Antrim WWTF - Secondary Wastewater Treatment Plant in Antrim, New Hampshire

Antrim WWTF is a municipal wastewater treatment facility located in Antrim, Hillsborough County, New Hampshire. The plant serves a population of approximately 1,052 residents, making it a small-scale facility within the state's wastewater infrastructure. The plant provides secondary treatment, which is the standard biological treatment process required by the U.S. Clean Water Act for municipal wastewater. With a designed capacity of 794.93 thousand gallons per day and an average discharge volume of 412.61 thousand gallons per day, the facility operates well within its capacity. As a U.S. plant, it operates under an EPA National Pollutant Discharge Elimination System (NPDES) permit issued by the New Hampshire Department of Environmental Services. The treated effluent is discharged into local streams that flow into the Contoocook River, a tributary of the Merrimack River. The Merrimack River ultimately drains into the Gulf of Maine, supporting diverse aquatic life and recreational uses. The plant plays a key role in protecting water quality in this inland watershed.

The plant discharges into small streams that feed the Contoocook River, which flows into the Merrimack River and eventually reaches the Gulf of Maine. This watershed supports diverse fish populations, including migratory species, and provides drinking water for downstream communities. The plant's secondary treatment helps reduce nutrient loading and protect aquatic habitats in this ecologically sensitive river system.