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Unregulated Contaminant Monitoring Rule

What is the Unregulated Contaminant Monitoring Rule?

The Unregulated Contaminant Monitoring Rule (UCMR) provides EPA and other interested parties with scientifically valid data on the occurrence of contaminants suspected to be present in drinking water, but that do not have health-based standards set under the Safe Drinking Water Act (SDWA). The data serves as a primary source of occurrence and exposure information that EPA uses to develop regulatory decisions. The final rule “Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) for Public Water Systems” was published in the Federal Register on December 20, 2016. The UCMR 4 contaminant list includes ten cyanotoxin chemical contaminants, two metals, eight pesticides and one pesticide manufacturing byproduct, three brominated haloacetic acid (HAA) groups, three alcohols, three other semivolatile chemicals, and two indicators.

Who Will Be Required to Monitor?

Participation is based on retail population served for community water systems and non-transient non-community water systems.  All large ground water and surface water systems serving more than 10,000 persons are required to perform assessment monitoring for additional chemicals and cyanotoxins.  EPA has also randomly selected some systems serving 10,000 or fewer to perform assessment monitoring for additional chemicals and cyanotoxins.

When Will Systems Be Required to Monitor?

Participating systems in Florida will be required to monitor in 2018 through 2020.

Additional Information

More information on UCMR4, including scope, analytical methods and contaminants can be found at the EPA Unregulated Contaminants page.

Last Modified:
December 7, 2022 - 11:48am

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