Overview
WLSSD Regional WWTF serves Duluth, Minnesota, treating wastewater for approximately 110,000 people. The plant is located near the western tip of Lake Superior, the largest of the Great Lakes.
The WLSSD Regional WWTF is a major wastewater treatment facility serving the city of Duluth, Minnesota, and surrounding areas in Saint Louis County. With a population served of approximately 110,000, it is classified as a large agglomeration under US regulatory frameworks. The plant is operated by the Western Lake Superior Sanitary District (WLSSD), a regional authority responsible for wastewater treatment and solid waste management. As a US facility of this scale, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Minnesota Pollution Control Agency. These permits set strict limits on effluent quality to protect receiving waters. Plants of this size typically employ secondary or advanced treatment to meet permit requirements. The plant discharges treated effluent into the St. Louis River, which flows into the Duluth-Superior harbor and ultimately into Lake Superior. Lake Superior is the largest freshwater lake by surface area in the world and supports a diverse aquatic ecosystem, including native fish species such as lake trout and whitefish. The plant plays a critical role in protecting this sensitive Great Lakes environment from nutrient pollution and other contaminants.
Environmental context
The WLSSD Regional WWTF discharges into the St. Louis River, which flows through the Duluth-Superior harbor and into Lake Superior. Lake Superior is the largest of the Great Lakes and holds about 10% of the world's surface freshwater. Its cold, deep waters support a unique ecosystem with species like lake trout, burbot, and various native mussels. The river and harbor area are important for migratory birds and fish spawning. Protecting water quality in this watershed is critical due to the lake's long retention time and sensitivity to nutrient loading.
Frequently asked questions
The WLSSD Regional WWTF is located at 2540 South 27th Avenue West in Duluth, Minnesota, United States. It serves the city of Duluth and surrounding areas in Saint Louis County.
The plant serves approximately 110,000 people, classifying it as a large municipal wastewater treatment facility under US EPA guidelines.
The plant discharges treated effluent into the St. Louis River, which flows into the Duluth-Superior harbor and then into Lake Superior, the largest of the Great Lakes.
As a US facility, the plant operates under the Clean Water Act and is regulated by an NPDES permit issued by the Minnesota Pollution Control Agency. These permits set effluent limits to protect water quality.
Plants of this scale in the US typically employ secondary treatment (biological treatment) as a minimum, with many incorporating advanced treatment for nutrient removal to meet stringent NPDES permit requirements.
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