by Todd Feurer, CBS Chicago web producer

CHICAGO (CBS) — Hoping to resume installing water meters in homes with lead service lines without increasing the risk of contamination, city officials plan to test new ultrasonic meters in 150 homes in Chicago.

Mayor Lori Lightfoot paused the installation of traditional water meters in homes with lead service lines last July, after tests found 22% of homes tested since 2017 had elevated lead levels in the tap water after meters were installed.

Now the city is planning a pilot program to study new technology, ultrasonic water meters which use sound waves to measure the amount of water flowing in a pipe rather than a rotating disc inside the pipe.

The city’s Department of Water Management wants to know if the new technology would be a viable alternative to traditional water meters.

“The City of Chicago is committed to providing clean, safe drinking water for every resident that meets or exceeds EPA guidelines,” the mayor said in a statement. “This study represents the next step in determining our path forward toward providing our city’s communities more affordable drinking water that prioritizes their health and safety, and helps us create a solution to resume the MeterSave program.”

The city is seeking 150 volunteers to have ultrasonic meters installed in single-family homes, where crews will test tap water for lead levels before and after new meters are installed.

The city’s Water Management Department said tests in a small number of homes where ultrasonic meters already have been installed so no significant change in existing lead levels.

“We are committed to studying new methods of meter installations so that resuming the MeterSave program becomes a reality,” said Water Management Commissioner Randy Conner. “It is our hope that during this study the ultrasonic meters will show no association with residential lead levels.”

The Chicago Tribune reported in November 2018 that, even after learning nearly 1 in 5 homes with water meters had elevated lead levels, the city continued installing new meters under Mayor Rahm Emanuel.

The city has since offered free filter sets, certified to remove lead, to all 165,000 homes with water meters.

The U.S. Environmental Protection Agency has found that lead levels in tap water can spike when lead service pipes are physically disturbed by water main replacements, meter installations, or street work.