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National Pollutant Discharge Elimination System (NPDES)

National NPDES Information
Related Mid-Atlantic Information
What's Happening in the
Mid-Atlantic's Water Protection Division Click to view the Water Protection Division's News
  • Overview
  • Resource Extraction
  • Pretreatment
  • Stormwater
  • Industrial/Municipal Wastewater
  • Meetings, Training and Related Links

Created by the 1972 Federal Pollution Control Act, the National Pollutant Discharge Elimination System (NPDES) Program authorizes discharges from point sources to waters of United States. In addition to pipes, ditches, channels, tunnels, conduits, floating craft or containers, a "point source" also includes concentrated animal feeding operations, which are places where animals are confined and fed.



NPDES permits are issued for wastewater discharges by EPA Region 3 States, with the exception of the District of Columbia and Federal facilities in Delaware where EPA Region 3 is the permitting authority. Read more...

NPDES Topics
  • Permits
  • Enforcement

Concentrated Animal Feeding Operations

Feedlot on a farm

Owners and/or operators of Concentrated Animal Feed Operations (CAFOs) must obtain NPDES permits from the appropriate permitting authority.  EPA Region 3 has authorized state agencies in Delaware,Exit EPA Click for Disclaimer Maryland,Exit EPA Click for Disclaimer Pennsylvania,Exit EPA Click for Disclaimer Virginia,Exit EPA Click for Disclaimer and West VirginiaExit EPA Click for Disclaimerto implement the NPDES program, which includes issuing permits to CAFOs.  EPA Region 3 maintains oversight of the state NPDES programs in a variety of ways such as reviewing and commenting on draft permits prior to issuance. EPA Region 3 is the permitting authority in the District of Columbia where there are no known CAFOs.  States may regulate additional agricultural operations under either their NPDES permit program or other state programs. Read more about Concentrated Animal Feeding Operations.

Below are States NPDES CAFO programs and General Permit approval letters. The approvals did not address the States' Technical Standards, which is the body of information that guides the design and construction of equipment used to operate CAFOs, the agronomic rates of manure application used to developing Nutrient Management Plans (CMPs), and other conservation practices. Upon completion of the review modification of States technical standards may be required.

West Virginia (2 pp, 138K, About PDF)

Virginia (2 pp, 206K, About PDF)

Maryland (3 pp,339K, About PDF)

Manure, litter, and process wastewater from a CAFO cannot enter a stream, river, or other surface water unless the discharge is in compliance with an NPDES permit. When EPA has gathered information that demonstrates an owner and/or operator of a CAFO has violated the Clean Water Act or its implementing regulations, EPA uses its discretionary authority to determine the appropriate enforcement response for the alleged violation(s). Violations may include discharging without a permit, failure to apply for a permit, or failure to comply with the permit. The significance of the violations may range from minor violations that are easily corrected to more severe violations that result in major impacts to the environment and human health and may require capital improvements at the facility to correct. These factors are considered before determining the appropriate enforcement response. Formal enforcement actions usually include a compliance schedule that identifies key actions to take by specific deadlines to return to compliance, and some formal enforcement actions may include penalties for violations.

The Chesapeake Bay is North America’s largest and most biologically diverse estuary. The Bay’s waters are threatened by pollution from a variety of sources. To address non-compliance with environmental laws and associated environmental impacts to this watershed, EPA has developed the Chesapeake Bay Compliance and Enforcement Strategy (13pp, 291K, About PDF), which guides the use of EPA’s compliance and enforcement tools to target pollution sources impairing the Bay watershed and regulated by federal environmental statutes.

View CAFO Enforcement Actions in the Mid-Atlantic

District of Columbia | Delaware | Maryland | Pennsylvania | Virginia | West Virginia

  • Permits
  • Enforcement

Miners working in a mine.

Miners working in a mine.

The NPDES Resource Extraction program reviews state-submitted permits for various types of mining facilities including underground and surface mines, quarries, coal preparation plants, loading facilities, and coarse refuse disposal sites. EPA evaluates permits for consistency with the Clean Water Act and coordinates with state representatives to resolve permitting and water quality issues specific to mining and resource extraction facilities. Some of the predominant challenges EPA faces includes coordinating with the states on implementation of narrative water quality standards, ensuring that technology based and water quality-based effluent limits are consistent with state and federal criteria, and verifying that permits are consistent with their approved Total Maximum Daily Loads.

EPA's Mid-Atlantic Region has a natural gas drilling tip line for reporting dumping and other illegal or suspicious hauling and/or disposal activities.

Visit the Region's Marcellus Shale site for more information.

The NPDES Enforcement Branch protects human health and the environment by ensuring that coal mining operations are in compliance with the National Pollution Discharge Elimination System (NPDES). By making compliance determinations and taking enforcement actions when necessary, we prevent the discharge of pollutants, such as iron, manganese, aluminum, selenium, in excess of permit limits. Discharges from mines can have significant environmental and human health consequences.  Metals can be toxic to macroinvertebrates and fish and sediment-laden runoff can result in increased turbidity and decreased oxygen in receiving waters, which in turn can result in loss of in-stream habitat for fish and other aquatic species.

Mining operations are regulated under the Clean Water Act (CWA), including discharges of pollutants to streams from valley fills (CWA Section 402) and the valley fill itself where the rock and dirt is placed in streams and wetlands (CWA Section 404). Coal mining operations are also regulated under the Surface Mining Control and Reclamation Act of 1977 (SMCRA). The NPDES Enforcement Branch works closely with state lead agencies and other federal agencies to ensure these laws are implemented. Recent enforcement actions:

View Mining Enforcement Actions in the Mid-Atlantic

District of Columbia | Delaware | Maryland | Pennsylvania | Virginia | West Virginia

  • Overview
  • Legal Authority
  • Local Limits
  • Publications, Technical Assistance & Training

The General Pretreatment Regulations, 40 CFR Part 403, were established in the early 1980's to help municipal sewage treatment plants (known as "publicly owned treatment works" or "POTWs") control industrial discharges to the sewers. EPA's Pretreatment Program has dramatically reduced the variety and quantity of pollutants (PDF) (4 pp, 249K, About PDF) going through our municipal wastewater treatment plants to our nation's waters. In addition, the program has reduced the pollutants in municipal sewage sludge, allowing this material to be used to fertilize soil. Read more about EPA's National Pretreatment Program.


Problems that may occur when industrial wastewaters are discharged into sewage treatment systems

Problems that may occur when industrial wastewaters
are discharged into sewage treatment systems

EPA's Pretreatment Program in the Mid-Atlantic Region regulates about 1,800 significant and categorical industries. The program is managed by EPA in Delaware, the District of Columbia, and Pennsylvania and by the states (with oversight by EPA) in Maryland, Virginia, and West Virginia. Federal, state, and local partnerships are key to the successful implementation of EPA's Pretreatment Program.







Contact Us
You will need Adobe Acrobat Reader to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader

Sampling Plan Checklist (PDF) (2 pp, 27K)
Used by Region 3 to review POTW local limits sampling plans.

Sampling Plan Guidance (PDF) (5 pp, 53K)

Setting Local Limits (PDF) (10 pp, 26K)

Mid-Atlantic Region's Spreadsheet for Calculating Local Limits, Version 5.0

User's Manual (PDF) (39pp, 714KB) (applies to both spreadsheets)

General Version (applies to all states)

Pennsylvania version (includes PA water quality standards)

National Local Limits Development Guidance

Contact Us


Pretreatment Guidance Available From Region 3 (PDF) (4 pp, 30K, About PDF)
Fill out the form and send it to the address given on the form.
Many of these and other documents are also available for downloading on the national EPA Pretreatment Publications page.

Annual Reporting

Publicly Owned Treatment Works that are implementing pretreatment programs must submit an annual report to both EPA and the state as required by their NPDES permits.

Technical Assistance

Delaware DNREC's Pollution Prevention Program
District of Columbia none
Maryland MDE'S Pollution Prevention Office
Pennsylvania PA DEP's Office of Energy & Technology Deployment
Pennsylvania Small Business Development Centers
Lehigh University Industrial Assessment Center
Virginia VA DEQ's Office of Pollution Prevention
West Virginia WV DEP's Pollution Prevention Program
Mid-Atlantic Regional Office Environmental Sustainability Resource Center


The 24th Annual Industrial Pretreatment Conference will be held at the Inn at Reading on April 23rd & 24th , 2015.  Look for more details regarding the conference in late February or early March 2015.

Web based pretreatment training is available.

  • Permits
  • Enforcement
  • Program Audits

EPA Region 3 Response to the Petition to Exercise Residual Designation Authority (RDA) for Stormwater Discharges from Commercial, Industrial and Institutional Facilities [pdf, 1p, 26k. about pdf]

Petition for a Determination that Stormwater Discharges from Commercial, Industrial, and Institutional Sites Contribute to Water Quality Standards Violations and Require Clean Water Act Permits (The Residual Designation Authority (RDA) Petition) [pdf, 22p, 426k. about pdf]

EPA Region III Response Cover Letter to the RDA Petition [pdf, 2p,77k. about pdf]

EPA Region III Response Enclosure to the RDA Petition [pdf, 26p,5.8m. about pdf]

The NPDES stormwater permit regulations, put into law by the EPA, cover 3 classes of stormwater discharges on a nationwide basis: Industrial Permits and Municipal Separate Storm Sewer Systems (MS4)

Construction Permits The NPDES stormwater program requires construction site operators engaged in clearing, grading, and excavating activities that disturb 1 acre or more, including smaller sites in a larger common plan of development or sale, to obtain coverage under an NPDES permit for their stormwater discharges.

Industrial Permits To minimize the impact of stormwater discharges from industrial facilities, the NPDES program includes an industrial stormwater permitting component that covers 10 categories of industrial activity that require authorization under an NPDES industrial stormwater permit for stormwater discharges.

MS4 Permits Polluted stormwater runoff is commonly transported through Municipal Separate Storm Sewer Systems (MS4s), from which it is often discharged untreated into local waterbodies. To prevent harmful pollutants such as sediment, nutrients, bacteria, oils, antifreeze, and paint from being washed or dumped into an MS4, regulated municipalities and other entities must obtain a NPDES permit and develop a stormwater management program.

Find out what type of MS4 is in your area (6 pp, 104K, About PDF)
View urbanized area maps to determine if you require MS4 permit coverage.
Exit EPA Click for Disclaimer This page provides links to non-EPA web sites.



EPA has been actively evaluating MS4 programs over the past several years to determine if municipalities and other entities are in compliance with their MS4 permits and to gauge their overall effectiveness. Many of these evaluations have taken place in the form of audits and inspections, for which reports are generated. The reports identify potential permit violations and programmatic issues as well as give compliance assistance and suggestions for program improvement. The reports do not represent a formal finding of violation.

View Stormwater Enforcement Actions in the Mid-Atlantic

District of Columbia | Delaware | Maryland | Pennsylvania | Virginia | West Virginia

In order to assess compliance with MS4 permits, which require the implementation of Minimum Control Measures (MCMs), state and EPA staff must perform inspections and gather relevant information. It is EPA Region 3’s goal to inspect and/or gather information on a large number of Phase I and Phase II MS4s through direct inspection, review of state files, conferences and workshops, and other methods. Below are inspection reports from recent inspections. More inspection reports will be added as the inspections are performed and the reports are finalized.

Visit EPA's Enforcement and History Compliance Online (ECHO) to search inspections for construction and industrial permitting.

You will need Adobe Acrobat Reader to view some of the files on this page. See EPA's PDF page to learn more about PDF ,and for a link to the free Acrobat Reader.
Program Audits
Maryland Date of Evaluation
Dec 9 - 10, 2008
City of Baltimore
(105 pp, 4110K)
Apr 7 - 9, 2009
Montgomery County
(31 pp, 85K)
Sep 20 - 22, 2004
Delaware Date of Evaluation
Apr 4 - 6, 2006
District of Columbia Date of Evaluation
Feb 20 - 22, 2007
Virginia Date of Evaluation
Arlington County (44 pp, 5.7M) Sep 13- 15,2005
City of Hampton (26 pp, 90K)
Jun 14 - 15, 2005
Hanover County (12 pp, 35K)
Jul 14, 2005
Henrico County (28 pp, 95K)
Jul 12 - 13, 2005
City of Norfolk (26 pg, 86K)
Apr 26 - 28, 2005
City of Portsmouth (28 pp, 7.8M )
Nov 8 - 9, 2005
  • Permits
  • Enforcement
  • CSO & SSO

Industrial Wastewater discharges result from water use in industrial/manufacturing operations or from municipal/domestic/household sewage collection and treatment. Wastewater discharges also include discharges from vessels, silvicultural activities, concentrated aquatic animal production facilities and aquaculture projects.

NPDES permits are issued for these direct dischargers of wastewater by EPA Region 3 States, with the exception of the District of Columbia and Federal facilities in Delaware where EPA Region 3 is the permitting authority.

Industrial/manufacturing facilities that discharge wastewater to a publicly owned treatment works (POTW), which in turn discharges into surface waters, are not subject to NPDES permits. These discharges are considered indirect and are controlled by the Pretreatment program.

MS4 and NPDES Permits Issued by EPA in the Mid- Atlantic Region

The activities of Wastewater Enforcement are to implement the National Pollution Discharge Elimination system (NPDES) program for municipal point sources. The ultimate goal of the program is to bring publicly owned treatment works (POTWs) with separate collection systems and combined collection systems into compliance with water quality standards. The Clean Water Act (CWA) made it illegal for any point source to discharge any pollutants into the waters of the United States without a permit.

View Wastewater Enforcement Actions in the Mid-Atlantic

District of Columbia | Delaware | Maryland | Pennsylvania | Virginia | West Virginia

An illustration of the three types of systems that
are used for sewage and stormwater disposal.
Read more about Combined Sewer Overflows
Where does all the dirty water go?

Combined sewer collection systems convey wastewater consisting of untreated sewage and industrial wastewater to a treatment facility or Publicly Owned Treatment Works (POTW). A combined sewer overflow, or CSO, is the discharge of wastewater and stormwater from sewers during a heavy rainfall directly into a river stream, lake or ocean. As a result, during heavy rain, as much as 90 percent of the total wastes that enter combined sewer systems are discharged untreated with an estimated 2,460 CSO discharge points from approximately 238 communities in the Mid Atlantic Region. CSOs can necessitate beach closings and shell fishing bans.

A major challenge for the Mid Atlantic region is that many communities have a very old infrastructure that was designed and built prior to modern sanitary engineering practices. Many Mid Atlantic communities have received funding assistance to help improve their CSOs through the Clean Water State Revolving Fund (CWSRF).

Sanitary Sewer Overflows (SSOs) are discharges of raw sewage from municipal sanitary sewer systems. SSOs can release untreated sewage into basements or out of manholes and onto city streets, playgrounds and into streams before it can reach a treatment facility. SSOs are often caused by blockages in sewer lines and breaks in the sewer lines.

For More Information

CSO Control Policy

A Guidance for Small Communities (PDF)(2pg, 83K) About PDF

Webcast for Small Communities: Options and Tools for Complying with the Policy

Federal Register Notice - CSO Control Policy (PDF) (12 pp, 1567K, About PDF)

Guidance for Nine Minimum Controls(PDF) (69 pp, 4064K, About PDF)

Guidance for Long-Term Control Plan (PDF) (201 pp, 14703K, About PDF)


You will need Adobe Acrobat Reader to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.




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