Phase II GIS-Based Sediment Quality Database for the St. Louis River Area of Concern (AOC) - Technical Documentation

In 1987, the St. Louis River was designated as one of 43 Areas of Concern (AOC) in the Great Lakes basin due to degradation of environmental quality conditions in the river and adjoining watershed (IJC 1989). Contaminated sediments contribute to several use impairments in the St. Louis River AOC, including the issuance of fish advisories, restrictions on dredging, and habitat impairments to bottom-feeding organisms. A number of ecosystem health indicators have been selected to support the assessment of sediment quality conditions within the St. Louis River AOC, including sediment chemistry, sediment toxicity, benthic macroinvertebrate community structure, tissue chemistry, the physical characteristics of sediments, and biomarkers in fish (Crane et al. 2000). Investigations conducted using data on multiple indicators provide a weight-of-evidence approach for assessing the effects of contaminated sediments on the beneficial uses of this aquatic ecosystem. Due to the large amount of sediment quality data that have been collected from the St. Louis River AOC since 1990, funding is being obtained by the MPCA and its collaborators in a phased approach to further the development of the GIS-based sediment quality database. The Duluth office of the MPCA recently changed the scope of GLNPO grant number GL97540401-2 in order to develop a comprehensive sediment management plan for the lower St. Louis River AOC. Continuation of the GIS-based database (i.e., Phase II) was identified as one task of this grant, for which Judy Crane is the MPCA project manager and Brian Fredrickson is the MPCA grant manager. MESL was retained in September 2003 to complete additional Phase I tasks and to conduct the Phase II updates of the GIS-based database and ArcView 3.2 projects. In addition, MESL was tasked with converting the ArcView 3.2 projects to a version compatible with a more recent version of ESRI's mapping software (i.e., ArcMap 8.3). A QAPP was completed and approved by GLNPO in May 2004 (Crane 2004) so that the Phase II work could begin.