Information about Perfluoroalkyl and polyfluoroalkyl substances (PFAS) and Unregulated Contaminants

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The EPA uses the Unregulated Contaminant Monitoring Rule (UCMR) to collect data for contaminants that are suspected to be present in drinking water and do not have regulatory standards set under the Safe Drinking Water Act (SDWA). The EPA established Minimum Reporting Limits (MRLs) for various contaminants. The CLCWA was chosen as a location for testing.  The monitoring provides the EPA and other interested parties with nationally representative data on the occurrence of contaminants in drinking water, the number of people potentially being exposed, and an estimate of the levels of that exposure. This data can support future regulatory determinations and other actions to protect public health. These levels are set for monitoring purposes and have not been established as a level of a contaminant in drinking water at which there is a known or expected risk to health.

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As of April 10, 2024, the EPA announced the final National Primary Drinking Water Regulation (NPDWR) and established Maximum Contaminant Levels (MCL) (The highest level of a contaminant that is allowed in drinking water, (set as close to the MCL Goal as feasible, below which there is no known or expected risk to health)) for six PFAS. Information available at https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas

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The CLCWA has sampling results that show 8 PFAS that are at or exceed the established MRL. Of the 8, 2 PFAS (PFOA and PFOS) meet or exceed the established MCL. The CLCWA provides approximately 98% of purchased surface water from the City of Houston’s Southeast Water Purification Plant (SEWPP). Public water systems have five years (by 2029) to implement solutions that reduce any PFAS that testing show that drinking water levels exceed these MCLs. The CLCWA will continue to monitor any processes implemented by the City of Houston as they continue closely studying the results and preparing for solutions to best find, control, remove and prevent PFAS contamination. Information available at https://www.houstonpublicworks.org/sites/g/files/nwywnm456/files/005-pfas_faq.pdf

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Sampling results for U.S. EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) are available to the public (approximately quarterly) via EPA's UCMR Occurrence Data webpage and National Contaminant Occurrence Database (NCOD) at https://www.epa.gov/dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule.  UCMR 5 requires monitoring for 29 per- and polyfluoroalkyl substances (PFAS) and lithium. 

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The results will also be included in the yearly CCRs published by the CLCWA on July 1.