Drinking Water: PFAS

EPA has published a PFAS rule establishing new maximum contaminant levels (MCLs) for six PFAS compounds: PFOA, PFOS, PFHxS, HFPO-DA, and PFNA as contaminants with individual MCLs, and PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS using a Hazard Index MCL to account for the combined and co-occurring levels of these PFAS in drinking water.

$$\text{Hazard Index* (1 unitless)} = {\left(\left[HFPO-DA\right]\over\left[10\text{ ppt}\right])\right) + \left(\left[PFBS\right]\over\left[2000\text{ ppt}\right])\right) + \left(\left[PFNA\right]\over\left[10\text{ ppt}\right])\right) + \left(\left[PFHxS\right]\over\left[10\text{ ppt}\right])\right)}$$

By the April 26, 2029 compliance deadline, community and non-transient non-community water systems that have PFAS levels that violate one or more of the above MCLs must have taken action to reduce levels of these PFAS in their drinking water and must provide notification to the public of any violation.

* On May 14, 2025, the EPA announced key changes to its PFAS regulations. EPA intends to retain maximum contaminant levels (MCLs) for PFOA and PFOS but remove MCLs for the Hazard Index, HFPO-DA, PFHxS and PFNA. The MCL compliance deadline is intended to be extended from April 26, 2029, to April 26, 2031.  A new draft PFAS rule is expected in Fall 2025 and intended to be finalized in Spring 2026.

Initial monitoring requirements

Community and non-transient non-community water systems must monitor for these PFAS and have three years to complete initial monitoring (by April 26, 2027), followed by ongoing compliance monitoring at all points of entry.

Initial public notice requirements

Community and non-transient non-community water systems must also provide the public with information on the levels of these PFAS in their drinking water beginning on April 26, 2027. If your water system is testing through UCMR5, then  UCMR5 testing and public notification must still be completed as required.

If your water system has PFAS detections in your water supply, notify us at [email protected]. We will work with you to understand the results and help you determine what the next steps should be.

Community and non-transient non-community water systems must complete initial monitoring at all entry points to the distribution system. Based on system size and source water at an entry point, systems must conduct initial monitoring either twice or quarterly during a 12-month period.

Yes. UCMR5 testing and public notification must still be completed as required.

Yes. If a water system has already tested for PFAS using the allowed methods (either EPA Methods 533 or 537.1 ), these tests might count for the initial monitoring depending on how much time has passed.  To qualify for reduced compliance sampling, make sure the laboratory’s Method Reporting Limit (MRL) for both PFOA and PFOS is 2 parts per trillion (ppt) or lower.

  Check EPA’s quick reference guide to determine if your water system has enough samples at each point of entry to meet the initial monitoring requirements.

Contact us at [email protected] for help in determining whether your sample results are valid for initial monitoring. 

Yes, Utah Public Water Systems have to follow the new EPA rules about PFAS.

The PQL is defined as the lowest concentration of a contaminant achieved reliably and accurately within specified limits = during routine laboratory operating conditions. These levels are set at specific concentrations and provide the precision and accuracy that the EPA estimates can be achieved across laboratories nationwide and are the most appropriate levels for use in determining the lowest feasible level that can be implemented. PQLs are used for MCL compliance determination. 

An MCL is the Maximum Contaminant Level. The MCL is the maximum level allowed of a contaminant in water which is delivered to any user of a public water system.

The method detection limit (MDL) is defined as the minimum measured concentration of a substance that can be reported with 99% confidence that the measured concentration is distinguishable from method blank results. In other words, MDL is the smallest amount of a substance that a test can detect.

A trigger level is used to establish how often to test a water system during compliance monitoring. Trigger levels are set at 50% of the Maximum Contaminant Levels (MCLs) for regulated PFAS. Based on initial monitoring, systems that have any samples greater than or equal to the trigger levels for any of the regulated MCLs are required to conduct quarterly monitoring (one sample taken every quarter) at that entry point. Based on initial monitoring, systems that have all sample results below the trigger levels for all regulated PFAS can reduce monitoring to once every three years at those entry points.

A point of entry is where samples are collected to test the drinking water quality before it is distributed to homes and businesses. 

The point of entry sample location might show the quality of water from different sources if those sources are combined together before reaching any connection.  

The point of entry should represent source water after it has undergone any treatment (disinfection, metals removal, blending), and is always upstream of the first culinary connection.

Beginning in 2023, multiple companies have announced settlements for collective claims against manufacturers related to PFAS drinking water contamination in public water systems. Over a period of 13 years, the settlement will provide funds for public water systems for testing and treating PFAS contamination. 

To learn more go to the Aqueous Film-Forming Foam (AFFF) Products Liability Litigation (MDL 2873) website. 

Go to participation.PFASWaterSettlement.com.

To find laboratories that are certified to test for PFAS to meet the new PFAS rule, go to our Utah Certified Laboratory list. 

To qualify for reduced compliance sampling, make sure the laboratory’s Method Reporting Limit (MRL) for both PFOA and PFOS is two parts per trillion (ppt) or lower.

To meet the requirements of the new PFAS rule, you must use either EPA Method 533 or Method 537.1 (version 2.0) for PFAS sampling.

Note: To qualify for reduced compliance sampling, make sure the laboratory’s Method Reporting Limit (MRL) for both PFOA and PFOS is 2 parts per trillion (ppt) or lower.

Studies have found the health effects of PFAS exposure may include:

• Increased cholesterol
• Changes in liver enzymes
• Decreased infant birth weight
• Decreased vaccine response in children
• Increased high blood pressure in pregnant women
• Increased risk of kidney or testicular cancer

Find more about exposure, testing, and health resources.

Initial monitoring sampling needs to be conducted at representative sampling conditions. Please email [email protected] for more guidance.

Please email [email protected] for guidance on shared sources.

In general, existing plumbing and sampling kits do not pose a concern for PFAS contamination, with the exception of Teflon tape. While we have not observed any cross-contamination from Teflon tape, we recommend noting its presence in your Chain of Custody (COC) documentation.

To learn more about PFAS cross-contamination and sampling, read our PFAS Sampling Guide. 

No. The Utah Division of Drinking Water is not requiring public water systems to sample emergency sources in order to meet the PFAS initial monitoring requirements. However, public water systems may choose to test emergency drinking water sources if they are interested in doing so.

You can always reach out to your water provider directly for results, but there are also three other ways you can look for PFAS sample results in your drinking water. First, If you receive your water from a Community drinking water system, you should receive an annual consumer confidence report from your water provider. Second, you can find PFAS results from drinking water samples on DDW’s PFAS results and sampling location map. Finally, you can check EPA’s Fifth Unregulated Contaminant Monitoring Rule Data Finder for PFAS results.