National Pollutant Discharge Elimination System(NPDES)

The National Pollutant Discharge Elimination System (NPDES) has made a significant impact on the improvement of our nation’s water quality.  The program, created in 1972 under the Clean Water Act, is responsible for controlling and regulating point sources of discharge of pollutants to waters within each state to maintain, protect, and restore the water quality of streams, lakes, and rivers. Point sources are discrete conveyances such as pipes or man-made ditches.

In 1990, Phase I of the NPDES stormwater program was established.  It required NPDES permit coverage for large or medium municipalities that had populations of 100,000 or more.  Nine years later (1999), Phase II of the NPDES Stormwater program was signed into law. This regulation builds upon the existing Phase I program by requiring smaller communities, also known as small municipal separate storm sewer systems (MS4s), to be permitted, and develop and implement a comprehensive stormwater management program that includes six minimum measures.

        Phase I of NPDES
         Who is Affected?     
         • Construction sites disturbing greater than five acres 
         • Companies that fall in one of the eleven categories of industrial sites  
         •  Large and medium municipalities (MS4’s) with populations
            100,000 or greater

        Phase II of NPDES 
        Who is Affected?     
       • Construction sites disturbing one to five-acres
        • Municipalities in urbanized areas not covered by Phase I,
          otherwise known as small MS4s.

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Legal Responsibilities Under NPDES

• Owners or operators who directly discharge stormwater from various categories of activities to waters of the state are required to obtain permit coverage.
• Permittees may be required to verify compliance with permit requirements by monitoring their discharge, maintaining records, and/or filing periodic reports.
   
  NPDES in the Clean Water Act, Section 402  

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EPA Stated Goals for NPDES

• By 2005, the EPA aims to increase the number of watersheds to meet water quality standards.
  If the goal is met by this date, 5,000 additional miles of U.S. waters will meet water quality standards and specific interim milestones will be achieved within 50,000 miles of impaired waters.
  
• By 2005, EPA aims to reduce pollutant loadings from key point and nonpoint sources by at least 11% from 1992 levels.
  If this goal is met, using both pollution control and prevention approaches, EPA will have reduced at least three billion pounds of pollutant source loadings from key sources including a combined 11% reduction from industrial sources, publicly owned treatment works, and combined sewer overflows.

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NPDES Permits

Under NPDES, industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters. 

Each state is unique!  In most cases, the NPDES permit program is administered by each authorized state and may require certain specific technical standards or procedures.  Owners, developers and contractors should check the state and local plan for specific permit requirements.   

Below is a summary of EPA’s requirements and the permit process.  Check with your state to find out specific requirements and permit applications.
 
Overview of NPDES Water Permit Process 
NPDES Strategic Permit Plan 

Search for State Permit Requirements

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