The Nahant Marsh Superfund Site is located at 4220 Wapello Avenue, City of Davenport, Scott County, Iowa. The Nahant Marsh Superfund Site includes about 115 acres of wetland and adjacent upland cover all of which are part of a 500 acre marsh complex. Between 1969 and 1995, a private gun club used the marsh for a trap and skeet shooting range. An estimated 243 tons of lead shot were deposited in a 70 acre portion of the marsh based on gun club shooting records. As a result of U.S. Environmental Protection Agency (EPA) directed a remedial investigation, feasibility study and removal action for the Site paid for out of the Superfund account.
The remedial investigation and risk assessments determined that an area of 20 acres in the marsh and 3 acres of soil cover between the marsh and the shooting platforms posed unacceptable risks to human health and the environment. A removal action was designed for these 23 acres. About 60,000 cubic yards of contaminated marsh sediments and surface upland soils were removed and temporarily stored in a 10 acre open field within the property for treatment and disposal. The excavated sediment and soils were treated with a phosphate compound and transported to the Scott County landfill for use as intermediate cover materials.
The removal action was completed between February and May 1999 and was coordinated with the U.S. Fish and Wildlife Service (FWS). The slope of the upland area was re-graded to as close as possible to the original contours and re-seeded with a cover of an annual plant species. The marsh substrate and shoreline contours were shaped to enhance the habitat for wildlife and left as open water areas.