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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

Case Study

In order to better understand the realities of their overflow problems and, ultimately, help the city avoid flooding, the city of South Bend, Indiana engaged Xylem in utilizing BLU-X, a real-time decision support system consisting of smart sensors and actuators that track conveyance capacity.

The Saint Joseph River has long shaped South Bend’s economy, especially during the mid-20th century, when the river was the conduit to heavy industrial development such as Studebaker and the Singer Sewing Company. To reduce the 1-2 billion gallons of polluted water dumped in the Saint Joseph River annually, and the huge environmental, social, and economic costs associated with the ongoing issue, the City embraced a way to harness intelligent watershed technology to optimize its existing sewer system, without the need to build costly new grey infrastructure.

THE CHALLENGE

Prior to 2008, virtually every time it rained heavily, the City of South Bend faced sewer overflows into the landmark Saint Joseph River because the City`s aging sewer system could not handle the excess discharge, an average of some 1-2 billion gallons annually. In 2011, the City — under the leadership of Public Works Director Eric Horvath — entered into a consent decree, agreeing to a long-term control plan (LTCP) of their sewer overflow estimated at more than $860 million. For South Bend, with a population of just over 100,000, this equated to a burden of nearly $10,000 per citizen, which is economically unfeasible given that the average annual household income is around $32,000.

What solutions did Xylem and South Bend 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

Estimated $500 million in capital work savings

$1.5 million per year in operations and maintenance cost-savings

Over 70% reduction in combined sewer overflow volumes (roughly 1 billion gallons per year)

All sensor data presented on one unified platform, and integrated into South Bend’s existing IT networks

Services Provided

• BLU-X real-time decision support system (RT-DSS) for optimizing sewer infrastructure
• 165 networked sensors and software agents optimally operating 13 gates and valves city-wide
• All sensor data presented on one unified platform
• Integration into South Bend’s existing IT networks
• Real-time alert system to identify grit, FOG, sewer collapse & blockages

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 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

Today, new advancements in technologies and data analytics are helping utilities build asset management programs using a risk-based approach to pipeline condition assessment with the lowest financial impact.

There is no one-size-fits-all approach to assessing metallic pipelines. An approach should be tailored within the context of your risk tolerance while taking into consideration the material, diameter, and past failure history. Many different methods and technologies can be combined to provide data and information to make decisions and prioritize pipelines. The approach can range from do-nothing to a full in-line inspection making targeted repairs and be progressive in nature.

This white paper will highlight:

  • how to develop a risk-based program
  • how to define which of the three approaches to assessing metallic pipe best fits your goals and risk-tolerance
  • how other utilities are finding success using these approaches to: extend remaining useful life, optimize capital expenditures, prevent failures, and increase confidence and level of service.

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

Intermunicipal Service Oeiras and Amadora is 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.

Project Details

Services
SmartBall leak detection inspection
Pipe Material
Ductile iron
Inspection Length
2781 meters (2.6 miles)
Diameter
600mm (24-inch)
Transmission Type
Water

Project Highlights

Total of 1.7 miles (2.78kms) of 5-year-old pipeline inspected

Inspection located one (1) leak 863 meters from insertion

Leak repaired and allowed SIMAS Oeiras e Amadora to recover costs associated with the loss of non-revenue water

Challenge

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.

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.

In addition to physical losses of water caused by a 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.

Solution

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.

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.

Results

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.

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.

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.

Case Study

The Maine Department of Transportation is the office of state government responsible for the regulation and maintenance of roads and other public infrastructure in the state of Maine. The department manages 2,919 bridges and spans in total, inspecting 2,414 in 2014.

Project Details

Services
SoundPrint® Acoustic Monitoring – Bridges

Monitoring system commissioned in 2003

Operated until bridge retired in 2006

Bridge Type
Suspension
Monitored Length
2040 ft (622 m)
Number of Main Cables
9.6 in (244mm) parallel strand cables
Number of Sensors
22

Project Highlights

Rapidly deployed monitoring system allowed resumption of two-way traffic

Identified & located 4 wire break events and 23 wire cut events

Confirmed effectiveness of cable strengthening measures

Estimated economic benefit in range of $25-36 million

Challenge

The Waldo Hancock Bridge, located in the state of Maine, was completed in 1931. Its deck carried one lane of traffic per direction, while two narrow reinforced concrete sidewalks were used for pedestrian traffic.

Partially due to the National Bridge Inspection Standards (NBIS) stipulated by the Federal Highways Administration (FHWA), a number of inspections of the superstructure were carried out starting in the early 1990s. Portions of the main cables were unwrapped and inspected in 1992, 1998, and 2000. Due to signs of stage-3 corrosion during the 1998 small-scale investigation, the 2000 investigation was expanded to include more panel points on the North cable.
This investigation included four openings on the North cable, and one opening on the South cable. The safety factor had originally ranged from 3.0 to 3.2, based on no damage of the main cable. The wire breaks counts observed reduced the safety factor to just below 2.4 at two of the five locations investigated.

Since the cable condition was worse than anticipated, the bridge owner decided to implement a significant rehabilitation program to extend the life of the structure.

The major component was to replace the external main cable protection system. is replacement enabled an extensive visual inspection of the strands, with further wedging performed at select areas. During this exercise, it was discovered that the extent of the corrosion was beyond what the five panel inspection showed. At the worst location, 10 of the 37 strands were not carrying load, with one strand 100 percent corroded. is occurred on the South cable, where previously only one panel was inspected, reducing the calculated safety factor to 1.5 at the posted carrying limit of 12 tons.

Solution
This situation required emergency strengthening measures. First, a SoundPrint® acoustic monitoring system was installed on both main cables. To save installation time, a wireless system with 22 sensors was used. Load restrictions were placed on the bridge, and until the acoustic monitoring system was fully functional, the bridge was restricted to one-way traffi c for a short time. A total of eight supplementary strands were placed above each main cable, connected directly to each cable band with supplementary suspenders. The heavy concrete sidewalk was removed and replaced with a steel-wood combination.
Results

The acoustic monitoring system detected 4 wire breaks in the first 50 days of monitoring the cables (1 on the North cable, and 3 on the more damaged South cable). Once the supplementary cables were installed and the deck lightened, the wire breaks on the main cables stopped. To give all parties confidence, wires were periodically cut to demonstrate the effectiveness of acoustic monitoring system. Nine wires were cut and successfully recorded before the monitoring began, and a further 14 individual wires were cut and recorded over the following two years. In this case, the acoustic monitoring system was used to:

  • Provide utility during the critical period when strengthening measures were required
  • Extend the life of the bridge for an additional three years and four months, until a replacement bridge could be designed and built.

Approximately $1.1 million was spent monitoring the bridge using acoustics over this time period. Client estimated that the economic benefit of removing the load restrictions for heavy trucks, and not fast-tracking the new bridge was in the range of $25-$36 million.

Case Study

The District of Columbia’s water distribution system serves 600,000 residents and 16.6 million annual visitors to the nation’s capital. Local water utility DC Water provides water and wastewater service to the region, with water distribution assets that include approximately 1,300 miles of water pipes, 1,800 miles of sewer lines, 36,000 pipeline valves and 9,300 public fire hydrants.

Project Details

Services
Asset management

Operations improvement

Information services

Engineering support

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

 

Hands-on inspection of all

9,300

fire hydrants in district

 

Program replaces/upgrades about

3,000

most critical hydrants

Program gathers location data, operational capabilities, flow rate and maintenance
History

Possibly first city in U.S. to use Google Earth to display hydrant location & maintenance information

Challenge

Almost half of DC Water’s fire hydrants were antiquated units made at a local prison foundry that closed decades ago, causing problems with their incompatible hose outlet threads, nonstandard hydrant components and the lack of any source for replacement parts.

The other half of DC Water’s fire hydrants included about 24 different hydrant makes and models, but only two of those hydrant types met approved industry standards. Further, the utility was unsure of the precise location of many of their hydrants. They had no reliable information about their maintenance history, their operational flow rate–or even if they worked at all.

Several high-profile incidents involving inoperable fire hydrants at the scenes of major fires in the Washington DC area accelerated a planned DC Water project to inspect, operate and assess the mechanical condition and operational reliability of all the hydrants located within the District of Columbia. To help lead the program, DC Water partnered with the industry leader in hydrant management solutions, Wachs Water Services.

Solution

The project called for a hands-on inspection of all 9,300 public fire hydrants within the District of Columbia, replacing or upgrading about 3,000 of the most critical fire hydrants and installing about 600 new hydrants each year.

The project also required gathering and recording vital hydrant location data, and operational capabilities and flow rate, maintenance history, and current functional status into DC Water’s GIS (geographical information systems) and CMMS (computerized maintenance management systems) so the vital information could be accessed quickly during an emergency response.

Results

The Wachs Water Services team began with an analysis of the utility’s existing records, maps and documentation to help find “cannot locate” hydrants and their connecting valves and pipelines, and enter the correct location data into the utility’s GIS system.

Teamed with DC Water employees, Wachs Water Services field crews methodically located, operated, and flow tested the thousands of fire hydrants and isolation valves, repairing or replacing them as needed, and “color banding” the hydrants to serve as a visual indicator so firefighters are instantly aware of the water flow capacity of a particular hydrant.

As the field technicians operated each hydrant, they also recorded its precise GPS location, and collected critical data describing the operational status of each hydrant, including manufacturer, model, installation data, repair history, flow rate and number of turns to open. This hydrant attribute data was entered into DC Water’s GIS system for quick system-wide retrieval and analysis.

DC Water became one the first US cities to use Google Earth to publicly display hydrant location and maintenance information. DC Water has become a national example of how to comprehensively upgrade and renew an aging water distribution system to better serve the public.

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.

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

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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.

At Singapore International Water Week 2016, one of Pure`s licencees presented a poster on two acoustic-based technologies (tethered Sahara® and free-swimming SmartBall®) used to locate 674 leaks on large-diameter trunk mains operated by this Malaysia water operator.

Conducted over four months, the in-line inspection and resulting repairs has saved total of 46.7 million liters of water daily. The pipe diameters ranged from 300mm to 2,200mm.

 

SmartBall in-line leak inspection platform

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.

Sahara in-line leak detection platform

The tethered Sahara tool 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 parachute-like tool is drawn by product flow 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.

 

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.

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

Abstract

Acoustic leak detection inspection tools have become a common technique to identify minute pipeline leakage before the leak and the defect producing it can become a larger problem or even a rupture level event. While these inspection tools only identify small defects once they reach the through wall stage and result in leakage, they can be an effective means of demonstrating the pressure tightness of a pipeline and ruling out the presence of through wall defects that are below the detection threshold of other ILI inspection tools; in so doing finding a way into both the leak detection and pipeline integrity toolboxes.

Enbridge Pipelines owns and operates a 12” pipeline that transports crude oil over 870KM. A majority of the line resides in permafrost conditions in a remote region, thus the window for inspections or work to be done on the pipeline is limited. Additionally the pipeline consists of long segment lengths between traps, which traverse multiple water crossings and experiences large changes in elevation. Therefore, availability, scheduling, and transport of inspection equipment are critical. The SmartBall® leak detection tool was selected for a twofold purpose: to test the technology’s capabilities, and to inspect the line specifically for any leaks.

Inspection of 3 segments of the 12” pipeline provides some unique challenges to inspection providers, requiring tools with up to 12 days of operational run-time capability and the ability to operate in product temperatures as low as -15 degrees Celsius. The generation of SmartBall® tools at the time did not have the run time and data capacity required to inspect the entire length of each of the pipeline segments. As a result, Enbridge and Pure Technologies collaborated on the development of a custom, long duration, high data capacity, SmartBall acoustic leak detection tool specifically for the 12” pipeline application.

Authors

  • Laura Seto, P.Eng., Pipeline Integrity Department, Enbridge Pipelines Inc., Calgary, AB, Canada
  • Tim Ross, P.Eng., Pure Technologies Ltd., Calgary, AB, Canada

Abstract

Recently the industry has been emphasizing broken prestressing wires as a basis for the management of Prestressed Concrete Cylinder Pipe (PCCP). The approach includes: evaluating broken wires, establishing a threshold level of broken wires for repair, and repairing only sections that exceed the threshold.

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). The approach may reduce risk and be more sustainable in terms of costs (current and future).

For some areas, the San Diego County Water Authority found the comprehensive rehabilitation approach, steel relining of PCCP, to be more sustainable in terms of costs. In addition, the approach significantly reduced the risk of a pipeline failure. However, in other areas, a localized, as-needed repair approach, such as Carbon Fiber, was more sustainable in terms of costs.

Authors

  • Nathan D. Faber, P.E., San Diego County Water Authority, Escondido, CA, USA.
  • Martin R. Coghill CEng MICE, Jacobs Engineering Group Inc., San Diego, CA, USA.
  • John J. Galleher, P.E., Pure Technologies, San Diego, CA, USA.

Introduction

Underground pipelines are among the most valuable, yet neglected, assets in the public arena. They provide essential services such as supply of energy and drinking water and collection of wastewater. But we install the cheapest we can, bury it and forget about it – at least until something goes wrong. Then we are faced with having to fix the problem under emergency conditions, often considering only immediate needs and not the future operation of the pipeline in question.

This infrastructure must be seen as an asset, and managed as such. Properly maintained the pipe networks are valuable assets that are critical to delivering services to customers, and in any business the means of connecting product or service to customers is a major link in the business value chain. Not to maintain this network is negligent bordering on criminal.

Authors

  • Mike Wrigglesworth; Pure Technologies, 300-705 11th Ave SW, Calgary, AB, Canada, T2R 0E3; +1.403.266.6794
  • Michael S. Higgins, P.E.; Pure Technologies, 8920 State Route 108, Suite B; Columbia, MD 21042; 443-766-7873

Introduction

In the past, the focus for leak detection programs in water delivery systems has been primarily on distribution (reticulation) networks and service connections. Even today, trunk main leaks tend to be addressed only when there is a pipe rupture or when there is visual evidence of the leak above ground. So are leaks from trunk mains a problem?

The introduction of a new leak detection technology, called SmartBall®, has the potential to resolve the uncertainty about the rate of loss, if any, from trunk mains. Following two years of development, the system has been available commercially since June 2007 and experience to date has demonstrated that it a valuable tool for identifying, locating and quantifying leakage. Results indicate that trunk main leakage is indeed a concern for many agencies, and that most leaks are not evident from visual inspection or metering.

Introduction

A significant percentage of the United States force mains have been in use for several decades and never been assessed or proactively managed. To safely rely on these pipelines, their condition should be periodically checked to ensure there are no locations susceptible to failure.

In addition, many wastewater agencies are faced with EPA consent decrees that require condition assessment of force mains. As a result, many agencies are now faced with the daunting task of assessing their sewer force mains—a task that until recently was often not feasible due to operational constraints. However, Pure Technologies continues to improve technology and can now obtain a realistic assessment of a force main within the common constraints of most wastewater agencies.

Authors

  • Michael S. Higgins, P.E.; Pure Technologies, Columbia, MD, USA.

Abstract

Acoustic monitoring has played a major role in the management of one of the world s largest civil engineering projects. After experiencing failures on their pipeline between 1999 and 2001, the Man-Made River Authority (MRA) undertook an aggressive condition assessment program. This program led to the development of a comprehensive Pipeline Risk Management System (PRMS), making the Great Man-Made River Project one of the best managed pipelines in the world. The planned expansion of the existing acoustic monitoring system, a key component of the PRMS, will allow for monitoring of over 700km of pipeline.

This paper will discuss steps taken to-date, the acoustic monitoring technology and the expansion of this key component to the management strategy for the pipeline.

Authors

  • A. Lenghi. Man-Made River Authority. Benghazi, Libya.
  • N. Amaitik. Man-Made River Authority. Benghazi, Libya.
  • M. Wrigglesworth. Pure Technologies Ltd. Calgary, AB., Canada.

Introduction

In 1996, Providence Water experienced a catastrophic failure of its 102″ PCCP aqueduct pipeline. Subsequently, the main underwent an extensive assessment and repair and was returned to service with plans that the main would be re-inspected in approximately 5 years.

In 2005, Providence Water re-inspected the aqueduct. Since the previous inspection, the state-of-the-art for assessing PCCP mains has progressed significantly. Non-destructive technologies available for assessing and monitoring PCCP pipe have made significant strides. Providence Water implemented state-of-the-art inspection procedures to obtain the best possible assessment of the aqueduct. Following the assessment of 4.5 miles of the aqueduct, Providence Water opted to install a fiber optic acoustic monitoring sensor to continuously monitor the condition of the aqueduct and identify pipe sections experiencing ongoing wire break activity.

Providence Water utilized the following technologies during the most recent 2005/2006 inspection/monitoring program:

  • Electromagnetic Inspection – to detect wire breaks in the prestressing wire
  • Visual and Sounding Inspection – to inspect for cracks or delaminations
  • Resistivity Testing – to determine the actual number of wire breaks on excavated pipe sections (vs. the estimated number based on the electromagnetic inspection)
  • Acoustic Monitoring – to detect future wire breaks as they occur in the operational aqueduct

Following the initial inspection, one pipe section was found to be in a state of incipient failure. As a result, several nearby pipe sections were strengthened and a decision was made to install the acoustic monitoring system. This paper focuses on the assessment and monitoring technologies used during this project and describes the capabilities and limitations of these technologies.

Authors

  • Michael S. Higgins, P.E.; Pure Technologies, Columbia, MD, USA.
  • Paul J. Gadoury, P.E., Peter LePage, Rich Razza; Providence Water Supply Board, Cranston, RI, USA.
  • Jack Keaney, P.E., Ian Mead, P.E., CDM, Providence, RI, USA.

Introduction

The City of Phoenix is currently in a multi-year program to investigate 150 miles of prestressed concrete cylinder pipelines (PCCP). The failure of a 60-inch pipeline focused the efforts of the investigation to a pipeline known as the Superior pipeline.

The Superior pipeline is a 2.2-mile long, 29-year old pipeline that ruptured on October 3, 2006, resulting in extensive damage to the surrounding community. The pipeline was immediately shutdown and the failed section of pipeline was repaired. However, the condition of the remaining pipe and the potential for additional failures was a concern.

To identify wire breaks, Pressure Pipe Inspection Company (PPIC) conducted Remote Field Transformer Coupling investigations. In addition, visual and sounding investigations were conducted by Openaka of Branchburg, New Jersey to identify internal defects. These investigations identified pipe segments that were in need of immediate repair prior to putting the pipeline back in service. This information provided baseline wire break information for the subsequent investigations.

Prior to putting the pipeline back into service, 11,700 linear feet of fiber optic was installed by Pure Technologies allowing the City to acoustically monitor wire breaks in real time. This information was critical as the pipeline needed to be back in service to meet the high demand for water during the hot Phoenix summer. Real time wire break monitoring allowed the City and Brown and Caldwell to slowly resume the operation of the pipeline to prevent another failure. Monitoring of the pipeline was conducted from February 2007 through January 2008 and the pipeline was found to be extremely active with an initial average of three wire breaks occurring each day.

This paper focuses on the investigations conducted and conclusive results relative to:

  • Benefits of multiple technologies for PCCP investigations
  • Calibrated vs. non-calibrated curves for electromagnetic analysis
  • Real time data collection through fiber optics to monitor pipeline conditions
  • Verification of fiber optic results using electromagnetic analysis
  • Pressure and surge monitoring

Authors

  • Ronald Ablin, P.E., Brown and Caldwell, Phoenix, AZ, USA.
  • Brandy Kelso, P.E., City of Phoenix Water Services Department, Phoenix, AZ, USA.
  • Bethany Williams, P.E., The Pressure Pipe Inspection Company, Phoenix, AZ, USA.
  • Myron Shenkiryk, Pure Technologies, Phoenix, AZ, USA.