[Federal Register Volume 89, Number 194 (Monday, October 7, 2024)]
[Notices]
[Pages 81077-81079]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-23024]


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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OW-2022-0365 and EPA-HQ-OW-2022-0366; FRL 8310-02-OW]


Final Recommended Aquatic Life Criteria and Benchmarks for Select 
PFAS

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability.

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SUMMARY: As part of the Environmental Protection Agency's (EPA) 
commitment to safeguard the environment from per- and polyfluoroalkyl 
substances (PFAS), the agency is announcing the availability of 
national ``Final Recommended Freshwater Aquatic Life Ambient Water 
Quality Criteria and Acute Saltwater Aquatic Life Benchmarks for 
Perfluorooctanoic Acid (PFOA)'' and ``Final Recommended Freshwater 
Aquatic Life Ambient Water Quality Criteria and Acute Saltwater Aquatic 
Life Benchmarks for Perfluorooctane Sulfonate (PFOS),'' pursuant to the 
Clean Water Act (CWA). The EPA is also announcing the availability of 
Acute Freshwater Aquatic Life Benchmarks for eight data-limited 
perfluoroalkyl substances (PFAS): perfluorobutanoic acid (PFBA), 
perfluorohexanoic acid (PFHxA), perfluorononanoic acid (PFNA), 
perfluorodecanoic acid (PFDA), perfluorobutanesulfonic acid (PFBS), 
perfluorohexanesulfonic acid (PFHxS), 2H-perfluoro-2-decenoic acid (8:2 
FTUCA), and 2H,2H,3H,3H-pefluorodecanoic acid (7:3 FTCA). These final 
CWA recommended criteria and benchmarks provide information that States 
and Tribes may consider when adopting water quality standards. 
Consistent with Clean Water Act sections 304(a)(1) and (a)(2), the EPA 
expects to update these recommended criteria and benchmark values from 
time to time as new information becomes available. This announcement is 
in accordance with Clean Water Act section 304(a)(3), which directs the 
EPA to publish information developed under sections 304(a)(1) and 
(a)(2) in the Federal Register and make it available to States, Tribes, 
and the public.

SUPPLEMENTARY INFORMATION:

I. How can I get copies of these documents and other related 
information?

    The EPA has established a first docket for the ``Final Recommended 
Freshwater Aquatic Life Ambient Water Quality Criteria and Saltwater 
Acute Benchmarks for Perfluorooctanoic Acid (PFOA)'' under Docket ID 
No. EPA-HQ-OW-2022-0365 and a second docket for the ``Final Recommended 
Freshwater Aquatic Life Ambient Water Quality Criteria and Saltwater 
Acute Benchmarks for Perfluorooctane Sulfonate (PFOS)'' under Docket ID 
No. EPA-HQ-OW-2022-0366. Publicly available docket materials are 
available either electronically through www.regulations.gov or in hard 
copy at the EPA Docket Center, WJC West Building, Room 3334, 1301 
Constitution Ave. NW, Washington, DC. The Docket Center's hours of 
operations are 8:30 a.m.-4:30 p.m., Monday through Friday (except 
Federal holidays). For further information on the EPA Docket Center 
services and the current status, see: https://www.epa.gov/dockets.
    The ``Final Recommended Freshwater Aquatic Life Ambient Water 
Quality Criteria and Saltwater Acute Benchmarks for Perfluorooctanoic 
Acid (PFOA)'' document can be accessed on the EPA's website through the 
following link: https://www.epa.gov/system/files/documents/2024-09/pfoa-report-2024.pdf. The ``Final Recommended Freshwater Aquatic Life 
Ambient Water Quality Criteria and Saltwater Acute Benchmarks for 
Perfluorooctane Sulfonate (PFOS)'' document can be accessed on the 
EPA's website through the following link: https://www.epa.gov/system/files/documents/2024-09/pfos-report-2024.pdf. The ``Final Acute 
Freshwater Aquatic Life Benchmarks for Eight Data-Limited PFAS: PFBA, 
PFHxA, PFNA, PFDA, PFBS, PFHxS, 8:2 FTUCA, and 7:3 FTCA'' document can 
be accessed on the EPA's website through the following link: https://www.epa.gov/system/files/documents/2024-09/pfas-report-2024.pdf.

II. What are PFAS, including PFOA and PFOS?

    Per- and polyfluoroalkyl substances (PFAS) are human-made organic 
chemical compounds composed of a carbon chain bound to multiple 
fluorine atoms. PFAS have been manufactured and used by a broad range 
of industries since the 1940s, and there are estimated to be thousands 
of PFAS present in the global marketplace that are used in a range of 
commercial and industrial products. PFOA and PFOS are two of the most 
widely used and studied chemicals in the PFAS group. PFAS are not 
naturally occurring and have no biologically important functions or 
beneficial properties to aquatic life. PFAS, including PFOA and PFOS, 
can persist in the environment and have been detected in U.S. rivers, 
lakes, and streams. At elevated concentrations, PFAS can be toxic to 
fish and other aquatic species.

III. What are CWA national ambient water quality criteria and 
benchmarks developed by the EPA?

    CWA section 304(a) directs the EPA to develop and publish water 
quality criteria that reflect the latest scientific knowledge. The EPA 
develops national recommended ambient water quality criteria for the 
protection of aquatic life based on the highest numeric concentrations 
of pollutants, with specific recommendations on the duration and 
frequency of those concentrations, that are protective of aquatic 
ecosystems as a whole. The EPA's section 304(a)(1) criteria 
recommendations generally follow the Guidelines methods (Guidelines for 
Deriving Numerical National Water Quality Criteria for the Protection 
of Aquatic Organisms and Their Uses), which recommend toxicity data for 
a minimum of eight families of aquatic animals be used in developing 
aquatic life criteria to ensure criteria will protect aquatic 
ecosystems as a whole. Water quality criteria are based solely on data 
and scientific judgments about the relationship between pollutant 
concentrations and potential environmental effects. The EPA's 
recommended water quality criteria are not regulatory, nor do they 
automatically become part of a State's water quality standards. States 
must adopt into their standards water quality criteria that protect the 
designated uses of their water bodies. States can establish water 
quality criteria based on the EPA's recommended criteria, modify

[[Page 81078]]

recommended criteria to reflect site-specific conditions, or develop 
proposed standards using on other scientifically defensible methods. A 
State's or Tribe's water quality criteria are not legally effective 
under the Clean Water Act until they have been adopted into a State's 
or Tribe's water quality standards and are approved by the EPA.
    Aquatic life benchmarks, developed under section 304(a)(2) of the 
CWA, are informational values that the EPA generates when there are 
limited high quality toxicity data available and data gaps exist for 
several aquatic organism families. The EPA develops aquatic life 
benchmarks to provide information that States and Tribes may consider 
in their water quality protection programs. In developing aquatic life 
benchmarks, data gaps may be filled using new approach methods (NAMs), 
such as computer-based toxicity estimation tools (e.g., EPA's Web-ICE; 
Version 3.3; https://www.epa.gov/webice/) or other new approach methods 
intended to reduce reliance on additional animal testing (https://www.epa.gov/chemical-research/epa-new-approach-methods-work-plan-reducing-use-vertebrate-animals-chemical), including the use of read-
across estimates based on other chemicals with similar structures. The 
EPA's aquatic life benchmark values are not regulatory, nor do they 
automatically become part of a State's water quality standards.

IV. What are the EPA's recommended criteria for PFOA and PFOS in 
freshwater for the protection of aquatic life?

    The EPA has developed separate PFOA and PFOS criteria to protect 
aquatic life from the effects of these individual chemicals. The EPA 
developed these final recommended aquatic life ambient water quality 
criteria following the general approach outlined in the EPA's 
Guidelines.<SUP>1</SUP> The EPA developed the final PFOA and PFOS 
recommended criteria to protect aquatic life designated uses 
established for freshwaters. The final criteria documents contain acute 
and chronic water column criteria for freshwaters (see Table 1 of this 
document). Acute criteria protect aquatic species from short-term 
exposures to high pollutant concentrations while chronic criteria 
protect aquatic species from long-term and repeated pollutant 
exposures. The final criteria also contain chronic criteria expressed 
as PFOA and PFOS concentrations in fish muscle tissue, fish whole-body 
tissue, and in invertebrate tissue (see Table 1 of this document). Many 
States and Tribes measure PFAS in fish tissues and these tissue-based 
criteria values allow States and Tribes to assess the health of fish 
and invertebrates in their freshwaters. The chronic freshwater and 
chronic fish/invertebrate tissue-based criteria for both chemicals are 
intended to be independently applicable and no one criterion takes 
primacy.
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    \1\ The EPA's Guidelines for Deriving Numerical Water Quality 
Criteria for the Protection of Aquatic Organisms and Their Uses can 
be accessed through the EPA web page at: https://www.epa.gov/sites/default/files/2016-02/documents/guidelines-water-quality-criteria.pdf.
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    The PFOA and PFOS criteria establish maximum concentrations (i.e., 
magnitude component), averaged over a given time period (i.e., duration 
component), that if not exceeded more than the allowable number of 
times during a specified time period (i.e., frequency component), are 
expected to protect aquatic ecosystems as a whole. The duration 
components of criteria are set to be substantially shorter than the 
length of toxicity tests used to derive the criteria magnitude and 
restrict allowable fluctuations in pollutant concentrations over time. 
The frequency components of aquatic life criteria ensure aquatic 
communities have adequate time to recover following a criteria 
exceedance event. The EPA's final recommended PFOA and PFOS criteria 
magnitudes combined with the associated duration and frequency 
components are expected to protect fish and other aquatic species in 
freshwaters (see Table 1).

                               Table 1--Final Recommended Freshwater Aquatic Life Water Quality Criteria for PFOA and PFOS
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                                   Acute water column     Chronic water
       Criteria component              (CMC) \1\         column (CCC) \2\    Invertebrate whole-body       Fish whole-body             Fish muscle
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PFOA Magnitude..................  3.1 mg/L...........  0.10 mg/L..........  1.18 mg/kg ww \4\.......  6.49 mg/kg ww \4\.......  0.133 mg/kg ww.\4\
PFOS Magnitude..................  0.071 mg/L.........  0.00025 mg/L.......  0.028 mg/kg ww \4\......  0.201 mg/kg ww \4\......  0.087 mg/kg ww.\4\
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Duration........................  1-hour average.....  4-day average......  Instantaneous.\3\
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Frequency.......................  Not to be exceeded   Not to be exceeded   Not to be exceeded.\5\
                                   more than once in    more than once in
                                   three years, on      three years, on
                                   average.             average.
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\1\ Criterion Maximum Concentration.
\2\ Criterion Continuous Concentration.
\3\ Tissue data provide instantaneous point measurements that reflect integrative accumulation of PFOA or PFOS over time and space in aquatic life
  population(s) at a given site.
\4\ Wet-Weight.
\5\ PFOA and PFOS chronic freshwater tissue-based criteria should not be exceeded, based on measured tissue concentrations representing the central
  tendency of samples collected at a given site and time.

V. What are the EPA's saltwater acute benchmarks for protecting aquatic 
life from PFOA and PFOS?

    Data limitations did not allow for derivation of PFOA or PFOS 
national recommended water quality criteria to protect saltwater 
organisms. Therefore, the EPA derived PFOA and PFOS aquatic life 
benchmark values under section 304(a)(2) of the CWA using the best 
available data on the effects of PFOA and PFOS to provide information 
that States and Tribes may consider in their water quality protection 
programs. These benchmark values are based solely on data and 
scientific judgments about the relationship between pollutant 
concentrations and potential environmental effects. Like national 
recommended water quality criteria, the EPA's acute PFOA and PFOS 
aquatic life benchmark values for saltwater are nonbinding and 
nonregulatory.
    The EPA derived acute saltwater benchmarks using available toxicity 
data on PFOA and PFOS, supplemented with data estimated using the EPA's 
Web-ICE tool. With data gaps addressed using both laboratory and 
estimated toxicity test data, the acute saltwater benchmarks for PFOA 
and PFOS were calculated following methods outline in the EPA's 
Guidelines.\1\ The EPA's acute saltwater benchmarks for PFOA and PFOS 
values are the maximum concentrations of these PFOA and PFOS 
(individually, not in mixture), with associated frequency and duration 
specifications, that are expected to support protection of aquatic life 
from acute effects in saltwater (see Table 2).

[[Page 81079]]



                       Table 2--Acute Saltwater Aquatic Life Benchmarks for PFOA and PFOS
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                          Chemical                                      PFOA                      PFOA
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Magnitude...................................................                 7.0 mg/L                0.55 mg/L.
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Duration....................................................                   One hour average.
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Frequency...................................................   Not to be exceeded more than once in three years
                                                                                  on average.
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VI. What are the EPA's freshwater acute benchmarks for protecting 
aquatic life from eight additional PFAS?

    Toxicity data to support benchmarks for these eight PFAS benchmarks 
were limited relative to the data requirements traditionally used to 
develop aquatic life criteria. Therefore, the EPA derived PFAS aquatic 
life benchmark values under section 304(a)(2) of the CWA using the best 
available data on the effects of these PFAS to provide information that 
States and Tribes may consider in their water quality protection 
programs. These benchmark values are based solely on data and 
scientific judgments about the relationship between pollutant 
concentrations and potential environmental effects. Like national 
recommended water quality criteria, the EPA's eight separate acute 
aquatic life benchmark values for eight different data-limited PFAS in 
freshwater are nonbinding and nonregulatory.
    Compared to PFOA and PFOS, acute freshwater data were more limited 
for these eight PFAS that the EPA evaluated. The EPA developed the 
benchmarks by using the available laboratory-based data on the effects 
of those chemicals on freshwater organisms, supplemented with data 
estimated using the EPA's Web-ICE tool, following the same peer-
reviewed approach applied in development of the acute saltwater 
benchmarks for PFOA and PFOS. With data gaps addressed using both 
laboratory and estimated toxicity test data, the acute benchmarks for 
these eight PFAS were calculated following methods outline in the EPA's 
Guidelines.\1\
    The EPA's acute freshwater benchmark values are the maximum 
concentrations of these PFAS (individually, not in mixture), with 
associated frequency and duration specifications, that are expected to 
support protection of aquatic life from acute effects in freshwaters 
(see Table 2 of this document). These acute benchmarks for these eight 
PFAS (Table 3) provide information for States and Tribes to consider as 
protective values in their water quality protection programs.

                                            Table 3--Acute Freshwater Aquatic Life Benchmarks for Eight PFAS
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                        Chemical                             PFBA        PFHxA       PFNA        PFDA        PFBS        PFHxS     8:2 FTUCA   7:3 FTCA
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Magnitude \1\...........................................        5.3         4.8        0.65        0.50         5.0        0.21       0.037       0.012
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Duration................................................                                         One hour average.
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Frequency...............................................                   Not to be exceeded more than once in three years on average.
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\1\ Values expressed as mg/L, or ppm.


Bruno Pigott,
Principal Deputy Assistant Administrator.
[FR Doc. 2024-23024 Filed 10-4-24; 8:45 am]
BILLING CODE 6560-50-P