An NPDES permit is typically a license for a facility to discharge a specified amount of a pollutant into a receiving water under certain conditions. The permit will contain limits on pollutant discharges, monitoring and reporting requirements, and other provisions to ensure that the discharge does not hurt water quality or human health. In essence, the permit translates general requirements of the Clean Water Act into specific provisions tailored to the operations of each facility discharging pollutants. The two basic types of NPDES permits issued are individual and general permits.
- An individual permit is a permit specifically tailored to an individual facility. Once a facility submits the appropriate application(s), the permitting authority develops a permit for that particular facility based on the information contained in the permit application (e.g., type of activity, nature of discharge, receiving water quality). The authority issues the permit to the facility for a specific time period (not to exceed five years) with a requirement that the facility reapply prior to the expiration date.
- A general permit covers a group of dischargers with similar qualities within a given geographical location. General permits may offer a cost-effective option for permitting agencies because of the large number of facilities that can be covered under a single permit.