Mercury From Army Base Poisons The Wisconsin River

Mercury From Army Base Poisons The Wisconsin River

by Laura Olah, Executive Director of Citizens for Safe Water Around Badger

Despite tens of millions of dollars and scores of environmental studies by the U.S. Army and its contractors, serious contamination near Wisconsin’s Badger Army Ammunition Plant in south-central Wisconsin has gone undetected, placing our environment and our community in serious jeopardy. Prompted by the discovery of mercury contamination in the Wisconsin River by the Wisconsin Department of Natural Resources (WDNR), new studies reveal a toxic legacy reaching to all corners of the sprawling 7,400-acre Army Base.

In November 1998, the WDNR collected four sediment cores from Gruber’s Grove Bay — the outfall for all industrial wastewater discharges from the Badger plant. Analysis at the State Laboratory of Hygiene revealed extremely high levels of several heavy metals and ammonia. Levels of mercury (24 mg/kg) and lead (800 mg/kg) found in sediments were determined to pose a threat to humans and aquatic organisms from both bioaccumulation and direct toxicity. By comparison, mercury at concentrations up to 4 mg/kg was the focus of a contaminated sediment removal project at Starkweather Creek in nearby Dane County. Very high ammonia concentrations, which also represent a threat to aquatic organisms, ranged from 190 to 196 mg/kg.

The WDNR describes Gruber’s Grove as “probably one of the worst localized mercury contaminated sediment situations that we know about on a statewide basis.” Cleanup of the Lake Wisconsin bay, an impoundment of the Wisconsin River north of Prairie du Sac, may cost as much as $20 million.

The WDNR’s biggest concern is how the contamination is affecting the ecology of the lake. Biological studies confirmed benthic organisms were, in fact, nonexistent. Methylmercury levels were found as high 149 micrograms/kilogram (mg/kg). By comparison, the average level of methylmercury for the Wisconsin River, as a whole, is only 5.9 mg/kg.

Methylmercury is the form of mercury that builds up in the tissues of fish and other organisms and can have a devastating effect on aquatic ecosystems. Although mercury levels in fish caught in the bay are higher than found in fish in the rest of Lake Wisconsin, the WDNR said levels do not exceed the human health standard.

The WDNR’s findings have prompted re-examination of other areas at Badger. In an area known as the Settling Ponds, recent soil sampling has detected high levels of mercury, nitroglycerine, and other toxins. Cleanup of the Settling Ponds, a 67-acre site that spans the width of the plant, may cost as much as $56 million. Still other sites at Badger, including the Oleum Pond, located in the northeast corner near Devil’s Lake State Park, and the Ballistics Pond, located in the northwest corner, have mercury-contaminated sediments.

Badger Army Ammunition Plant was constructed in 1942 to produce propellant for cannons rockets, and small arms ammunition. Production occurred during World War II, the Korean conflict, and the Vietnam conflict. During these years, Badger employed as many as 10,000 workers. The base is currently inactive and is slated for closure.

Environmental studies conducted during the late 1970s and early 1980s discovered that contaminants such as propellant grains, dinitrotoluenes (an explosive), organic solvents, and acids had been released during production. Thirty-one sites were initially identified; total environmental cleanup costs at Badger may exceed $200 million.

Surface water and ground water resources in and around the Badger Army Ammunition Plant, located in the Wisconsin River Watershed, include 13 ponds within the site; some of the ponds are formed in borrow pits or are old farm ponds. Others are natural kettle ponds. Previous biological surveys have indicated these surface water resources provide valuable habitat for unique fauna, particularly aquatic beetles and amphibians. The largest water body on the site is the 7-acre Ballistics Pond, which drains about 1,000 acres north of the plant and 450 acres of plant property.

Ground water at Badger is hydrologically connected to the nearby Wisconsin River. Ground water contaminants — tricholorethylene, carbon tetrachloride, and chloroform — emanating from the Badger Plant — have migrated several miles offsite and have reached the Wisconsin River. The Wisconsin River, together with its associated tributaries and wetlands, provides drinking water, supports and sustains wildlife, and provides habitat for endangered species including the Mississippi Paddlefish and the American Bald Eagle.

During Badger’s active years, process and sanitary wastewater was discharged through shallow settling ponds to Gruber’s Grove Bay. Although the ammonia, lead, and zinc are readily traced to historical activities at Badger, the Army reports mercury was never used in the production of explosives; other potential sources for mercury at Badger are being investigated. Nonetheless, the Army has allocated funding for cleanup of contaminated sediments.

The remedial design work for cleanup at Gruber’s Grove Bay is currently underway. The cleanup involves dredging the bay and disposing of sediments inside the Badger property. The dredged materials are pumped into fabric tubes for dewatering while the water is treated and then spread on cropland at Badger. The Army will bury the dry-filled tubes in a 5-acre area inside the plant; community members have not supported creating this new disposal site at Badger.

In addition to our work to ensure that the environmental and ecological integrity of Gruber’s Grove Bay is restored, Citizens for Safe Water Around Badger is working to bring regional and national focus to the health of our rivers and aquatic ecosystems. In 1998, the WDNR’s fish advisory for mercury contamination stood at 321 lakes and rivers, including many of Wisconsin’s favorite fishing waters such as Lake Monona, Trout Lake, and segments of the Wisconsin – our largest river.

In the coming year, CSWAB will continue our work to bring together the community, legislators, regulators, local and tribal governments, and the U.S. Department of Army to restore the integrity of damaged natural systems at Badger including its air, various water sources, and soil. Through this community-based effort, we will build the foundation for a sustainable and healthy future.


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West Grand Boulevard Collaborative, & Yellow Dog Watershed Preserve.