6560-50-P
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 141
[EPA-HQ-OW-2022-0114; FRL 8543-04-OW]
RIN 2040-AG18
PFAS National Primary Drinking Water Regulation; Correction
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule; correction.
SUMMARY: The U.S. Environmental Protection Agency (EPA) is correcting formatting and
entry designations in a final rule that was published in the Federal Register on April 26, 2024.
The rule finalized National Primary Drinking Water Regulations under the Safe Drinking Water
Act for five individual per- and polyfluoroalkyl substances (PFAS): perfluorooctanoic acid
(PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS),
perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA, commonly
known as GenX Chemicals). The rule finalized a NPDWR for two or more mixtures of PFNA,
PFHXs, HFPO-DA and perfluorobutane sulfonic acid (PFBS). This document corrects
formatting and entry designations in the final regulation.
DATES: Effective on June 25, 2024.
ADDRESSES: The EPA has established a docket for this action under Docket ID No. EPA-HQOW-2022-0114. All documents in the docket are listed on the https://www.regulations.gov web
site. Although listed in the index, some information is not publicly available, e.g., Confidential
Business Information (CBI) or other information whose disclosure is restricted by statute.
Certain other material, such as copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy form. Publicly available docket materials are available
electronically through https://www.regulations.gov.
FOR FURTHER INFORMATION CONTACT: Alexis Lan, Office of Ground Water and

Drinking Water, Standards and Risk Management Division (Mail Code 4607M), Environmental
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; telephone number
202-564-0841; email address: PFASNPDWR@epa.gov.
SUPPLEMENTARY INFORMATION:
The EPA is making several corrections for inadvertent errors in the regulatory text for the final
rule:
I. Does this action apply to me?
This action makes formatting changes for the incorporation of the April 26, 2024, final PFAS
National Primary Drinking Water Regulation into the Code of Federal Regulations. The agency
included in the April 26, 2024, final rule a list of those entities that may be potentially affected
by the final PFAS National Primary Drinking Water Regulation.
II. What does this correction do?
The EPA issued a final rule in the Federal Register on April 26, 2024 (89 CFR 32532) (FRL
8543-02-OW), finalizing National Primary Drinking Water Regulations under the Safe Drinking
Water Act for PFAS: PFOA, PFOS, PFHxS, PFNA, HFPO-DA, and as well as two or more
mixtures of PFNA, PFHXs, HFPO-DA and PFBS. The EPA inadvertently listed incorrect entry
designations in § 141.61. This document corrects the designation of entries in the tables in §
141.61(c)(1) and § 141.61(c)(2). With the corrections to § 141.61(c)(1) and § 141.61(c)(2), the
subsequent tables in § 141.61(c) are also renumbered; tables 5 and 6 are changed to tables 3 and
4. These corrections to § 141.61 are also now reflected appropriately in amendatory instructions
7 and 8. This document corrects the final regulation.
III. Why is this correction issued as final rule?
Section 553 of the Administrative Procedure Act (APA) (5 U.S.C. 553(b)(3)(B)) provides that,
when an agency for good cause finds that notice and public procedure are impracticable,
unnecessary, or contrary to the public interest, the agency may issue a final rule without
providing notice and an opportunity for public comment. The EPA has determined that there is a

good cause for making this correction final without prior proposal and opportunity for comment,
because the EPA inadvertently listed the designation of entries incorrectly in § 141.61 in the
document published in the Federal Register. The EPA finds that this constitutes good cause
under 5 U.S.C. 553(b)(3)(B).
Corrections
In FR Doc. 2024– 07773 beginning on page 32532 in the Federal Register of April 26,
2024, the EPA is making the following corrections:

§ 141.60 [Corrected]
1. On page 32744, in the third column, in § 141.60, in paragraph (a)(4), “The effective date for
paragraphs (c)(34) through (40) of § 141.61 (listed in table 4 to paragraph (c)) is April 26, 2029.”
is corrected to read “The effective date for § 141.61(c)(2)(i) through (vii) is April 26, 2029.”
2. On page 32744, starting in the third column, amendatory instruction 8 for § 141.61 and the
accompanying regulatory text are corrected to read as follows:
8. Amend § 141.61 by:
a. In paragraph (a), revising the introductory text and adding a table heading;
b. In paragraph (b), revising the introductory text and the table heading;
c. Revising and republishing paragraph (c); and
d. Adding paragraphs (d) and (e).
The revisions and additions read as follows:
§ 141.61 Maximum contaminant levels for organic contaminants.
(a) The following maximum contaminant levels for volatile organic contaminants apply
to community and non-transient, non-community water systems.
Table 1 to paragraph (a) -- Maximum Contaminant Levels for Volatile Organic
Contaminants
*****
(b) The Administrator, pursuant to section 1412 of the Act, hereby identifies as indicated
in table 2 to this paragraph (b) granular activated carbon (GAC), packed tower aeration (PTA),
or oxidation (OX) as the best technology, treatment technique, or other means available for
achieving compliance with the maximum contaminant level for organic contaminants identified
in paragraphs (a) and (c) of this section, except for per- and polyfluoroalkyl substances (PFAS).
Table 2 to paragraph (b) -- BAT for Organic Contaminants in Paragraphs (a) and (c) of
this Section, Except for PFAS
*****

(c) The following maximum contaminant levels (MCLs) in paragraphs (c)(1) and (2) of
this section for synthetic organic contaminants apply to community water systems and nontransient, non-community water systems; paragraph (c)(2) of this section also contains healthbased water concentrations (HBWCs) for selected per- and poly-fluoroalkyl substances (PFAS)
used in calculating the Hazard Index.
(1) MCLs for Synthetic Organic Contaminants, Except for PFAS.
CAS No.
(i) 15972-60-8
(ii) 116-06-3
(iii) 1646-87-3
(iv) 1646-87-4
(v) 1912-24-9
(vi) 1563-66-2
(vii) 57-74-9
(viii) 96-12-8
(ix) 94-75-7
(x) 106-93-4
(xi) 76-44-8
(xii) 1024-57-3
(xiii) 58-89-9
(xiv) 72-43-5
(xv) 1336-36-3
(xvi) 87-86-5
(xvii) 8001-35-2
(xviii) 93-72-1
(xix) 50-32-8
(xx) 75-99-0
(xxi) 103-23-1
(xxii) 117-81-7
(xxiii) 88-85-7
(xxiv) 85-00-7
(xxv) 145-73-3
(xxvi) 72-20-8
(xvii) 1071-53-6
(xxviii) 118-74-1
(xxix) 77-47-4
(xxx) 23135-22-0
(xxxi) 1918-02-1
(xxxii) 122-34-9
(xxxiii) 1746-01-6

Contaminant
Alachlor
Aldicarb
Aldicarb sulfoxide
Aldicarb sulfone
Atrazine
Carbofuran
Chlordane
Dibromochloropropane
2,4-D
Ethylene dibromide
Heptachlor
Heptachlor epoxide
Lindane
Methoxychlor
Polychlorinated biphenyls
Pentachlorophenol
Toxaphene
2,4,5-TP
Benzo[a]pyrene
Dalapon
Di(2-ethylhexyl) adipate
Di(2-ethylhexyl) phthalate
Dinoseb
Diquat
Endothall
Endrin
Glyphosate
Hexacholorbenzene
Hexachlorocyclopentadiene
Oxamyl (Vydate)
Picloram
Simazine
2,3,7,8-TCDD (Dioxin)

(2) MCLs and HBWCs for PFAS.

MCL (mg/l)
0.002
0.003
0.004
0.002
0.003
0.04
0.002
0.0002
0.07
0.00005
0.0004
0.0002
0.0002
0.04
0.0005
0.001
0.003
0.05
0.0002
0.2
0.4
0.006
0.007
0.02
0.1
0.002
0.7
0.001
0.05
0.2
0.5
0.004
3 × 10−8

CAS. No.

Contaminant

(i) Not
applicable

Hazard Index PFAS
(HFPO-DA, PFBS, PFHxS,
and PFNA)
HFPO-DA

(ii) 12249917-6
(iii) 45187-153
(iv) 10842753-8
(v) 72007-682
(vi) 45285-516
(vii) 4529890-6

MCL (mg/l)
(unless otherwise
noted)
1 (unitless)1

HBWC (mg/l) for
Hazard Index
calculation
Not applicable

0.00001

0.00001
0.002

PFHxS

No individual
MCL
0.00001

PFNA

0.00001

0.00001

PFOA

0.0000040

Not applicable

PFOS

0.0000040

Not applicable

PFBS

0.00001

The PFAS Mixture Hazard Index (HI) is the sum of component hazard quotients (HQs), which are
calculated by dividing the measured component PFAS concentration in water by the relevant health-based
water concentration when expressed in the same units (shown in ng/l for simplification). The HBWC for
PFHxS is 10 ng/l; the HBWC for HFPO-DA is 10 ng/l; the HBWC for PFNA is 10 ng/l; and the HBWC
for PFBS is 2000 ng/l.
Hazard Index = ([HFPO-DAwater ng/l]/[10 ng/l]) + ([PFBSwater ng/l]/[2000 ng/l]) + ([PFNAwater ng/l]/[10
ng/l]) + ([PFHxSwater ng/l]/[10 ng/l])

HBWC = health-based water concentration
HQ = hazard quotient
ng/l = nanograms per liter
PFASwater = the concentration of a specific PFAS in water

(d) The Administrator, pursuant to section 1412 of the Act, hereby identifies in table 3 to
this paragraph (d) the best technology, treatment technique, or other means available for
achieving compliance with the maximum contaminant levels for all regulated PFAS identified in
paragraph (c) of this section:
Table 3 to paragraph (d) -- Best Available Technologies for PFAS Listed in Paragraph (c)
of this Section
Contaminant
Hazard Index PFAS (HFPO-DA, PFBS,
PFHxS, and PFNA)
HFPO-DA

BAT
Anion exchange, GAC, reverse osmosis,
nanofiltration
Anion exchange, GAC, reverse osmosis,
nanofiltration

Contaminant
PFHxS
PFNA
PFOA
PFOS

BAT
Anion exchange, GAC, reverse osmosis,
nanofiltration
Anion exchange, GAC, reverse osmosis,
nanofiltration
Anion exchange, GAC, reverse osmosis,
nanofiltration
Anion exchange, GAC, reverse osmosis,
nanofiltration

(e) The Administrator, pursuant to section 1412 of the Act, hereby identifies in table 4 to
this paragraph (e) the affordable technology, treatment technique, or other means available to
systems serving 10,000 persons or fewer for achieving compliance with the maximum
contaminant levels for all regulated PFAS identified in paragraph (c) of this section:
Table 4 to paragraph (e) -- Small System Compliance Technologies (SSCTs) for PFAS
Small System Compliance Technology1
Granular Activated Carbon
Anion Exchange
Reverse Osmosis, Nanofiltration3

Affordable for Listed Small System
Categories2
All size categories
All size categories
3,301 – 10,000

Section 1412(b)(4)(E)(ii) of SDWA specifies that SSCTs must be affordable and technically feasible for
small systems.
2 The Act (ibid.) specifies three categories of small systems: (i) those serving 25 or more, but fewer than
501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but
fewer than 10,001.
3 Technologies reject a large volume of water and may not be appropriate for areas where water quantity
may be an issue.

Bruno Pigott,
Assistant Administrator.

[FR Doc. 2024-12645 Filed: 6/10/2024 8:45 am; Publication Date: 6/11/2024]