Glendale addresses its water leakage problem. It cost the city over $300,000 last year.

Over the last five years, the portion of water leaking out of Glendale's utility system has more than doubled, and the city is looking to find and fix the leaks, which could save Glendale thousands of dollars.

At the Oct. 9 common council meeting, Charlie Imig, Glendale’s director of public works and Tom Nennig, director of engineering for City Water LLC, described the city’s background water leakage problem and asked the council to commission a study to fully assess and assuage the issues. The council voted unanimously in favor of commissioning the study.

The city purchases its water from the North Shore Water Commission and then bills residents based on their use.

What is background water leakage and how much is acceptable?

But not all of the water the city pays for ends up in residents homes. Some of that “non-revenue water” is used for city activities like firefighter training and water quality flushing. And some of it is documented by the city when it fixes water main breaks and service leaks. But much of it never sees the light of day, Nennig said.

Every water distribution system has background leakage — undetected water main or service leaks that do not surface above ground, Nennig said.

“If we don’t know about them, we can’t fix them,” he said.

Public works officials in southeast Wisconsin agree that the goal is to keep the estimated background leakage below 5%, Nennig said.

In 2017, the estimated volume of Glendale's unbilled water was around 5.85% of the volume of water purchased from the North Shore Water Commission. By 2021, that figure nearly tripled, rising to 17.51%, although it did ease somewhat the following year to 15.47%.

In 2017, the estimated dollar value of the water lost to undetected background leakage was approximately $124,659. In 2022, it was $341,926. These estimates are based on the utility’s annual bill from the North Shore Water Commission for providing water to the City of Glendale.

While residents aren’t directly billed for the lost water, the cost of it pushes water rates that residents pay higher, Imig said.

New staff members brought the water issue to light

Staff turnover within village government brought a new awareness to the issue, he said. “We're looking at these numbers a lot closer than we used to. The objective was, ‘hey, this is a higher number. Let's see what we can do about it,’” he said.

Information on background water leakage is gleaned from the Public Service Commission of Wisconsin’s annual report, which tracks utility services in Wisconsin.

Study will employ satellite technology to detect the leaks

For the study, the city will contract with Asterra, a company that detects leaks using AI and algorithms, to conduct a one-year leak detection survey. The study will use satellite technology that detects soil moisture caused by water leaks, according to the memo Imig and Nennig submitted to the council. Analyzing the this data, Asterra will identify flagged areas throughout the city that may have a leak.

A leak detection crew will then manually survey the targeted areas that have a high possibility of a leak. This process allows crews to focus on pinpointing suspected leaks as opposed to conducting an acoustical survey of the entire city to try and find the areas to try and pinpoint a leak, according to the memo.

Asterra is giving the City of Glendale a discount of $21,000 to complete the scan of the city, since the work will be completed at the same time Asterra does scans for the Milwaukee Water Works and other communities in the Milwaukee Area. The total cost of the study is $23,000 and is scheduled to start this fall.

Imig said the project will ultimately decrease the city’s lost revenue from background water leakage. The city will have to pay the cost of repairing the leaks, but in the long run, he said, the city will save money.

If the leak detection survey identifies two average-sized service leaks, each losing 10,000 gallons a day, the cost or survey will pay for itself within a year, said Nennig.

Contact Claudia Levens at Follow her on X at @levensc13.

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This article originally appeared on Milwaukee Journal Sentinel: The city of Glendale is addressing its growing water leakage problem