In 1994, natural resource personnel discovered lead poisoning problems from trap and skeet range operations at Nahant Marsh, Davenport, Iowa. Shortly thereafter, officials from Region VII of the U.S. Environmental Protection Agency (USEPA) and Region 3 of the U.S. Fish and Wildlife Service (USFWS) started to discuss the contaminant problems and solutions for Nahant Marsh.
The USEPA initiated site characterization work under their authorities in 1996. The USFWS was tasked to complete the first phase of the ecological risk assessment under an existing interagency cooperative agreement for Superfund technical assistance. The phase one work included a screening level assessment of lead shot contamination. The screening level assessment follows Steps One and Two of the eight steps for the Superfund ecological risk assessment process (USEPA 1997).
The eight steps in the ecological risk assessment process are outlined below (USEPA 1997).
| Step One | Screening level problem formulation, develop tentative assessment endpoints and toxicity affects evaluation. |
| Step Two | Screening level exposure estimates and risk calculations. |
| Step Three | Baseline problem formulation, in depth ecotoxicological literature review, develop conceptual model, evaluate exposure pathways, finalize assessment endpoints and risk questions. |
| Step Four | Develop measurement endpoints and study design |
| Step Five | Verification of study design. |
| Step Six | Site investigation and data analysis |
| Step Seven. | Risk characterization. |
| Step Eight | Risk management. |
A site history and the results of the screening level ecological risk assessment are contained in this report. Screening level problem formulation, exposure estimates and risk calculations for this assessment were based on field information collected by USFWS and field data collected by a USEPA contractor (Ecology and Environment, Inc., Overland Park, Kansas - E & E) Preliminary Assessment and Site Investigation reports.