June 28, 2022
Regulating PFAS Under the Clean Water Act
In recent decades, improvements in monitoring
Effluent Limitation Guidelines
technologies and analytical methods, combined with health
The CWA requires EPA to publish ELGs, which are the
research, have increased national attention to the presence
required minimum standards for specific pollutants in
of emerging contaminants in surface water. Detections of
industrial wastewater discharges. EPA has developed ELGs
one particular group of contaminants, per- and
for 59 industrial source categories. For industrial facilities
polyfluoroalkyl substances (PFAS), have heightened public
that discharge directly to regulated waters, EPA or states
and congressional interest in the U.S. Environmental
incorporate the limits established in ELGs into the NPDES
Protection Agency’s (EPA’s) authorities under the Clean
permits they issue. For indirect dischargers—facilities that
Water Act (CWA) to address PFAS in surface water.
discharge to publicly owned treatment works (POTWs)—
pretreatment standards established in ELGs to prevent pass
Overview
through and interference at the POTW apply.
EPA has several CWA authorities it may use to address
contaminants, such as PFAS, in surface water (for more
The CWA also requires EPA to annually review all existing
information, see CRS Report R45998, Contaminants of
ELGs and publish a biennial plan that includes a schedule
Emerging Concern Under the Clean Water Act, by Laura
for review and revision of promulgated ELGs, identifies
Gatz). Under the CWA, a primary mechanism to control
categories of industrial sources discharging toxic or
contaminants in surface waters is through permits. The
nonconventional pollutants that do not have ELGs, and
statute prohibits the discharge of pollutants from any point
establishes a schedule for promulgating ELGs for any
source (i.e., a discrete conveyance) to waters of the United
newly identified categories. EPA’s most recent biennial
States without a permit. The CWA authorizes EPA, and
plans have included details on the agency’s efforts to
states with delegated CWA permitting authority, to limit or
determine whether the agency should update ELGs for
prohibit discharges of pollutants in the National Pollutant
certain industrial source categories to set effluent
Discharge Elimination System (NPDES) permits they issue.
limitations for PFAS. In these plans, EPA noted that while
These permits incorporate technology-based and water-
there has been significant study in recent years of the
quality-based requirements.
presence of PFAS in the environment and drinking water,
there has been relatively little study of the discharges of
The CWA requires EPA to establish technology-based
PFAS to surface water and POTWs. Hence, EPA’s recent
effluent (i.e., discharge) limits for industrial dischargers,
biennial plans and related actions have included efforts to
known as Effluent Limitation Guidelines (ELGs). EPA is
identify and characterize PFAS discharges, including the
also required to issue water quality criteria for use in
types and concentrations of PFAS discharged and the
establishing water quality standards and water-quality-
significant sources of PFAS discharges.
based effluent limitations. The CWA also authorizes EPA
to utilize certain NPDES permit authorities to address
In the Roadmap, EPA broadened the goals it included in
contaminants; to set pollutant limits and monitoring and
recent biennial plans to address PFAS discharges through
reporting requirements for contaminants in biosolids (i.e.,
ELGs and targeted the end of 2024 as the deadline for
sewage sludge from wastewater treatment facilities) if
“significant progress in its ELG regulatory work.”
sufficient scientific evidence shows there is potential harm
Specifically, EPA established timelines for action on the
to human health or the environment; and to designate
following industrial categories: Organic Chemicals,
contaminants as toxic or hazardous pollutants.
Plastics, and Synthetic Fibers (OCPSF); Pulp, Paper, and
Paperboard; Textile Mills; Electroplating; Metal Finishing;
To date, EPA has not published any final technology-based
Leather Tanning and Finishing; Paint Formulating;
effluent limits or water quality criteria to address any PFAS
Electrical and Electronic Components; Plastics Molding
but has taken steps toward doing so. EPA announced
and Forming; Landfills; and Airports.
projected timelines for these actions in its latest agency-
wide PFAS plan, the 2021 PFAS Strategic Roadmap. EPA
NPDES Authorities
has not established requirements for PFAS in biosolids but
In cases where EPA has not established an ELG for a
included an associated action and timeline in the Roadmap.
particular industrial category or type of facility, or where
In some instances, EPA has used NPDES permit authorities
pollutants or processes were not considered when an ELG
to address PFAS and has taken steps to encourage states to
was developed, the permitting authority (EPA or states)
use such authorities. EPA has not designated any PFAS as a
may still impose technology-based effluent limits on a case-
toxic pollutant or hazardous substance.
by-case basis. The permitting authority may also require
facilities with NPDES permits to monitor for pollutants or
conduct special studies as a means to collect data to support
future permit limits. The permitting authority may also
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Regulating PFAS Under the Clean Water Act
include best management practices in permits on a case-by-
life criteria for perfluorooctanoic acid (PFOA) and
case basis to carry out CWA provisions. However, the use
perfluorooctane sulfonate (PFOS). It also stated that the
of some of these authorities can be limited when analytical
agency intends to issue benchmarks for other PFAS that do
methods to detect specific pollutants are not available.
not have sufficient data to define a recommended aquatic
life criteria value. EPA targeted the fall of 2024 for
In the Roadmap, EPA discussed plans to leverage some of
publishing human health criteria for PFOA and PFOS. In
these NPDES authorities. Central to these plans was the
May 2022, EPA published draft recommended aquatic life
September 2021 publication of a draft EPA-validated
criteria for PFOA and PFOS for public comment. EPA
laboratory analytical method to test for 40 PFAS
intends to issue final PFOA and PFOS criteria, considering
compounds in eight different environmental media,
public comment and any new toxicity data.
including surface water and wastewater. Specifically, for
federally issued permits, EPA indicated that it plans to
Biosolids Requirements
require monitoring at facilities where PFAS are expected or
Biosolids, also known as sewage sludge, are a product of
suspected to be present in discharges, using the analytical
the wastewater treatment process. Biosolids may be applied
method. EPA also discussed plans to issue guidance to state
to land for beneficial purposes (e.g., agriculture) or
permitting authorities recommending that they leverage the
disposed of through incineration or surface disposal. CWA
same NPDES authorities where appropriate.
Section 405(d) requires EPA to establish numeric limits and
management practices to protect public health and the
In April 2022, EPA issued a memorandum, in line with the
environment from the reasonably anticipated adverse
Roadmap, detailing how the agency will address PFAS
effects of pollutants during the use or disposal of biosolids.
discharges in EPA-issued NPDES permits and for indirect
It also requires EPA to review its biosolids regulations at
dischargers where EPA is the pretreatment control
least every two years to identify additional toxic pollutants
authority. The memorandum recommends that EPA permit
that may be present in biosolids and then promulgate
writers include certain permit conditions for facilities where
regulations for those pollutants if sufficient scientific
PFAS are expected or likely to be present in discharges.
evidence shows they may adversely affect public health or
These conditions include effluent monitoring for the 40
the environment. EPA’s process to determine whether a
PFAS detectable by EPA’s draft analytical method and best
pollutant may warrant regulation includes sewage sludge
management practices and pollution prevention conditions
surveys (i.e., surveys to identify the presence of pollutants
(e.g., product elimination or substitution when a reasonable
in biosolids using samples taken from wastewater treatment
alternative to PFAS is available, minimizing accidental
plants), risk screening for pollutants found in biosolids, and
discharge through good housekeeping practices, equipment
risk assessments for pollutants identified in biosolids that
decontamination, or replacement). The memorandum also
exceed a level of concern.
includes recommended permit conditions for POTWs where
EPA is the permitting authority and where EPA is the
To date, EPA has not established numeric limits or
pretreatment control authority, including effluent, influent,
monitoring or reporting requirements for PFAS in biosolids.
and biosolids monitoring requirements and best
In the Roadmap, EPA states that it plans to complete, by
management and pollution prevention practices. It also
winter 2024, a risk assessment for PFOA and PFOS in
states that EPA regions are expected to notify potentially
biosolids, which EPA will use to determine whether to
affected downstream public water systems of draft permits
regulate these contaminants in biosolids.
with PFAS-specific monitoring, best management practices,
or other conditions.
Toxic Pollutants or Hazardous Substances
The CWA authorizes EPA to designate contaminants as
Water Quality Criteria
toxic pollutants (§307) or as hazardous substances (§311),
CWA Section 304(a) requires EPA to develop and publish
which may trigger other actions under the CWA and the
and “from time to time thereafter revise” criteria for water
Comprehensive Environmental Response, Compensation,
quality that accurately reflect the latest scientific
and Liability Act (for more information, see CRS Report
knowledge. Water quality criteria provide concentrations
R45986, Federal Role in Responding to Potential Risks of
for specific contaminants or conditions in a water body that,
Per- and Polyfluoroalkyl Substances (PFAS)). EPA has not
if not exceeded, will protect particular designated uses of
designated any PFAS as toxic pollutants or hazardous
the water body (e.g., protection of aquatic life, public
substances under CWA authorities and did not indicate in
drinking water supply, recreation). These criteria are
the Roadmap that it plans to do so.
recommendations to states and tribal governments for use in
developing their own water quality standards, which they
Recent Congressional Action
use to protect and restore waters and to inform water-
Recent Congresses have held hearings and introduced and
quality based effluent limits in permits. EPA has developed
passed legislation to address PFAS in surface water. The
several types of criteria targeted to protect different
Infrastructure Investment and Jobs Act (P.L. 117-58)
designated uses, such as human health, aquatic life, and
provides $1 billion over five fiscal years to address
recreational criteria.
emerging contaminants (including PFAS) in wastewater
through the Clean Water State Revolving Fund. The PFAS
In the Roadmap, EPA announced plans to develop national
Action Act of 2021 (H.R. 2467), passed by the House in
recommended ambient water quality criteria for PFAS to
July 2021, would require EPA to take a number of
protect aquatic life and human health. EPA targeted winter
regulatory actions to address PFAS under certain federal
2022 as its deadline for publishing recommended aquatic
environmental laws, including the CWA, among other
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Regulating PFAS Under the Clean Water Act
actions. Members have introduced additional bills related to
Laura Gatz, Analyst in Environmental Policy
PFAS in surface water that have not passed either chamber.
IF12148


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