PFAS Monitoring for Small Water Utilities: What You Need to Know in 2026

Per- and polyfluoroalkyl substances (PFAS) have emerged as one of the most challenging drinking water contaminants facing water utilities today. Often called "forever chemicals" because they don't break down naturally in the environment, PFAS are synthetic chemicals used for decades in firefighting foam, non-stick cookware, water-resistant fabrics, and industrial applications. Now these chemicals are showing up in drinking water sources across the country.

The regulatory landscape for PFAS has evolved rapidly and continues to change. In April 2024, the EPA established the first-ever enforceable drinking water standards for six PFAS compounds. But in May 2025, the EPA announced it would rescind standards for four of those compounds while maintaining limits for PFOA and PFOS. For small water utilities, understanding these changes and preparing for upcoming monitoring requirements is critical.

What Are PFAS?

Per- and polyfluoroalkyl substances are a group of thousands of synthetic chemicals characterized by strong carbon-fluorine bonds that make them extremely persistent in the environment and in the human body. PFAS have been manufactured since the 1940s and used in countless consumer and industrial products.

The most widely studied PFAS include:

• PFOA (perfluorooctanoic acid) — used in Teflon production and firefighting foam
• PFOS (perfluorooctane sulfonate) — used in Scotchgard, firefighting foam, and industrial surfactants
• PFHxS (perfluorohexane sulfonic acid) — used in firefighting foam and surface treatments
• PFNA (perfluorononanoic acid) — used in fluoropolymer production
• PFBS (perfluorobutane sulfonic acid) — a shorter-chain replacement for PFOS
• GenX (HFPO-DA, hexafluoropropylene oxide dimer acid) — a replacement for PFOA in chemical manufacturing

PFAS contamination in drinking water sources typically comes from industrial discharges, wastewater treatment plant effluent, landfill leachate, firefighting training sites, and agricultural application of biosolids or contaminated wastewater. Once in groundwater or surface water, PFAS persist for decades or centuries.

EPA's PFAS MCL Rule: The Original 2024 Standard

On April 10, 2024, the EPA announced the final National Primary Drinking Water Regulation (NPDWR) for PFAS. This historic rule established legally enforceable Maximum Contaminant Levels (MCLs) for six PFAS compounds in drinking water.

The original 2024 rule set:

• 4.0 parts per trillion (ppt) MCL for PFOA
• 4.0 ppt MCL for PFOS
• Individual MCLs for PFHxS, PFNA, and GenX
• A Hazard Index MCL for mixtures containing two or more of PFHxS, PFNA, GenX, and PFBS

The Hazard Index approach was particularly novel. Instead of setting a single MCL for mixtures, EPA used a formula that accounts for the combined health risk of multiple PFAS compounds present together. If the sum of the ratios of each compound's concentration to its individual MCL exceeded 1.0, the mixture exceeded the Hazard Index MCL.

This approach recognized that people are typically exposed to multiple PFAS simultaneously, and the combined exposure may present greater risk than any single compound alone.

The 2024 rule required public water systems to:

1. Monitor for all six PFAS compounds
2. Notify the public if levels exceed MCLs
3. Reduce PFAS levels below MCLs by implementing treatment if needed
4. Achieve MCL compliance by 2029

For many small systems, the 2024 rule presented daunting challenges. PFAS monitoring is expensive, treatment options are limited and costly, and the health-based MCLs were set at very low levels reflecting the severe toxicity of these compounds.

May 2025 Rescission: The Regulatory Landscape Changes

On May 14, 2025, EPA announced a significant change in direction. The agency announced it would maintain the MCLs for PFOA and PFOS but rescind the regulatory determinations and reconsider the MCLs for four compounds: PFHxS, PFNA, GenX, and the Hazard Index for PFAS mixtures.

According to EPA's announcement, the rescission and reconsideration are intended "to ensure that the determinations and any resulting drinking water regulation follow the legal process laid out in the Safe Drinking Water Act." The agency cited concerns about the adequacy of the scientific and regulatory process used to establish MCLs for these four compounds.

What the Rescission Means for Water Systems

For small water utilities, the rescission creates both relief and uncertainty.

The relief: Systems are no longer required to achieve MCL compliance for PFHxS, PFNA, GenX, or PFAS mixtures. This eliminates the complex Hazard Index calculation and reduces the number of compounds that might trigger treatment requirements.

The uncertainty: EPA may establish new standards for these compounds in the future after completing the reconsideration process. Systems that invested in monitoring or treatment for these compounds may need to adjust their compliance strategies as regulations evolve.

Importantly, the rescission does not prevent states from establishing their own drinking water standards for these compounds. Several states, including California, Massachusetts, Michigan, New Jersey, and Vermont, have already adopted state-specific PFAS standards that may be stricter than federal requirements. Water systems must comply with whichever standard is more stringent — state or federal.

Extended Compliance Deadline: From 2029 to 2031

Along with the May 2025 rescission announcement, EPA extended the compliance deadline for PFOA and PFOS MCLs from 2029 to 2031. This two-year extension provides water systems additional time to implement treatment, secure funding, and achieve compliance.

The extended timeline is particularly beneficial for small systems that face greater challenges in designing, funding, and constructing treatment facilities. Two additional years allows systems to:

• Complete more thorough source water assessments
• Evaluate multiple treatment technologies
• Apply for and receive infrastructure funding through state revolving funds or federal grants
• Design and construct treatment facilities without rushing
• Negotiate better pricing from contractors through competitive bidding

While the extension provides breathing room, systems should not delay action. Planning and design work takes time, and funding applications often have annual deadlines. Starting early ensures systems can meet the 2031 deadline without last-minute scrambles.

PFAS Monitoring Timeline

Understanding the PFAS monitoring timeline is essential for planning and budgeting. Here are the key dates:

Initial Monitoring (2027-2029)

Monitoring for PFOA and PFOS begins on April 26, 2027. All community water systems and non-transient non-community water systems must collect PFAS samples from each entry point to the distribution system.

The initial monitoring period runs for three years, with samples collected annually or more frequently depending on the results:

• Year 1 (April 2027 - March 2028): All systems collect at least one sample from each entry point
• Year 2 (April 2028 - March 2029): All systems collect a second annual sample
• Year 3 (April 2029 - March 2030): All systems collect a third annual sample

If any sample exceeds the MCL during initial monitoring, the system must increase sampling frequency to quarterly and begin treatment planning immediately.

Compliance Monitoring (2030 onward)

After completing initial monitoring, systems transition to ongoing compliance monitoring based on their results:

• Systems with no detections: Sample once every three years
• Systems with detections below MCL: Sample annually
• Systems exceeding MCL: Sample quarterly and implement treatment to achieve compliance by January 1, 2031

The monitoring frequency may be reduced over time if a system consistently shows no detections or low levels well below the MCL. However, any future detection or water source change triggers a return to more frequent monitoring.

Sampling Requirements and Lab Selection

PFAS sampling requires careful attention to protocol and quality control. Unlike many drinking water contaminants, PFAS are ubiquitous in the environment and can easily contaminate samples through improper handling or laboratory procedures.

Sampling Protocol

Water systems must follow EPA Method 533 or other EPA-approved analytical methods for PFAS analysis. Key sampling requirements include:

• Use laboratory-supplied sample bottles and preservatives
• Avoid contact between sample and any PFAS-containing materials (waterproof clothing, non-stick equipment, certain plastics)
• Collect samples at the entry point to the distribution system, before any treatment or blending
• Wear nitrile gloves (not latex, which may contain PFAS)
• Complete chain-of-custody documentation
• Ship samples on ice to arrive at the lab within the holding time

Many labs provide detailed sampling kits and instructions specific to PFAS analysis. Follow lab guidance exactly to ensure valid results.

Laboratory Selection

Not all drinking water laboratories are certified to analyze PFAS. Systems must use a laboratory certified by the state for PFAS analysis under EPA Method 533 or approved alternative methods.

When selecting a lab, consider:

• State certification status — verify the lab is certified for PFAS analysis in your state
• Method detection limits — ensure the lab can measure down to at least 4.0 ppt (the MCL level)
• Turnaround time — how quickly will you receive results?
• Cost — PFAS analysis is expensive, typically $300-$800 per sample depending on the number of compounds analyzed
• Data reporting — does the lab provide clear reports in the format required by your state?
• Quality control — ask about the lab's QC procedures, blank contamination rates, and proficiency testing results

Many state agencies maintain lists of certified labs. Your state drinking water program can provide contact information and may negotiate reduced pricing for small systems through bulk purchasing agreements.

Treatment Options Overview

If monitoring reveals PFAS levels exceeding the MCL, water systems must implement treatment to reduce concentrations below the standard. Several treatment technologies can effectively remove PFAS from drinking water, though each has advantages and limitations.

Granular Activated Carbon (GAC)

GAC is the most widely used treatment for PFAS removal. Activated carbon adsorbs PFAS molecules from water as it flows through a vessel filled with carbon media. GAC is effective for longer-chain PFAS like PFOA and PFOS but less effective for shorter-chain compounds.

Advantages:

• Proven technology widely available
• Can treat multiple contaminants simultaneously (PFAS, VOCs, taste and odor compounds)
• Modular systems can be sized for small flows
• Relatively straightforward operation

Limitations:

• Carbon must be replaced periodically as it becomes saturated (every 6-24 months depending on influent concentrations)
• Spent carbon requires specialized disposal or regeneration
• Operating costs can be high due to carbon replacement
• Less effective for short-chain PFAS

Estimated costs for small systems: $50,000-$200,000 for equipment installation plus $10,000-$50,000 annually for carbon replacement and disposal.

Ion Exchange (IX)

Ion exchange uses specialized resins that selectively remove PFAS by exchanging them for harmless ions like chloride. IX is highly effective for both long-chain and short-chain PFAS.

Advantages:

• Very effective PFAS removal across all chain lengths
• Can achieve very low effluent levels (below 2 ppt)
• Longer run times than GAC before media replacement
• Can target specific contaminants

Limitations:

• Sensitive to competing ions (sulfate, nitrate can reduce PFAS removal)
• Resin replacement and disposal costs
• May require brine disposal
• Less widely available than GAC

Estimated costs for small systems: $75,000-$250,000 for equipment installation plus $15,000-$60,000 annually for resin replacement and disposal.

Reverse Osmosis (RO)

Reverse osmosis forces water through a semi-permeable membrane that rejects PFAS molecules while allowing water to pass through. RO is extremely effective for PFAS removal but is the most expensive option.

Advantages:

• Removes essentially all PFAS (>99% removal)
• Also removes many other contaminants (nitrate, arsenic, hardness)
• Produces very high-quality water

Limitations:

• High capital cost
• High energy use (requires high pressure)
• Produces reject water (concentrate) requiring disposal
• Removes beneficial minerals, may require remineralization
• Requires more sophisticated operation and maintenance

Estimated costs for small systems: $500,000-$2,000,000+ for equipment installation plus $50,000-$150,000 annually for operations, maintenance, and concentrate disposal.

Point-of-Entry (POE) and Point-of-Use (POU) Treatment

For very small systems or systems with just a few contaminated connections, point-of-entry (whole-house) or point-of-use (individual tap) treatment devices may be more cost-effective than centralized treatment.

POE/POU devices use GAC, IX, or RO technology installed at individual homes. The water system maintains ownership and is responsible for monitoring and maintaining the devices.

Advantages:

• Lower capital cost if only a few connections are affected
• Can target specific contaminated sources
• Easier to implement quickly

Limitations:

• System must maintain devices at private residences (access, maintenance burden)
• Must ensure all taps providing drinking water are treated
• Devices require regular monitoring and cartridge/media replacement
• Not practical for systems with many contaminated connections

Alternative Strategies: Blending and Source Switching

In some cases, treatment may not be the most cost-effective approach. Two alternatives worth considering are blending and source switching.

Blending

If a system has multiple sources with varying PFAS levels, blending contaminated water with clean water can dilute PFAS concentrations below the MCL. Blending is only permissible if the blended water consistently meets the MCL at all times.

Systems must carefully monitor blending ratios and ensure consistent mixing. Any change in source water quality or flow rates could cause MCL violations.

Source Switching or Source Abandonment

If feasible, abandoning a contaminated source and replacing it with a clean source may be more cost-effective than treatment. This approach requires access to an alternative source with adequate capacity and acceptable water quality.

Small systems should evaluate whether nearby uncontaminated wells, surface water sources, or interconnections with neighboring systems could replace contaminated sources. Regional cooperation — shared sources, interconnections, consolidation — may provide solutions not achievable by a single small system.

Funding Sources for PFAS Compliance

PFAS treatment can be prohibitively expensive for small systems, but significant federal and state funding is available to help.

Drinking Water State Revolving Fund (DWSRF)

The Bipartisan Infrastructure Law (BIL) appropriated $10 billion in supplemental DWSRF funding specifically for emerging contaminants including PFAS. These funds can be used for:

• PFAS monitoring and source water assessments
• Treatment system design and construction
• Point-of-entry and point-of-use devices
• Source development to replace contaminated sources

BIL funding includes a mandate that 49% of funds must be provided as grants and forgivable loans to disadvantaged communities, making PFAS treatment affordable even for small systems with limited financial capacity.

Contact your state DWSRF program to learn about application deadlines, project eligibility, and the level of subsidy available for your system.

EPA PFAS-Specific Grants

EPA has established several grant programs targeted at PFAS response:

• Emerging Contaminants in Small or Disadvantaged Communities (EC-SDC) Grant Program — provides funding for treatment, monitoring, and technical assistance
• PFAS Treatment and Technical Assistance Grants — supports installation of treatment and capacity building

These competitive grant programs prioritize small and disadvantaged communities. Awards can cover 100% of project costs, making them ideal for systems that cannot afford loan repayment even at subsidized rates.

State-Specific Programs

Many states have established dedicated PFAS response funds using state general funds, settlement monies, or federal allocations. Programs vary by state but may include:

• Emergency grants for immediate treatment needs
• Planning and design grants
• No-interest or forgivable loans
• Technical assistance and training

Check with your state environmental or health agency to identify state-specific funding opportunities.

Legal Settlements and Manufacturer Contributions

Several major PFAS manufacturers have entered into legal settlements requiring contributions to drinking water system PFAS remediation costs. The largest settlements include:

• 3M settlement: $10.3 billion for PFAS contamination remediation nationwide
• DuPont, Chemours, and Corteva settlement: $1.185 billion for public water systems

These settlement funds are being distributed through various mechanisms. Water systems that detect PFAS in their source water may be eligible for reimbursement of monitoring costs, treatment costs, or damages. Consult with your state attorney general's office or legal counsel to understand eligibility and claim procedures.

Health Effects and Public Communication

Communicating about PFAS with customers is critical but challenging. The science is complex, the health effects are serious but not immediately apparent, and the regulatory situation is in flux. Transparent, factual communication builds trust and helps customers understand the steps you're taking to protect public health.

Key Health Effects

Scientific studies have linked PFAS exposure to numerous health problems:

• Cancer: Increased risk of kidney and testicular cancer
• Immune system effects: Reduced vaccine response, increased infections
• Thyroid disease: Disruption of thyroid hormones affecting metabolism
• Reproductive problems: Pregnancy-induced hypertension, decreased fertility
• Developmental effects: Low birth weight, delayed development in children
• Liver damage: Elevated liver enzymes, non-alcoholic fatty liver disease
• Cholesterol: Increased cholesterol levels

These effects occur at very low exposure levels, which is why EPA set MCLs at just 4.0 ppt for PFOA and PFOS — an extraordinarily low concentration reflecting the serious health risks.

Public Notification Requirements

If your system exceeds the PFOA or PFOS MCL, you must provide public notification within specific timeframes:

• Tier 1 notice (24 hours): Required if MCL violation poses acute risk (not applicable to PFAS)
• Tier 2 notice (30 days): Required for MCL violations
• Consumer Confidence Report disclosure: All PFAS detections must be reported in the annual CCR

Public notices must explain the violation, potential health effects, steps the system is taking to resolve the issue, and when compliance will be achieved. EPA provides template language, but personalize the notice to your community.

Special Considerations for Small Systems

Small water systems face unique PFAS challenges that larger utilities don't encounter:

Higher Per-Connection Costs

Treatment capital and operating costs are spread over fewer connections, resulting in much higher costs per household. A $200,000 GAC system serving 100 connections costs $2,000 per connection. The same technology serving 10,000 connections might cost $10 million total but only $1,000 per connection.

For small systems, rate impacts can be severe. Avoid sticker shock by communicating costs early, exploring regional solutions, and maximizing grant funding to reduce the amount financed through rates.

Limited Technical Expertise

Small systems often lack staff with expertise in advanced treatment technologies. Operating and maintaining GAC, IX, or RO systems requires training and technical knowledge that one- or two-person operations may not possess.

Take advantage of state-provided technical assistance, manufacturer training programs, and circuit rider programs that provide traveling technicians to assist small systems. Consider contracting with private operators or engineering firms for ongoing operational support.

Vulnerability to Source Contamination

Small systems often rely on a single well or a small number of sources. If that source is contaminated with PFAS, the entire system is at risk. Larger systems with diverse sources can often blend away contamination or switch between sources.

Small systems should evaluate emergency interconnections and backup source development before a PFAS detection occurs. Having contingency plans in place avoids service disruptions while treatment is installed.

Action Steps for Small Systems

Here's what small water systems should do now to prepare for PFAS monitoring and potential compliance:

Step 1: Understand Your Risk

Evaluate whether your source water is at risk for PFAS contamination. High-risk indicators include:

• Proximity to airports, military bases, or firefighting training facilities (where AFFF foam was used)
• Nearby industrial facilities (chemical manufacturing, metal plating, textile production)
• Landfills or wastewater treatment plant discharge upstream
• Agricultural areas where biosolids or contaminated wastewater irrigation was used

If your system has high-risk source characteristics, start planning now even before monitoring begins.

Step 2: Budget for Monitoring

PFAS monitoring is expensive. Set aside funding now for the initial monitoring period (2027-2030). At a minimum, budget for:

• $300-$800 per sample
• One sample per source per year for three years
• Possible increased sampling if initial results exceed the MCL

A small system with two wells should budget at least $2,000-$5,000 for the initial three-year monitoring period.

Step 3: Identify Funding Opportunities

Research DWSRF funding, EPA grants, and state programs available in your state. Attend pre-application workshops, connect with your state rural water association, and begin assembling application materials.

Even if you haven't detected PFAS yet, you may be eligible for funding to conduct monitoring, develop preliminary treatment plans, or conduct source assessments.

Step 4: Develop Contingency Plans

What will you do if monitoring reveals PFAS above the MCL? Develop contingency plans now:

• Identify potential treatment vendors and obtain preliminary cost estimates
• Evaluate alternative sources, blending options, or regional interconnections
• Determine timeline for treatment installation (design, bidding, construction)
• Plan public communication strategies

Having a plan ready allows rapid response if needed, minimizing the time customers are exposed to elevated PFAS levels.

Step 5: Stay Informed

PFAS regulations continue to evolve. The EPA's reconsideration of PFHxS, PFNA, GenX, and the Hazard Index may result in new or modified standards in the coming years. State agencies may adopt their own standards. Treatment technologies and funding opportunities are also changing rapidly.

Subscribe to updates from your state drinking water program, EPA, and organizations like the American Water Works Association (AWWA) or Rural Community Assistance Partnership (RCAP) to stay current on regulatory and technical developments.

Conclusion

PFAS contamination presents one of the most significant public health challenges facing drinking water systems today. For small utilities, the combination of expensive monitoring, costly treatment, and evolving regulations creates operational and financial pressures unlike anything most systems have faced before.

The good news is that effective treatment technologies exist, substantial funding is available, and the extended 2031 compliance deadline provides time to plan and implement solutions. Systems that start preparing now — budgeting for monitoring, evaluating treatment options, pursuing funding, and communicating with customers — will be well-positioned to achieve compliance while managing costs and maintaining service.

The regulatory path forward may be uncertain, but the commitment to protecting public health is clear. Small systems play an essential role in this effort, and with strategic planning and available support, PFAS compliance is achievable.

Sources

• EPA Per- and Polyfluoroalkyl Substances (PFAS)
• EPA Press Release: EPA Announces It Will Keep Maximum Contaminant Levels for PFOA, PFOS
• Federal Register: PFAS National Primary Drinking Water Regulation
• EPA Technical Overview of PFAS NPDWR for Drinking Water Utilities and Professionals
• EPA Bipartisan Infrastructure Law Resources for Drinking Water
• Fox Rothschild: EPA Keeps MCL for PFOA and PFOS, Extends Compliance Deadline