National Pollutant Discharge Elimination System Compliance Monitoring
CWA Topics
- National Pollutant Discharge Elimination System
- Pretreatment of Wastewater
- Biosolids
- Oil Spill Prevention
- Industrial Storm Water
- Concentrated Animal Feeding Operations
- Municipal Storm Water
- Wetlands
- Wastewater Trading Program
- Discharge Monitoring Report - Quality Assurance
As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States. Point sources are discrete conveyances such as pipes or man-made ditches. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit; however, industrial, municipal and other facilities must obtain permits if their discharges go directly to surface waters.
In most cases, the NPDES permit program is administered by authorized states. Since its introduction in 1972, the NPDES permit program is responsible for significant improvements to our nation's water quality.
Compliance Monitoring
EPA conducts inspections of facilities subject to the regulations to determine compliance. EPA inspections involve:
- reviewing discharge monitoring reports
- interviewing facility personnel knowledgeable of the facility
- inspecting the processes that generate and treat wastewater
- sampling wastewater discharges to navigable waterways and other points in the generation or treatment process
- reviewing how samples are collected and analyzed by the laboratory
NPDES inspection protocols can be found in Chapters 1 - 7 of the NPDES Compliance Inspection Manual.
The Clean Water Act NPDES Compliance Monitoring Strategy for the Core Program and Wet Weather Sources (PDF) (28 pp, 367K, About PDF) provides inpsection frequency goals for the core NPDES program and for wet weather sources including Combined Sewer Overflows (CSO), Sanitary Sewer Overflows (SSO), Concentrated Animal Feeding Operations (CAFO), and Storm Water.
The Clean Water Act/NPDES End of FY2005 Reporting for Section 106 Grant Program Analysis and Rating Tool (PART) Measure (PDF) (1 page, 33K, About PDF) displays regional data on significant noncompliance (SNC) rate trends for major NPDES permittees. Major permittees are in SNC based on self-reported data on effluent exceedances above permitted levels. SNC is also based on non-effluent limit violations such as:
- unauthorized bypasses
- unpermitted discharges
- pass-through of pollutants which cause water quality or health problems
- permit-schedule violations
- non-submission or late submission of permittee self-reported Discharge Monitoring Reports
- violation of a state or federal enforcement orders