An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

National Pollutant Discharge Elimination System (NPDES)

NPDES Permit Basics

  • What is an NPDES permit?
    • The Clean Water Act prohibits anybody from discharging "pollutants" through a "point source" into a "water of the United States" unless they have an NPDES permit. The permit will contain limits on what you can discharge, monitoring and reporting requirements, and other provisions to ensure that the discharge does not hurt water quality or people's health. In essence, the permit translates general requirements of the Clean Water Act into specific provisions tailored to the operations of each person discharging pollutants.
  • What is a point source?
    • The term point source is also defined very broadly in the Clean Water Act because it has been through 25 years of litigation. It means any discernible, confined and discrete conveyance, such as a pipe, ditch, channel, tunnel, conduit, discrete fissure, or container. It also includes vessels or other floating craft from which pollutants are or may be discharged. By law, the term "point source" also includes concentrated animal feeding operations, which are places where animals are confined and fed. By law, agricultural stormwater discharges and return flows from irrigated agriculture are not "point sources"
  • What is a water of the United States?
    • The term water of the United States" is also defined very broadly in the Clean Water Act and after 25 years of litigation. It means navigable waters, tributaries to navigable waters, interstate waters, the oceans out to 200 miles, and intrastate waters which are used: by interstate travelers for recreation or other purposes, as a source of fish or shellfish sold in interstate commerce, or for industrial purposes by industries engaged in interstate commerce.
  • What is a pollutant?
    • The term pollutant is defined very broadly in the Clean Water Act . It includes any type of industrial, municipal, and agricultural waste discharged into water. Some examples are dredged soil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial, municipal, and agricultural waste. By law, a pollutant is not sewage from vessels or discharges incidental to the normal operation of an Armed Forces vessel, or certain materials injected into an oil and gas production well.
  • Do I need an NPDES permit?
    • It depends on where you send your pollutants. If you discharge from a point source into the waters of the United States, you need an NPDES permit. If you discharge pollutants into a municipal sanitary sewer system, you do not need an NPDES permit, but you should ask the municipality about their permit requirements. If you discharge pollutants into a municipal storm sewer system, you may need a permit depending on what you discharge. You should ask the NPDES permitting authority.
  • How do NPDES permits protect water?
    • An NPDES permit will generally specify an acceptable level of a pollutant or pollutant parameter in a discharge (for example, a certain level of bacteria). The permittee may choose which technologies to use to achieve that level. Some permits, however, do contain certain generic 'best management practices' (such as installing a screen over the pipe to keep debris out of the waterway). NPDES permits make sure that a state's mandatory standards for clean water and the federal minimums are being met.
  • Can the general public participate in NPDES permitting decisions?
    • Yes. The NPDES administrative procedures require that the public be notified and allowed to comment on NPDES permit applications. When EPA authorizes a state to issue NPDES permits, EPA requires that the state provide the public with this same access .
  • How are the conditions in NPDES permits enforced by EPA and the states?
    • There are various methods used to monitor NPDES permit conditions. The permit will require the facility to sample its discharges and notify EPA and the state regulatory agency of these results. In addition, the permit will require the facility to notify EPA and the state regulatory agency when the facility determines it is not in compliance with the requirements of a permit. EPA and state regulatory agencies also will send inspectors to companies in order to determine if they are in compliance with the conditions imposed under their permits.
    • Federal laws provide EPA and authorized state regulatory agencies with various methods of taking enforcement actions against violators of permit requirements. For example, EPA and state regulatory agencies may issue administrative orders which require facilities to correct violations and that assess monetary penalties. The laws also allow EPA and state agencies to pursue civil and criminal actions that may include mandatory injunctions or penalties, as well as jail sentences for persons found willfully violating requirements and endangering the health and welfare of the public or environment. Equally important is how the general public can enforce permit conditions. The facility monitoring reports are public documents, and the general public can review them. If any member of the general public finds that a facility is violating its NPDES permit, that member can independently start a legal action, unless EPA or the state regulatory agency has taken an enforcement action.
  • What is the NPDES Permit Backlog?
    • The Clean Water Act specifies that NPDES permits may not be issued for a term longer than five years. Permittees that wish to continue discharging beyond the five year term must submit a complete application for permit renewal at least 180 days prior to the expiration date of their permit. If the permitting authority receives a complete application, but does not reissue the permit prior to the expiration date, the permit may be "administratively continued." For permits issued by EPA, existing permits are considered backlogged if EPA receives an application but does not reissue the permit prior to the expiration date. Additionally, applications for new EPA-issued permits are considered backlogged if not issued or denied within 180 days of receipt of the application. See NPDES permit backlog for more information.
  • Is it legal to have wastewater coming out of a pipe into my local receiving water (e.g., lake, stream, river, wetland)?
    • As long as the wastewater being discharged is covered by and in compliance with an NPDES permit, there are enough controls in place to make sure the discharge is safe and that humans and aquatic life are being protected. To find out if a discharge is covered by an NPDES permit, call the EPA Regional office or the state office responsible for issuing NPDES permits.
  • Is there any information available to me on permits in my area?
  • Typically, how long are NPDES permits effective?
    • The Clean Water Act limits the length of NPDES permits to five years. NPDES permits can be renewed (reissued) at any time after the permit holder applies. In addition, NPDES permits can be administratively extended if the facility reapplies more than 180 days before the permit expires, and EPA or the state regulatory agencythat issued the original permit, does not renew the permit before its expiration date through no fault of the permittee.
  • Is there a fee for coverage under an NPDES permit?
    • The EPA does not charge a fee for applying for or obtaining coverage under any National Pollutant Discharge Elimination System (NPDES) permit; however, many of the NPDES-authorized states do charge fees for permit applications, Notices of Intent, and/or permit coverage.
  • What are the primary differences between an NPDES individual permit and an NPDES general permit?
    • A National Pollutant Discharge Elimination System (NPDES) individual permit is written to reflect site-specific conditions of a single discharger (or in rare instances to multiple co-permittees) based on information submitted by that discharger in a permit application and is unique to that discharger whereas an NPDES general permit is written to cover multiple dischargers with similar operations and types of discharges based on the permit writer’s professional knowledge of those types of activities and discharges. Individual permits are issued directly to an individual discharger whereas a general permit is issued to no one in particular with multiple dischargers obtaining coverage under that general permit after it is issued, consistent with the permit eligibility and authorization provisions. As such, dischargers covered under general permits know their applicable requirements before obtaining coverage under that permit. Furthermore, obtaining coverage under a general permit is typically quicker than an individual permit with coverage under a general permit often occurring immediately (depending on how the permit is written) or after a short waiting period. Coverage under an individual permit may take six months or longer.
  • What is the process for applying for coverage under an NPDES general permit?
    • National Pollutant Discharge Elimination System (NPDES) general permits do not require that Operators “apply” for coverage; rather, general permits typically rely on the submission of a document called a Notice of Intent (NOI). An NOI differs from an individual permit application in that it is submitted by Operators after the general permit is issued by the permitting authority. An NOI for a general permit is a notice to the NPDES permitting authority of an Operator’s intent to be covered under a general permit, and typically contains basic information about the Operator and the planned discharge for which coverage is being requested. Some general permits, such as the EPA’s Pesticide General Permit, automatically cover some Operator discharges without submission of an NOI. In these instances, Operators must comply with applicable permit requirements for their pesticide applications without submission of any paperwork to the permitting authority (or in some instances, submission of some other type of notification document).
  • How do Operators apply for coverage under an NPDES individual permit?
    • An Operator must submit a permit application to apply for coverage under a National Pollutant Discharge Elimination System (NPDES) individual permit. The application form must be submitted to the permitting authority at least180 days before the expected commencement of the discharge. NPDES permit application requirements are in Part 122, Subpart B and identified on forms developed by the EPA. NPDES-authorized states are not required to use the EPA application forms; however, any alternative form used by an NPDES-authorized state must include the federal requirements at a minimum. The EPA’s application forms are available at the permit applications and forms page.
  • What does submittal of an NOI mean?
    • A Notice of Intent (NOI) for a general permit is similar to a permit application, in that it is notification to the regulatory authority of a planned discharge for which coverage under a specific National Pollutant Discharge Elimination System (NPDES) general permit is needed and contains information about the discharge and the Operator of that discharge. The NOI serves as the Operator’s notice to the permitting authority that the Operator intends for the discharge to be authorized under the terms and conditions of that general permit. By signing and submitting the NOI, the Operator is certifying that the discharge meets all of the eligibility conditions specified in the general permit (e.g., that a pesticide discharge management plan has been developed if necessary) and that the Operator intends to follow the terms and conditions of the permit. A fraudulent or erroneous NOI invalidates permit coverage. An incomplete NOI delays permit coverage until such time as the NOI has been completed.
  • Since filing a Notice of Intent (NOI), the preparer and/or certifying official on that NOI no longer hold that position with the company (or have left the company altogether). How does a new preparer, new certifying official or duly authorized representative of the Decision-maker file the annual report electronically?
    • The new preparer and/or new certifying official needs to register a new account in EPA’s Central Data Exchange. Once registered, they must contact the eNOI processing center to have the old information linked to the new account.
  • How can I find out about a proposed permit for a facility near me so that I can participate in the permitting process?
    • If a facility near you has applied for an NPDES permit, the permitting authority or company will have provided notice in a major local newspaper, usually in the legal section of the classified ads, or in an official publication such as the Federal Register. You also may call the appropriate state regulatory agency for information on applications for permits. For more information, refer to the Permitting Contacts section of this web site.

Top of Page