COVER SERIES | Water Management
Meeting Drinking Water Mandates With PAC
How powdered activated carbon can help utilities overcome supply chain shortages for PFAS treatment.
Ariel Li | Arq Inc.
| IMAGE 1: Powdered activated carbon (Image courtesy of Arq Inc.)
The Environmental Protection Agency (EPA)’s per- and polyfluoroalkyl substances (PFAS) drinking-water rule is likely to drive demand for granular activated carbon (GAC) systems past what suppliers, regeneration facilities and installers can currently maintain. Long lead times and limited contractor availability are now the norm, and the GAC media itself is facing a looming supply shortage as producers struggle to scale ahead of demand.
PFAS monitoring has been ongoing, and many utilities are just now learning their actual PFAS concentrations for the first time. Small utilities and those with low-level exceedances are discovering that powdered activated carbon (PAC) can offer a domestically available alternative that does not require as much capital outlay. Other utilities, facing higher concentrations or bigger systems, are turning to PAC as a way to start treating now while they plan, fund and build out a full GAC, ion exchange or membrane system or other long-term solution.
Expanding Domestic Carbon Sourcing Options
Much of the activated carbon the U.S. relies on is imported—the U.S. was the world’s second-largest importer of activated carbon in 2023. For utilities, that import dependency introduces long lead times, freight cost exposure, pricing impacts from tariffs and geopolitical supply risk, none of which utilities can afford when the compliance clock is ticking. PAC can offer utilities more domestic options.
The main reason for this is due to feedstock chemistry. GAC is typically manufactured from dense, hard raw materials like coconut shells (sourced primarily from the Asia-Pacific region) or high-rank bituminous coal, because it needs to hold its granular structure through repeated water flow and thermal reactivation.
PAC does not require that same structural durability, so it is commonly produced from softer, more varied feedstocks: lignite, bituminous and subbituminous coal, as well as wood. The U.S. has all of these sources in domestic abundance. This availability means utilities sourcing PAC are not competing for the same import-dependent coal supply chain but rather a different, more domestically accessible raw material pool.
Reducing Competition for Imported Media
Every utility racing toward PFAS compliance is competing for the same limited pool of media, regeneration capacity, design engineers and installation contractors—all on top of a long testing period—and that queue is getting longer.
At an Annual Conference and Exposition (ACE) 2026 readiness session, contractors and engineers identified where projects are getting stuck: Workforce shortages, permitting requirements and equipment lead times are creating significant challenges for PFAS project delivery. Suppliers are fielding growing questions from utilities about domestic manufacturing capacity and redundancy because availability itself has become uncertain. For a utility with a compliance deadline on the calendar, “get in line and wait” is risky.
Many utilities, particularly smaller systems and those with lower flow or minor PFAS exceedance levels, can meet treatment requirements with PAC dosing using existing equipment and infrastructure.
This option can be an advantage both for the utilities that choose it and for the rest of the sector, because every utility that treats successfully with PAC is one less utility competing for limited media, regeneration slots or installation crews.
As a result, more of the limited GAC capacity is available for the systems that genuinely have no substitute for a fixed-bed GAC system. Wider PAC adoption does not just help the utilities using it; it eases pressure on the GAC supply chain for everyone still in line.
Meeting Compliance Deadlines
The enforceable PFAS drinking-water standard finalized in 2024 is still the law today, but the ground underneath it is shifting.
In May, EPA proposed two changes to that rule: extending the compliance deadline for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from 2029 to 2031 and rescinding the standards for four other PFAS compounds (perfluorohexanesulfonic acid [PFHxS], perfluorononanoic acid [PFNA], hexafluoropropylene oxide dimer acid [HFPO-DA] and the associated Hazard Index mixture that includes perfluorobutane sulfonic acid [PFBS]).
As of this writing, neither proposal has been finalized. The 4 parts per trillion maximum contaminant levels for PFOA and PFOS remain unchanged and enforceable in the meantime—but everything around them, including which other PFAS compounds utilities may ultimately need to treat for and how much time they will have to do it, is still in flux.
That uncertainty makes long-term capital decisions difficult. A full system takes years to design, permit and build and represents a significant capital investment that utilities should not rush into while both the compound list and compliance timeline are still moving targets. Committing tens of millions of dollars to a system sized for six regulated PFAS compounds only to find that number has changed by the time it is operational is a real risk.
To get PFAS contamination under control now for the sake of public health and public trust, while the imported supply of media ramps up and regulations stabilize, PAC can serve as an effective stopgap, or as a primary treatment method with GAC used downstream as a polishing step once the picture is clearer.
Many utilities are focused on the 2029 enforcement date (or 2031, if EPA’s compliance extension passes), but the nearer-term pressure is April 2027, when every covered water system must have completed PFAS monitoring and reported the results to its users. That part of the rule has not changed. The moment a detection above the limit becomes public, consumer confidence issues and political pressure follow immediately. PAC is an option that lets a utility start reducing PFAS concentrations now.
Preparing for the PFAS Wave
The PFAS case for PAC comes down to three converging pressures. Global supply is strained, and PAC draws from a reliable domestic feedstock. The queue for imported media is long, and PAC lets many utilities exit it. And with the regulatory picture still moving, PAC lets utilities act without locking tens of millions of dollars into a system sized for rules that may not be final by the time it is built.
Ariel Li is the technical director of water products and applications at Arq Inc. For more information, visit arq.com.
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