repairing large leaks, with less priority being placed on identifying smaller ones. While repairing these large leaks is integral to preventing major failures that are expensive to the utility and disruptive to the surrounding environment; finding and repairing small leaks may present the best opportunity for long-term reduction of NRW loss.

Non-Revenue Water loss in the United States is estimated to be between 14 and 16 percent on average, while some systems are suspected to have revenue loss of up to 40 percent. In developing countries this number is much higher, with NRW loss as high as 65 percent in some areas.

The Benefits of Finding Small Leaks

Identifying and repairing small leaks early in their life may be the best course of action to address the problem of future water loss. Catching a leak while it is small prevents decades of sustained water loss that may not otherwise be detected. Over the years, unreported water loss could mean significant financial loss for the utility. Additionally, utilities that fail to proactively find and fix unreported water main leaks allow a growing backlog of new leaks to occur slowly over time. The result is mounting water loss volumes and “hot spots” in some locations; as a number of small leaks can ultimately lead to a major pipeline failure.

Acoustic leak detection sensors have been developed to run through in-service water trunk mains, bringing the sensor to the leak sound, rather than relying on the leak sound to find the sensor. Inline surveys work exceptionally well on large-diameter water transmission trunk mains, which are often poor at transmitting leak sounds and have limited access points to the pipe.

Inline Leak Detection Case Studies

Inline leak detection services have been proven to reliably identify very small leaks on water trunk mains with pinpoint precision, without requiring the water main to be taken out of service.

Engineering staff from Metropolitana Milanese in Milan were able to reduce their water loss and renew the condition of one of their critical mains by conducting proactive inline leak detection using Pure Technologies’ SmartBall® inline leak detection tool. They found a concentration of eight small leaks in a 240 meter section of pipe, exposing a weak area of pipe that could eventually lead to a critical failure. Metropolitana Milanese was then able to take proactive measures to defend against major ruptures.

SmartBall with case and insertion tools

The SmartBall tool is a free swimming leak detection technology that follows the product flow of the pipeline, picking up acoustic anomalies that identify and locate very small leaks and gas pockets. Because it has very little operational noise, the sizes of the detected leaks are minute. In optimal operational conditions leaks as small as 0.028 gal/min have been detected.

With the ability to detect even smaller leaks at 0.005 gal/min (in optimal conditions), Pure Technologies’ Sahara leak detection platform is another tool that can be deployed. Because it is a tethered system that is operator controlled, it is also able to map the location of the leak within 0.5 meters (3 feet). The Sahara tool simultaneously provides real-time visual inspection of live pipeline conditions thanks to an inline video system that travels along the pipe with the acoustic sensor.

Carried out regularly, comprehensive leak detection programs can not only identify large, potentially catastrophic leaks, but also smaller leaks that over time contribute to NRW and eventually become damaging themselves.

To solve the mystery behind Non-Revenue Water (NRW), utilities need to play detective and think like a modern day Sherlock Holmes. Pipeline operators can look for clues using deduction, engineering forensics and the latest leak detection tools designed to help find the real and apparent sources of water loss in their water networks. Real losses refer to water lost from leaks and main failures, while apparent losses come from theft and metering inaccuracies.

Problems arise because NRW often goes unnoticed until a leak surfaces or a catastrophic failure happens. Sherlock Holmes might conclude his case with “death by a thousand small cuts,” while utilities might conclude their investigation with the loss owing to “a thousand small leaks.”

Every day, billions of gallons of water are lost worldwide due to factors including leaks, water main failures, theft and metering inaccuracies. Not only does this represent a waste of this critical resource that many people cannot reliably access, but it also represents a huge loss of revenue and energy required to pump and treat the water. To that, add a loss of confidence in the utility, especially with disgruntled ratepayers asking why their water bills are so high.

Worldwide, the NRW cost to utilities is staggering

The NRW loss boggles the mind. The World Bank estimates that NRW costs utilities worldwide about US$14 billion annually. By reducing these losses by half in areas with the highest NRW, the World Bank estimates that US$2.9 billion cash would be generated, giving an additional 90 million people access to treated water.

While the NRW rate in the United States is estimated by the United States Environmental Protection Agency (EPA) in the range of 10 to 40 percent, the water loss rate in developing countries can be as high as 60 percent – owing to fewer resources available to put against water loss management programs.

Clearly, focusing leak and theft detection system-wide is the first step in a NRW-reduction strategy to mitigate problems and improve pipeline reliability.

Globally, Pure Technologies is regarded as a highly reputable service provider with the experience, expertise and technology services designed to help manage NRW projects for both small and large utilities.

Over the course of investigating more than 3,200 kilometers (2,000 miles) of pipeline, Pure’s inline leak detection services have effectively found an average of 3.5 leaks per kilometer (2.2 leaks per mile) in large-diameter water trunk mains.

Pure helps K-Water develop its leak detection program in South Korea

Pure has developed a successful NRW leak detection program with K-water, the national bulk water utility in South Korea that supplies water across the country.

Through its water system, K-Water controls everything from collection, treatment and pumping to maintenance, inspection and rehabilitation of the nation-wide pipeline system. The pipes in these critical bulk trunk mains are primarily large-diameter, and supply water to many of the smaller cities across South Korea.

In addition to supplying treated water to these small cities, many municipalities have contracted K-water to manage and maintain their water systems as they battle the challenges of ageing infrastructure buried in often mountainous terrain.

While K-water’s critical trunk mains have a very low NRW rate, usually around 2 percent, many of its clients suffer from high rates of NRW as their aging pipeline infrastructure begins to leak.

Sahara® tethered pipeline inspection system to the rescue

To address leaks and ageing systems, K-water adopted Pure’s advanced Sahara® technology, a tethered system that combines acoustic leak detection and inline video. While many utilities around the world use this tool for large-diameter leak detection, K-water instead chose to use it as a complete condition assessment tool to provide information on its pipelines as well as the accurate location of leaks.

K-water’s expert internal engineering group utilizes the Sahara video feature to assess the condition of its steel pipes by identifying defects on the pipe wall and joints.

By using this inline detection tool, K-water has been very successful in reducing water loss, saving millions of gallons of water annually.

As the K-water example points out, carrying out regular, comprehensive leak detection programs can help utilities significantly reduce water loss. Not only do these initiatives save money and improve pipeline reliability, the programs also contribute to utility confidence in promoting long term sustainable water use.

Though not quite as old as Rome’s ancient aqueduct system, the water and wastewater infrastructure operated by many North American utilities might, to some observers, appear just as antiquated.

For many pipeline operators, failures on pipelines installed decades ago are increasing in frequency, and as large-diameter pipeline assets begin to fail more frequently, the results can be more severe. This ongoing problem leaves utilities between a rock and hard place on whether to maintain or replace their assets.

Pipeline operators might do as the astute Romans did – take a step-by-step proactive approach to manage their transmission systems, enhanced today with the help of modern inline technologies.

The U.S. Environmental Protection Agency and American Society of Civil Engineers estimate the funding costs associated with buried infrastructure ranges from more than $200 billion to $1 trillion over the next 25 years. Pure Technologies is helping utilities manage their buried infrastructure through its Assess and Address® approach to pipeline management. This approach has saved clients hundreds of millions of dollars in capital replacement costs.

Assess and Address the System for Potential Problems

Conventional pipeline management allowed a pipeline to fail multiple times before replacement. While this “three strikes and you’re out” approach may work well for small-diameter distribution pipelines, it isn’t a cost-effective solution for large-diameter pipelines, especially those built without redundancy and without practical options to shut down.

A capital replacement program for large-diameter pressure pipelines not only carries a high price, but also poses significant logistical challenges, especially in urban centers. The headaches get bigger if a section of problematic pipeline runs through the downtown core and is the main source of water for a hospital or office tower.

Through the assessment of more than 8,000 miles of large-diameter pipelines, it is clear that even problematic transmission mains can be managed. In fact, Pure has found that 96 percent of pipe sections do not have any deterioration at all and are in “like new” condition, while less than 1 percent of pipe sections require immediate repair.

Better Understanding Ensures Fewer Surprises

In order to effectively manage a pipeline system, utility operators must first understand their pipeline system. Since many systems were built decades ago, the drawings are often out of date, as features have been added or removed over the years. By completing the knowledge-gathering process before attempting inspections or repairs, utility operators can avoid surprises and create a streamlined pipeline management effort.

By working with a firm that specializes in condition assessment, utility operators can gain a better understanding of their network, and create a prioritized plan for inspection or renewal.

As an example of smart collaboration, Pure Technologies has partnered with Washington Suburban Sanitary Commission (WSSC) in a multi-year program to manage approximately 145 miles of prestressed concrete cylinder pipe (PCCP) water transmission mains that serve nearly 2 million customers outside of Washington, DC. By adopting the Assess and Address model, WSSC has been able to evaluate and actively monitor the condition of its PCCP inventory instead of completing an expensive capital replacement project. To date, over 70 miles of PCCP is being safely managed for approximately 6 percent of the capital replacement cost, saving WSSC nearly $2 billion, which was the estimated capital cost of replacing the assets entirely.

Pure’s fundamental approach to pipeline management programs is to maximize the life of the existing pipeline. Maintaining an existing pipeline though proactive repair and management is in the utility’s economic interest. Our approach identifies deteriorated pipe sections, allowing for isolated repairs that extend the life of a pipeline, rather than making broad recommendations to replace the entire pipeline with capital funds.

Based on the average annual capital spending of large water utilities, it would take decades to replace large-diameter assets entirely, without factoring in the need for other capital renewal projects. Not only is this expensive and time consuming, it is also logistically challenging and disruptive to replace large sections of pipeline.

The Assess and Address Approach Involves 4 Steps

To successfully implement a pipeline management program, utilities can generally follow four key steps:

  1. Understand – Review current pipeline data, complete a risk evaluation, and develop appropriately scaled condition assessment strategies for prioritized pipelines.
  2. Assess – Execute condition assessment using a variety of tools to collect data and evaluate the data to assign condition ratings. This step includes a report of findings and recommendations on how to manage the pipeline.
  3. Address – Problematic locations identified in the condition assessment can be renewed immediately or planned for future re-inspection.
  4. Manage – After rehabilitation, the risk of failure is lower and proactive management measures should be employed to maintain a low risk.

As a result of Pure’s pipeline management programs with clients that range from small towns to major cities, utilities have seen a significant per-mile reduction in costs, while obtaining technically superior data on the real condition of their most critical pipeline assets. With such impressive numbers, it’s something ancient Roman engineers would appreciate.

Many utilities across the United States are dealing with the challenges of aging water and sewer infrastructure, much of which was installed many decades ago. Despite their age, buried water and wastewater pipelines remain the most valuable asset a utility owns. In many cases, the value of buried pipelines represents two-thirds of the utilities total assets.

For water service providers, an increased number of leaks and pipe failures have resulted in negative public perception about the condition of water infrastructure. For wastewater utilities, force main failures are leading to more strict regulation and consent decrees mandating renewal of wastewater assets.

As these challenges become more prominent with the media and public, utilities are under more pressure to renew this infrastructure through rehabilitation or replacement programs.

Unfortunately, the vast majority of utilities do not have nearly enough capital budget to embark on major rehabilitation or replacement programs. This reality has created a major funding gap between what is needed to rehabilitate, replace and expand water and sewer infrastructure and what is actually possible. Some estimates of this gap are as high as US$1 trillion over the next 25 years.

Bridging the Infrastructure Financing Gap

Even if adequate funding were available, the rehabilitation or replacement of assets based on age alone would be irresponsible with so much value tied up in these assets. Utility operators should treat these assets as they would their vehicle. In the case of a car, the first instinct when there is a problem is not to replace the entire car. Instead, the car would be evaluated by a professional and repaired where needed. This often represents a small fraction of the cost of replacing the entire car, and can restore it to fully working condition.

Embarking on a pipeline management program follows the same mentality – assess the condition of the pipeline assets before replacing them entirely. This is supported by the fact that the U.S. Environmental Protection Agency estimates that 70 to 90 percent of pipe that is replaced has remaining useful life. By replacing pipelines without first determining their condition, utilities are likely replacing a large amount of pipe with remaining useful life. This is particularly important for large-diameter pipelines, since the cost of replacement can be upwards of US$2.5 million per mile of pipeline.

One of the most important aspects of a management program is using risk to make a plan. Depending on the size of the utility and system, there might be hundreds of miles of large-diameter pipeline. While assessing an entire system can seem daunting, it is not as daunting as replacing the entire system, and can be made a lot more manageable by using risk to prioritize the pipelines.

This process involves analyzing various factors such as but not limited to: redundancy, location, operating pressure and environmental factors to identify pipelines that carry a high risk if they were to fail. After completing this process, asset owners are equipped with a risk-based pipeline-by-pipeline list that can be used to develop yearly prioritized inspection plans; the most critical assets are assessed and renewed first, while low-risk assets are scheduled for a later stage in the program.

Examples of successful pipeline management

This approach has been employed for several utilities across the United States, many of which have managed and renewed their critical assets for between 5 and 15 percent of the replacement cost estimate, which has at times is in the billions of dollars.

One example of this is the Washington Suburban Sanitary Commission (WSSC), who manages roughly 145 miles of prestressed concrete cylinder pipe (PCCP) for 6 percent of the US$2 billion replacement cost. Since employing this approach, WSSC has drastically improved the reliability of its water network by avoiding large-diameter pipe failures. To see a full WSSC case study, click here.

The Miami-Dade Water and Sewer Department (WASD) has also successfully managed its large-diameter pipeline assets using a risk based approach. The majority of WASD’s large-diameter water and wastewater pipelines is made of PCCP. In total, WASD has more than 250 miles of PCCP 48-inches and larger that has been installed since 1949. In 2010, WASD began the Infrastructure Assessment and Replacement Program (IAARP) to renew its water and wastewater assets, including pipelines, treatment facilities and pumping stations.

As WASD inspects its PCCP assets each year, the typical number of segments showing any type of degradation has not exceeded 2.5 percent on average; less than 1 percent requires some sort of rehabilitative action with no parts of the system being immune to rehabilitation, regardless of their age or manufacturer. Considering that less than 1 percent of pipes require immediate action, a full replacement program would end up replacing pipelines that, for 99 percent of the system, have a significant remaining useful life. To read the full article about WASD’s program, click here.

In August 2011, Pure Technologies brought out the redesigned PureRobotics wastewater crawler unit to conduct an electromagnetic inspection on a 42-inch (1050mm) sewer force main for a major utility in Ontario, Canada. Pure was able to inspect 3,400 feet from a single access in both directions of the line. New improvements to the tracks assisted in pushing the crawler through the heavy debris at the bottom of the pipe that would otherwise entrap other robotic inspection systems.

Sewer pipes below a road

A critical component of Queensland Urban Utilities’ sewerage network is a series of large-diameter sewer rising mains – also known as force mains – which are responsible for transporting 50 per cent of raw sewage in the Brisbane area for treatment. The mains are made of mild steel cement-lined (MSCL) pipe and prestressed concrete pipe (PCP), of diameters ranging from 1295 to 1840 millimetres (52 to 74 inches). The reliability of these sewer rising mains are important from both a customer and environmental perspective.

Building upon previous assessments conducted by Pure Technologies’ Engineering Services, Queensland Urban Utilities sought to identify industry best practices for assessing these critical large-diameter rising mains. The goal of the assessment was to understand the current condition of the mains and identify what remedial works or condition monitoring approaches would help maintain the safe operation of the mains, while extending the life of the assets in accordance with management plans.

In consultation with Pure Technologies, a comprehensive assessment methodology was developed which included: SmartBall® leak and gas pocket detection; ground surveys to determine residual ground cover; isolation, dewatering and cleaning of the mains; CCTV and laser profiling to determine internal deterioration; valve inspections; PureEM™ inspection to determine structural deterioration of the pipe walls; internal visual inspection to confirm and further document findings; transient pressure monitoring to identify loading conditions; and an engineering assessment with rehabilitation recommendations.

PureNET Overhead

A customised EM tool was designed to assess the condition of QUU’s
steel pipe.

Field Data Collection

The inspection provided QUU with actionable information about their assets.

 

Related Topics

“Queensland Urban Utilities is keen to embrace new technologies to improve our customer service and the reliability of our water and sewerage network,” says Jonathan Farrell, Design Manager at QUU. “The technical expertise provided by Pure has allowed us to undertake an accurate condition assessment and have the appropriate data to make an informed decision on the current condition of the mains. This will allow us to plan cost-effective, timely upgrades to ensure the asset reaches its design life.”

This was a first-of-its-kind assessment in Australia applying new inspection technologies, including the customisation of a 48-detector PureEM tool, as well as a new risk assessment technique for metallic pipes. Detections from the PureEM inspection (i.e. discrete areas of structural deterioration) were validated utilising alternate electromagnetic and ultrasonic techniques, which provided supplemental condition information for the structural assessment.

Inspection and assessment work on two of these critical mains has been completed at this point. The inspection identified specific pipes along the mains with deterioration; but more importantly, the engineering assessment with structural modeling determined that less than 1 per cent of pipes are at a higher risk of failure, meaning the main is in primarily good shape. This data coupled with engineering recommendations is enabling Queensland Urban Utilities to make informed decisions on the mains, including: selective repair or replacement, condition monitoring, and operational changes (i.e. safe working pressure), all for a fraction of the capital replacement costs.

In addition, the work associated with the assessment has provided Queensland Urban Utilities with some valuable lessons learned on the safe management and operation of the mains.

 

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Cast Iron Pipes

Managing Metallic Pipelines

Pure offers a number of leading edge technology options for assessing the condition of ferrous water and wastewater mains.

Padre Dam Municipal Water District Assesses Steel Pipeline with Advanced Inline Technology

In November 2012, PDMWD wanted to assess the condition of a 1.2-mile (2-kilometer) stretch of 20-inch (500-mm) mortar-lined steel pipeline that was thought to be in poor condition and may need replacement. Before committing to the large capital project, PDMWD completed a non-destructive inline assessment.

Steel Pipes

Steel Pipe

In an article from the August 2013 Issue of Municipal Sewer and Water, the author explores how Baltimore City Public Works (BPW) is managing its again water system using Acoustic Fiber Optic Monitoring and free-flowing electromagnetic (EM) technology.

Across the United States, there are many thousands of water and wastewater utilities that serve populations less than 50,000. Although the majority of attention surrounding aging infrastructure focuses on the challenges of large utilities, these small utilities are often faced with greater challenges.

Smaller utilities often have fewer resources – both financial and personnel – devoted to managing their water and wastewater systems. At times, this can lead to the utility having  less information available about their system, such as pipe drawings, break and leak history and condition data.

Coupled with having fewer resources, small utilities often have primary mains that are non-redundant and represent the sole source of supply or collection for the population, making a leak, rupture or shutdown of any kind very disruptive.

The City of Tarpon Springs, FL serves a population slightly less than 25,000. With limited resources and a mandate to provide both reliable water supply and wastewater collection for its customers, the City decided to assess the condition of one of its primary 14-inch force mains that experienced a failure in summer 2013.

The Dixie Highway Force Main is made of 14-inch ductile iron pipe (DIP) and poly-vinyl chloride (PVC) pipe, which was installed after the failure. In summer 2014, the City decided to complete condition assessment on nearly 1 mile of the force main to identify specific areas of concern before investigating further replacement.

Since internal hydrogen sulfide corrosion is the primary cause of DIP force main failure – and was the cause in 2013 – an inline survey was completed to collect relevant condition data.

For the inspection, the City used the SmartBall® tool, which can locate leaks, gas pockets and pipe wall stress in metallic pipelines. Leaks or failures on wastewater pipelines can have a devastating effect on the environment and can lead to litigation and consent decrees. In addition, gas pockets in force mains are of significant concern as hydrogen sulfide gas within the wastewater can be converted to sulfuric acid by bacteria in the slime layer on the pipe wall, which may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Leaking Pipe

The SmartBall PWA tool is removed after the 1-mile inspection.

Sahara Insertion

Staff at Tarpon Springs Water were onsite during the inspection.

While inline leak and gas pocket assessment is a well-developed approach for force main operators, the development of pipe wall assessment (PWA) technology provides a more comprehensive level of condition information – areas of the pipe wall with damage will be under more stress than areas with limited or no damage.

By identifying stress anomalies, it provides operators with a detailed report of areas that warrant a more detailed assessment or testing.

The SmartBall assessment identified no leaks and nine gas pockets along the force main. Three of the gas pockets are located along the PVC section of pipe, indicating that gas pockets re-emerged in the PVC section of pipe in less than a year after replacement. It was recommended that air release valves be installed along the force main to clear gas pockets.

In addition, the PWA survey identified six areas that indicated stress within the pipe wall. One of the stress anomalies corresponds with a transition from buried pipe to exposed pipe, and therefore is caused by the change in load. The remaining five PWA anomalies do not correspond to any known features and could represent pipe degradation. The City during the insertion of the air release valves will be performing some field validation of these pipes.

By assessing the entire force main in advance of replacement, the City of Tarpon Springs is now able to make more informed decisions about its critical asset while avoiding the costly and mostly unnecessary strategy of replacement of the entire force main length. This mentality is an excellent example for other small utilities that are looking for ways to manage aging critical infrastructure, since replacing assets is very expensive within limited capital budgets.

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SmartBall Pipe Wall Assessment

Pipeline Leak Detection Systems

Highly accurate inline leak detection systems that can detect leaks and gas pockets in operational pipelines. These systems are used primarily on larger diameter water and wastewater transmission mains of all materials as well as oil & gas pipelines.

Frankfort Electric and Water Plant Board Verifies Distress on Ductile Iron Pipe Using Electromagnetics

In June 2013, FEWPB agreed to utilize an electromagnetic (EM) assessment technology on 700 feet of 1974 era DIP after the successful assessment of almost five miles of its prestressed concrete cylinder pipe (PCCP). The 700-foot section of 48-inch DIP runs directly from one of FEWPB’s water treatment plants and connects with the primary transmission main.

Ductile Iron Pipe

Ductile Iron Pipe (DIP)

Introduced into the U.S. marketplace in 1955, ductile iron pipe (DIP) is pressure pipe commonly used for potable water and sewage distribution. The predominant wall material is ductile iron, a spheroidized graphite cast iron, although an internal cement mortar lining usually serves to inhibit corrosion from the fluid being distributed, and various types of external coating are used to inhibit corrosion from the environment.

Abstract

Comprehensive condition assessment of wastewater force mains provides significant challenges to owners/operators of collection systems as the ability to shut down or expose the pipeline for a thorough inspection is often impractical due to operational and/or financial considerations. Traditional gravity sewer inspection techniques (i.e. visual-based technologies) do not always transfer easily to their wastewater pressure pipe counterparts and visual assessments do not provide the structural condition of force mains – something that is critical in determining the true pipe condition. Therefore, a different set of inspection tools and assessment techniques is required for force mains.

The most effective strategy to safely manage a force main inventory is to implement a risk-based approach for any data collection, inspection, condition assessment, and management techniques. Using asset risk to guide the management strategies, an owner/operator can ensure they are implementing the right approach, at the right time, with the lowest financial impact. While recent advances in force main inspection technologies, assessment techniques, and repair/rehabilitation methods now allow for substantial extension of existing asset service life, a risk-based approach to their implementation will ensure resources are focused on the correct pipelines. The goal should always be to focus the proper resources in managing the asset while safely getting the most service life out of the force main.

Authors

  • Travis B. Wagner, Pure Technologies Ltd., Columbia, MD, USA
  • Jennifer Steffens, Pure Technologies Ltd., Atlanta, GA, USA

Abstract

Bar-wrapped pipe (“BWP”) is commonly used in pressure pipelines due to its reliability, cost effectiveness and durability. Failure of BWP can occur as a result of long term leakage and subsequent corrosion or as a result of leakage and deterioration of the reinforcing bars over time. The failure can also be the direct result of a transient pressure or other sudden catastrophic events.

The consequence of failure may result in a significant disruption of operation and service for a water utility without any warning. This is a concern because assessing the condition of a damaged BWP is very challenging. In this paper, a nonlinear finite element analysis was used to evaluate the performance of a damaged BWP.

For the structural evaluation, stresses and strains developed in the damaged BWP were evaluated. Cracking and spalling of the mortar lining will eventually lead to the corrosion of the steel components. In an effort to account for the steel deterioration, the model was adjusted by reducing the thickness of the steel cylinder. This study investigates the behavior of a deteriorating BWP under various levels of distress and various internal pressures. The results based on a 24-inch pipe transmission main, are used to define criteria to evaluate the performance of a damaged BWP. Based upon the finite element results obtained in this study, suggestions for future work are presented and discussed.

Authors

  • Ali Alavinasab, Pure Technologies, Branchburg, NJ, USA.
  • Muthu Chandrasekaran, Pure Technologies, Columbia, MD, USA.
  • Edward Padewski III, Pure Technologies, Branchburg, NJ, USA.

For water service providers in Texas, providing customers with consistent, reliable access to water is crucial, particularly in the summer months when dry conditions impact the water supply.

In order to ensure that residents receive consistent water supply, the City of Irving and a partnering agency have collaborated in times of need to supply the other with water.

In one specific instance, the City of Irving was able to keep customers of the partnering agency supplied with water from one of its 48-inch transmission mains. The combined effort between the utilities showed excellent organizational cooperation to achieve the most important goal for any utility – finding a way to provide consistent service.

In January 2014, the two agencies teamed up again, this time to assess the critical 48-inch Jamison Main that links the two utilities. The transmission main was constructed in 1955 and is made up primarily of Bar-Wrapped Concrete Cylinder Pipe (BWP). Since its construction, however, the main has had modifications: in 1965 and 1968 sections of Prestressed Concrete Cylinder Pipe (PCCP) were added to accommodate the construction of Texas Stadium, and in 2009, another section of PCCP was added during the reconstruction of Loop 12 Highway.

The Difference Between PCCP and BWP

While BWP and PCCP look similar in cross-section, the pipe materials deteriorate in different ways and therefore are assessed differently.

For BWP, it is important for operators to identify and locate corrosion on the steel cylinder, since it is the main structural component and the bars are made with mild steel and are wrapped under less tension than PCCP; BWP essentially behaves like a mortar-lined and coated steel pipe.

PCCP is a concrete pipe that remains under compression because of the prestressing wires, with the thin-gauge steel cylinder acting as a water barrier. The high strength steel wire in PCCP is smaller in diameter and wrapped under higher tension, therefore corrosion makes it quite vulnerable to breakage.

Electromagnetic inspection tool

Electromagnetic inspection tool

Robotic tool insertion

Pure Technologies staff insert the robotic tool for assessment

As the prestressing wires in PCCP begin to break, the pipe becomes weaker and is more likely to fail catastrophically. It is important to locate and quantify the amount of broken wires in PCCP as they are the main structural component.

Because of the differences, the two materials are assessed using electromagnetic (EM) technology that identifies different signs of deterioration in each pipe.

In BWP, inspections identify both the presence of broken bars – which could indicate corrosion on the cylinder – and broad areas of corrosion on the cylinder itself. This approach allows operators to renew pipe sections with an undesirable amount of corrosion that could lead to pipe failure.

In PCCP, EM technology locates and quantifies the amount of broken wires. This method is extremely effective in identifying pipe sections that are suitable for renewal once the number of wire breaks passes a certain limit.

The Condition Assessment Program

For the Jamison Water Transmission Main assessment, the SmartBall® leak detection and PureRobotics® platforms were used to identify deterioration on both the primary pipe material, BWP, and the added sections of PCCP.

Completing a leak detection survey is an important aspect of a condition assessment project, since leaks are often a preliminary indication of a potential failure location. Pre-screening is particularly important in in BWP, since the steel cylinder is the main structural component and the pipe behaves similarly to a mortar-lined and coated steel pipe.

The leak detection survey identified one acoustic anomaly associated with a leak in 2.7 miles of inspection. The screening of the pipeline helps determine the baseline condition of the asset.

The PureRobotics platform was used for the structural assessment portion of the project. The tool is equipped with PureEM™ technology, which can identify distress on both pipe BWP and PCCP, but also features CCTV and above-ground tracking. By completing a structural assessment, damaged areas of the pipe can be targeted for selective renewal.

The Condition Assessment Program

In addition to gaining a valuable baseline condition of the transmission main, the assessment provided both utilities with more information about the location of additions to the critical transmission main.

The CCTV and line-locating feature were used to identify the exact location of two unknown manholes, which in turn were used as additional tracking locations. With more tracking locations during inline inspection, areas of distress can be more accurately located. The CCTV inspection also identified the location of a 48-inch gate valve and 90-degree bends.

Another challenge surrounding this main was accurate mapping of the sections that were added on after the original construction. Additions or alterations to existing pipelines can sometimes lead to inaccurate drawings. By tracking the tethered robotics tool above the ground using a manned sensor, Irving and its partnering agency were able to map out the relocated portions of the pipeline. This provides valuable information for future maintenance, assessment and renewal programs.

Through close collaboration, these two service providers were able to effectively manage a shared asset with the goal of preventing disruptive and expensive pipe failures. The information gained from the structural assessment will allow for the implementation of a cost-effective long-term pipeline management plan and effectively defer the replacement of the pipeline for the foreseeable future.

 

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Case Study

Case Study: Trinity River Authority of Texas

After completing leak detection and structural condition assessment on 8.5 miles of PCCP and Bar-Wrapped Pipe, Trinity River Authority verified the results of inspection, finding three distressed pipe sections.

Technical Paper

Failure Risk of Bar-Wrapped Pipe with Broken Bars and Corroded Cylinder

This study investigates the behavior of a deteriorating BWP under various levels of distress and various internal pressures. The results based on a 24-inch pipe transmission main, are used to define criteria to evaluate the performance of a damaged BWP. Based upon the finite element results obtained in this study, suggestions for future work are presented and discussed.

Abstract

The topics of liability and negligence as they relate to water main failures are discussed from both a historical and current viewpoint. The historical perspective is provided in a 1948 Journal AWWA article, and we consider changes in liability issues from that time to the present. Case studies from various states are also presented that will provide water utilities insights into sovereign immunity and what constitutes discretionary function.

Some of the key findings for water utilities were: that they should understand the laws and relevant legal decisions in their state because each state has its own laws related to how immunity is determined; that even immunity, in some states and or cases may not be the final determining factor that can relieve them from liability for breaks and leaks; that they should implement a written policy or plan to address deteriorating infrastructure; and that they should keep accurate and comprehensive records.

Authors

  • Frank J. Blaha, P.E., Senior Account Manager, Water Research Foundation
  • Peter E. Gaewski, P.E., Retired
  • Paul R. McCary, J.D., Partner, Murtha Cullina LLP
  • Graham T. Coates, J.D., Associate, Murtha Cullina LLP

To proactively address its large-diameter Prestressed Concrete Cylinder Pipe (PCCP) for deterioration, Tampa Bay Water (TBW) completed a leak and gas pocket survey and electromagnetic (EM) condition assessment of the South-Central Hillsborough Regional Wellfield Transmission Main in April 2013. The results of the assessment were verified in 2014 to determine the remaining useful life of the pipeline, which is responsible for delivering 10 percent of TBW’s 24 million gallons of raw water per day.

Based on the EM inspection, only 0.5 percent (11 of 2,177) of pipe sections contained varying levels of distress; subsequent structural and finite element analysis determined that only a fraction of the distressed pipes warranted further consideration. In addition to the structural assessment, the leak and gas pocket survey identified only one small leak.

The results show the critical transmission main is in excellent condition and can be safely managed despite being nearly 30-years-old. Some PCCP users throughout the United States have experienced major failures as their assets approach 40 years of operation.

TBW maintains a large pipeline network that serves the Tampa Bay and St. Petersburg metropolitan area and includes approximately 80 miles of PCCP. The pipeline inspections were completed on 8 miles of 42-, 48- and 54-inch PCCP that convey wellfield supply to the Lithia Water Treatment Facility.

For the leak and gas pocket survey, SmartBall® technology was used as a forerunner for the EM condition assessment and provided TBW with an initial condition of the pipeline.

Early identification and repair of leaks can reduce Non-Revenue Water (NRW), but also helps determine the baseline condition of a pipeline, since leaks can be an indication that a pipeline might fail. In addition, locating and eliminating gas pockets reduces pressure on the pumps that are attempting to push water past a pocket. As pockets grow in size, they can significantly affect the flow of water and capacity of the pipeline if not released.

After the prescreening survey, TBW completed an EM inspection using PipeDiver®, a free-flowing EM tool that is able to accurately locate and quantify broken wire wraps in PCCP. The wire wraps in PCCP act as the main structural component; broken wraps are the main indication that this type of pipe will eventually fail.

TBW’s asset management program allowed them to prioritize and take the first steps in determining the remaining useful life of a critical asset. This will lead to more informed decision-making for the future management of this main through reinspection, monitoring or renewal.

 

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Technical Paper

Beyond the Wires: A Sustainable Approach to Prestressed Concrete Cylinder Pipe Management

While evaluating wire breaks are an important part of PCCP management, it is important to acknowledge additional factors beyond wire breaks. By acknowledging additional condition factors, limitations of wire break assessment, and considering other rehabilitation approaches, there may be a more sustainable PCCP management approach (or combination of approaches).

Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Free-Swimming Pipeline Inspection

PipeDiver® – Free-Swimming Pipeline Inspection

Specifically designed for structural assessment of Prestressed Concrete Cylinder Pipe (PCCP) lines that are live or can’t be taken out of service due to a lack of redundancy or operational constraints.

Critical large-diameter water transmission mains frequently run beneath city streets in busy urban environments. Like the majority of water infrastructure across North America, these pipes are reaching the end of their design life. However, pipelines in urban environments pose a significantly greater risk and challenge to water utilities.

These pipelines are high-risk because of their high consequence of failure; if a pipe beneath a busy downtown street fails, the repair costs can quickly escalate and the failure causes a massive disruption to businesses and commuters. In some cases, failures in urban environments have cost utilities upwards of $5 million to remediate. A failure not only carries a high repair bill, but contributes to a negative public perception of the utility which can harm consumer confidence and lead to negative public relations.

With such high risk, utilities often prioritize these mains ahead of those with lower consequence of failure. However, because these mains are located in high-traffic areas, assessing them is far more challenging than assessing a linear main in a rural area.

Dealing with above ground obstructions, commuter delays and a lack of access points means that operators need to have close control over inspection technologies. In addition, the technology must provide the best possible information to allow for accurate repair and excavation decisions.

Like other major metropolitan areas, the City of Montréal has aging pipeline infrastructure that runs through its downtown core. In Montréal – one of the oldest cities in North America – this infrastructure is very old and beginning to reach the end of its design life. In order to proactively identify problem areas in its Prestressed Concrete Cylinder Pipe (PCCP) assets, the City is in the midst of an inspection program using advanced non-destructive technologies. In total, the City will assess the condition of over 40 kilometers of PCCP by 2015.

In the majority of cases, assessing the condition of assets to identify problem areas has high value for utilities, since the majority of pipelines have remaining useful life, despite their age. This allows for selective rehabilitation in favour of full-scale replacement. This is particularly important in urban areas, since excavation costs are higher and more disruptive in urban environments.

PureRobotics platform

The PureRobotics platform remains tethered to the surface during inspection. 

Pipe with damaged areas

Verification showed large areas of damage to both the prestressing wires and steel cylinder.

Related Topics

For a large portion of the condition assessment, the City is using the PureRobotics™ platform, since it is ideal for challenging urban environments. The tool remains tethered to the surface during inspection and is controlled by an operator. It also features live high definition video to observe internal pipe conditions. These features allow the City to see internal pipe conditions and closely verify areas with potential problems.

In addition, the tool identifies broken prestressing wire wraps in PCCP. As PCCP ages, the prestressing wires, which make up the main structural component, begin to break due to a number of factors.

The presence of broken wires in PCCP is the main indication that the pipe will eventually fail. Unlike metallic pipe materials that typically fail after a long period of leakage, PCCP is prone to sudden failures when too many wires break in one area. The diagram below demonstrates how PCCP typically fails.

How PCCP Fails

Recently, the City has completed the assessment of just over 17 kilometers of its urban PCCP assets with diameters of 600, 750 and 900 millimeters (24, 30 and 36 inches). Of the 2,798 pipe sections assessed in this 17 kilometers, only 97, or 3.5 percent, have shown evidence of distress. This is slightly below the industry average of 5 percent of pipe sections with distress.

Using condition assessment, the City has been able to identify isolated distress on its critical urban mains, while leaving pipeline assets with remaining useful life in operation.

After completing the initial phases of condition assessment, the City has excavated certain sections of pipe for validation of the inspection results, as well as repair of any damage.

Both the excavation locations and presence of distress have been very accurate. This has allowed the City to repair isolated pipe sections, which restores the overall condition of the pipeline. This will help to prevent failures that would significantly disrupt day-to-day life in the city.
In addition, the City now has a baseline condition of all of the assessed pipelines, which helps in the development of future capital planning for monitoring or re-inspection.

By proactively assessing its PCCP mains, the City of Montréal is taking steps to prevent pipe failures, while allowing for more fiscally responsible asset management in the future.

 

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PureRobotics™ – Pipeline Inspection

Robotic Pipeline Inspection

PureRobotics uses powerful modular robotic pipeline inspection systems that can be configured to inspect virtually any pipe application 12-inches (30.5 centimeters) and larger.

Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Technical Paper

Beyond the Wires: A Sustainable Approach to Prestressed Concrete Cylinder Pipe Management

While evaluating wire breaks are an important part of PCCP management, it is important to acknowledge additional factors beyond wire breaks. By acknowledging additional condition factors, limitations of wire break assessment, and considering other rehabilitation approaches, there may be a more sustainable PCCP management approach (or combination of approaches).

After spending eight years assessing the condition of and monitoring 77 miles of 48-inch and larger PCCP with a variety of methods, WSSC has shifted its focus to 68 miles of 36- and 42-inch mains. Many of these assets have been in the ground for decades and have never been inspected for structural deterioration.

To assess the mains, WSSC is using PureRobotics™ equipped with electromagnetic (EM) sensors. The tool is also equipped with high-definition closed-circuit television (HD-CCTV), which allows WSSC to identify cracks of the inner concrete core and determine joint condition.

WSSC recently produced a video to demonstrate how the tool works and its role within the overall PCCP assessment program.

How the Technologies Work

The EM sensors on the robotic tool identify the quantity and location of broken wire wraps in PCCP pipelines. The wire wraps in PCCP are the main structural component – as wraps begin to deteriorate and break, the pipe section becomes weaker and more likely to fail catastrophically.

By identifying broken wire wraps, WSSC is able to repair or replace specific pipe sections when they reach a wire break limit. The robotics tool used by WSSC also has an inertial mapping unit, which allows damaged pipes to be located with very close location accuracy, usually within 3 feet.

After acquiring a baseline condition of its transmission mains, WSSC plans to install an Acoustic Fiber Optic (AFO) monitoring system to track ongoing deterioration. The AFO system records the sounds of wire wraps snapping, which allows WSSC to intervene and replace a pipe section when too many wire wraps snap in a short span – which indicates accelerating distress – or the amount wire breaks reaches a certain level.

WSSC’s PCCP program is one of the largest and most advanced infrastructure management programs in the industry; however the cost of assessing, monitoring and managing its most critical assets is roughly 6 percent of the $2-billion capital replacement estimates.

To date, WSSC’s inspections have shown that about 95 percent of pipes are in “like new” condition and less than 2 percent require any immediate rehabilitation or replacement. By identifying select distressed areas, WSSC was able to avoid a full replacement program and avoided massive capital replacement costs by rehabilitating the identified sections.

 

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

WSSC Logo

Washington Suburban Sanitary Commission Avoids Critical Failure Through the use of Fiber Optic Monitoring

To prevent critical water main failures, the Washington Suburban Sanitary Commission (WSSC) has installed acoustic fiber optic cable in many of its Prestressed Concrete Cylinder Pipe (PCCP) transmission mains. This technology has prevented a number of major pipeline failures, most recently in Prince George’s County on a 54-inch transmission main.

PureRobotics™ – Pipeline Inspection

Robotic Pipeline Inspection

PureRobotics uses powerful modular robotic pipeline inspection systems that can be configured to inspect virtually any pipe application 12-inches (30.5 centimeters) and larger.

For water service providers, providing customers with consistent, reliable access to clean water is crucial. In densely populated urban areas, such as the Greater Toronto Area (GTA), this often requires operators to manage and assess pipelines that cannot be removed from service, yet provide water to a large number of end-users.

In April 2013, The Regional Municipality of York, in conjunction with the Regional Municipality of Peel and the Ontario Clean Water Authority (OCWA), assessed the condition of the York-Peel Feeder Main, which stretches roughly 25 kilometers, (18 km in York Region and 7 km in Peel) through both Regions. The pipeline is made of 1800-mm (72-inch) Prestressed Concrete Cylinder Pipe (PCCP) and provides a crucial supply of water to residents and businesses in York Region.

In spring 2014, York Region repaired three leaks found through a prescreening survey and verified the condition of one pipe section showing signs of structural deterioration identified through electromagnetic (EM) inspection.
Identifying leaks in large-diameter transmission mains is important in reducing Non-Revenue Water (NRW) – which can be defined as water that is produced for consumption and lost before it reaches the customer. Reducing NRW helps eliminate waste and contributes to the conservation of a crucial natural resource.

In addition to the environmental benefit of reducing water loss, eliminating leaks plays an important role in pipe integrity. The presence of leaks often indicates a potential failure location and by identifying leaks, utilities can reduce pipe failures and gain a better understanding of the overall condition of their system.

For its prescreening survey, York Region used SmartBall® technology, which is a free-flowing tool that identifies the sound of leaks as it travels through a live, operational pipeline. In total, the prescreening survey identified seven anomalies that resembling leaks. Four of these leaks were matched up with existing pipeline features while the other three were verified and repaired by York Region. One of these leaks was located on a 1200mm, high-pressure line running adjacent to the 1800mm line.

While prescreening and leak detection is an important part of condition assessment, critical large-diameter transmission mains warrant a more detailed inspection to identify areas of structural deterioration. By doing this, utilities can identify specific pipe sections that are at risk of failure before they rupture.

Although inspection shows that a large percentage of pipe sections have no deterioration at all, eliminating the risk of one failure can be very beneficial, since the typical cost associated with a large-diameter pipe rupture is between US$500,000 and US$1.5 million, not including the reputational damage a failure can cause.

To identify distress in its PCCP transmission main, York Region completed a non-destructive EM inspection using PipeDiver® technology. PCCP is a concrete pipe that remains under compression because of the prestressing wires, with the thin-gauge steel cylinder acting as a water membrane. As the prestressing wires in PCCP begin to break, the pipe becomes weaker and is more likely to fail catastrophically. It is important to locate and quantify the amount of broken wires in PCCP as they are the main structural component.

When assessing PCCP, PipeDiver technology locates and quantifies the number of broken wires. This method is extremely effective in identifying pipe sections that should be target for renewal once the number of wire breaks passes a certain limit.

The inspection covered 4,280 pipe sections and identified 17 pipe sections that had signals indicative of wire break damage. This represents less than one per cent of the feedermain, meaning the asset is in very good condition. York Region accurately verified the condition of one section of pipe with an unacceptable amount of wire breaks.

A portion of the project also used the condition assessment data to complete detailed risk analysis that will provide York Region with a better understanding of how their pipes perform. This allows for the development of a baseline condition of the entire transmission main and aids the development of long term management, renewal and re-inspection plans.

Although this pipeline was constructed in 2005 and is relatively young, the condition assessment was completed proactively to ensure the continued safe operation of the asset. Managing risk through proactive condition assessment is an excellent tool for operators of large-diameter pipelines. The York-Peel Feedermain conveys roughly 165 million liters per day and in time, will achieve a maximum capacity of 380 million liters per day.

 

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Free-Swimming Pipeline Inspection

PipeDiver® – Free-Swimming Pipeline Inspection

Specifically designed for structural assessment of Prestressed Concrete Cylinder Pipe (PCCP) lines that are live or can’t be taken out of service due to a lack of redundancy or operational constraints.

The most pressing issue surrounding water and wastewater assets is with aging pipelines. While there are many of miles of pipes beneath the ground, the most critical are large-diameter water and wastewater mains, which are often the most valuable asset a municipality owns. These pipelines provide critical services for communities and are beginning to leak and rupture more frequently; not only does this disrupt these vital services but also costs municipalities billions of dollars annually.

While the cost of replacement is high, it is less expensive than allowing these assets to operate until failure. However, for many utilities, it doesn’t need to be all or nothing – the majority of water and wastewater systems can be safely and efficiently managed using a risk-based condition assessment approach.

The primary misconception that many operators have is that the majority of aging pipelines need replacement. This thought process often comes after a critical large-diameter failure, which can cause a negative public perception that the majority of pipe in a system is in near-failing or poor condition. Replacing large sections of pipe is not only extremely expensive – the average cost to replace one mile of pipe is US$1.8 million – but is also extremely difficult logistically, especially as urbanization continues.

Fortunately for utilities, the vast majority of pipelines can remain operational well beyond their intended design life, provided they are managed properly.

Pipe distress is a localized problem, meaning that one pipe section that is badly deteriorated or has failed could be neighbored by pipes that have virtually no damage at all. This is because local factors – such as load, soil conditions, operating conditions and installation – affect how quickly a pipe deteriorates. Through more than 8,000 miles of pressure pipe assessment, Pure Technologies has found that only 4 percent of pipe has some level of distress while less than 1 percent requires immediate renewal.

By managing assets, operators can combine the best of each approach – renewing large-diameter pipe with isolated damage and replacing lower cost assets – to achieve the highest return on investment. Proactive utilities have realized that when implementing condition assessment for a system of pipelines, a risk-based approach is an effective way to ensure resources are invested in an intelligent, defensible and repeatable manner that maximizes the benefit of a program.

Engineers analysing data

Risk-based condition assessment combines state-of-the-art technologies with expert engineering analysis.

Worker performing assessment

Condition assessment can help operators identify specific pipe sections that require renewal.

Defining Risk

To determine risk, operators must measure the probability and consequence of uncertain future events – in this case, pipe failure. This can be determined by multiplying two factors, consequence and likelihood of failure. Consequence of Failure (COF) refers to the damage a failure would cause based on factors such as its location, the amount of users it supplies and its size and operating pressure. Likelihood of Failure (LOF) refers to the probability of a failure occurring based on factors such as age, pipe material, soil conditions, operating pressure, failure history, among others.

Generally, the Consequence of Failure is well-defined by the potential damage a pipeline failure would impose on the surrounding environment and is generally fairly static, or, once defined it is unlikely going to change rapidly. With this in mind the key to managing risk – or the uncertainty that a pipeline could fail – is in understanding the likelihood of failure. This can be achieved by quantifying the physical condition of the pipeline and understanding and quantifying the factors that affect the potential for deterioration of the assets.

To determine the physical condition of an asset, there are a number of technologies that can identify both the presence and level of distress. When determining which to use for each asset, risk is the most important factor. For high-risk assets, a detailed assessment is needed, while lower risk assets may warrant a lower-resolution screening or no assessment at all, as the cost of assessment would outweigh the benefit of replacing the asset entirely.

Naturally, as the resolution increases on an inspection technology, so does the certainty it provides to the operator, as well as the cost of the project. However, when deciding how to best assess critical pipeline assets, a simple comparison to how people should handle a significant health concern draws an important parallel for operators of large-diameter pipelines.

For example, if a person gets chest pain when they exercise – a serious problem – there are different levels of medical certainty they can attain. Going online to search medical journals or websites and completing a self-diagnosis is a free option, but it provides little certainty of long term health. A second option is visiting a general practitioner. He will be able to decide whether or not something is wrong, but won’t be able to diagnose it specifically and will recommend further investigation. To be confident in the results, the person would need to visit a heart specialist and complete specific tests.

While each of these options gets more detailed and expensive, the risk of leaving a heart problem untreated outweighs the cost of a detailed evaluation from a specialist. Utility managers should treat their critical large-diameter pipeline assets the same way a significant health problem, as the risk of uncertainty far outweighs the cost of being sure.

As municipal operators continue to grapple with aging water and wastewater infrastructure, identifying and managing risk should be an important consideration in the development of pipeline management, renewal and replacement programs.

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Pipeline Inspection and Condition Assessment Services

Pipeline Inspection and Condition Assessment Services

We provide water and wastewater organizations a comprehensive suite of technologies that provide actionable pipeline information to better understand the condition of their pipe.

Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.