GUIDANCE FOR THE USE AND APPLICATION OF SEDIMENT QUALITY TARGETS FOR THE PROTECTION OF SEDIMENT-DWELLING ORGANISMS IN MINNESOTA

In Minnesota, contaminated sediments represent one of several nonpoint sources of nutrients and toxic chemicals to the overlying water of stormwater ponds, wetlands, lakes, harbors, and rivers. In affected sediments, complex chemical and physical interactions affect the mobility and bioavailability of contaminants to bottom-feeding (i.e., benthic) organisms. The Minnesota Pollution Control Agency (MPCA) is responsible for the assessment, management and remediation, or cleanup, of contaminated sediment sites in Minnesota. Staff members from several programs within the MPCA are involved in this effort. The goals are to protect human health and the environment, to restore water bodies to unimpaired uses, and to achieve applicable water quality standards. Currently, the MPCA does not have sediment quality standards. Specific indicators (e.g., sediment chemistry) can be used to determine if the designated uses of the aquatic ecosystem are being protected, and where necessary, restored. A suite of sediment quality indicators were developed for the St. Louis River Area of Concern (AOC) in northeastern Minnesota (Crane et al. 2000). These indicators can be used in other areas of Minnesota to assess sediment quality.