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Aquatic Life Criteria - Aluminum

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What is Aluminum?

Aluminum is a natural element and the most common metal in the earth's crust. It is found in most soils and rocks. Aluminum can enter the water via natural processes, like weathering of rocks.

Aluminum is also released to water by mining, industrial processes using aluminum, and waste water treated with alum, an aluminum compound.

How does Aluminum Affect Aquatic Life?

Aluminum is considered a non-essential metal because fish and other aquatic life don’t need it to function. Elevated levels of aluminum can affect some species ability to regulate ions, like salts, and inhibit respiratory functions, like breathing. Aluminum can accumulate on the surface of a fish’s gill, leading to respiratory dysfunction, and possibly death.

2018 Final Aquatic Life Criteria for Aluminum in Freshwater

EPA has published final updated aquatic life criteria for aluminum in freshwater that reflect the latest science and allow stakeholders to develop criteria reflecting the impacts of local water chemistry on aluminum toxicity to aquatic life. 

Documents Supporting the Development of the 2018 Final Aquatic Life Criteria for Aluminum in Freshwater

In 2017, EPA released draft Aquatic Life Criteria for Aluminum in Freshwater which can be accessed at  To view the Draft National Recommended Ambient Water Quality Criteria for Aluminum document, download a copy from the docket (EPA-HQ-OW-2017-0260). The following documents supported the development of the Final criteria. A link to EPA’s responses to public comments on the 2017 draft criteria document is given. Also provided are links to external peer review reports on new toxicity data added to the Multiple Linear Regression (MLR) bioavailability models and the updated MLR update used in the 2018 aluminum criteria development, as well as EPA’s responses to those external peer review comments.

Draft Technical Support Document for 2018 Final Aquatic Life Criteria for Aluminum in Freshwater

EPA released a draft technical support document, in the form of a questions and answers document, to support the implementation of EPA’s recently published recommended CWA section 304(a) Aquatic Life Ambient Water Quality Criteria for Aluminum. The draft technical support document addresses the adoption, assessment and listing, and NPDES permitting processes for the new aluminum criteria. The public comment period on the draft document closed on September 13, 2019.  EPA is in the process of revising the document to address comments the Agency received.

1988 Aquatic Life Criteria for Aluminum

The 2018 Aquatic Life Criteria for Aluminum supersedes the 1988 criteria.  You can view the 1988 criteria on our historical water quality criteria documents page.

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