Following years of pressure and dedicated work by CSWAB, the Army announced this week that it will be offering a contract for the removal of mercury-contaminated sediments at Gruber’s Grove Bay on Lake Wisconsin (and not the sand cover suggested by the Wisconsin DNR)!
The Army plans to award a technology-specific contract for a vacuum-type dredge utilizing a sediment curtain this year. The actual bay cleanup will be completed in 2020.
The primary public health concern associated with mercury in the bay is contamination of fish tissue. Mercury accumulates in fish tissue as methylmercury. This form of mercury presents the greatest risk to human health through consumption of contaminated fish. Testing by the U.S. Army confirmed that mercury levels in game fish caught in Gruber’s Grove Bay are higher than found in fish in the rest of the Wisconsin Riverway.
Despite two previous dredge actions, approximately 16 acres of Gruber’s Grove Bay of Lake Wisconsin still contains mercury-impacted sediment. Mercury concentrations in certain areas of the bay are as high as 6.3 milligrams per kilogram (mg/kg), far above the cleanup goal of only 0.36 mg/kg established by Wisconsin DNR.
During active production years, Badger Army Ammunition Plant discharged industrial wastewater directly to Lake Wisconsin resulting in the contamination of lake bottom sediments. Sediment contaminants include lead, copper, arsenic, ammonia, nitroglycerine, PCBs and methylmercury – the most toxic form of mercury. Mercury is a highly toxic element and there is no known safe level of exposure. Ideally, neither children nor adults should have any mercury in their bodies.
THANK YOU to all the individuals, organizations and donors who actively supported our campaign!
More information and our petition are posted online at: https://cswab.org/news-action/alerts/.