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National Pollutant Discharge Elimination System (NPDES)

Industrial Wastewater

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Wastewater discharges from industrial and commercial sources may contain pollutants at levels that could affect the quality of receiving waters or interfere with publicly owned treatment works (POTWs) that receive those discharges. The NPDES permitting program establishes discharge limits and conditions for industrial and commercial sources with specific limitations based on the type of facility/activity generating the discharge.

Resources for discharge requirements based on the sector generating the discharge include:

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Mining operations are often complex undertakings that may be situated in or near diverse and sensitive environments. These operations generate tailings and waste rock for disposal and also create wastewater discharges and air emissions.

As a result, mining can affect surface and ground water quality, drinking water supplies and air quality. Impacts from operating as well as abandoned mines can cause extensive losses of aquatic and terrestrial habitat.

Mining has impacted thousands of miles of streams and rivers throughout the western U.S. due to active and historic mining of metallic ores (e.g., iron, copper, lead, zinc, molybdenum, tungsten) and precious metals (gold, platinum, and silver). Similarly, eastern U.S. watersheds are impacted by both active and abandoned coal mines after 150 years of mining activities.

These situations, combined with an increasing population, make mining issues a priority. Population growth has intensified the use of aquatic and riparian ecosystems for recreation, and increased the demand on aquifers for domestic water supply.

The Clean Water Act (CWA) requires all point source discharges from mining operations, including discharges from associated impoundments, be authorized under an NPDES permit. The NPDES program regulates discharges from three general categories of mining activities as well as the considerations associated with abandoned mines.

More information about the Good Samaritan Initiative:

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Oil and Gas

Treatment and disposal of wastewater from shale gas extraction

Shale gas extraction produces large volumes of wastewater from hydraulic fracturing in addition to relatively small volumes of water from the formation (i.e., the geologic rock unit from which extraction is taking place). That wastewater can contain high concentrations of dissolved solids (salts), naturally occurring radionuclides, and metals, as well as other pollutants used in drilling and completion of wells.

  • Natural Gas Drilling in the Marcellus Shale under the NPDES Program Frequently Asked Questions (FAQs) and Shale Gas Extraction FAQs – March 17, 2011 memorandum and companion FAQs from James Hanlon, former Director of EPA’s Office of Wastewater Management to the EPA Regions to assist state and federal permitting authorities in addressing treatment and disposal of wastewater from shale gas extraction.

    The FAQs discuss wastewater issues and pollutants associated with shale gas extraction and how existing regulations may be used to address them. For example, there are additional regulations that cover oil and gas extraction, centralized waste treatment, acceptance and notification requirements for publicly owned treatment works, pretreatment, and stormwater. These FAQs should assist EPA regional offices and states as they work with the regulated community to address shale gas extraction wastewater.
  • Natural Gas Extraction - Hydraulic Fracturing - Information about EPA's scientific and regulatory activities related to natural gas extraction and hydraulic fracturing.

Gulf of Mexico Oil and Gas NPDES Program

NPDES General Permit for the Western Gulf of Mexico Outer Continental Shelf - On September 19, 2017, EPA Region 6 reissued the NPDES general permit for the Western Gulf of Mexico Outer Continental Shelf (GMG900000). The general permit covers discharges from approximately 3,500 oil and gas extraction facilities located greater than 3 miles offshore of Louisiana and Texas. The permit becomes effective on October 1, 2017, and replaces the previous permit that was issued in 2012. Permittees covered by the previous version of the permit that expired on September 30, 2017, will be automatically covered by the reissued permit starting October 1, 2017, until April 1, 2018, but must submit an electronic Notice of Intent by April 1, 2018, to continue coverage past that date.

Western and Central Gulf of Mexico Offshore Oil and Gas NPDES Program - Information about NPDES general permits for offshore oil and gas in the central to western portions of the Gulf of Mexico. These general permits are managed under the jurisdiction of EPA Region 6.

Eastern Gulf of Mexico Offshore Oil and Gas NPDES Program - NPDES oil and gas permits issued by EPA for the eastern portion of the Outer Continental Shelf (OCS) of the Gulf of Mexico. These permits are managed by EPA Region 4.

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