PFAS Monitoring: How Can Water Systems Meet the Requirements?

Julie Huerta

Regulatory Compliance Specialist

Koby Boman

Water/Wastewater Treatment Engineer

Viraj deSilva

Senior Treatment Process Engineer

As water systems develop and work through their plans for complying with new federal limits on PFAS in drinking water, it’s important to understand the requirements and timetable for monitoring contaminants.

Public water systems should already be sampling their water under the Environmental Protection Agency’s Fifth Unregulated Contaminant Monitoring Rule (UCMR 5). ). Participants in this monitoring include all public water systems serving 3,300 to 10,000+ people, along with 800 randomly selected systems serving fewer than 3,300 people. While those samples can be used to fulfill the initial sampling requirements for the National Primary Drinking Water Regulation, they might not be sufficient for all the monitoring rules.

All public water systems should review their initial monitoring requirements and make plans that align with them. Water utilities also should check with their state regulators for state-specific guidance.

What’s the Monitoring Timeline?

Water systems are subject to these three monitoring activities:

• UCMR5 Monitoring: Fifth Unregulated Contaminant Monitoring Rule (January 2023 through December 2025) – 29 PFAS compounds
• Initial Monitoring: Final PFAS regulation 40 CFR 141.902(b)(1) (April 2024 through April 2027) – six PFAS compounds
• Routine Compliance Monitoring: Final PFAS regulation 40 CFR 141.902(b)(2) (Starting May 2027) – six PFAS compound

What Else Do I Need to Know About Monitoring?

PFAS Compounds Covered: Under UCMR 5, monitoring is required for 30 chemical contaminants, including 29 PFAS compounds.

Frequency and Timing: The sampling schedule varies by water system type.

• Year-round surface water systems must conduct four samples over 12 months, spaced three months apart.
• Year-round groundwater systems must sample twice within the same period, spacing samples five to seven months apart.

Locations: Public water systems must choose representative sampling locations. Samples are typically collected at each entry point to the distribution system.

Reporting Requirements: Public water systems must inform customers of the results within 12 months. Community water systems also must include these results in their Annual Consumer Confidence Reports. The EPA publishes PFAS monitoring data quarterly.

What Steps Can My Water System Be Taking Now to Comply?

• Assess whether your UCMR 5 monitoring activities meet the initial monitoring requirements described in the Final PFAS Regulation. See the EPA’s Monitoring and Reporting Fact Sheet for details of the initial monitoring requirements.
• Set up your own sampling and lab analysis. Also, check state-specific expectations that could apply to your system and choose a lab approved by the EPA or your state agency for PFAS sampling.
• Consider additional internal monitoring (beyond regulatory requirements), which can help you better understand where PFAS may occur within your system and what to do about it. This also will help build confidence in your results.

What Are the Long-term Monitoring Expectations?

2027: Water systems must start conducting initial and compliance monitoring of six targeted PFAS compounds (PFOS, PFOA, PFNA, PFBS, PFHxS and GenX) and include information on PFAS levels in their Annual Consumer Confidence Reports. Note: The maximum contaminant levels (MCLs) for PFOA and PFOS, set at 4.0 ppt, present significant compliance challenges for many water systems. Compliance with the PFAS regulatory MCLs will be determined by calculating each sample point’s annual running average of quarterly results.

April 2029: Public water systems with PFAS contamination exceeding the MCLs will be required to implement the best available practices to reduce PFAS levels in their water supplies and to notify the public of the violation.

How Freese and Nichols Can Help

With our team’s expertise and experience in environmental science and water treatment, we can assist with all aspects of PFAS regulatory compliance. Freese and Nichols PFAS experts can help with multiple aspects of sampling and monitoring:

• Planning and sample collection to meet the initial monitoring requirements
  • For systems collecting UCMR 5 samples: We can help assess whether additional monitoring is needed to meet initial requirements.
  • For systems not scheduled for UCMR 5: We can assist with initial monitoring planning, coordination and collection.
• Planning and sample collection to meet routine monitoring requirements

(Note for Texas Water Systems: Texas public water systems are responsible for coordinating initial monitoring that lasts through April 2027. After that, the Texas Commission on Environmental Quality plans to handle sample collection and analysis for routine PFAS sampling.)

• Designing and conducting supplemental monitoring to better understand your system’s PFAS results

While regulations require monitoring at the outlet of each water treatment plant, some systems have multiple sources that feed the plant. If PFAS are detected at the plant outlet, it is important to understand which sources could be impacted by PFAS.

To Learn More:

• Contact David Jackson, david.jackson@freese.com, Viraj deSilva, viraj.desilva@freese.com, Jimmy Gibson, jimmy.gibson@freese.com, Julie Huerta, julie.huerta@freese,com, or Koby Boman, koby.boman@freese.com (for regulation-specific questions)
• Visit our PFAS services page

Julie Huerta directs Freese and Nichols’ program to help clients meet new federal drinking water standards. She is based in Houston, Texas.

Koby Boman, PE, is a Water/Wastewater Treatment Engineer focusing on regulatory compliance, based in Houston.

Viraj deSilva, PhD, PE, BCEE is a Senior Treatment Process Engineer and national PFAS expert based in Tampa, Florida.