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Regulatory Updates

PFAS Discharges in NPDES Permits

Catriona V. Smith (Cat), R.E.M | December 16, 2022

In a follow-up to the Environmental Protection Agency (EPA) Office of Water’s April 28, 2022 memo, EPA released “Part 2” of this memo on December 5, 2022, providing guidance to permit writers in authorized states for use when administering the National Pollutant Discharge Elimination System (NPDES) permitting and/or pretreatment program as it relates to restricting discharges of per- and polyfluoroalkyl substances (PFAS) to water bodies.

Interestingly, this second memo is almost identical in recommendations to the first, with a few additions as shown in the table below.

PFAS in NPDES/Pretreatment Permits 1
EPA Guidance Topic April 28, 2022 Memo – EPA-Issued NPDES/Pretreatment Permits  December 5, 2022 Memo – State-Issued NPDES/Pretreatment Permits
Applicability – should also consider Centralized Waste Treatment facilities, remediation sites, chemical manufacturing not covered by OCPSF, and military bases for monitoring (in addition to 12 industrial categories in PFAS Strategic Roadmap2)
Submit a “complete” permit application, including additional information requested by permitting authority Not mentioned


Quarterly Effluent Monitoring – recommends EPA Draft Method 1633 to analyze for the 40 target PFAS compounds included in that method. Applicable to aqueous, solids, biosolids and tissue samples.

Includes wastewater residuals 3

Quarterly influent and biosolids monitoring (POTWs only) – as above
Report quarterly PFAS data in Discharge Monitoring Reports (DMRs)
Biosolids Assessment (at POTWs) to identify PFAS in biosolids and upstream industrial contributors, in addition to developing local limits and BMPs for upstream industrial contributors 4 Not mentioned
Annual report documenting potential PFAS sources and reduction/elimination actions, applicable effluent results and adjustments to plan
Best Management Practices (BMPs) – Special Conditions Language
BMPs for PFAS products/ingredients (substitution, reduction, elimination, discharge minimization, equipment decontamination/replacement)
BMPs for PFAS-containing firefighting foam – Aqueous Film Forming Foam (AFFF) – use prohibition, eliminate PFOS and PFOA foams, require immediate cleanup including diversions and other means to prevent discharges to storm sewers.
Update inventories of potential PFAS contributors (industrial users [IU]) to POTWs; submit to EPA within one year
Develop IU BMPs or local limits for PFAS (POTWs)
Quarterly Monitoring for IUs Not mentioned


Site-specific technology-based effluent limits (TBELs) based on best professional judgement (BPJ) for PFAS discharges Not mentioned


Water quality-based effluent limits in additional to TBELs, if necessary to achieve water quality (WQ) standards Not mentioned


If a state has a numeric criterion or a numeric translation of an existing narrative WQ standard for PFAS, this should be applied in permitting decisions
Permitting authority to provide public notice to downstream public water systems (PWS) of draft permits with PFAS-specific conditions
Collaborate with drinking water program counterparts

1 Industrial Direct Dischargers and Publicly Owned Treatment Works [POTWs].

2 Organic chemicals, plastics & synthetic fibers (OCPSF); metal finishing; electroplating; electric and electronic components; landfills; pulp, paper & paperboard; leather tanning & finishing; plastics molding & forming; textile mills; paint formulating; and airports.

3 EPA also noted that “Certain industrial processes may generate PFAS-contaminated solid waste or air emissions not covered by NPDES permitting and permitting agencies should coordinate with appropriate state authorities on proper containment and disposal to avoid cross-media contamination.”

4 Monitoring of PFAS for purposes of project development to identify best solutions for reductions is eligible for funding from the Clean Water State Revolving Fund (CWSRF).

5 This could also include requirements for monitoring of sewage sludge prior to introduction to a POTW.

What Can You Do to Prepare?

  • Ask your State regulators if and how they are planning on implementing this guidance
  • Assess potential liabilities: Inventory potential PFAS materials and dispose if possible
  • Evaluate phase out and replacement of PFAS-containing raw materials or intermediates
  • Identify past spills or releases of PFAS-containing materials or areas where PFAS firefighting foam was used
  • Replace PFAS firefighting foams with non-PFAS options
  • Manage the issue: Develop a plan for enhanced PFAS management including response to Agency information requests, sampling, storage, disposal options, etc.

For more information, please contact: Cat Smith, REM;

Catriona Smith

Catriona (Cat) Smith has over 30 years of professional experience in the interpretation and application of regulations for industrial facilities relating to compliance, remediation and negotiations with regulatory agencies. Her clients include upstream and downstream oil and gas, chem-pharma, petrochem, manufacturing and federal, state, and local governments. Ms. Smith is a Vice President and Environmental Sector Market Director for TRC, with nationwide responsibilities to manage our clients’ PFAS challenges, support and grow our Oil and Gas clients and bring multi-disciplinary solutions to their complex projects. Contact Cat at

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