National Pollutant Discharge Elimination System Sample Clauses

National Pollutant Discharge Elimination System. The CWA generally prohibits point source discharges of pollutants into waters of the United States without an NPDES permit. A point source is any discernible, confined and discrete conveyance, such as a pipe, ditch, channel, tunnel, conduit, discrete fissure or container. It also includes ves- sels or other floating craft from which pollutants are or may be discharged. By law, the term point source also includes concentrated animal feeding operations, which are places where animals are confined and fed. Significantly, Congress exempted agricultural stormwater discharges and return flows from irrigated agriculture from the definition of point sources, even when it is collected and discharged from a pipe, ditch or other discrete conveyance. Discharge of storm water from municipal separate storm sewer systems require an NPDES permit. Regulatory Authorities and Stakeholders The CWA’s NPDES Program recognizes three categories of pollutants: » Conventional pollutants include biological oxygen demand (BOD), total suspended solids (TSS), coliform, pH, and oil and grease. » Toxic pollutants are designated by EPA as those pollutants or combination of pollutants, including disease-causing agents, “which after discharge and upon exposure, ingestion, inhalation or assimilation into any organism, either directly from the environment or indirectly by ingestion through food chains” will “cause death, disease, behavioral abnor- malities, cancer, genetic mutations, physiological malfunctions (including malfunctions in reproduction) or physical deformations, in such organisms or their offspring.” Thus far, EPA has designated 65 categories of toxic pollutants under the CWA. » Nontoxic nonconventional include any pollutants not included in the first two categories but that still might pose a threat (e.g., ammonia and heat). NPDES permits include discharge limits and monitoring requirements. Discharge limits are based on technology and on WQS, and may be based on the mass of pollutant allowed to be discharged, the concentration of the pollutants in the effluent, indicator concentrations, effluent toxicity, efflu- ent flow rate or visual observations (e.g., sheen, foam, or floating solids). To find out if a discharge is covered by an NPDES permit, call the EPA Regional office or the state office responsible for issu- ing NPDES permits. A state must calculate a water quality-based limitation for a NPDES discharger where there is a reasonable potential that a discharger will cause...