Understanding EPA PFAS Monitoring and Reporting Requirements for Public Water Systems

With growing concerns over the presence of per- and polyfluoroalkyl substances (PFAS) in drinking water, the EPA has introduced strict regulations mandating public water systems (PWS) across the United States to conduct rigorous PFAS testing. Here’s what you need to know about these regulations and what they mean for your water supply.

Mandatory Testing for Public Water Systems

As of April 2024, all public water systems in the U.S. must perform initial and ongoing testing for PFAS. This sweeping regulation affects approximately 66,000 PWS nationwide. These systems include:

• Surface Water Systems: Water sourced from rivers, lakes, and reservoirs.
• Groundwater Systems: Wells that supply water to rural schools, hospitals, and other facilities.
• Community Water Systems: Groundwater sources that service residential communities such as trailer parks and mobile home areas.

While private wells owned by homeowners or small business operators are not required to conduct PFAS tests, the EPA strongly recommends testing. Those using private wells should reach out to their state environmental or health agency for a list of state-certified labs.

Maximum Contaminant Levels (MCLs) for PFAS

There are over 12,000 identified PFAS compounds. PFAS, or per- and polyfluoroalkyl substances, are a large and diverse group of synthetic chemicals that include a wide variety of structures and properties. Despite the high number of PFAS compounds, the EPA has established strict MCLs on a subset of these chemicals due to their prevalence and persistence:

• PFOA: 4.0 parts per trillion (ppt)
• PFOS: 4.0 ppt
• PFHxS: 10 ppt
• PFNA: 10 ppt
• GenX (EFP-DA): 10 ppt

Initial Monitoring Requirements

To comply with the EPA’s regulations, initial PFAS sampling and monitoring must be completed within three years of the rule’s promulgation—by April 2027. The initial monitoring phase is crucial as it determines the extent of ongoing testing required for each PWS. Results from this phase must be included in an Annual Water Quality Report, ensuring transparency with customers.

Here’s what the initial monitoring entails:

• Surface Water Providers: Four quarterly tests over 12 months, with 2-4 samples per test collected at the entry point to the distribution system.
• Groundwater Systems Serving > 10,000 People: Four quarterly tests over 12 months.
• Groundwater Systems Serving < 10,000 People: Two semi-annual tests over 12 months.

A PWS may provide previously collected PFAS data instead of conducting new sampling if it is available.

Ongoing Monitoring Requirements

After the initial monitoring phase, most PWS will default to quarterly testing. However, the frequency of testing can be adjusted based on the results:

• If any four consecutive quarters show PFAS levels below the Maximum Contaminant Levels (MCL), the system can shift to annual testing.
• After three consecutive annual tests showing PFAS levels below the MCL, the frequency can be reduced further to one test every three years.
• If all four initial monitoring samples are below the MCL, testing is required only once every three years.

Public Notifications and Reporting

If PFAS levels exceed the established MCLs, public water systems must issue annual public notices to their customers, disclosing the detected levels of PFAS. This requirement ensures that customers are informed and aware of PFAS levels associated with their water supply.

Projected Impact 

For public water systems, the EPA’s PFAS monitoring and reporting regulations mean committing to an ongoing process of testing, transparency, and, where necessary, mitigation efforts to ensure compliance. The EPA estimates that 6-10% of PWS, roughly 4,000-6,700 systems, will need to take action to reduce PFAS levels to meet the MCLs.

For more than 4 decades, RJ Lee Group has been at the forefront of environmental health & safety testing. From asbestos, to lead, to heavy metals, we have helped thousands of clients maintain regulatory compliance while protecting their employees and the environment. In response to increased concerns over PFAS compounds, we have expanded our equipment and expertise to continue to support our clients' needs.

Based on our years of experience, we recommend that all public water systems begin testing as soon as possible because bringing a system into compliance can be a complex and time-consuming process. The sooner you know where you stand, the more time you will have to address any concerns. Click below to schedule a time to talk to us about your PFAS testing needs or to request a PFAS sample collection kit. 

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