Point source pollution is contamination discharged from a single identifiable source, such as a pipe, ditch, or outfall. It is regulated under the Clean Water Act through the NPDES permit system.
Point source pollution refers to water contaminants that enter a water body from a discrete, identifiable conveyance such as a pipe, ditch, channel, tunnel, or concentrated animal feeding operation. Common point sources include municipal wastewater treatment plants, industrial facilities, power plants, and stormwater systems in urbanized areas. The Clean Water Act defines point sources broadly and requires them to obtain National Pollutant Discharge Elimination System (NPDES) permits that specify effluent limits for various pollutants. NPDES permits are based on technology-based effluent limitations and, where necessary, more stringent water quality-based limits to meet ambient water quality standards. Significant progress has been made in reducing point source pollution since the passage of the Clean Water Act in 1972, with secondary treatment now standard at most municipal wastewater plants. Despite these improvements, combined sewer overflows, sanitary sewer overflows, and industrial discharges remain significant sources of water quality impairment. Point source controls are generally more straightforward to implement and enforce than non-point source measures because the discharge location and responsible party can be clearly identified.