Treating PFAS Chemicals in Drinking Water: Responding to EPA Regulations

Mitigation of health risks posed by a large class of “forever chemicals” that have been identified as potentially harmful to human health — known as per- and polyfluoroalkyl substances (PFAS) — has been a growing concern for water utilities.

But since March, when the U.S. Environmental Protection Agency (EPA) released its recommendations for establishing maximum contaminant levels (MCLs) for six PFAS substances that concern has been elevated to a call to action.

Public comment closed in May, and EPA is on track to finalize the regulations by the end of the year, with a three-year compliance timeline. During the compliance period, utilities will be required to monitor their water sources for PFAS — substances that have been linked to cancer risks, lower birth weights and other health impacts — and will be required to have PFAS treatment in place at the end of the period if levels are above the MCLs.

Treatment of drinking water and infrastructure upgrades to comply with MCLs will present a significant new burden for many water utilities — one that will add to other major stresses such as losing senior staff to retirement, upgrading infrastructure, identifying lead service lines, hardening cybersecurity, dealing with droughts and climate change, and other new regulatory initiatives.

“Water utilities are at very different stages in addressing PFAS contamination, depending on whether they’re in a state that regulates PFAS and other factors,” said Stephen Rupar, national drinking water practice leader at WSP in the U.S. “Some haven’t yet tested for PFAS, some are testing and disclosing contamination levels, and some with known contamination have invested in treatment.”

Whatever their PFAS situation is, water utilities will all have to comply with EPA MCLs once finalized. Many water utilities are currently sampling for 29 PFAS compounds and lithium in accordance with EPA’s latest revision of the unregulated contaminant monitoring rule. EPA released initial results of the sampling on Aug. 17, available here. These results confirm that PFAS contamination of drinking water is a major concern in many communities.

Water utilities will also be required to inventory service line materials and report on the presence of lead by October 2024 to comply with the EPA’s Lead and Copper Rule Revisions (LCRR).

“Water utilities are under a lot of stress now,” said Rupar, who added that he and his team are assisting small water utilities with the lead and copper rule. “We’re managing a programmatic system to communicate information about the LCRR, and status of lead inventory work between utilities and their customers. Our system includes a customer self-assessment tool, which we think will vastly improve utilities’ data.”

Estimates of how much utilities will have to spend to comply with the proposed PFAS MCLs vary widely. While the EPA estimates total annual costs for capital and operating expenses of between $772 million and $1.2 billion, the American Water Works Association estimates more than three times that amount: $3.8 billion annually. The Environmental Business Journal estimated water utilities will spend $31 billion in combined capital expenditures and operating expenses over the next 20 years.

In one high-profile case, the Cape Fear Public Utility Authority in Wilmington, North Carolina, invested $43 million to build eight deep-bed granular activated carbon (GAC) filters to remove PFAS from its raw water supplies. The 200,000-customer utility — which EPA Administrator Michael S. Regan visited for the March announcement of the PFAS MCLs — also expects to spend $5 million annually to operate the system.

When the filters were commissioned in October 2022, local leaders joined Cape Fear’s board and staff to toast the project’s efficacy — with PFAS-free water.

Many water utilities, like Cape Fear, hope to recover their PFAS costs from potentially responsible parties.

“The water utilities didn’t release these chemicals into the environment, someone else did,” Rupar said. “Our utility clients are interested in figuring out where the PFAS in their water sources came from, who the responsible parties are, and whether liability can be adjudicated and funding secured to remediate or treat the contamination.”

The largest PFAS liability settlement to date involves 3M, which has agreed to pay affected water utilities $10.3 billion over 13 years to remediate PFAS. According to the Reuters news agency, that settlement will likely be resolved in a final “fairness” hearing in February.

WSP is supporting water utility clients seeking to identify potentially responsible parties, and in some cases, working with industrial clients to assess and settle their PFAS liabilities.

“Our advanced groundwater modeling technologies are very useful for those applications,” Rupar said.

Thanks to the Bipartisan Infrastructure Law (BIL), water utilities have significant funding options for PFAS treatment, including $4 billion through the Drinking Water State Revolving Fund (DWSRF), $5 billion through EPA’s Emerging Contaminants in Small or Disadvantaged Communities Grant Program, and an additional $12 billion in BIL DWSRF funds for safer drinking water.

WSP has assisted many water utility clients in obtaining grants from the DWSRF and other sources. Rupar points out that DWSRF funds can be obtained for testing, research and capital investment. But they are advising many utilities consider developing alternative water supplies, optimizing operation of existing alternative sources and other strategies before investing in PFAS treatment.

“The available options for treatment have big drawbacks,” said Matthew Burns, WSP's technical director of environment. “The current technologies require large footprints, cost a lot to maintain and they are not destructive. So, PFAS laden treatment residuals need to be managed and options are far from ideal and very costly. For many utilities, source water management strategies may be a better path to achieving proposed PFAS MCLs than treatment — at least until the more efficient treatment technologies now in development are made available.”

While the problem is of great concern and EPA is pressing for action, Rupar said it’s also important that water utilities proceed with an understanding of their situation and a clear plan of action to make sure that the path taken is appropriate for them.

Although WSP has extensive experience with both GAC and ion exchange treatment for PFAS, “we are advising most clients not to jump to treatment right away,” Rupar said. “There are other things they may be able to do, such as operate their sources differently, drill a new well or connect to another water system.”

He added that WSP has produced blending plans for water suppliers with PFAS. “For example, if a utility has three wells and only one has PFAS, they can lean more heavily on the other two. There’s also the potential to abandon a source with high PFAS levels.”

Interconnecting with adjacent water utilities whose testing shows low PFAS concentration is another option — although the utility must weigh the economic disadvantages of purchasing water on the wholesale market against other strategies.

To evaluate and prepare for treatment down the road, utilities can benefit from a footprint study to identify the physical space that would be required for a PFAS treatment system.

“That way, you’ll avoid putting a new administrative building on what could have been your best site for PFAS treatment,” Rupar said. “You’ll also better understand capital expenses and their impact on your budget.”

WSP will soon release a benchmarking study outlining what water utilities are doing to meet the PFAS MCLs, how much they’re spending, and on what methods and technologies.

“There are often less costly alternatives … drill another well, find another water source, dilute the water,” Rupar said. “If it is best for a client to go the treatment route, WSP has that experience. But we are committed to exhausting all viable options that prioritize public safety without overspending for a solution that could be unnecessary.”

WSP’s Matt Burns and Usha Vedagiri take a closer look the impact of these PFAS rules on industrial and commercial locations in their article, “Three Considerations to Help Airports Prepare for PFAS regulations.”

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