ST IGNACE STP, Saint Ignace

Overview

ST IGNACE STP serves Saint Ignace, Michigan, treating wastewater for approximately 2,678 residents. The plant discharges into the Straits of Mackinac, a critical waterway connecting Lake Michigan and Lake Huron.

ST IGNACE STP is a municipal wastewater treatment facility located in Saint Ignace, Michigan, on the northern shore of the Straits of Mackinac. The plant serves a small community of about 2,678 people, situated in Mackinac County in the Upper Peninsula. Its location near the Mackinac Bridge places it at a strategic point where Lake Michigan and Lake Huron meet. As a U.S. facility, ST IGNACE STP operates under the Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all point-source discharges. For a plant of this size, secondary treatment is typically mandated to meet effluent limits that protect water quality. The designed capacity is 1.00 million gallons per day, indicating the plant is sized for the local population. The plant's treated effluent is discharged into the Straits of Mackinac, a narrow waterway that connects Lake Michigan and Lake Huron. This area is ecologically significant, supporting diverse aquatic life including lake trout, whitefish, and migratory fish species. The Straits also serve as a vital shipping channel and are near the Hiawatha National Forest, adding to the environmental importance of maintaining high water quality standards.

Environmental context

ST IGNACE STP discharges into the Straits of Mackinac, which connects Lake Michigan to Lake Huron, part of the Great Lakes system. This waterway is ecologically sensitive, supporting cold-water fisheries and serving as a migratory corridor for fish species. The surrounding watershed includes forested areas and wetlands that contribute to the region's biodiversity. Protecting water quality here is critical for downstream ecosystems, including the St. Marys River and ultimately the Atlantic Ocean via the St. Lawrence Seaway.

Frequently asked questions

ST IGNACE STP is located on North State Street in Saint Ignace, Michigan, in Mackinac County. It sits near the Straits of Mackinac, close to the Mackinac Bridge connecting Michigan's Upper and Lower Peninsulas.

The plant serves approximately 2,678 residents of Saint Ignace and surrounding areas in Mackinac County. This classifies it as a small municipal wastewater treatment facility.

The plant discharges treated effluent into the Straits of Mackinac, a waterway connecting Lake Michigan and Lake Huron. The discharge is regulated under the Clean Water Act via an NPDES permit issued by the Michigan Department of Environment, Great Lakes, and Energy (EGLE).

ST IGNACE STP protects the Straits of Mackinac and the connected Great Lakes system, including Lake Michigan and Lake Huron. These waters flow into the St. Clair River, Lake St. Clair, the Detroit River, Lake Erie, and eventually the St. Lawrence River and Atlantic Ocean.

Under the Clean Water Act, municipal plants of this size typically require secondary treatment, which includes biological processes to remove organic matter and suspended solids. NPDES permits set specific effluent limits for biochemical oxygen demand (BOD), total suspended solids (TSS), and other pollutants to protect receiving water quality.