The canal behind Chapaton Pump Station on Nine Mile Road in St. Clair Shores. The Macomb County Public Works Office has increased the retention capacity to reduce treated combined sewer overflows by up to 30%.

The canal behind Chapaton Pump Station on Nine Mile Road in St. Clair Shores. The Macomb County Public Works Office has increased the retention capacity to reduce treated combined sewer overflows by up to 30%.

File photo by Patricia O’Blenes


Chapaton changes spell improvement for Lake St. Clair

By: Kristyne E. Demske | Metro | Published May 11, 2021

 The break wall at the end of the Nine Mile Pier behind Chapaton, as seen in June 2020.

The break wall at the end of the Nine Mile Pier behind Chapaton, as seen in June 2020.

File photo by Patricia O’Blenes

ST. CLAIR SHORES — Stating that the county wants to protect Lake St. Clair for generations to come, the Macomb County Public Works Office announced that changes made at Chapaton Pump Station in St. Clair Shores will prevent up to 30% more treated combined sewer overflows from being discharged into the waterway.

The office installed five new manhole covers and seals atop the 70-foot deep wet well inside the pump station, located at 23001 Nine Mile Road. Engineers then determined that the operational level inside the wet well could be increased to a higher elevation, allowing more combined sewage to be temporarily contained further upstream in the 12-foot diameter interceptor pipe.

Chapaton Pump Station was constructed in 1968 to handle the combined sanitary and stormwater overflows from Eastpointe and most of St. Clair Shores. When it collects more than it can handle, the excess is treated and discharged in a manner permitted by the state into Lake St. Clair.

“We have a permit from the state to do what we’ve been doing,” Macomb County Public Works Commissioner Candice Miller said in a YouTube video showcasing the improvements to Chapaton on April 29.

She said, however, that Macomb County officials don’t believe discharging treated combined sewage overflows, or CSOs, into the lake is something that should continue because “water quality equals quality of life.”

“This is our drinking water supply,” she said. “We can’t just keep pushing this onto the next generation.”

Fewer and smaller overflows in the Chapaton basin also save the county money on the amount of chemicals needed to treat CSOs.

Macomb County Public Works investigated new ways to reduce treated CSOs after the Michigan Department of Environment, Great Lakes, and Energy denied it a permit in 2020 to use the 1,400-foot man-made canal — through which treated CSOs travel to Lake St. Clair from the 28-million-gallon underground storage basin at Chapaton — as storage space for overflows. That project would have reduced the overflows by 80%. The new operational changes the department has been able to make, however, will reduce overflows by 25%-30%.

“This is a tremendous step forward,” Miller said. “We’re going to keep working at this thing.”

The changes will allow up to 8.6 million gallons to be stored upstream in the sewer system each year instead of being discharged as a treated CSO. Macomb County wants to be part of the solution, Miller said, not the problem.

“As much as we discharge, Oakland County discharges five times as much as we do. Wayne County, their numbers are off the charts,” she said.

Although the treated discharge meets all clean water standards, Miller said they want to do more.

“The largest room is the room for improvement. We can improve, and in Macomb County, we are committed to water quality,” she said. “There’s nothing more magnificent than our Great Lakes. Continuing to discharge our overflows, no matter how well they’ve been treated,” is not something the county wants to continue.