Copenhaven V STP - Secondary Wastewater Treatment in Town of Denmark, New York

Copenhaven V STP is a municipal wastewater treatment facility located on Mill Street in the Village of Copenhagen, within the Town of Denmark, Lewis County, New York. The plant serves a population of approximately 865 residents, classifying it as a small community system under US regulatory frameworks. The plant provides secondary treatment, a standard level required by the US Clean Water Act for municipal facilities. With a designed capacity of 416.39 volume units and an average daily discharge of 370.97 volume units, the plant operates at about 89% capacity, indicating consistent utilization. As a small plant in a rural area, it is subject to state-level NPDES permitting through the New York State Department of Environmental Conservation. The treated effluent is discharged into nearby streams that drain into the Black River watershed, eventually reaching Lake Ontario. This water body is part of the Great Lakes system, which supports diverse aquatic life and provides drinking water for millions. The plant's operation helps protect downstream water quality in this ecologically significant region.

The plant discharges into local tributaries of the Black River, which flows into the eastern basin of Lake Ontario. Lake Ontario is the easternmost Great Lake and supports a complex ecosystem including native fish species and migratory birds. The watershed is primarily rural with agricultural land use, making nutrient management important to prevent algal blooms in the lake.