WSSC Proactively Avoids Water Main Breaks Using Acoustic Fiber Optic Technology

Carla Reid, General Manager and Chief Executive Officer of WSSC, lets us know how Acoustic Fiber Optic (AFO) Technology has helped the water utility to avoid several catastrophic main breaks since installing the system.


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.


Case Study

City of Baltimore deploys acoustic optic fiber monitoring to avert potential pipe failure without the expense of excavating the entire line to find it.

Public utilities rarely make headline news unless an unexpected water main break shuts down a road or floods a neighborhood. Then the public swarms negatively all over the story.

In this instance, the opposite happened, and the public responded positively when the City of Baltimore Department of Public Works (DPW) announced that they had averted a “potentially disastrous water main break” in southwest Baltimore because of preemptive monitoring of the pipeline.

Project Details

SoundPrint® Acoustic Fiber Optic Monitoring
Pipe Material
Monitoring Length
16-foot section
54 inch
Transmission Type

Project Highlights

AFO hears “pings” on 16-foot segment

15 wire wrap breaks identified over 2-week period

$200,000 repair cost miniscule to the millions a catastrophic failure might have cost

Project Photos


The City of Baltimore Department of Public Works operates more than 7,000 miles of water and sewage mains.

In May 2017, analysts from Pure Technologies (Pure) notified DPW that something was wrong with a 16-foot segment of the Southwest Transmission Main that runs beneath Desoto Road (under the Interstate-95) and carries potable water for southwest portions of the City of Baltimore, Baltimore County, and portions of Anne Arundel and Howard Counties. Fortunately, this section of the 54-inch PCCP main was equipped with a SoundPrint® acoustic fiber optic (AFO) monitoring system, the outgrowth of a collaborative project between the city and Howard County in 2007.

The AFO system not only gave DPW an early warning of a distressed pipe section. It also offered them a cost-effective way to pinpoint a potential failure without the time and expense of excavating the entire line to find it.


Developed by Pure Technologies, the SoundPrint acoustic fiber optic monitoring technology is an industry leading system that tracks and records pipeline deterioration on prestressed concrete cylinder pipes (PCCP), the material of the pipe of which the Southwest Transmission Main was constructed.

Once installed in a pipeline, the SoundPrint AFO system remotely detects the acoustic signature of wire wrap breaks or “pings” and records their specific pipe location. If break activity increases, utility staff are alerted and can intervene on the deteriorating pipe in advance of a failure, much like DPW did with the Southwest Transmission Main.

Unlike electromagnetics, which identifies the number of wire breaks that exist at a point in time, acoustic monitoring identifies the number of wire breaks that occur during the monitoring period, effectively identifying the location of active deterioration for the lifespan of the asset.


In the case of Desoto Road, “our monitoring system reported an alarming 15 wire breaks over a two-week period, raising concerns of a failure and potentially catastrophic water main break,” DPW spokesman Jeffery Raymond said.

The “pings” from the snapped wire wraps, recorded by the acoustic monitors, set off alarm buttons at the Office of Asset Management formed by Public Works Director Rudy Chow.

“I created this office precisely to collect and utilize data that can help us stop problems before they happen,” explained Chow. “Our team moved quickly to prevent what could have been a disastrous water main break,”

The best option for fixing the pipe segment, it was determined, was to utilize high-strength tendon cables. The process called for excavating around the distressed section of pipe, then installing the tendon cables around the pipe’s circumference.

While the cost of repairs the Southwestern Transmission Main cost DPW $200,000, that amount is miniscule compared to the millions of dollars that unplanned emergency repairs can cost a utility. In this instance, an ongoing preventive maintenance program certainly did pay off for the agency.

As a footnote, repair of the Southwest Transmission Main project won the 2017 CEAM Small Project of the Year Award for the City of Baltimore.

“Our monitoring system reported an alarming 15 wire breaks over a two-week period, raising concerns of a failure and potentially catastrophic water main break.”

Jeffery Raymond

DPW spokesman

Case Study

The Washington Suburban Sanitary Commission (WSSC) is the 8th largest water and wastewater utility in the United States, serving over 460,000 customer accounts and 1.8 million residents in Montgomery and Prince George’s County, Maryland (suburban Washington D.C.).

WSSC operates nearly 5,500 miles of water mains, with approximately 145 miles comprised of large-diameter Prestressed Concrete Cylinder Pipe (PCCP) equal to or greater than 36-inches in diameter.

Project Details

Acoustic Leak Detection
PipeDiver® – Condition Assessment
PureRobotics® – Pipeline Inspection
SoundPrint® AFO – Acoustic Fiber Optic (AFO) monitor­ing
Pipe Material
Inspection Length
145 miles

Project Highlights

The Assess & Address cost was roughly 6% of the capital replacement estimate of $2 billion

95% of the pipes inspected by Pure Technologies have no deterioration at all

Pure has identified less than 2% of pipes in need of immediate repair

A capital replacement program would have replaced a large amount of pipe in good condition


After WSSC began experiencing major PCCP failures in the 1970s, it developed a strong commitment to infrastructure management technology in favor of large capital replacements. Beginning in 2007, WSSC and Pure Technologies began a partnership to create a comprehensive PCCP management program.

Pure Technologies Assess & Address approach to pipeline management is built on extensive research and data from over 8,000 miles of pressure pipe inspection which has found that less than 1 percent of pipelines need immediate repair. Assess & Address programs focus on identifying vulnerable areas of a pipeline and completing selective rehabilitation and replacement in favor of full-scale capital replacement, often saving the utility millions of dollars.


Pure Technologies uses several solutions for WSSC’s PCCP management program that effectively inspect the pipeline for leaks, gas pockets, and structural deterioration. Pure also provides real-time monitor­ing of the pipelines to alert the WSSC when indi­vidual pipe segments experience prestressed wire breaks and are approaching a high risk of failure.

Pure’s SmartBall® Acoustic Leak Detection Technol­ogy is used to identify leaks and pockets of trapped gas, allowing for proactive repair. The SmartBall inspection tool is a non-destructive, free-swimming technology that measures the acoustic activity associated with leaks and gas pockets in pressurized pipelines. Early identification and repair of leaks and gas pockets reduces water loss and structural deteri­oration and is crucial in understanding the baseline condition of a pipeline. Pure Technologies regularly deploys SmartBall leak detetction as part of the pro­gram having identified several major transmission mains leaks within WSSC’s system to date.

WSSC Pipelines are also inspected for structur­al deterioration using several of Pure’s platforms. Manned visual and sounding inspections of dewa­tered pipes help identify visible structural damage like corrosion, delamination, and cracking. Pure also uses PipeDiver® and PureRobotics® Electromagnet­ic (EM)Technology Platforms to locate and quantify broken prestressing wires in each pipe section.

Information from these inspection techniques are combined to provide actionable information (including structural modeling and analysis), which allows WSSC to safely manage their PCCP inventory while minimizing renewal projects.

In addition to regular condition assessment, WSSC began using Acoustic Fiber Optic (AFO) monitoring in 2007. Ultimately, the program will monitor up to 145 miles of 36-inch and larger PCCP within WSSC’s system.

AFO technology monitors the condition of PCCP by tracking the amount of wire breaks in each pipe section. The system allows WSSC to monitor pipe­line deterioration and see at-risk pipes before they fail. As wire breaks occur, the data is analyzed and reported to WSSC by e-mail and advanced GIS and web-based reporting systems, allowing for real-time management of WSSC’s system.


While WSSC’s PCCP program is one of the largest and most advanced infrastructure management programs in the industry, the cost of Pure Technologies Assess & Address model is roughly 6 percent of the $2-billion capital replacement estimates.

To date, Pure Technologies inspections have shown that about 95 percent of WSSC’s pipes are in “like new” condition and less than 2 percent require any immediate rehabilitation or replacement. By identifying select distressed areas, WSSC was able to avoid a full replacement program and avoided massive capital replacement costs by rehabilitating the identified sections.

Since the program’s inception, no PCCP failures have occurred for any transmission main managed under the program.

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

Worker inspecting pipe

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

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

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

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

Team of workers with a metallic pipe

Many proactive utilities involved in guiding Pure’s research efforts

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

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

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

Small diameter metallic pipe leak

Case for using inline tools for small diameter pipelines

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

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

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

A new approach to metallic pipeline management

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

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

  • Understand
  • Assess
  • Address
  • Manage

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

Starting an effective pipeline management program

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

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

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

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

Sinkhole in a street

Reducing the Consequence of Failure

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

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

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

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

Reducing the Likelihood of Failure through condition assessment

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

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

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

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

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

Massive pressured water lleak on a street

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

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

Asset management begins with condition assessment

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

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

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

Matching assessment technology with the pipeline conditions and project goals

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

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

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

Sahara® Leak and Gas Pocket Detection

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

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

SmartBall® Leak and Gas Pocket Detection

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

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

PipeDiver® Condition Assessment

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

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

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

PipeWalker™ Condition Assessment

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

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

PureRobotics® Pipeline Inspection

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

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

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

Matching the level of resolution to the risk of the line

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

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

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

Staff members behind an open pipe

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

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

Map with pipeline location

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

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

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

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

SoundPrint® AFO Fiber Optic wire

SoundPrint Acoustic Fiber Optic technology tracks and records pipeline deterioration

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

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

John Walker

Operations Manager, Lake Huron and Elgin Area Primary Water Supply

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

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

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

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

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

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

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

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

That’s a comforting thought, well worth celebrating.

 commissioning of a 50 km AFO system on the Lake Huron Water System’s water main transmission pipeline

Last week, government officials, special guests and educators gathered in London, Ontario to celebrate the successful funding, installation and commissioning of a 50 km AFO system on the Lake Huron Water System’s water main transmission pipeline – a 1200mm diameter PCCP supplying more than 500,000 people in southwestern Ontario.

Optic Fiber inside a pipe and Press Conference

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

The event was covered by the London Free Press, which wrote the following story.

Water supply safeguard comes down the pipe

Now, we can keep an ear out for problems with a pipeline that brings fresh water to London. The city and region took the wraps off a new, fibre-optic cable installed in the water pipeline from Lake Huron to London with an announcement Friday at London Convention Centre.

If that pipe is about to break or leak, new monitoring technology will warn water watchers, preventing a ­rupture.

“We have an acoustic fibre-optic system that allows pipelines to be managed, identifying problems before they become bigger. When a pipeline fails, it is a big mess,” said Mike Wrigglesworth, senior vice-president of Pure Technologies, the Alberta firm supplying the cable.

Staff members behind an open pipe

The $7.5-million project has installed the acoustic cable on a 50-kilometre stretch between the Grand Bend water treatment plant and an Arva reservoir, covering seven municipalities, which are sharing the cost with Ottawa and the province.

The acoustic cable lets staff “listen” to the pipeline for steel wires snapping as the pipe breaks down. There are hundreds of such wires in each section of pipeline.

“One wire breaking in a pipe is no big deal, but 30 or 40 is a weak section of a pipeline,” Wrigglesworth said.

“It can inform which sections of pipe are deteriorating, in real time, and we can be pro-active,” said Wrigglesworth. “We can identify which sections of pipe have a problem and make a plan to repair.”

A repair might cost $75,000, a “huge savings” over the cost of fixing a rupture, which could run to as much as $1.5 million, he said.

The Lake Huron-to-London pipeline has broken twice, in 2010 and 2012.

Under the new system, “We will get an email to say a section of pipe has a break, they even give us the map location of where it happens,” said John Walker, operations manager for the Lake Huron and Elgin area primary water supply, which oversees the regional and city water system.

“At some point, we will have to extend this (acoustic cabling) to Lake Erie,” Coun. Harold Usher said of the city’s other water supply pipeline. “Everything we do in one, we will do in the other. We cannot have farmer fields flooded.”

The $7.5-million upgrade to the Lake Huron-to-London water line is part of $179.1-million in water safety infrastructure investments across Southwestern Ontario. The federal and provincial governments are paying about $50 million each, with municipalities picking up the balance. In all, eight projects will be completed by 2017.

Celebration Cake

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

Working on a new potable water transmission main

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

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

Outside and inside a tunnel

Some pipeline sections tunneled in excavated depths of 50 meters

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

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

SoundPrint® acoustic fiber optic (AFO) inside a pipe

Acoustic monitoring versus electromagnetic inspection technology

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

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

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

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

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

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

Pipeline construction along a road

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

Contract 1 (underway) includes visual inspection and mapping

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

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

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

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

Fiber optic

With the deteriorating state of many aging water mains found in cities across North America, urbanites are frequently witnessing unexpected plumes of water erupt as man-made geysers in their own metropolitan backyards.

While natural geysers are awe inspiring, urban geysers are much less so, due to their destruction to property, roads and the environment. Because an uninterrupted water flow is the lifeblood of every well-managed city, getting an early warning on the weak spots within the water network translates into smart municipal business, and can help prevent catastrophic blowouts down the road.

No company understands this reality better than Pure Technologies (Pure), developers behind Acoustic Fiber Optic (AFO) technology that monitors the structural health of PCCP transmission mains. Pure’s near real time AFO technology is now embraced by a growing number of pipeline operators across North America and Asia.

Map of pipeline operators across North America and Asia using AFO technology.

Reasons why water mains crack, leak and burst

Many utilties operate water mains made from prestressed concrete cylinder pipe (PCCP). This pipe consists of a concrete core, a thin steel cylinder, high tensile prestressing wire and a mortar coating. When the mortar cracks, water seeps in and corrodes the reinforcing wire.  As the wire breaks, it creates a weak spot, and as internal water overwhelms the core, the wire gives way and the pipe can burst, often with a geyser-like force.

Pure’s AFO technology monitors in near real time, the structural integrity of prestressed pipe by recording the “pings” or number of wire breaks in each main section.

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

Koebel stresses that while it may take weeks, months or even years, eventually one extra straw will break the camel’s back and for a pipeline, that last additional cracking wire has the potential to turn a small leak into a large problem.

“Once a baseline condition has been established through electromagnetic inspection, the AFO system allows us to track the deterioration rate and identify at-risk pipes before these fail. It’s preventative medicine, and as a safeguard, it’s proven to work. The fiber never lies,” adds Koebel.

Pure AFO developed to replace limitations of hydrophone array technology

Prior to Pure’s deployment of its first acoustic fiber optic system in 2007, transmission mains were chiefly monitored using cumbersome hydrophone array technology.

This older sonic technology has limitations, especially since the system’s success depends on an array of submerged microphones embedded in the cable, all in functioning order, spaced from 100 to 200 feet apart. That’s the downside – the equipment failure rate is high in a permanent immersion environment, and each hydrophone array has a monitoring distance limited to less than eight kilometers (five miles) of pipeline.

Comparatively, AFO technology is reliable at recording breaking (pinging) wire wraps, since the entire cable is acoustically sensitive from the start of the data acquisition unit to the end of the fiber. An AFO system can monitor 20 kilometers (12 miles) with a single system and 40 kilometers (24 miles) with a dual system. Moreover, Pure’s AFO system can be installed and function whether the mains are dewatered or in service.

Tech working inside a pipe


Big boom theory helps promote AFO technology and PCCP management

To address the limitations of hydrophone array technology, Pure’s research and development team set out to develop a better way to improve the accuracy and reliability of pipeline monitoring.  The elusive research effort took seven years, and after consulting with leaders in the field of digital signal processing and acoustic sensing, Pure developed its own proprietary acoustic technology for PCCP environments.

“Based on the operating expense and limitations of hydrophone arrays, selling our new AFO solution was relatively easy,” says Peter Paulson, co-founder of Pure and one of the researchers behind the development of the innovative AFO technology.

According to Paulson, Pure proved the efficacy of their monitoring system during an early test run for pipeline clients.

“At the time, we had set up a demo pipeline operation on our grounds, and in a distant tent we gathered clients around to listen in around a computer screen. One of our test engineers then cut a single prestressed wire from the pipeline located a block away. Because we had amplified the sound print, the immediate resounding “boom” startled the attendees into recognizing that our AFO technology really does work. We built our reputation from there.”

The rest is acoustic fiber optic history. AFO technology is now regarded as the leading standard of PCCP monitoring.

Pure surpasses 1,120 km AFO monitoring milestone

Pure has surpassed 1,120 kilometers (700 miles) globally of active AFO monitoring. Currently within North America and China, Pure is monitoring 56 mains from a combined total of 17 clients. Pure’s active AFO system has recorded more than 43,600 wire breaks from its managed roster of pipelines located in North America and China alone.

For every AFO system, the pipeline data is streamed to a Pure data analyis team who analyze the acoustic information. Any and all wire breaks captured by the AFO system are reported within one business day to the client. If any problem is detected and confirmed, the client is notified and they can then proactively manage their pipeline by choosing how to intervene before serious damage occurs.

Koebel likens AFO data management to road repairs. “Better to repair a pothole than tear up the entire street to find the problem,” he says. “In essence, that’s the value we bring to the table. If clients don’t hear from us that means they’ve got good pipes.”

Historical pipe installation

An archived photo from installation of the pipeline five decades ago.

When your pipeline operates well for five decades, it’s easy to be lulled into a false sense of security about the condition of your buried assets. Out of sight, out of mind.

Then, in an instant, that mindset can change.

For Canadian River Municipal Water Authority (CRMWA), that wakeup call happened after dealing with two unexpected failures in quick succession earlier this year. The failure repercussions quickly introduced CRMWA to Pure Technologies, a leader in technologies for the inspection, monitoring and management of critical infrastructure.

CRMWA provides water to 11 member cities in the Texas Panhandle and South Plains region, near the cities of Amarillo and Lubbock. The water authority, which serves more than 500,000 people, draws water from Lake Meredith through a 358-mile aqueduct system completed in 1966. Comprised of approximately 55 miles of non-cylinder prestressed concrete pipe (PCP) along with approximately 300 miles of reinforced concrete pipe (RCP) and bar wrapped concrete cylinder pipe (BWP), the main aqueduct can deliver up to 118 million gallons of water daily to the 11 member cities.

Digging out failed pipes

One of the pipe failures that caused a blowout.

December 30: First blowout ends flow to 9 cities

The first indication of a problem occurred with a pipe rupture on Dec. 30, 2015, which abruptly ended the flow of water to nine of CRMWA’s member cities, leaving the cities to use precious reserves or their own water.

With the initial failure of a 72-inch (1830-millimeter) diameter non cylinder prestressed concrete pipe (PCP), the water agency lost millions of gallons of water, forcing a temporary pipeline shutdown to make immediate repairs.

January 5: Soon after the first blowout was repaired, an adjacent pipe began leaking

Five days later, on Jan. 5, CRMWA completed repair number one, and started to refill the system when an adjacent pipe began leaking.

This new leak lead to an emergency mobilization from Pure at the request of CRMWA. Pure’s condition assessment technologies have helped clients prevent more than 2,300 failures worldwide, resulting in billions of dollars in savings, and hundreds of billions of gallons in water savings. Pure has also located more than 4,000 leaks on water mains using its leak detection technologies.

Broken concrete pipe exposing the internal anatomy

One of the EM anomalies verified and excavated for repairs.

January 5-6: Pure mobilized to begin a manned electromagnetic survey

The same day, a crew of three mobilized from Dallas to the failure site near Amarillo. The purpose was to conduct a non-destructive evaluation using Pure’s electromagnetic inspection technology on the pipe immediately adjacent to the damaged sections. Over the next two days, Pure scanned 8,822 feet with internal manned electromagnetics.

January 8: Based on expedited EM analysis, Pure informed CRMWA of two large anomalies in two pipes near the first failure.  Over the next two days CRMWA completed the second leak repair, and hoped for more time to conduct a third repair where Pure called a large electromagnetic anomaly.

January 11: After Pure demobilized from the job site, the client turned on the pipeline, and after flowing for 12 hours, a second failure occurred, in the area located where Pure’s EM analysis indicated a potential problem.

January 12-13: Over the next few days, Pure verified five electromagnetic anomalies in three pipes near the failure site while CRMWA completed additional repairs. Based on the verified results, CRMWA requested a total of approximately 47 miles of manned EM inspection, which was completed by mid-March.

“The electromagnetic inspection was well worth the cost. Now we know the condition of our pipelines. We know the locations of our problems. The scan revealed 16 pipes where corrosion had put the lines at risk for developing additional blowouts. Those have been repaired much more cheaply and quickly than the costs of fixing blowouts.”

Kent Satterwhite

General Manager, CRMWA

Preparing the pipeline paid off by finishing ahead of schedule

CRMWA worked around the clock leading up to the inspections to dewater and prepare the pipeline for the internal inspections. The hard work paid off well, with no holdups on the inspection progress. The excellent planning by CRMWA and Pure allowed the inspection to wrap up ahead of schedule. Once the internal inspection was completed, Pure was also able to perform a destructive calibration on a pipe section which CRMWA provided, which was helpful for the analysis of the data collected. CRMWA was also able to repair 16 pipes that were very close to failure as identified by the electromagnetic surveys.

Sometimes one unexpected pipeline problem can compel long term planning and action, as it did with CRMWA. The Water Authority now has a defined plan to assess the condition of their pipeline, giving them the confidence to move forward with greater assurance and peace-of-mind.

Man with fish inside pipe

After a long day,  Pure and CRMWA celebrated with a fish dinner, caught while draining the raw water line.

Fish inside a cooler

A ruptured sewer pipe can attract a lot of unwanted attention, even when it happens on private property. Last year, hours before celebrities were to arrive at the Golden Globes Awards show at the Beverley Hills Hotel, a reputed sewer pipe burst, spewing a mess of wastewater on the red carpet, according to media reports. When large pipes fail, it’s usually breaking news. And when the failed pipeline is part of a pressurized wastewater force main network, repercussions to the environment and the public have the potential to be catastrophic, with fallout to a utility’s reputation. In Canada, pressurized force mains that carry sewage make up only about 7.5 percent of the typical wastewater system compared to gravity mains. Because sewer force mains tend to run constantly, and often operate without redundancy, there is little opportunity to assess the pipes. When problems arise, and a critical force main is out of commission, the entire wastewater system can stop, causing overflows or the need to implement costly bypass pumping. Worse still, pollution generated by a raw sewage leak can flood to the surface and into a watercourse. Clean-up costs can be staggering and environmental impacts can be devastating.

PureRobotics device

The PureRobotics platform can assess the structural integrity of force mains and provide inline video to observe internal pipe conditions.

Force mains have unique signs of impending failure

Internally, force mains have unique warning signs of failure. Because of the sewage flow, trapped gas pockets can allow concentrations of hydrogen sulfide gas to be released from solution and subsequently convert to sulfuric acid by bacteria on the pipe wall, leading to corrosion of the pipe wall. As the pipe wall corrodes internally, it becomes weaker and more likely to fail unexpectedly. While corrosion and defect failures on sewer pipelines are a fact of life for wastewater utilities, these failures do not occur systemically. As a result, knowing when to replace and when to preserve assets through close inspection is more critical than ever.

SmartBall with extraction tool and controls

Managing force mains proactively can help utilities prevent environmental regulation violations that are expensive to mitigate.

Addressing the high consequence of failure in wastewater pipes

Aging pipes, increasing costs of failures and high replacement costs represent significant challenges facing force main owners. As a result, utilities have come to rely on Pure Technologies for its suite of technologies that can identify the weak links. Selective rehabilitation of force mains maximizes the life of the asset, typically at 10-15 percent of replacement costs. Pure’s strategy employs a risk-management approach that looks at likelihood of failure (LOF) and consequence of failure (COF). LOF variables are related to the chance that a pipe could fail, and include: pipe age, material, operating conditions and soil conditions, among other things. COF variables may include the pipe size, its location, environmental and social consequences of a rupture, interruption to service and tarnished public reputations.

Low risk assessment

For low risk force mains, screening and desktop evaluations such as hydraulic analysis and pressure management within the system are often enough to manage the assets. As risk goes up, however, utilities should look at higher resolution technologies that offer more confidence for higher predictability.

Medium resolution assessment

The SmartBall® Pipe Wall Assessment (PWA) tool is Pure’s best technology for identifying leaks, gas pockets and wall stress locations in metallic sewer force mains. PWA technology looks at pipeline walls affected by loading and bedding conditions, as well as other factors that cause stress on the pipe, including structural damage caused by internal or external corrosion. As the free-swimming SmartBall tool rolls through the pipeline, it collects both acoustic and electromagnetic (EM) data. The acoustic sensor is used to identify the sound of wastewater leaving the pipeline, or more often, the sound of trapped gas at the top of the pipeline. Trapped gas within a force main may lead to internal corrosion and eventual breakdown of the pipe wall which is the primary cause of force main failures. In addition to the acoustic data, the SmartBall platform also collects EM data to identify areas of the pipe wall that are under stress. Areas of the pipe wall with damage will be under more stress than areas with limited or no damage. Stress on the pipe wall can also be caused by other factors such as excessive loading and hard bedding surrounding the pipe. Recent developments in SmartBall technology now allow for the combination of leak and gas pocket surveys with PWA surveys in a single deployment, providing a complete screening tool for force mains. Based on initial surveys using the SmartBall PWA tool, areas where gas pockets overlap with stress anomalies represent the largest area of concern of force main owners, as it indicates a high likelihood of corrosion.

High resolution assessment

In force mains with a higher risk, utilities should also consider assessment with a higher resolution tool in addition to a pre-screening survey that detects anomalous changes. For lines that cannot be taken out of service, Pure can deploy the PipeDiver tool, which uses electromagnetic sensors to detect areas of damage along the pipeline. The inline inspection system is an innovative, free-swimming condition assessment platform specially designed for in-service inspection of pressure pipelines. Configured with PureEM™ sensor arrays, the tool can be used with precision to identify wire breaks in PCCP and broad areas of cylinder corrosion in metallic pipe.

No one solution for every pipe or pipeline

While there is no silver bullet for assessing every pipeline, if a utility has a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows force main owners to develop a sustainable long-term strategy for managing their critical force main assets.

Water and sewer utilities across North America are facing a major funding gap related to their buried pipeline infrastructure. Based on current estimates, utilities do not have enough capital available to fix or replace their aging assets. In addition to the funding gap, utilities are under scrutiny because of increased incidences of pipeline failures that are disruptive to communities and expensive to mitigate.

This new reality has forced utilities to squeeze more remaining life out of existing assets, creating more demand for condition assessment programs that allow utilities to identify specific areas of damage and selectively repair pipelines in favor of full replacement.

Historically, condition assessment has been in the realm of a few specialized firms that respond to high profile pipeline failures; however, the industry has changed and condition assessment is becoming widely used and trusted. This approach has been adopted by many utilities that have successfully managed risk and extended the life of assets for a fraction of the cost of a replacement program.

According to a study by Pure Technologies, the majority of pipelines 16 inches and above can be cost-effectively managed for between 5 and 15 percent of the replacement cost. The study found that pipeline damage is typically not systematic across an entire pipeline, but is usually localized due to factors such as design, manufacturing, installation, environmental, operational or maintenance factors.

Equipped with this information, utilities can be assured that assessing the majority of their mains before replacement can reduce their infrastructure gap and extend the useful life of assets.

However, one question that often gets asked about condition assessment programs is how a utility should choose the right condition assessment solution.

The easiest way to solve this challenge is to employ a risk-based approach to condition assessment using a variety of tools that offer different resolutions.

Staff inserting tools

Defining Risk and Pipeline Priorities

Risk is a measure of the probability and consequence of uncertain future events, in this case, potential pipeline failure. A basic approach can be used to define risk even in complex systems; simply, risk is a product of Consequence of Failure and Likelihood of Failure (CoF x LoF).

Consequence of Failure (COF) refers to the damage a failure would cause based on factors like its location, the amount of users it supplies, and its size and operating pressure. Likelihood of Failure (LOF) refers to the probability of a failure occurring based on factors such as age, pipe material, soil conditions, operating pressure, failure history, among others.

Generally, the Consequence of Failure is well defined by the potential damage a pipeline failure would impose on the surrounding environment and is generally fairly static – or – once defined, it is unlikely going to change rapidly.

With this in mind the key to managing risk, or the possibility that a pipeline could fail, is in understanding the Likelihood of Failure. This can be achieved by quantifying the physical condition of the pipeline and understanding and quantifying the factors that affect the potential for deterioration of the assets.

Once risk is defined, the pipeline inventory can be prioritized which helps in the selection of condition assessment approaches and the application of the appropriate technologies. In general, high-risk pipelines warrant a detailed assessment while low risk pipelines can use lower resolution alternatives.

Using Risk to Select Condition Assessment Techniques

When selecting condition assessment techniques, qualifications and technical judgment should be used in lieu of price. High resolution tools come with a higher cost, but saving money on a low resolution condition assessment is not a responsible alternative for a high-risk main.

For example, the savings gained by selecting a low resolution technology for a large-diameter pipeline with a high CoF are often miniscule in comparison to the repair and capital programming decisions that result from the low resolution condition assessment data. If the data is inconclusive or inaccurate, a utility may unnecessarily invest millions in a capital replacement program that was not required, easily eliminating the savings achieved by selecting the less expensive condition assessment option.

Tech monitoring results

Additionally, the cost of a failure should be considered when selecting a lower-cost assessment for a critical pipeline. The average cost of a large-diameter pipe failure is between US $500,000 and $1.5 million; money saved on lower-resolution assessments can easily be negated by the cost of mitigating a single failure and the resulting reputational damage.

One method of selecting a technology is to compare uncertainty to risk. As mentioned earlier, risk is a measure of the probability and consequence of uncertain future events. When dealing with a high-risk asset, it is important that the solution allows the utility manager to minimize the uncertainty of the condition assessment. More importantly, it is crucial that the utility manager knows the condition of the asset to the best extent possible, particularly in areas where there is a high Consequence of Failure.

Pure Technologies has a suite of condition assessment tools with different resolutions. Our low resolution solutions can provide basic condition data on leaks, air pockets and areas of pipe wall stress that could represent damage. This is a valuable prescreening option for high-risk mains, or alternatively for lower risk mains, can be enough detail for a utility to manage the asset.

Pure’s medium and high resolution tools provide more comprehensive data for higher risk pipe. Our high resolution tools can provide detailed accuracy, for example, locating small pits on metallic pipe. The data collected from both medium and high resolution tools is often used by utilities to create rehabilitation plans for critical mains.

Regardless of the solution provider, it is important that utilities employ a balanced, risk-based approach to condition assessment that uses appropriate tools. The most important factor a utility owner can remember is that there is no silver bullet to assess an entire system.

For decades, the best way to manage aging pipeline assets was using instinct, which was a precarious method at best. However, with the development of new methods for managing critical water assets, operators are more equipped than ever to manage risk in a way that allows for scientifically defensible and cost-effective decisions.

In March/April edition of Water Canada Magazine, the Regional Municipality of Peel will be featured for its risk management approach to managing its existing and new infrastructure. The article outlines the project’s objectives and how Peel Region is attempting to manage risk with its new water assets.

Read Full Article in Water Canada Magazine »

The Peel water supply system has a total of 4,500 water mains that cover 700 kilometers. The pipe diameters in the system range from 300 to 2,100 millimeters with seven pressure zones.

Meanwhile, Peel’s population is expected to grow from its current 1.3 million to approximately 2.5 million in the next two decades. The region needs to fund new infrastructure while also maintaining the existing aging pipes, all within the constraints of a rate-based water supply system that is supplemented with new development charges.

One approach the region is taking to accommodate a growing population is constructing new transmission mains. The Hanlon Water Project will construct a new 2400-millimeter (96-inch) Prestressed Concrete Cylinder Pipe (PCCP) transmission main. The water main construction project is the largest in Peel’s history and will run approximately 14.5 kilometers from the Lakeview Water Treatment Plant on Lake Ontario to the Hanlan Reservoir and Pumping Station at Tomken Road and Britannia Road East.

With the construction of a new PCCP pipeline, Peel Region is taking the opportunity to make its infrastructure smarter using advanced monitoring technology. In total, 14.5 kilometers (9 miles) of new pipe will be equipped with SoundPrint® Acoustic Fiber Optic technology, which monitors the condition of PCCP in real-time.

The monitoring system is able to record the acoustic signature of prestressing wire breaks in the pipe. In PCCP, the high-strength steel prestressing wire wraps are the main structural component – as these wires begin the break, specific pipe sections become weaker and more likely to fail. Each time a wire wrap breaks, Peel Region will receive a notification with the location of the wire break, allowing them to track how many wire breaks have occurred on each pipe section. This will allow the region to intervene once a pipe section has an undesirable number of wire breaks and is at risk of failure.

However, beyond preventing potential pipe failures, the monitoring system will also allow the asset to be monitored for its entire service life, which is rare for most pipelines, which typically begin to get monitored at some point during their service life. In theory, with regular maintenance, the monitored PCCP mains could have an indefinite service life, since deterioration will be tracked and mitigated on an ongoing basis.


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Assess & Address Pipeline Management Program

Pipeline Monitoring

Providing real-time critical data of a prestressed pipeline allows the asset owner to effectively monitor changes in structural integrity and address necessary improvements.

WSSC needed to repair a 54-inch Prestressed Concrete Cylinder Pipe (PCCP) that was near failure. The decision was made after WSSC’s Acoustic Fiber Optic (AFO) Monitoring system, which is installed on about 75 miles of WSSC’s PCCP, identified several wire breaks in a short period of time.

The alternative, however, would have been much worse.

Had the pipeline failed, residents in Prince George’s County would have been without water for much longer than a few days. A failure would have also been more expensive than proactively replacing a pipe section, since more excavation and restoration is required to remediate a failed pipe. Luckily, four WSSC workers were able to fix an old valve, which allowed water to be diverted to residents and prevented complete water shut off.

WSSC explains the seriousness of the situation

“We wouldn’t be doing this if there wasn’t an imminent problem with this pipe.”

WSSC spokesman Jim Neustadt on WTOP Radio.

“[The acoustic system] tells us this pipe is headed out… We can’t just sit back and wait.”
– WSSC spokesman I.J. Hudson in the Washington Post.

Another WSSC official suggested a failure to the 54-inch pipe would have similar effects to previous failures WSSC has seen.

“Think about River Road when that water main exploded in 2008, and there was a pouring of water going down River Road. We don’t want this situation to end up like that.”

– WSSC spokeswoman Lyn Riggins on WTOP radio.

PCCP is concrete pipe that’s reinforced by high-strength steel wires; as wires in a pipe section snap, the pipe becomes more likely to fail. The AFO system used by WSSC identifies these wire breaks as they occur, and when the number reaches a certain limit, WSSC is advised to intervene on specific pipe sections to prevent failures.

After WSSC began experiencing major PCCP failures in the 1970s, it developed a strong commitment to infrastructure management technology in favor of large capital replacements. Beginning in 2007, WSSC and Pure Technologies began a partnership to create and Assess and Address™ PCCP management program. The program combines the early-warning system with regular condition assessment of its large-diameter pipes using inline leak detection and electromagnetic technologies.

WSSC in the news

Several stories surrounding the pipe intervention focused on how WSSC is managing its PCCP pipelines to prevent costly pipeline failures.

WSSC early warning system
Watch how WSSC is addressing its aging infrastructure by identifying the most critical problems using state-of-the-art inspection and monitoring technology. [ Source: WUSA9 ]
WUSA9 Story
See how WSSC’s monitoring system identified the problem in Prince George’s County to avoid a major pipeline failure. [ Source: WUSA9 ]
Gary Gumm Interview at WYSA9
WSSC’s Chief Engineer Gary Gumm outlines how challenging managing critical infrastructure is and what WSSC is doing to ensure that its customers have reliable service. [ Source: WUSA9 ]

WSSC is the 8th largest water and wastewater utility in the United States, serving over 460,000 customer accounts and 1.8 million residents in Montgomery and Prince George’s County, Maryland (suburban Washington D.C.). WSSC operates nearly 5,500 miles of water mains, with approximately 145 miles comprised of large-diameter Prestressed Concrete Cylinder Pipe (PCCP) equal to or greater than 36-inches in diameter.

The Washington Post Covers the Pipe Intervention

The Washington Post produced two notable stories providing information for Prince George’s residents, as well as discussion on why the intervention happened.

Four WSSC workers helped avert disaster by fixing defective valve

For almost 12 hours on July 16, WSSC mechanics chiseled years of thick rust off gears that corrosion had frozen in place and then fashioned new gears out of the gunked-up pieces of metal. By doing this, WSSC was able to isolate a shorter section pipeline to make repairs on the damaged 54-inch pipe section and avoid shutting down water service completely to Prince George’s residents.

To see the full story in the Washington Postclick here.

To see a video from WUSA9 on how workers closed the valve, click here.

Through management of its critical PCCP transmission mains, WSSC continues to show strong commitment to renewing its aging infrastructure and providing quality service to residents in its area.

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemnented for only a fraction of the capital replacement cost.

Case Study

Case Study Download: Washington Suburban Sanitary Commission

Beginning in 2007, WSSC and Pure Technologies began a partnership to create a comprehensive PCCP management program for WSSC’s large-diameter transmission mains. The Washington Suburban Sanitary Commission (WSSC) is the 8th largest water and wastewater utility in the United States, serving over 460,000 customer accounts and 1.8 million residents in Montgomery and Prince George’s County, Maryland (suburban Washington D.C.)

Metropolitan Water District of Southern California (MWD) is a regional wholesaler providing drinking water to nearly 19 million people at a rate of 1.7 billion gallons of water per day. In March 2013, (MWD) completed approximately 8 miles of electromagnetic (EM) inspection on a 78-inch water transmission main.

EM inspections locate and quantify the amount of wire breaks in PCCP pipelines, which is one of the main indicators that a pipeline will eventually fail.

The project also included visual and sounding inspection, structural curves and Acoustic Fiber Optic (AFO) monitoring installation for 4.5 miles of the transmission main. The visual and sounding is used to get an immediate assessment on the pipeline and to determine if there are any sections of pipe that are in an eminent state of failure. AFO was installed to monitor deterioration as it happens. The technology monitors the condition of prestressed pipe by recording the amount of wire breaks in each pipe section in real time. The AFO system allows MWD to track pipeline deterioration and together with the structural curves identifies at-risk pipes before they fail.

Due to the size and importance of this pipeline, the shutdown window for inspection and installation was very short and required careful planning and execution by MWD. The entire process was successfully completed in less than four days, well ahead of the planned schedule.

AFO Spool
Robotics Set Up

By combining the data from the EM inspections and activity on the AFO monitoring system, MWD can identify the amount of wire breaks on each section of pipe and prevent costly failures and service disruptions.

In terms of reducing NRW, locating leaks on large-diameter transmission mains represents the best opportunity for improvement. Leaks on small-diameter distribution mains are the most common, but the volume of water lost from these leaks represents a much smaller percentage of NRW than leaks on large-diameter pipes. Focusing leak and theft detection on transmission mains is the first step in a NRW-reduction strategy.

With over 2,000 miles of large-diameter pipelines inspected, Pure Technologies has located more than 4,000 leaks for an average of 2.2 leaks per mile using advanced inline leak detection technologies. Locating these large-diameter leaks has significantly reduced NRW, saved millions of gallons of water and helped prevent failures for utilities around the world.

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Pipeline Monitoring

Pipeline Monitoring

Providing real-time critical data of a prestressed pipeline allows the asset owner to effectively moniture changes in structural integrity and address necessary improvements.

Free-Swimming Pipeline Inspection

Electromagnetic Pipeline Inspection

Electromagnetic testing provides the best condition assessment data for large diameter PCCP (AWWA C301) and BWP (AWWA C303) pressure pipelines.

After prestressed wire break activity on the Cutzamala Pipeline, The Mexican National Water Commission (CONAGUA) intervened on two pipe sections that were near failure.

The wire breaks were identified by an Acoustic Fiber Optic (AFO) monitoring system that detects wire breaks on pipelines that utilize prestressing wires for structural stability; however, CONAGUA took quick and decisive action to prevent a failure.

After shutting down the pipeline, it took only 24 hours to assemble a crew that included almost 100 people to verify and replace the damaged sections and return the critical pipeline to operation. One of the distressed sections had visible corrosion while the section directly next to it had wire break activity but no visible damage.

The prevention of a major failure was crucial, as the Cutzamala system supplies water to about 5 million people living in Mexico City. The system features two parallel pipelines that stretch about 75 kilometers and are made 99-inch Prestressed Concrete Pipe (PCP) and Prestressed Concrete Cylinder Pipe (PCCP). Both pipe designs utilize high strength steel prestressing wire as the primary strength member. PCP differs from PCCP slightly in that it does not have the steel cylinder core, but instead is made of stronger concrete.

CONAGUA currently has AFO technology installed on about 70 kilometers (43 miles) of the two pipelines combined. The technology monitors the condition of prestressed pipe by recording the amount of wire breaks in each pipe section. The system allows CONAGUA to track pipeline deterioration and identify at-risk pipes before they fail.

Pipe Excavation
Pipe Scanner

Pipeline monitoring was initially adopted for the Cutzamala system due to a number of failures that disrupted service. After realizing that complete replacement was too expensive and unrealistic, CONAGUA decided to install AFO. The results have been positive so far, with the system identifying wire breaks along the monitored sections, allowing for the successful preventative repair of pipe sections.

In July 2012, CONAGUA also completed an electromagnetic (EM) condition assessment of the Cutzamala pipelines using PipeDiver® technology, a free-swimming tool that allows for non-destructive condition assessment of pipelines while they remain in service. The tool travels through the pipeline with the flow of water, collecting electromagnetic (EM) data that is analyzed to understand the baseline condition of the pipe.

The EM assessment provided CONAGUA with a baseline condition for each pipe section, while the monitoring system alerts operators about wire breaks on specific sections as they happen.


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Pipeline Monitoring

Pipeline Monitoring

Providing real-time critical data of a prestressed pipeline allows the asset owner to effectively monitor changes in structural integrity and address necessary improvements.

As part of a comprehensive pipeline management program, Washington Suburban Sanitary Commission (WSSC) and Pure Technologies have been monitoring sections of Prestressed Concrete Cylinder Pipe (PCCP) using Pure’s Acoustic Fiber Optic monitoring since 2007.

In October 2012, WSSC took the opportunity to proactively verify a 0.5 mile section of the River Road transmission main that had experienced elevated wire break activity. The individual pipes to be rehabilitated were selected from a comprehensive list of all monitored pipelines that contains all pipe sections that have an elevated risk of failure according to Finite Element Analysis and a combination of data sets, primarily collected from electromagnetic (EM) inspections and AFO monitoring.

AFO Install

This is part of a new drive from WSSC to initiate repairs on pipelines experiencing a high number of wire breaks before the situation becomes critical and prior to the normal 5 to 6-year inspection cycle.

Using an EM verification tool and internal visual and sounding, Pure verified all the wire breaks recorded with AFO and determined that all of the pipes were significantly more distressed than they were two years ago after the initial EM inspection.

In addition to the wire breaks, a hollow section was found on one of the pipes that signals a broad loss of prestressed wires. This hollow section was not found during the initial EM inspection and shows that the pipe section was beyond its allowable amount of wire break damage.

The verification of the four damaged pipe sections on River Road shows WSSC’s commitment to preventing pipeline failures through ongoing proactive pipeline management.

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Pipeline Monitoring

Pipeline Monitoring

Providing real-time critical data of a prestressed pipeline allows the asset owner to effectively moniture changes in structural integrity and address necessary improvements.

Pure Technologies is currently installing Acoustic Fiber Optic (AFO) monitoring on the Cutzamala pipeline in Mexico in an ongoing four phase project that started in 2010.

The initial phase of the project began in 2010 with the installation of about 25 kilometers of AFO, as well as a data acquisition and management system (DAQ) in the Pericos Tank. The second phase, which is currently being completed by the Pure Technologies team, will complete the remainder of the middle portion of the line with 47 kilometers of fiber and a DAQ in the St. Isabel Tank.

AFO technology monitors the condition of prestressed pipe by tracking the amount of wire breaks in each pipe section. The system allows a utility to monitor pipeline deterioration and see at-risk pipes before they fail. The four phase project was organized by priority, with the highest-risk areas of the system receiving AFO first.

Because of a number of failures before the AFO system was installed, the utility became more conscious of their pipeline condition, but realized it was unrealistic and too costly to replace the entire line, leading to the decision to adopt AFO. Since the completion of phase one, the results have been very successful; there has been a lot of acoustic activity on the pipelines, which has allowed the utility to detect and identify distressed pipes and prevent failures.

AFO Installation
AFO Up Close

Phases three and four will be completed in 2013 and 2014. Phase three will install about 30 kilometers fiber from the Torre TO-5 to the St. Isabel Tank with a DAQ in each tank. The final phase will install about 48 kilometers of fiber from the Pericos Tank to the Analco Tunnel, with an additional two DAQ’s.

The Cutzamala pipeline runs from the State of Mexico to the border of Mexico City and is one of the most important transmission mains in the country, supplying water to about 5 million people living in Mexico City. There are two parallel pipelines in the Cutzamala system each about 75 kilometers long.


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Pipeline Monitoring

Pipeline Monitoring

Providing real-time critical data of a prestressed pipeline allows the asset owner to effectively moniture changes in structural integrity and address necessary improvements.

Pipeline Inspection Services

Pipeline Inspection Services

Our suite of pipeline services give operators information which enables them to implement cost-effective and proactive risk management systems and timely and targeted rehabilitation or replacement programs.

Pure Technologies pinpointed wire breaks on a large-diameter water main in Tucson using Acoustic Fiber Optic monitoring, possibly preventing a major failure.

On August 13, Tucson Water went into emergency mode when several wire breaks occurred in a short period of time on one of its 96-inch Prestressed Concrete Cylinder Pipe (PCCP) water transmission mains, indicating there was a high risk of failure. Tucson Water was able to react quickly to the wire breaks by reducing the pressure in the pipe and diverting water from another main to serve its customers, subsequently preventing a failure.

In the following days, Pure and Tucson Water verified the pipe and found it to be more damaged than originally expected, requiring more repairs. The condition of the pipe made it clear that Tucson Water’s decision to shut down and repair the line immediately prevented a failure.

This same pipeline failed in 1999 about 700-feet upstream from this pipe, dumping 38 million gallons of water into neighborhoods and costing the city $2.5 million. Since that time, Pure has been working with Tucson to develop a pipeline management program including electromagnetic (EM) assessment and AFO monitoring. Tucson Water was the first utility in North America to install an AFO system throughout their entire PCCP inventory.

Below is an ABC News 4 Tucson story outlining how Tucson Water’s AFO system identified an at risk pipe before it failed.

Pure and Tucson Water will continue to monitor the large-diameter water mains in Tucson to identify areas of distress and proactively repair pipe sections.




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Assess & Address Pipeline Management Program

Pipeline Monitoring

Providing real-time critical data of a prestressed pipeline allows the asset owner to effectively moniture changes in structural integrity and address necessary improvements.

Pure Technologies worked with Baltimore City Public Works on July 16, 2012 to dig up a 54-inch pipe section that was ready to fail along the Gwynns Falls/Southwestern Transmission Main.

The excavated pipe section was severely damaged, and had it failed, would have caused significant damage, inconvenience and financial cost. The removal of the distressed pipe section shows Baltimore City’s commitment to preventing major failures in The City’s water system.

A feature story on WBAL-TV 11 from July 17 shows Pure working on verifying their results of the Gwynns Falls/Southwestern Transmission Main.

Pipeline Inspection in Baltimore
Water Main Repairs Get Expensive

Pure engineers inspected this line in March 2012 using PipeDiver® — a free-swimming tool that uses Electromagnetics (EM) to detect broken prestressing wires in Prestressed Concrete Cylinder Pipe (PCCP) – and found that the pipeline had wires broken in several sections.

In recent months, the situation became critical and removal of a severely damaged pipe section was strongly recommended when prestressing wires began breaking more frequently. The increase in wire break activity was detected early on through Pure’s Acoustic Fiber Optic (AFO) monitoring system that was installed during a 2007 project with Howard County. This system gives utilities an early warning alarm when pipelines begin to rapidly deteriorate, ultimately allowing the utility to resolve problems early on and prevent catastrophic failure.

After the city shut down and dewatered the transmission main, Pure’s team mobilized on site to inspect the distressed pipe section more closely. In the verification process, the wire break locations were confirmed through impact testing. Two large cracks were also found upon visual inspection, which created a hollow section in the pipe, confirming Pure’s suspicion that a failure could have occurred at any time.

Pure also inspected the distressed pipe section with an EM verification tool. After a combined analysis of data collected from the EM tool, PipeDiver®, and the AFO monitoring system, a good correlation was found between the distressed locations predicted by all three technologies. As a result, the damaged pipe was removed from the ground and the pipe was returned to operation on Saturday, July 21, 2012.

Through proactive measures, The City of Baltimore was able to avoid a major failure that would have caused significant disruptions to service and substantial financial cost. The City is committed to Pure’s proactive approach in pipeline management to continue preventing major failures.


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PipeDiver® Draws Media Attention for Baltimore

PipeDiver® Draws Media Attention for Baltimore

In early March, a group of reporters and video crews from local news stations gathered around the insertion site for a high profile PipeDiver® electromagnetic inspection in Baltimore, Maryland. It was necessary to perform the inspection without shutting down service to residents.

Free-Swimming Pipeline Inspection

PipeDiver® – Free-Swimming Pipeline Inspection

Specifically designed for structural assessment of Prestressed Concrete Cylinder Pipe (PCCP) lines that are live or can’t be taken out of service due to a lack of redundancy or operational constraints.


Managing Prestressed Concrete Cylinder Pipe (PCCP)

Large diameter prestressed concrete cylinder pipelines (PCCP) are a significant investment for many water and wastewater agencies. Assessing and monitoring the condition of these pipes is becoming an increasingly important and challenging task.


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.


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


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.


  • 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.


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


  • 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.