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Newton Creek/Hog Island Inlet Remediation

The Department of Natural Resources has been working on investigation and cleanup of contaminated sediments and floodplain soils in Newton Creek and Hog Island Inlet in the City of Superior since the early 1990’s. An investigation completed in 1995 found that ecological impacts associated with the contamination were severe. In 1996 the Department signed a Memorandum of Understanding with Murphy Oil USA, Inc. under which Murphy agreed to clean up the upstream impoundment area and an upstream segment A of Newton Creek and provide $200,000 towards the cleanup of Hog Island Inlet. Bureau of Remediation and Redevelopment staff oversaw that work and continued the investigation of the remainder of Newton Creek and Hog Island Inlet. In 2003, four thousand cubic yards of contaminated sediments and floodplain soils were removed from segments of Newton Creek. The Department was successful in obtaining funding from a Coastal Restoration Grant through the Wisconsin Coastal Management Program ($250,000), the Great Lakes National Program Office ($300,000), the Wisconsin Great Lakes Harbors and Bays Fund ($100,000) and the Bureau of Remediation & Redevelopment’s Environmental Repair Fund to complete the cleanup of impacted soils and sediments.

Work began on the final stage of the cleanup on Newton Creek and Hog Island Inlet in June 2005. Earlier in the year a project agreement was signed by the Great Lakes National Program Office and the Department under which 65% of the project costs would be covered through the Great Lakes Legacy Act with the remainder coming from the Bureau of Remediation and Redevelopment’s Environmental Repair Fund, Murphy Oil and other local sources. The project was completed on November 17 under budget and on schedule.

During the project, 60,000 tons of contaminated sediment was disposed of at the City of Superior landfill. Impacted sediment containing PAHs, lead, VOCs and metals was dredged and sorted based on lead content. Approximately half of the material containing over 50 parts-per-million (ppm) of lead was disposed of as waste at the landfill, with the other half containing less than 50 ppm of lead, beneficially used as landfill cover. The sediment removal was largely accomplished “in the dry” through a dewatering process using pumps. Water that met background turbidity and mercury limits was discharged into the St. Louis River until sampling indicated that these limits would be exceeded, at which point the water was discharged through the City’s wastewater treatment facility. During the dewatering process, a “fish rescue” operation took place which resulted in over 1,800 fish, 138 freshwater clams, and 38 painted turtles being transferred from the inlet into the river.

This project marks the first time contaminated sediments have been removed from a toxic hot spot in the St. Louis River Area of Concern, an important step in returning the AOC to full public use. This project has been successful due to partnerships between local governments,federal and state agencies, local industries, and the St. Louis River Citizens Action Committee. Extensive coordination between DNR programs was required to make this project a success. In addition to the human health hazard that has been eliminated, Hog Island Inlet has significant potential for recreational uses and fish and wildlife habitat and discussions are currently underway with a number of stakeholders to discuss the enhancement of these values in this restored waterway.