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Aquatic Life Criteria - Copper

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What is Copper?

Copper is an abundant trace element that occurs naturally in the Earth’s crust and surface waters. Copper can be found as a pure metal in nature and has a high thermal and electrical conductivity. Copper compounds are generally found as copper (II) salts.

How does Copper Enter Surface Water?

Copper is commonly found in aquatic systems as a result of both natural and anthropogenic sources. Natural sources of copper in aquatic systems include geological deposits, volcanic activity, and weathering and erosion of rocks and soils. Anthropogenic sources of copper include mining activities, agriculture, metal and electrical manufacturing, sludge from publicly-owned treatment works (POTWs), pesticide use and more. A major source of copper in the marine environment is antifouling paints, used as coatings for ship hulls, buoys, and underwater surfaces, and as a contaminant from decking, pilings and some marine structures that used chromated copper arsenate (CCA) treated timbers.

How does Copper Affect Aquatic Life?

Copper is an essential nutrient at low concentrations, but is toxic to aquatic organisms at higher concentrations. In addition to acute effects such as mortality, chronic exposure to copper can lead to adverse effects on survival, growth, reproduction as well as alterations of brain function, enzyme activity, blood chemistry, and metabolism.

Copper Criteria

2007 Freshwater Copper Criteria Update

EPA issued a revised national recommended freshwater aquatic life criterion for copper (Aquatic Life Ambient Freshwater Quality Criteria—Copper 2007 Revision). As a companion to the criteria document, EPA has also released documents to supplement training materials and help states, tribes, permittees, and other interested stakeholders on implementing the nationally recommended criteria.