The Fourth Unregulated Contaminant Monitoring Rule

LEGEND, Arizona is EPA UCMR4 certified for performing Metals, TOC, and HAA9 analyses in-house (AZ00031). The additional parameters will be sub-contracted to another EPA UCMR4 certified laboratory at no additional cost. Contact us for additional information and pricing or call at 602-324-6100.


The fourth Unregulated Contaminant Monitoring Rule (UCMR 4) was published in the Federal Register on December 20, 2016. UCMR 4 requires monitoring for 30 chemical contaminants between 2018 and 2020 using analytical methods developed by EPA and consensus organizations. This monitoring provides a basis for future regulatory actions to protect public health. (

General information is available on the EPA UCMR page or by calling the Safe Drinking Water Hotline at 1-800-426-4791.

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Whether you have questions about our services, need assistance, or have regulatory concerns, we can help.
Contact any of our locations.