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Water: Habitat Protection

Overview of EPA Authorities for Natural Resource Managers Developing Aquatic Invasive Species Rapid Response and Management Plans: CWA Section 402-The National Pollutant Discharge Elimination System (NPDES)

What is CWA Section 402?

CWA Section 402 establishes the NPDES permit program to regulate point source discharges of pollutants into waters of the United States. An NPDES permit sets specific discharge limits for point sources discharging pollutants into waters of the United States and establishes monitoring and reporting requirements, as well as special conditions. (For more information about the NPDES permit program, see http://cfpub.epa.gov/npdes.)

EPA is charged with administering the NPDES permit program, but can authorize states to assume many of the permitting, administrative, and enforcement responsibilities of the NPDES permit program. Authorized states are prohibited from adopting standards that are less stringent than those established under the Federal NPDES permit program, but may adopt or enforce standards that are more stringent than the Federal standards if allowed under state law. At the time of publication, 45 states and the Virgin Islands have assumed NPDES authority.2 (See http://cfpub.epa.gov/npdes/statestats.cfm for a list of states with full or partial NPDES authority and http://cfpub.epa.gov/npdes/contacts.cfm?program_id=45&type=STATE for contact information for state NPDES authorities.)


Does CWA Section 402 apply to AIS rapid response or control actions?


Hydrilla Verticillata.
Photo by Raghavan Charudattan, University of Florida.

An interpretive statement issued by EPA in January 2005 stated that the application of a pesticide to waters of the United States consistent with all relevant requirements under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) does not constitute the discharge of a pollutant (and consequently does not require a Federal NPDES permit) in the following two circumstances:

  • the application of pesticides directly to waters of the United States to control pests. Examples of such applications include applications to control mosquito larvae, aquatic weeds, or other pests that are present in the waters of the United States.

  • the application of pesticides to control pests that are present over waters of the United States , including near such waters; that results in a portion of the pesticides being deposited to those waters, for example, the aerial application of pesticides to waters of the United States. Examples include aerial applications of insecticides to a forest canopy where waters of the United States may be present below the canopy, or applications of pesticides over or near water for control of adult mosquitoes or other pests.

EPA notes that the application of a pesticide in violation of FIFRA is not covered by the interpretive statement, and the applicator is subject to enforcement actions under any and all appropriate authorities including, but not limited to, FIFRA and CWA. EPA has proposed incorporating the 2005 interpretive statement into regulations. Further information can be found at 70 Fed. Reg. 5093 (February 1, 2005)


For more information about FIFRA and FIFRA compliance, see the FIFRA Section of this document, the EPA Pesticide Registration Program website www.epa.gov/pesticides/factsheets/registration.htm, or the National Pesticide Information Center website http://npic.orst.edu/brochure.pdf. Exit EPA Disclaimer (PDF, about PDF)


Continue to CWA Section 404 >>

2 At the time of publication, the only states that have not assumed either full or partial NPDES authority are Alaska, Idaho, Massachusetts, New Hampshire, and New Mexico.

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