British Columbia Municipality Takes Proactive Approach to Water Loss, Pairing Inline and External Leak Detection Solutions
By Justin Hebner & Chris Wike
The Resort Municipality of Whistler (RMOW) is nestled in the scenic Coast Mountains of British Columbia, Canada. When RMOW was incorporated in 1975, fewer than 1,000 people lived in Whistler. It has since grown from a winter sport paradise to a year-round destination resort with 14,000 permanent residents and more than three million annual visitors.
Whistler is expected to see strong, sustained growth, but this brings challenges for the region’s water supply. Whistler’s total water use has been steadily climbing, and the community set a new peak water demand record during the summer of 2021.
Climate change is creating more challenges for Whistler’s water supply. Water demand is highest in the summer months when fire risk is high. Wildfire emergencies are growing in number and severity while reductions in winter snowpack could stress water supplies.
Developing more infrastructure to increase water supply would be cost prohibitive for the community. RMOW is committed to finding better ways to manage their existing supply and infrastructure. For these reasons, water conservation is vital to helping Whistler meet growing water demand while minimizing environmental impacts. In 2019, RMOW launched a proactive leak detection and condition assessment program as part of their water conservation and supply plan.
The Case for Condition Assessment
RMOW operates nearly 200 km (~145 miles) of water mains with 20 individual pressure zones. While their water distribution infrastructure is relatively new, it still requires ongoing investment to reduce water loss and ensure reliable service.
In 2018, a failure on the Lorimer Road main caused a water shortage in Whistler Village just before a mountain biking festival. Tourism fueled by this event leads to some of the water system’s highest demand days. The break caused water in municipal reservoirs to fall below fire storage levels. RMOW moved to Stage 4 water conservation for the first time — a move they anticipated using only during severe drought lasting several months.
Excavating the damaged pipe, installed in the early 1990s, revealed extensive corrosion. RMOW wanted to assess the remainder of the pipeline and others in their high-pressure transmission system to identify areas of concern and determine the level of risk.
A Holistic Approach to Water Loss
In 2019, RMOW partnered with Pure Technologies, a Xylem brand for leak detection and condition assessment services. Over the past three years, the team has assessed close to 12 kilometers of water mains ranging in diameter from 150 to 600 millimeters (~6 to 24 in.) using an inline, free-swimming acoustic tool to pinpoint leaks and air pockets on these critical pipelines.
The noise produced by pressurized water forcing its way through a crack, pinhole, or joint makes a distinct sound. This sound is commonly used to identify leaks. However, inline inspection tools are ideal for large-diameter pipelines because they bring the acoustic sensor inside the pipeline, directly to the leak. These tools can pinpoint very small leaks. They can also discern between multiple leaks along a section of pipeline and determine whether the leak is on the pipe barrel, at a joint, or on a feature such as a valve.
Complimenting this approach, external leak detection was completed on the distribution system in four different pressure zones across Whistler. This is where RMOW expected to find the most leaks.
External leak detection tools are an effective, non-invasive way to locate leaks on distribution pipelines. Utilities can and should use a combination of leak detection methods to cost-effectively reduce real water loss and improve the efficiency and reliability of their network.
Leak inspections can identify problem areas — such as corrosion, deteriorated joints, and cracking — before they result in a pipe failure. By proactively identifying and repairing leaks, utilities can save money and prevent the damage and disruption of a failure. Knowing the frequency and location of leaks can also help utilities prioritize pipelines for more detailed assessment.
In 2021, the program expanded to include the inline inspection of three wastewater force mains. In addition to leaks, Pure Technologies’ SmartBall platform also identifies gas pockets. Internal hydrogen sulfide corrosion is a leading cause of force main failure and starts when gas pockets form inside the pipeline. If caught early, gas pockets can be mitigated and damage averted by installing and maintaining air release valves.
Force main failures and leaks threaten water quality and public health. Whistler thrives because of the region’s outstanding outdoor recreation opportunities, so protecting source waters and the surrounding watershed is imperative for RMOW.
First Inspections in 2019
The Lorimer Road and Alta Lake pipelines were the first prioritized for inspection in RMOW’s Water Leakage Reduction Program. These ductile iron water mains are responsible for providing a critical supply of water throughout Whistler. RMOW was particularly interested in collecting data on a section of the Alta Lake pipeline that runs below the lake and was installed in 1987.
Pure Technologies inspected both pipelines for leaks and air pockets using the free-swimming, inline SmartBall platform. The team inserted the tool into the pipelines at the 21 Mile Pump Station and extracted it from RMOW fire hydrants. Deploying the tool through these existing features and inspecting while the pipeline remained in service prevented down time for Whistler customers. Sensors placed along the pipelines tracked the tool’s progress in real time. This enabled RMOW to keep service connections open for as long as possible. Tracking also results in more accurate data that is less sensitive to flow changes.
The SmartBall platform identified one large leak on the Lorimer Road water main. Contractors verified and repaired the leak by replacing a tee and valve cluster. Leaks on transmission mains can greatly impact water loss volumes, especially when left undetected. Proactive leak detection can also prevent costly failures, particularly in metallic pipelines, like the Lorimer Road main, that tend to leak before breaking.
The team also collected more than 30 days of detailed pressure data on both the Lorimer Road and Alta Lake water mains to better understand their hydraulic loading conditions. Surge pressures put a significant amount of stress on the pipeline, and they can cause a pipe to fail especially when combined with pipe wall degradation and air pockets.
Transient pressure monitoring indicated that structural fatigue was not a concern on either the Alta Lake or Lorimer Road water mains. Using pressure data, external loading information, and wall thickness based on pipe class, Pure Technologies determined that the thickness of both pipelines exceeds ANSI/AWWA C150 design standards.
Pure Technologies partnered with Watermark Solutions, Ltd. to perform external leak detection surveys on smaller water mains within RMOW’s network. Their first survey included three kilometers of distribution mains and service lines in Whistler’s Alta Vista Neighborhood. Trained operators used advanced ground microphone technology to audibly detect pressurized leaks on pipelines, water services, valves, and hydrants. The team identified three leaks within the Alta Vista Neighborhood. Once identified, they pinpointed the leaks with digital correlator technology and found that all three were located on domestic services.
Watermark Solutions also calculated the internal roughness coefficient of the water mains in the Alta Vista Neighborhood. C-Factor analysis provides a measure of the pipe’s interior condition and indicated that the system was in good condition.
What’s Next for Whistler’s Water?
Since 2019, inspections have taken place each fall during Whistler’s low demand period. The team has detected and verified two large transmission main leaks as well as a force main gas pocket located at a creek crossing.
In addition to the leak at Lorimer Road, the SmartBall platform also identified a leak on the 300-mm Mons Road Pipeline. This plastic water main was buried under about three meters of cover, and there were no visible signs of a leak on the surface. Inline leak detection was the ideal solution for this pipeline given the depth of cover and the fact that sound does not travel well in plastic pipe. The number of bends in the pipeline also made locating the leak challenging. However, with the tool’s magnetometer data, the team pinpointed the leak location using storm grates and a nearby fire hydrant as reference points.
RMOW partnered with an engineering firm and contractor to excavate, confirm, and repair both large leaks. The precision of the leak detection technology helped the contractor make efficient repairs — reducing shutdown times and limiting excavation.
External leak detection surveys have identified 10 distribution leaks across four neighborhoods on water mains, service lines, inline valves and a hydrant. With most of these leaks on domestic services, RMOW is working with homeowners to ensure the water loss is addressed.
RMOW is encouraged by the results of the inline and external leak detection surveys and plans to continue assessing additional pipelines in their network.
Authors
Justin Hebner is business development manager, Western Canada, with Pure Technologies, a Xylem brand. He is responsible growing for Pure Technologies’ pipeline condition assessment services and has 15 years of experience in the water and wastewater industry.
Chris Wike is utilities group manager, infrastructure services, with the Resort Municipality of Whistler in British Columbia.
