An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Determining quantities / concentrations of hazardous constituents released in waste stream

Are facilities required to determine the quantities or concentrations of hazardous constituents released within a waste stream that is listed under CERCLA?

No. The determination of the exact quantities of hazardous substances released in a mixture, solution, or waste stream may be difficult; such a determination is not required by CERCLA. Potential releasers may choose instead, to report waste stream releases when the total amount of the waste stream released equals or exceeds the RQ listed for the waste stream constituent with the lowest RQ.