[US] EPA Withdraws End-of-Pipe Control Guidance for PFAS: Treatment Threshold Retreats from Discharge Outfalls to Drinking Water Treatment Plants

In an internal memorandum dated 2026 年 8 月 11 日, the U.S. Environmental Protection Agency listed several documents as "suitable for rescission," including the memorandum titled "Addressing Perfluorinated and Polyfluorinated Alkyl Substances in Water Pollutant Discharge Permits and Pretreatment and Monitoring Programs" issued by 2022 年 4 月, an action that was publicly reported in mid-2026 年 9 月. This memorandum was precisely the operational manual guiding states in using existing authorities under the Clean Water Act to intercept perfluorinated and polyfluorinated alkyl substances (commonly known in the industry as "forever chemicals") at the discharge permitting end. During the same period, the EPA had another draft guidance on perfluorooctanoic acid and perfluorooctane sulfonate in sludge in the public comment stage, with the deadline extended to 2026 年 10 月 5 日.

What This Memorandum Originally Governed

The memorandum of 2022 年 4 月 primarily did three things, with the third having the broadest impact.

• Providing drafting language for state permitting authorities — explaining how to incorporate monitoring requirements for perfluorinated compounds, best management practices, and, where justified, numeric limits into National Pollutant Discharge Elimination System permits;
• Binding the EPA's own issued permits — clarifying how the EPA handles perfluorinated compound matters when directly issuing discharge permits;
• Controlling indirect dischargers — in jurisdictions where the EPA serves as the pretreatment authority, regulating industrial facilities that discharge wastewater to municipal sewage plants rather than directly to rivers.

The third item is critical because the industrial pretreatment system is the first gate protecting municipal sewage plants from upstream shock loads. Municipal plants are typically designed for domestic sewage, and their treatment facilities and sludge disposal pathways lack dedicated processes for persistent organic pollutants. Without unified federal guidance, enforcement standards among states immediately began to diverge.

The Law Has Not Changed, but the Practical Enforcement Approach Has

From a legal perspective, the obligations under the Clean Water Act have not changed due to this rescission, a point that environmental groups also confirm: permit writers have lost none of their statutory authority, and discharges that were illegal yesterday remain illegal today. However, the value of guidance lies precisely in "enabling non-lawyers to enforce this law consistently."

• Permit writers lose a citable basis — when facing an industrial discharge permit renewal application, engineers need to determine whether to require monitoring, which analytical methods to use, and what numeric limits are based on. With federal guidance, a simple "follow EPA guidance" is far more defensible in administrative appeals than individual judgment;
• Fragmentation of the enforcement landscape — states such as New Jersey, Michigan, and Massachusetts that have established their own control programs continue to advance, while states that previously relied on federal guidance are mostly stalled;
• Industrial dischargers gain negotiating room — companies can challenge perfluorinated compound provisions in permits, citing the absence of corresponding federal guidance as one reason.

Cost Shifting Brought About by the Shift in Governance Checkpoints

The most substantive consequence of this action is the shift of the treatment stage from the "cheap end" to the "expensive end."

• Source end (weakened by this action) — the advantages of treating industrial wastewater at the discharge point are very clear: smallest volume, highest concentration, lowest cost per unit mass of pollutants removed, and costs borne by the discharger;
• Terminal end (still being enforced) — water utilities must treat all incoming water after pollutants have been diluted by rivers, with the largest volume, lowest concentration, highest unit cost, and costs shifted to water utility customers. Current drinking water standards still maintain a mandatory limit of 4 parts per trillion for perfluorooctanoic acid and perfluorooctane sulfonate, primarily achieved through granular activated carbon or ion exchange.

In other words, one fewer requirement in a discharge permit may mean one more set of activated carbon tanks at the water utility.

Another Track on the Sludge Side: Public Comment in Progress

While the discharge end is retreating, the process on the sludge side has not stopped — it is simply taking a different path.

• Timeline — The Environmental Protection Agency released draft guidance on perfluorooctanoic acid and perfluorooctane sulfonate in sludge on 2026 年 6 月 29 日, with the comment period extended to 2026 年 10 月 5 日;
• What was corrected — The draft is regarded as a correction to a previous draft risk assessment. The EPA considered that the earlier assessment relied too heavily on high-risk hypothetical scenarios and did not conduct a nationwide survey of sludge conditions, leading the public to mistakenly believe that "all land application poses unacceptable risks" and to mistake the starting concentration of one part per billion as a universal safety threshold;
• What was clarified — The new draft does not propose mandatory limits for sludge, nor does it revise relevant regulatory provisions, and it provides no timeline for subsequent legislation. It mainly focuses on source identification and monitoring, adding composite liners to surface disposal units, performance testing for incomplete combustion emissions from incinerators, and guiding the use of funding channels such as state-level water recycling funds and the Water Infrastructure Finance and Innovation Act;
• States continue to tighten — States such as Connecticut and Maine have already banned the sale and use of sewage sludge containing perfluorinated compounds. In Maine, approximately 40% of sludge was originally land-applied as biosolids; after the ban took effect, disposal costs rose significantly due to limited landfill capacity and the lack of local incineration facilities.

It should be noted that this guidance is voluntary in nature, and its significance lies in its potential to influence future regulatory direction and state requirements, rather than creating immediate new compliance obligations.

Three References for China's Wastewater Industry

Despite the different jurisdictions, the technical and economic conclusions of this event are universal.

• Source control remains the most cost-effective checkpoint — Treating high-concentration industrial wastewater at the workshop discharge point costs far less than broad-area remediation after pollution has spread. Park-level segregated collection, characteristic pollutant lists, and corporate discharge ledgers require modest investment but determine the degree of passivity later on.
• Pre-treatment agreements must be detailed — When municipal wastewater treatment plants sign connection agreements with upstream enterprises, they should specify concentration limits for characteristic pollutants, testing frequency, liability for exceedance, and emergency response procedures, locking down responsibility boundaries in advance.
• Sludge disposal pathways need advance planning — As sources such as surfactants and fluorine-containing textile finishing agents are gradually identified, the compliance threshold for sludge land application will continue to rise. It is recommended that projects with sufficient capacity simultaneously evaluate two pathways — drying and incineration, and building materials utilization — to avoid being caught off guard when a single disposal route is cut off by policy.

Our Assessment

TIANYI TECH has long provided wastewater treatment and reclaimed water reuse system solutions for municipal and industrial park clients. Our observation is: the "step back" in perfluorinated compound regulation in Europe and the United States does not deny the problem itself, but rather represents a redivision of governance responsibilities and cost sharing. For Chinese enterprises, rather than predicting when standards will tighten, it is better to start doing what can be done now — establishing a list of incoming water sources, conducting screening for characteristic pollutants, and reserving interfaces for advanced treatment at key nodes. Even if standards remain unchanged in the future, these investments can directly reduce operational risks.

About TIANYI LIMITED: TIANYI LIMITED is deeply engaged in the field of wastewater treatment and reclaimed water reuse, committed to providing efficient, low-carbon, and sustainable water treatment solutions for municipal and industrial clients.