Sewage overflow no threat to groundwater

Graham Jaehnig/Daily Mining Gazette The North Houghton County Water and Sewage Authority experienced two combined sewer overflow (CSO) discharges with the recent heavy rains, but the discharge is no threat to the public, as the CSO stations treat the water before discharging it.

CALUMET TOWNSHIP — The North Houghton County Water and Sewage Authority reported a combined sewer system discharge on Aug. 31, and again on Sept. 2, but there is no threat to the public or to groundwater.

The discharge was reported to the Department of Environmental Quality, said Township Supervisor Paul Lehto, which is a requirement of state law. The facility is designed to meet final performance criteria specified in a permit, according to the DEQ, and the cause of the discharge was excess rain, and is referred to as a combined sewer overflow (SCO).

There are two CSO stations in the township, Lehto said. One is near the Bi-Centennial Arena, and the other one is On First Street. The First Street SCO station was the one to discharge both times, and the water was discharged into St. Louis Creek, according to a report from the DEQ.

Lehto said that such a discharge occurred with the flooding on June 17, and has actually happened a couple of times since then.

In heavy rains, the CSO stations catch the rain, chlorinate it, and it discharge it, Lehto said.

“The CSO stations are permitted by the DNR (Department of Natural Resources), and we have to report it every time they discharge. We haven’t had a problem with them since they’ve been installed.” In addition to being permitted by the DNR, the stations were designed by that department, and the water is tested twice, once going in and once going out, said Lehto.

He said that the two stations are some 30 years old, and are being replaced as part of the sewer project.