RIPLEY - Large construction machines with long booms removing sediment from the bottom of Portage Lake in Ripley are remediating some of the legacy of the copper mining era.
Linda Hanson, Michigan Department of Environmental Quality water resources division regulator working in the Department of Natural Resources district headquarters in Baraga, said the removal of the sediment is the result of an application by Marion, Ind.-based Indiana-Michigan Power Company.
"It was a voluntary clean up of impacted sediments," she said.
Daily Mining Gazette/Kurt Hauglie
Workers from White Lake Dock & Dredge of Montague, Mich. are seen removing sediment from Portage Lake in Ripley Friday. The site was where a coal-to-gas manufacturing plant existed from the early 20th century.
The property where the clean up is taken place used to be the site of a manufactured gas plant built in the early 20th century, Hanson said.
The dredging work is being done by White Lake Dock & Dredge of Montague, Mich., Hanson said. The application for the work permit indicates the plan is to remove 2,500 to 6,000 cubic yards of sediment.
Hanson said before the permit was issued, a two-year-long review of the proposed project was done, including any possible impact on water quality or aquatic life.
"This was highly scrutinized," she said.
The Army Corps of Engineers, which oversees work done to navigable waters, also issued a permit for the work, Hanson said.
In a May 2008 article in the Gazette, Amy Keranen, DEQ remediation and redevelopment division environmental quality analyst in Calumet, said coal tar was found on the site by crews from the Environmental Protection Agency, and it was decided remediation should take place.
In 1904, Keranen said for the 2008 article, the property was acquired by the Portage Lake Gas and Coke Company and buildings were constructed to turn coal into gas, which typically was used for lighting and heat for industry and residences. In 1907, ownership changed to Houghton County Gas & Coke. In 1928, ownership changed again to Michigan Gas and Electric Company. There have been other name changes and owners since then. Another subsequent owner, American Electric Power based in Columbus, Ohio, intended to remove the coal tar in the summer of 2008.
Hanson said before the dredging started in the first week of November, some buildings, a dock and some pilings were removed. Dredging is expected to be completed by the end of November.
Hanson said the sediment removed from the lake is placed on the ground next to the water behind containment barriers so water can drain out of it. The water is collected and pumped to the Portage Lake Water and Sewage Authority treatment plant near Houghton. The sediment is taken to the K&W Landfill in Ontonagon for disposal.
"There's a lot of restrictions on their work," she said.