Stratford Millhouse WWTF - Columbia, New Hampshire Wastewater Treatment

Stratford Millhouse WWTF is a municipal wastewater treatment facility located in Columbia, New Hampshire, within Coos County. The plant serves a small population of 168 residents, providing secondary treatment to meet state and federal water quality standards. The plant has a designed capacity of 75.71 thousand cubic meters per day and currently treats an average daily flow of 68.14 thousand cubic meters. As a secondary treatment facility, it uses biological processes to reduce organic matter and suspended solids before discharge. Under the US Clean Water Act, such plants must comply with National Pollutant Discharge Elimination System (NPDES) permits issued by the New Hampshire Department of Environmental Services. The treated effluent is discharged into local streams that drain into the Connecticut River, which flows southward to Long Island Sound. The plant plays a key role in protecting downstream water quality in this ecologically important river system, which supports diverse aquatic life and provides drinking water for communities along its course.

The plant discharges into tributaries of the Connecticut River, which flows through New Hampshire and Vermont before emptying into Long Island Sound. The Connecticut River watershed supports a variety of fish species, including Atlantic salmon and American shad, and provides critical habitat for migratory birds. Protecting water quality in this basin is essential for maintaining the ecological health of the river and the Sound.