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Water: Permitting (NPDES)



There are 3 general categories of mining activities that are regulated by EPA: hardrock mining (typically extracting metallic ores such as iron or copper), non-metals mining (typically extracting minerals such as gypsum or sand and gravel) and coal mining.

For more information on these categories see: http://water.epa.gov/scitech/wastetech/guide/industry.cfm.

Regulation of the mining sector involves every major EPA program. Mining operations generate tailings and waste rock that must be disposed of, and 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 and abandoned mines can also cause extensive losses of aquatic and terrestrial habitat.

Throughout the western United States there are thousands of miles of mining impacted streams and rivers caused by active and historic mining of metallic ores (e.g., iron, copper, lead, zinc, molybdenum, tungsten) and precious metals (gold, platinum and silver). Similarly, large scale coal mining in the eastern half of the United States has been underway for the past 150 years and the impacts to watersheds from active as well as abandoned coal mines require regulatory oversight to protect these valuable environmental resources. These situations, combined with an increasing population, has made mining issues a priority. The growth in population has intensified the use of aquatic and riparian ecosystems for recreation, and has increased the demand on aquifers for domestic water supply.

The Clean Water Act (CWA) requires all point source discharges from mining operations be authorized under an NPDES permit, as described in Section 402 of the CWA. The construction of impoundments to serve as repositories for tailings and treatment of waste from mining and mineral processing operations are regulated by Section 404 of the CWA, as well as, Section 402 in the case of discharges from these impoundments into any waters of the United States.

EPA Regional offices have used statutory authority granted by the Clean Water Act (CWA) to regulate all mining activities (i.e., coal, hardrock and non-metals) through the NPDES permits program since the 1970's. Although mining permits are issued by various State agencies, the Office of Water(OW) may review State issued permits to ensure compliance with water quality criteria and ensure that effluent guidelines for ore/coal mining and processing are properly applied to wastewater discharges from these activities.

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