• NPDES permits consist of at least five sections.
• Most states run their own Pollutant Discharge Elimination System permitting programs.

The permitting program for wastewater is the National Pollutant Discharge Elimination System (NPDES), which regulates discharges of pollution from point sources and is designed to limit the amount of pollutants that reach waters of the United States. The NPDES is responsible for issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing permits, and imposing and enforcing pretreatment requirements, under the Clean Water Act (CWA). While NPDES is a federal program, most states run their own Pollutant Discharge Elimination System permitting programs.

Discharge of a pollutant is defined as:

• Any addition of any “pollutant” or combination of pollutants to “waters of the United States” from any “point source,” or
• Any addition of any pollutant or combination of pollutants to the waters of the shoreline or the ocean from any point source other than a vessel or other floating craft which is being used as a means of transportation.
• This definition includes additions of pollutants into waters of the United States from: surface runoff which is collected or channeled by humans; discharges through pipes, sewers, or other conveyances owned by a state, municipality, or other person which do not lead to a treatment works; and discharges through pipes, sewers, or other conveyances, leading into privately owned treatment works. This term does not include an addition of pollutants by any “indirect discharger.”

A general permit is an NPDES permit issued under 122.28 authorizing a category of discharges under the CWA within a geographical area. The restriction on quantities, discharge rates, and concentrations of pollutants which are discharged from point sources into waters of the United States, shorelines, or the ocean are known as “effluent limitations.”

NPDES permits cover a wide range of industrial activities. The regulations related to the NPDES program are found in 40 CFR:

• Part 121 — State certification
• Part 122 — The federal NPDES permit program
• Part 123 — State program requirements
• Part 124 — Procedures for decision making
• Part 125 — Technology standards
• Part 129 — Toxic pollutant effluent standards
• Part 130 — Water quality planning and management
• Part 131 — Water quality standards
• Part 133 — Secondary treatment standards
• Part 135 — Citizen suits
• Part 136 — Analytical procedures
• Part 257 — State sludge disposal regulations
• Part 401 — General provisions for effluent limitations guidelines and standards
• Part 403 — General pretreatment regulations
• Parts 405-471 — Effluent guidelines
• Part 501 — State sewage sludge management program requirements
• Part 503 — Standards for use or disposal of sewage sludge

NPDES permits consist of at least five sections.

1. Cover page: Lists the name and location of the facility, a statement authorizing the discharge, and a listing of the specific locations for which a discharge is authorized.
2. Effluent limitations: The primary mechanism for controlling discharges of pollutants to receiving waters.
3. Monitoring and reporting requirements: Used to characterize wastestreams and receiving waters, evaluate wastewater treatment efficiency, and determine compliance with permit conditions.
4. Special conditions: Conditions developed to supplement numeric effluent limitations. Examples include additional monitoring activities, special studies, best management practices (BMPs), and compliance schedules.
5. Standard conditions: Pre-established conditions that apply to all NPDES permits and delineate the legal, administrative, and procedural requirements of the NPDES permit.

Fact sheet: The Environmental Protection Agency (EPA) says that in addition to the five sections listed above, a permit will always be accompanied by a fact sheet or statement of basis explaining the rationale for the permit conditions.