GRANT TOWNSHIP — An estimated 400,000 gallons of partially-treated wastewater made its way through soil, sand and, eventually, into Lake Superior earlier this month after a leak was discovered in the Copper Harbor Wastewater Treatment Center.
According to the Keweenaw Report, Copper Harbor Municipal Services Superintendent Tom Wierciak discovered that the primary holding tank had an abnormally low water level during a routine check of the facility in Grant Township. Upon further investigation, Wierciak found an area of bedrock along the lakeshore that he believed showed signs of discharge from a leak.
He then notified the Michigan Department of Environmental Quality.
“Grant Township has been very responsive. They did their notification procedure immediately. I requested they also notify the [Western U.P.] Health Department to see if they had any concerns,” said Randy Conroy, the district geologist with the Michigan DEQ.
The Western U.P. Health Department waived testing for bacteria of Lake Superior. Conroy said this was due to the fact that not many people are using that recreation area this time of year.
As for the permanent residents of the area, there is no current threat to public safety or contamination of drinking water.
“The well field providing the water supply for the Grant Township residents is much further south and this seepage, the release, migrated the opposite direction, to the north,” said Conroy. “There’s no direct contact possibility based on the current circumstances.”
Wierciak believes that the liner in the primary treatment holding tank developed a leak. The liner is 28 years old and has a life expectancy of 35 years, and Wierciak told Keweenaw Report that the liner should not have failed.
He also said that the water that seeped out of the liner was not raw sewage, but was partially treated.
Grant Township is currently working with OHM, a Hancock-based civil engineering firm, to determine the best way to repair the liner. The facility is currently able to continue processing its current intake (estimated to be around 4,000 gallons per day) by diverting sewage to a partitioned secondary tank.
The DEQ is citing the township for an unauthorized discharge violation.