We invite you to comment on the draft wastewater permit for Northshore Mining Co.
Northshore Mining Company operates a taconite processing facility and tailings basin located in Silver Bay.
The facility consists of the processing plant at Silver Bay, steam plant, fluoride treatment system, the Mile Post 7 tailings basin area, water treatment plant, the pipelines and rail lines that route wastes and process water between the processing plant and Mile Post 7, and the drainage area contributing surface runoff to the Mile Post 7 tailings basin.
The site also includes the former Silver Bay Power Company steam electric generating plant which was indefinitely idled in 2019. The processing plant draws water from Lake Superior at a maximum rate of 43.2 million gallons per day and discharges water not used in processing back to Lake Superior at the same maximum rate.
The Mile Post 7 tailings basin consists of a reclaim pond, seepage recovery ponds, a water treatment plant, and pressure relief wells. The water treatment plant is designed to discharge treated water to the Beaver River at an average and maximum rate of 6.0 and 7.5 million gallons per day. The pressure relief wells discharge to an unnamed tributary to the East Branch of the Beaver River at an average and maximum rate of 4,000 and 10,000 gallons per day.
The draft industrial wastewater permit limits total fluoride, pH, dissolved iron, amphibole fibers, total suspended solids, turbidity, and chronic toxicity from the tailings basin water treatment plant. The draft permit also limits dissolved iron, pH, and total suspended solids from the relief wells and pH from the Silver Bay Power plant. The draft permit also includes special requirements specific to iron-ore processing and the operation of the tailings basin and sets intervention limits for various parameters in the groundwater monitoring wells and downhill surface water monitoring locations.
For the draft permit, the MPCA calculated limits for fluoride in the draft permit using the primary drinking water standard, which assures the most protective limit to protect human health. The previous permit used the secondary drinking water standard to calculate final fluoride limits, which is meant to protect for aesthetic and cosmetic issues for a longer duration of consumption than the primary drinking water standard.
Wastewater from industrial and commercial sources may contain pollutants at levels that could adversely affect the water quality in area wetlands, streams, rivers, and lakes. Water quality permits - or National Pollutant Discharge Elimination System (NPDES) permits - establish specific limits and requirements to protect Minnesota's surface and groundwater quality. All wastewater must be treated before it goes into surface water to protect human health and aquatic life. Permits are regularly reviewed and updated as they expire, allowing the MPCA to incorporate new information about the impacts of pollutants on the environment in future permits
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We invite you to comment on the draft wastewater permit for Northshore Mining Co.
Northshore Mining Company operates a taconite processing facility and tailings basin located in Silver Bay.
The facility consists of the processing plant at Silver Bay, steam plant, fluoride treatment system, the Mile Post 7 tailings basin area, water treatment plant, the pipelines and rail lines that route wastes and process water between the processing plant and Mile Post 7, and the drainage area contributing surface runoff to the Mile Post 7 tailings basin.
The site also includes the former Silver Bay Power Company steam electric generating plant which was indefinitely idled in 2019. The processing plant draws water from Lake Superior at a maximum rate of 43.2 million gallons per day and discharges water not used in processing back to Lake Superior at the same maximum rate.
The Mile Post 7 tailings basin consists of a reclaim pond, seepage recovery ponds, a water treatment plant, and pressure relief wells. The water treatment plant is designed to discharge treated water to the Beaver River at an average and maximum rate of 6.0 and 7.5 million gallons per day. The pressure relief wells discharge to an unnamed tributary to the East Branch of the Beaver River at an average and maximum rate of 4,000 and 10,000 gallons per day.
The draft industrial wastewater permit limits total fluoride, pH, dissolved iron, amphibole fibers, total suspended solids, turbidity, and chronic toxicity from the tailings basin water treatment plant. The draft permit also limits dissolved iron, pH, and total suspended solids from the relief wells and pH from the Silver Bay Power plant. The draft permit also includes special requirements specific to iron-ore processing and the operation of the tailings basin and sets intervention limits for various parameters in the groundwater monitoring wells and downhill surface water monitoring locations.
For the draft permit, the MPCA calculated limits for fluoride in the draft permit using the primary drinking water standard, which assures the most protective limit to protect human health. The previous permit used the secondary drinking water standard to calculate final fluoride limits, which is meant to protect for aesthetic and cosmetic issues for a longer duration of consumption than the primary drinking water standard.
Wastewater from industrial and commercial sources may contain pollutants at levels that could adversely affect the water quality in area wetlands, streams, rivers, and lakes. Water quality permits - or National Pollutant Discharge Elimination System (NPDES) permits - establish specific limits and requirements to protect Minnesota's surface and groundwater quality. All wastewater must be treated before it goes into surface water to protect human health and aquatic life. Permits are regularly reviewed and updated as they expire, allowing the MPCA to incorporate new information about the impacts of pollutants on the environment in future permits
Contact Information
*Indicates Required Fields