St. Louis River, the largest U.S. tributary to Lake Superior,
drains 3,634 square miles, entering the
southwestern corner of the lake between
Duluth, MN and Superior, WI. The river flows 179 miles through three
distinct areas; coarse soils, glacial till and outwash deposits at
its headwaters; a deep narrow gorge at Jay Cooke State Park; and red
clay deposits at its lower reaches. As the river approaches Duluth
and Superior it takes on the characteristics of a 12,000 acre (4856
hectare) freshwater estuary. While the upper part of the estuary has
some wilderness-like qualities, the lower portion is decidedly urban.
The RUSS will be located in this lower urban portion.
The lower St. Louis River is one of 42 Areas of Concern (AOC)
in the Lake Superior basin. An AOC is a site that has serious
environmental pollution problems that require remedial action
and the development of a Remedial Action Plan (RAP) to outline
ways to restore the area. See EPA GLNPO for more information
on the Great Lakes AOCs. The Minnesota Pollution Control Agency
has a web page that discusses contaminated sediments within the
St Louis River.
A large publically owned wastewater treatment plant (Western
Lake Superior Sanitary District, WLSSD) discharges below the
potential RUSS site and the river carries a heavy load of suspended
sediments from non-point sources. The river also has a number
of sites known to contain contaminated sediments.
The lower St Louis provides good fish habitat and is an excellent
warm water fishery. However, the recent invasion of exotic fish
(Eurasian ruffe and round goby) may threaten native fish populations
Sea Grant exotic species ).