MAPLETON STP - Secondary Wastewater Treatment Plant in Mapleton, Maine

MAPLETON STP is a municipal wastewater treatment facility located in Mapleton, Aroostook County, Maine, United States. It serves a small population of 638 residents from Mapleton, Castle Hill, and Chapman, operating as part of the region's public sanitation infrastructure. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 302.83 thousand cubic meters per year and an annual discharge volume of 264.98 thousand cubic meters, it operates below its capacity. Under the U.S. Clean Water Act, such facilities are regulated through National Pollutant Discharge Elimination System (NPDES) permits issued by the Maine Department of Environmental Protection, ensuring compliance with water quality standards. The treated effluent is discharged into local waterways that drain into the Aroostook River watershed, which flows into the Saint John River and ultimately into the Bay of Fundy. This freshwater system supports diverse aquatic life and is important for regional fisheries and recreation. The plant's inland location reduces direct marine impact, but its discharge contributes to the overall health of the watershed.

MAPLETON STP discharges into the Aroostook River watershed, which flows into the Saint John River and eventually reaches the Bay of Fundy. This inland freshwater system supports diverse aquatic species, including Atlantic salmon and brook trout, and is an important migratory corridor. The plant's secondary treatment helps protect downstream water quality by reducing organic pollutants and suspended solids before discharge.