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National Pollutant Discharge Elimination System (NPDES)

NPDES Regulations

EPA originally published the general NPDES regulations at Title 40 of the Code of Federal Regulations (CFR) in 1972. The primary regulations developed by EPA to implement and administer the NPDES permit program are:

Other important regulations applicable to the NPDES program are:


Notice and Request for Comment: Trading Baselines

On September 5, 2019, EPA invited the public to consider and comment on policy options that may help promote market-based approaches to water quality improvements.


Final Rule: National Pollutant Discharge Elimination System (NPDES): Applications and Program Updates (Phase 1)

This final rule addresses a subset of the revisions proposed in 2016, modernizes the NPDES regulations, and promotes submission of complete permit applications.

Final Rule: Public Notification for CSOs to the Great Lakes

The January 8, 2018, rule implements Section 425 of the Consolidated Appropriations Act of 2016, which requires EPA to work with the Great Lakes States to establish public notification requirements for combined sewer discharges (CSOs) to the Great Lakes. The requirements address signage, initial notification of local public health departments and other potentially affected entities, initial notification of the public, annual notice provisions, and development of a public notification plan.


Final Rule: NPDES Electronic Reporting

This final rule substitutes electronic reporting for paper-based reports. It requires permittees and regulators to use existing, available information technology to electronically report information and data related to the NPDES permit program in lieu of filing paper-based reports.


National Pollutant Discharge Elimination System (NPDES): Use of Sufficiently Sensitive Test Methods for Permit Applications and Reporting

EPA finalized minor amendments to the NPDES regulations to require that its Clean Water Act (CWA) regulations to codify that under the NPDES program, only "sufficiently sensitive" analytical test methods may can be used when completing an NPDES permit application and when performing sampling and analysis pursuant to monitoring requirements in an NPDES permit. 

Final Rule: Cooling Water Intakes – Existing Electric Generating Plants and Factories

This August 15, 2014, final rule covers roughly 1,065 existing facilities that are designed to withdraw at least 2 million gallons per day of cooling water. The facilities are required to choose one of seven options to reduce mortality to fish and other aquatic organisms. Facilities that withdraw at least 125 million gallons per day must conduct studies to help their permitting authority determine whether and what site-specific controls, if any, would be required to further reduce mortality of aquatic organisms. New units added to an existing facility are required to reduce mortality of aquatic organisms that achieves one of two alternatives under national entrainment standards.

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