119 S3529 IS: Public Health Air Quality Act of 2025
U.S. Senate
2025-12-17
text/xml
EN
Pursuant to Title 17 Section 105 of the United States Code, this file is not subject to copyright protection and is in the public domain.
II
119th CONGRESS
1st Session
S. 3529
IN THE SENATE OF THE UNITED STATES
December 17, 2025
Ms. Blunt Rochester (for herself, Ms. Duckworth, Mr. Durbin, Mr. Markey, Mr. Merkley, Mr. Van Hollen, and Mr. Padilla) introduced the following bill; which was read twice and referred to the Committee on Environment and Public Works
A BILL
To protect clean air and public health by expanding fenceline and ambient air monitoring and access to air quality information for communities affected by air pollution, to require hazardous air pollutant monitoring at the fenceline of facilities whose emissions are linked to local health threats, to ensure the Environmental Protection Agency promulgates rules that require hazardous air pollutant data measurement and electronic submission at fencelines and stacks of industrial source categories, to expand and strengthen the national ambient air quality monitoring network, to deploy air quality systems in communities affected by air pollution, and for other purposes.
1.

Short title
This Act may be cited as the “Public Health Air Quality Act of 2025”.
2.

Definitions
In this Act:
(1)

Accidental release
The term accidental release has the meaning given the term in section 112(r)(2) of the Clean Air Act (42 U.S.C. 7412(r)(2)).
(2)

Administrator
The term Administrator means the Administrator of the Environmental Protection Agency.
(3)

Air quality system
The term air quality system means an air quality sensor or set of sensors installed together with instruments to measure meteorology and store and transmit data.
(4)

Area source; hazardous air pollutant; major source; new source; stationary source
Except as otherwise provided, the terms area source, hazardous air pollutant, major source, new source, and stationary source have the meanings given those terms in section 112(a) of the Clean Air Act (42 U.S.C. 7412(a)).
(5)

Cumulative impact
The term cumulative impact means the totality of exposures to combinations of chemical and nonchemical stressors, and the effects of those exposures on health, well-being, and quality of life outcomes.
(6)

Cumulative risk
The term cumulative risk means the combined risks to health or the environment from multiple agents or stressors.
(7)

Emissions measurement system
The term emissions measurement system means a set of monitors, testing equipment, tools, and processes employed at a facility to measure emissions from direct and fugitive points at a source or facility or at the fenceline of the source or facility that employs Environmental Protection Agency-approved or promulgated test methods for all measured pollutants for which a method is available.
(8)

Federal equivalent method; Federal reference method
The terms Federal equivalent method and Federal reference method have the meanings given those terms in section 53.1 of title 40, Code of Federal Regulations (or to the same or substantially similar terms in successor regulations).
(9)

Method 325A
The term Method 325A means the most current version of the test method 325A published by the Environmental Protection Agency.
(10)

Method 325B
The term Method 325B means the most current version of the test method 325B published by the Environmental Protection Agency.
(11)

METHOD 327
The term Method 327 means the most current version of the test method 327 published by the Environmental Protection Agency.
(12)

Method TO–15A
The term Method TO–15A means the most current version of the test method TO–15 (including TO–15A) published by the Environmental Protection Agency.
(13)

National Air Toxics Trends Network
The term National Air Toxics Trends Network means the long-term hazardous air pollutants monitoring data network established by the Environmental Protection Agency to assess trends and emissions reduction program effectiveness.
(14)

National ambient air quality standard
The term national ambient air quality standard means a national ambient air quality standard established under section 109 of the Clean Air Act (42 U.S.C. 7409).
(15)

NCore
The term NCore has the meaning given the term in section 58.1 of title 40, Code of Federal Regulations (as in effect on the date of enactment of this Act).
(16)

Office of Research and Development
The term Office of Research and Development means the Office of Research and Development of the Environmental Protection Agency.
(17)

PFAS terms
The terms perfluoroalkyl substance and polyfluoroalkyl substance have the meanings given those terms in section 7331(2)(B) of the PFAS Act of 2019 (15 U.S.C. 8931(2)(B)).
(18)

Real-time
The term real-time means the actual or near actual time during which pollutant levels occur at or near the property boundary of a facility or in a nearby community.
(19)

Source
The term source is within the meaning of the Clean Air Act (42 U.S.C. 7401 et seq.).
(20)

Test method
The term test method means a method described in the most recent document of the Environmental Protection Agency entitled “Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air”.
3.

Health emergency air toxics monitoring network
(a)

Monitoring
(1)

In general
Not later than 18 months after the date of enactment of this Act, the Administrator shall publish notice in the Federal Register of, take public comment for a period of not less than 60 days regarding, and take final action to design and launch a plan and implement a program to administer or conduct, pursuant to authority provided under the Clean Air Act (42 U.S.C. 7401 et seq.), including sections 103, 112, 113, 114, and 303 of that Act (42 U.S.C. 7403, 7412, 7413, 7414, 7603), emissions measurement and quantification, including the best available form of fenceline monitoring of stationary sources of hazardous air pollutants that are on the list developed under subsection (c), including through expansion of the National Air Toxics Trends Network or through creating a new network, as appropriate.
(2)

Monitoring period
(A)

In general
The Administrator shall ensure monitoring begins pursuant to this section not later than 18 months after the date of enactment of this Act and shall maintain the monitoring required under paragraph (1) for a period of not less than 6 years after the date on which the monitoring required under that paragraph begins.
(B)

Subsequent monitoring
After the 6-year period described in subparagraph (A), the Administrator shall maintain the emissions measurement and quantification program under paragraph (1), consistent with this section, through—
(i)
maintaining monitors at all or some sources under the program under paragraph (1); and
(ii)
adding or moving monitors under the program under paragraph (1) to additional sources, following the process for substitution of sources in subsection (g).
(C)

Shortened period
If the Administrator determines, after public notice and a public comment period of not less than 60 days, that 6 years of monitoring, as required under subparagraph (A), is not necessary to protect public health or ensure compliance at the source or the facility involved, the Administrator may reduce or end the monitoring after at least 3 years of monitoring has occurred.
(D)

Additional inspections and testing
In addition to fenceline monitoring under the program under paragraph (1), the Administrator shall use the authority of the Administrator to inspect and require emission testing at sources on the list published pursuant to subsection (c) to the extent necessary to identify and address the emissions crossing the fenceline.
(b)

Publication of results
(1)

In general
The Administrator shall publish and maintain the plans for and the results of all measurements, including fenceline monitoring, conducted under the program under subsection (a)(1) on the website of the Environmental Protection Agency—
(A)
in a highly accessible format;
(B)
in a centralized database maintained in multiple languages; and
(C)
for a period of at least 10 years.
(2)

Immediate availability
The Administrator shall ensure that the monitoring data collected under the program under subsection (a)(1) are—
(A)
electronically submitted to the Administrator not later than 1 month after the date of collection of the data; and
(B)
made publicly available as expeditiously as practicable, but in any case not later than 7 days after the electronic submission of the data.
(c)

List of sources
(1)

Development
(A)

In general
Not later than 270 days after the date of enactment of this Act, the Administrator shall publish, after public notice and a public comment period of not less than 60 days, a list of stationary sources of hazardous air pollutants that, subject to subparagraph (B) do not already have fenceline monitoring in operation that is producing publicly available data and includes—
(i)
at least 45 of the sources listed—
(I)
as high-priority facilities in Appendix A of the report of the Office of Inspector General of the Environmental Protection Agency numbered 20–N–0128 and dated March 31, 2020; or
(II)
as contributing to high cancer risk at the census block level in Appendix C of the report of the Office of Inspector General of the Environmental Protection Agency numbered 21–P–0129 and dated May 6, 2021; and
(ii)
at least 55 other major sources or area sources that meet the criteria described in paragraph (2).
(B)

Substitution
(i)

In general
If the Administrator determines, after public notice and a public comment period of not less than 60 days, that a source described in subparagraph (A)(i) no longer contributes to high health risks or impacts that warrant continued monitoring to advance public health protection, inform improved compliance, or improve available data quality, the Administrator shall—
(I)
cease to include that source in the list under subparagraph (A); and
(II)
include instead an additional major source or area source described in subparagraph (A)(ii) to ensure that the list under subparagraph (A) includes not fewer than 100 high-priority sources.
(ii)

Description of reasons
For the purpose of providing notice, the Administrator shall publish in the Federal Register, and seek public comment for a period of not less than 60 days with respect to—
(I)
any determination to make a substitution under clause (i); and
(II)
an explanation of the reasons for any such determination demonstrating, based on monitoring data or other reliable information, that the substitution is likely to ensure that monitoring under this section occurs at the sources causing or contributing to the highest potential health risks or other impacts from hazardous air pollution.
(iii)

Requirement
The Administrator may include an additional major source or area source under clause (i)(II) only if the Administrator determines that the source is, or is likely to be, contributing local health risks or impacts that are equivalent to, or greater than, those of the source for which the new source is being substituted.
(2)

Criteria
The Administrator may include a major source or area source described in clause (ii) of paragraph (1)(A) on the list described in that paragraph only if the source—
(A)
emits at least 1 of the pollutants described in paragraph (3);
(B)
is—
(i)
located in, or within 3 miles of, a census tract with—
(I)
a cancer risk of at least 100-in-1,000,000; or
(II)
a chronic noncancer hazard index that is greater than or equal to 1; or
(ii)
in a source category with—
(I)
a cancer risk that is greater than 100-in-1,000,000 for the individual most exposed to emissions from the source category;
(II)
a total organ-specific hazard index for chronic noncancer risk that is greater than or equal to 1; or
(III)
an acute risk hazard quotient that is greater than or equal to 1; and
(C)
(i)
is classified in 1 or more of North American Industry Classification System codes 322, 324, 325, 326, 331, 332, 339, 424, and 562;
(ii)
(I)
is required to prepare and implement a risk management plan pursuant to section 112(r) of the Clean Air Act (42 U.S.C. 7412(r)); and
(II)
has had an accidental release required to be reported during the previous 5-year period pursuant to sections 68.42 and 68.195 of title 40, Code of Federal Regulations (as in effect on the date of enactment of this Act); or
(iii)
is determined by the Administrator to be a high-priority source or facility for emissions measurement because—
(I)
the facility is located within 350 feet of a residence, school, childcare facility (including a camp), hospital, park, sports or recreation facility, or other gathering place, community center, or institution where children and families regularly spend time; or
(II)
based on the best available science, the emissions of the source or facility are likely causing or contributing to, or have the potential to cause or contribute to, serious acute or chronic, including cancer and non-cancer, health or safety risks or impacts, including adverse neurological, developmental, or other health impacts in utero or childhood.
(3)

Pollutants
The pollutants described in this paragraph are—
(A)
ethylene oxide, CAS 75218;
(B)
chloroprene, CAS 126998;
(C)
benzene, CAS 71432;
(D)
1,3–butadiene, CAS 106990;
(E)
formaldehyde, CAS 50000;
(F)
acetaldehyde, CAS 75070;
(G)
lead compounds;
(H)
arsenic compounds;
(I)
antimony compounds;
(J)
cadmium compounds;
(K)
cobalt compounds;
(L)
nickel compounds;
(M)
manganese compounds;
(N)
vinyl chloride;
(O)
ethylene dichloride;
(P)
naphthalene;
(Q)
ethylbenzene;
(R)
methyl mercury;
(S)
epichlorohydrin;
(T)
xylenes;
(U)
acrylonitrile;
(V)
any other hazardous air pollutant included in the list described in section 112(b) of the Clean Air Act (42 U.S.C. 7412(b)) that the Administrator determines, after public notice and a public comment period of not less than 60 days, the air emissions of which—
(i)
are, or may be contributing to, serious health risks; or
(ii)
warrant emissions quantification and measurement due to the public interest in evaluating the emissions and effects of the pollutant; and
(W)
any pollutant or airborne chemical that is a precursor to atmospheric photochemical production of any other pollutant on the list described in section 112(b) of the Clean Air Act (42 U.S.C. 7412(b)).
(4)

Use of information and methods
In carrying out this subsection, the Administrator shall—
(A)
use—
(i)
the evaluations and methods of the Environmental Protection Agency for compiling and evaluating information about risks from air toxics in effect on January 1, 2025, that have been peer reviewed by the Science Advisory Board, including chemical assessments developed by the Integrated Risk Information System of the Environmental Protection Agency (commonly referred to as “IRIS”), or the most recent Air Toxics Screening Assessment or other current evaluation or report by the Environmental Protection Agency, acting through the Office of Research and Development, providing similar information about cancer and noncancer risks from hazardous air pollution based on measured or modeled emissions, using evaluations or methods that—
(I)
account for, and therefore demonstrate higher risks to, the individual or community most exposed to the emissions; and
(II)
account for adverse neurological, developmental, or other health impacts in utero, in childhood, and in adolescence;
(ii)
the Risk-Screening Environmental Indicators model of the Administrator in effect as of December 31, 2024;
(iii)
a prior health risk assessment that was performed by the Administrator for the applicable source or source category before January 1, 2025; or
(iv)
a new health risk assessment performed by the Administrator for the applicable source or source category that—
(I)
is more complete and addresses more or greater risks than previously considered;
(II)
follows the best available science (including the most recent guidance from the National Academy of Sciences and the most recent assessments under the Integrated Risk Information System of the Environmental Protection Agency (commonly referred to as “IRIS”) that were created pursuant to the document of the Environmental Protection Agency entitled “ORD Staff Handbook for Developing IRIS Assessments” and dated December 2022); and
(III)
considers, with respect to the applicable source or facility—
- (aa)
cumulative risks and cumulative impacts;
- (bb)
increased vulnerability that results from socioeconomic disparities;
- (cc)
multiple source exposure; and
- (dd)
exposure in utero, in childhood, in adolescence, and through the age of 85; and
(B)
consider—
(i)
the most recent emission tests available to the Administrator or received by the Environmental Protection Agency in public comment; and
(ii)
any fenceline or ambient monitoring data for which an Environmental Protection Agency-approved data quality check has been performed.
(d)

Methods and technologies
(1)

In general
Except as provided in paragraph (3), in carrying out the program under subsection (a)(1), the Administrator shall, for each stationary source on the list published under subsection (c)(1), employ an emissions measurement system to monitor the pollutants described in subsection (c)(3) emitted by the stationary source, including at least—
(A)
the most current Environmental Protection Agency-approved or promulgated emission test or monitoring method, including Method 325A, Method 325B, Method TO–15A, and Method 327, that expands the scope, strengthens the detection limit, or otherwise improves the effectiveness of the test method; or
(B)
for each stationary source described in paragraph (2), the best available method for continuous, real-time measurement of air pollutant concentrations.
(2)

Stationary sources described
A stationary source referred to in paragraph (1)(B) is—
(A)
not less than each of the 20 stationary sources on the list published under subsection (c)(1) that—
(i)
emits the greatest quantity or rate of pollutants described in subsection (c)(3); or
(ii)
causes the greatest health risk to the greatest number of people, based on the emissions of the pollutants described in subsection (c)(3) individually, as a group, or cumulatively, based on—
(I)
- (aa)
the latest evaluations and methods of the Environmental Protection Agency for compiling and evaluating information about risks from air toxics, or the most recent Air Toxics Screening Assessment or other current evaluation or report by the Environmental Protection Agency providing similar information about cancer and noncancer risks from hazardous air pollution based on measured or modeled emissions;
- (bb)
the Risk-Screening Environmental Indicators model of the Administrator;
- (cc)
a prior health risk assessment that was performed by the Administrator for the applicable source or source category; or
- (dd)
a new health risk assessment performed by the Administrator that—
(AA)
follows the best available science (including the most recent guidance from the National Academy of Sciences); and
(BB)
considers, with respect to the applicable source or facility, cumulative risks and impacts, increased vulnerability that results from socioeconomic disparities, multiple source exposure, and exposure in utero, in childhood, in adolescence, and over the course of a lifetime through the age of 85; and
(II)
the most recent emission tests available to the Environmental Protection Agency or received in public comment, and any fenceline or ambient monitoring data for which an Environmental Protection Agency-approved data quality check has been performed;
(B)
any other stationary source on the list published under subsection (c)(1) that—
(i)
is regulated under paragraph (7) of section 112(r) of the Clean Air Act (42 U.S.C. 7412(r)); and
(ii)
has had an accidental release or incident that is required to be reported during the previous 5-year period pursuant to sections 68.42 and 68.195 of title 40, Code of Federal Regulations (as in effect on January 1, 2025), under that paragraph; and
(C)
any other stationary source on the list published under subsection (c)(1) for which application of the methods described in subparagraph (A) alone may not be sufficient—
(i)
to monitor and report the pollutants described in subsection (c)(3) that are emitted by that stationary source; or
(ii)
to advance public health and safety.
(3)

Updates
(A)

Approved or promulgated methods
The Administrator shall—
(i)
not later than 2 years after the date of enactment of this Act, review and, after public notice and a public comment period of not less than 60 days, update each approved or promulgated test method described in this section to add as many of the pollutants described in subsection (c)(3) as practicable; and
(ii)
otherwise strengthen the test methods described in clause (i) to support effective hazardous air pollutant measurement and the full implementation of this Act.
(B)

New test methods
(i)

In general
Not later than 18 months after the date of enactment of this Act, the Administrator shall, after public notice and a public comment period of not less than 60 days, approve or promulgate, as applicable, any new test methods that are necessary to ensure effective fenceline monitoring of all pollutants and sources described in this section, including—
(I)
at least 1 method that represents the best and most accurate form of continuous, real-time fenceline monitoring based on the best available science; and
(II)
at least 1 method that represents the best and most accurate form of multimetal monitoring based on the best available science.
(ii)

Updates required
Not less frequently than once every 6 years, the Administrator shall review and, if necessary, after public notice and a public comment period of not less than 60 days, strengthen or add new test methods that meet the requirements under clause (i), which shall be based on—
(I)
the best available monitoring technologies that improve the quality or quantity of information provided by, or improve the precision or other type of scientific reliability of, a method; and
(II)
the advice of staff of the Office of Enforcement and Compliance, staff of the Office of Research and Development, regional or other staff within the Environmental Protection Agency responsible for, and with expertise on, the enforcement of this Act, and other monitoring experts.
(4)

Office of Research and Development
The Administrator shall act through the Assistant Administrator for Research and Development, and in coordination with the Assistant Administrator for Air and Radiation, to carry out this subsection.
(e)

Monitor placement and maintenance
(1)

In general
The Administrator shall, after public notice and a public comment period of not less than 60 days with respect to monitor placement and maintenance plans, place and maintain, or ensure placement and regular maintenance of, all monitors required under this section to ensure effective and reliable emissions measurement pursuant to this section.
(2)

Maintenance check
The maintenance required under paragraph (1) shall include a maintenance check of the monitor not less frequently than once every 180 days, unless—
(A)
the test method used by the monitor requires a maintenance check more frequently; or
(B)
a maintenance check is requested by a member of the public.
(3)

Public input
The Administrator shall, after public notice and a public comment period of not less than 60 days, create a process, including an accessible online resource or website, for the public—
(A)
to track the maintenance of monitors under this subsection; and
(B)
to request a maintenance check of a monitor.
(f)

Report
Not later than 6 years after the date of enactment of this Act, and not less frequently than once every 6 years thereafter, the Administrator shall submit to Congress and post publicly on the website of the Environmental Protection Agency a report describing the results of the program carried out under subsection (a)(1), which shall include—
(1)
the results of emissions measurement implemented under that program;
(2)
any actions of the Administrator taken based on that emissions measurement data or program; and
(3)
whether the Administrator proposes—
(A)
to continue emissions measurements at any or all of the stationary sources on the list published under subsection (c)(1); or
(B)
to implement emissions measurements of any additional stationary sources as determined under subsection (g).
(g)

Determination regarding additional sources
Not later than 6 years after the date of enactment of this Act, and not less frequently than once every 6 years thereafter, the Administrator shall—
(1)
after public notice and a public comment period of not less than 60 days, make a determination of whether to add or remove sources to the list published under subsection (c)(1)—
(A)
to ensure compliance of those stationary sources with existing emission standards under section 112 of the Clean Air Act (42 U.S.C. 7412);
(B)
to prevent and detect accidental releases;
(C)
to protect the health of the communities, including children and other vulnerable populations, most exposed to the emissions of hazardous air pollutants from such stationary sources to the maximum extent practicable; or
(D)
to ensure the 100 highest-priority sources or facilities, based on the best available science and the most current data on health risks and impacts (including the most current research on children’s health), have emissions measurement systems in place for pollutants required to be monitored under this section; and
(2)
publish a determination under paragraph (1) in the Federal Register.
(h)

Report
Not later than 1 year after the date of enactment of this Act, the Administrator shall submit to Congress and make publicly available online a report that—
(1)
describes the staffing that is available, necessary, and planned to carry out this section; and
(2)
demonstrates how the Administrator intends to carry out the duties and requirements of this section without impact or delay on any other duty or responsibility of the Administrator.
(i)

No exemption authority
No exemption from compliance with any standard or limitation under this section may be issued pursuant to section 112(i)(4) of the Clean Air Act (42 U.S.C. 7412(i)(4)) to any stationary source.
(j)

Authorization of appropriations
There is authorized to be appropriated to carry out this section $146,000,000 for the period of fiscal years 2026 and 2027.
4.

Community air toxics monitoring
(a)

Regulations
Not later than 2 years after the date of enactment of this Act, the Administrator shall promulgate regulations pursuant to authority provided by the Clean Air Act, which may include section 103, subsections (d), (f), and (r) of section 112, section 113, and section 114 of that Act (42 U.S.C. 7403, 7412, 7413, 7414), for each source category described in subsection (b), that—
(1)
require all sources in the source category to implement, not later than 1 year after the promulgation of the regulations, the best available form of emissions measurement, including continuous emissions monitoring and fenceline monitoring, to ensure compliance with the emission standards for hazardous air pollutants;
(2)
for facilities in the source category that are required to submit risk management plans under section 112(r)(7) of that Act (42 U.S.C. 7412(r)(7)), require each facility to implement—
(A)
continuous, real-time monitoring to provide for effective emergency response and provide information to prevent future releases; and
(B)
emissions measurement, including fenceline monitoring, to provide for effective emergency response and provide information to prevent future releases;
(3)
subject to subsection (e)—
(A)
establish a corrective action level at the fenceline for at least the top 5 hazardous air pollutants that drive the cancer, chronic noncancer, or acute risk for the source category; and
(B)
require corrective action for the release of any quantity of a substance listed pursuant to section 112(r)(3) of that Act (42 U.S.C. 7412(r)(3));
(4)
if any applicable corrective action level under paragraph (3)(A) is exceeded, require—
(A)
a root cause analysis and preventive action report;
(B)
full remedial action, including implementation of all control technologies, practices, processes, operational improvements, or other measures necessary to resolve the exceedance and protect the most exposed or most vulnerable individuals potentially affected by the exceedance (including children) and to make best efforts to prevent the exceedance from recurring, based on and applying input from the most affected individuals and communities; and
(C)
a public report that—
(i)
describes—
(I)
the results of the root cause analysis and preventive action report under subparagraph (A); and
(II)
the remedial actions taken under subparagraph (B); and
(ii)
certifies that a violation of the Clean Air Act (42 U.S.C. 7401 et seq.) has occurred; and
(5)
treat any requirement imposed by the regulations under this section as a requirement under section 112 of the Clean Air Act (42 U.S.C. 7412) that is enforceable under section 113 of that Act (42 U.S.C. 7413).
(b)

Source categories
The source categories described in this subsection include—
(1)
each category or subcategory of major sources or area sources that—
(A)
contains—
(i)
at least 1 of the stationary sources of hazardous air pollutants that are on the list published under section 3(c);
(ii)
major sources or area sources identified in the most recent National Emissions Inventory of the Environmental Protection Agency as emitting a pollutant described in section 3(c)(3);
(iii)
petroleum, chemical, petrochemical, or plastics manufacturing sources, marine vessel loading operations, or other sources that are classified in 1 or more of North American Industry Classification System codes 322, 324, 325, 326, 331, 332, 339, 424, and 562; or
(iv)
any other major source or area source of fugitive hazardous air pollutant emissions for which the Environmental Protection Agency is subject to a court-ordered or statutory deadline, engaged in a reconsideration proceeding, or subject to a court remand (or is likely within the 2-year period beginning on the date of enactment of this Act to become subject to such an obligation or action) to review and determine whether to revise the emissions standards that apply to that source category; or
(B)
contains any stationary source that—
(i)
is regulated under paragraph (7) of section 112(r) of the Clean Air Act (42 U.S.C. 7412(r)); and
(ii)
has had an accidental release or incident that is required to be reported during the previous 5-year period under that section and the regulations thereunder that were in effect as of January 1, 2025; and
(2)
any other source category for which the Administrator determines that requiring fenceline monitoring is likely to benefit public health or welfare, including children’s health, based on the best available science.
(c)

Determination of best available form of monitoring
(1)

In general
The Administrator, in consultation with the Office of Air and Radiation, the Office of Enforcement and Compliance Assurance, the Office of Environmental Justice and External Civil Rights, the Office of Children’s Health, and the Office of Research and Development, shall, for purposes of the regulations promulgated pursuant to subsection (a)—
(A)
determine the best available form of emissions measurement, including continuous emissions monitoring and fenceline monitoring; and
(B)
ensure the methods required under the regulations are at least as stringent as the most current Environmental Protection Agency-approved or promulgated emission test or monitoring method, including Method 325A, Method 325B, Method 327, and Method TO–15A.
(2)

Requirement
In carrying out paragraph (1)(B), the Administrator shall ensure that 1 or more of the methods described in or promulgated under section 3 or subsection (d) (including multimetal monitoring) is included in the regulations promulgated pursuant to subsection (a) if that method is the best available method for 1 or more of the pollutants for which monitoring is required under this section.
(d)

Methods and technologies
(1)

In general
For all stationary sources in the source categories described in subsection (b), as the best available fenceline monitoring method for those source categories, the Administrator may, in the regulations promulgated pursuant to subsection (a)—
(A)
require application, implementation, or employment of optical remote sensing technology to provide real-time measurements of air pollutant concentrations along an open-path; or
(B)
provide an explanation of why application, implementation, or employment of 1 or more of the technologies described in subparagraph (A) is not necessary—
(i)
to ensure compliance with the emission standards established under the regulations promulgated pursuant to subsection (d), (f), or (r) of section 112 of the Clean Air Act (42 U.S.C. 7412), as applicable; or
(ii)
to protect the public health, to prevent accidental releases, or to provide for effective emergency response.
(2)

Multiple-source or facility complexes
(A)

Definition of multiple-source or facility complex
In this paragraph, the term multiple-source or facility complex means 1 or more stationary sources co-located at the same site.
(B)

Multiple-source or facility complex monitoring
In the regulations promulgated pursuant to subsection (a), the Administrator shall ensure that the best available form of monitoring for a multiple-source or facility complex that contains not less than 2 stationary sources in 1 or more of North American Industry Classification System codes 324, 325, and 326, or a related chemical or petrochemical sector, is at least a combination of—
(i)
real-time, open-path monitoring; and
(ii)
Method 325A, Method 325B, and Method 327, as applicable depending on the types of emissions to be measured.
(C)

Requirement
In carrying out subparagraph (B), the Administrator shall consider whether any other multiple-source or facility complexes should be required to employ the combined monitoring methods described in that subparagraph.
(e)

Health priority approach
In promulgating the corrective action level for each of the hazardous air pollutants described in subsection (a)(3)(A), the Administrator shall—
(1)
consider the best available science, including applying the most health-protective approach possible and applying a precautionary approach to account for uncertainty;
(2)
ensure that the owner or operator of the source or facility reduces the emissions of the source or facility to prevent harm if the measured concentration at the fenceline would, or is likely to—
(A)
increase harm to public health or safety (including through an increased health risk to any individual, including a child); or
(B)
reach a level that may result in short-term, long-term, or chronic human exposure to air pollution (including any exposure that begins in utero, infancy, childhood, or adolescence) that increases the risk of—
(i)
health harms resulting from odors, irritation, sensitizing effects, or any combination of those harms;
(ii)
a chronic condition (including neurodevelopmental) or disease (including cancer and other illnesses); or
(iii)
death; and
(3)
take into account the aggregate and cumulative emissions and health risks from the facility, including multiple source categories, as applicable, to ensure full health protection from the entire facility based on the best available science.
(f)

Maintenance and public reporting
(1)

In general
In the regulations promulgated pursuant to subsection (a), the Administrator shall ensure that—
(A)
the owners or operators of sources subject to the requirements of this section—
(i)
perform regular inspections and maintenance of all measured equipment required under this section; and
(ii)
submit to the Administrator regular reports that—
(I)
include the measured emissions data collected by that emissions measurement equipment;
(II)
describe the status of that measurement equipment; and
(III)
contain a detailed explanation of the circumstances surrounding a delay in collecting or missing data;
(B)
the emissions measurement system required under this section is continuous and yields reliable data not less than 95 percent of the time, without any regulatory exemption or extension; and
(C)
any problem with the fenceline monitoring equipment required under this section is repaired within 2 days of discovering the problem.
(2)

Violation
In the regulations promulgated pursuant to subsection (a), the Administrator shall—
(A)
require the owner or operator of a stationary source subject to such regulations to report, with respect to the source, at least semiannually—
(i)
all exceedances of any corrective action level; and
(ii)
all corrective action planned and taken; and
(B)
for purposes of imposing penalties, treat each day on which a violation of a reporting requirement under subparagraph (A) continues as a separate violation.
(3)

Public reporting
(A)

In general
The Administrator shall make available on the website of the Environmental Protection Agency, in an accessible format that includes multiple languages spoken by residents living near the source where monitoring was conducted—
(i)
all emissions measurement plans, reports, and other information collected or required under this section;
(ii)
all emissions measurement data collected by monitoring equipment required under this section; and
(iii)
an option to sign up for community-wide or source-specific alerts that alert the user if the emissions concentrations measured pursuant to clause (i) or (ii), as applicable, exceed—
(I)
a health reference level of the Administrator that has been scientifically peer-reviewed;
(II)
a health reference level approved by the Administrator that has been scientifically peer-reviewed;
(III)
a health reference level approved by any State or Tribal government that has been scientifically peer-reviewed; or
(IV)
the applicable corrective action level under subsection (a)(3)(A).
(B)

Public notice and comment
The Administrator shall provide notice and receive public comment for not less than 60 days on the format and accessibility of the information required to be made available under subparagraph (A).
(C)

Publication
The Administrator shall publicize the information required to be made available under subparagraph (A) in each community that contains a source regulated under this section through not less than 2 of the most widely viewed local media formats for members of that community that live nearest the regulated source.
(g)

Office of Research and Development
The Administrator shall ensure that the Assistant Administrator for Air and Radiation coordinates with the Assistant Administrator for Research and Development, as well as any other appropriate offices of the Environmental Protection Agency, to carry out this section.
(h)

Report
Not later than 1 year after the date of enactment of this Act, the Administrator shall submit to Congress and make publicly available online a report that—
(1)
describes the staffing that is available, necessary, and planned to carry out this section; and
(2)
demonstrates how the Administrator intends to carry out the duties and requirements of this section without impact or delay on any other duty or responsibility of the Administrator.
(i)

No exemption authority
No exemption from compliance with any standard or limitation under this section may be issued pursuant to section 112(i)(4) of the Clean Air Act (42 U.S.C. 7412(i)(4)) to any stationary source.
(j)

Authorization of appropriations
There is authorized to be appropriated to carry out this section $50,000,000 for the period of fiscal years 2026 and 2027.
5.

NAAQS monitoring network
(a)

Deployment of NCore multipollutant monitoring stations
(1)

In general
The Administrator shall require the deployment of 80 additional NCore multipollutant monitoring stations.
(2)

Requirement
All monitors at the stations required to be deployed pursuant to paragraph (1) that measure pollutants for which the Administrator has established national ambient air quality standards shall—
(A)
be Federal reference method or Federal equivalent method monitors; and
(B)
produce monitoring data that are sufficient for determining whether the relevant national ambient air quality standard is met at the site.
(b)

Deadline
Not later than 18 months after the date of enactment of this Act, the Administrator shall ensure that all NCore multipollutant monitoring stations required to be deployed under subsection (a)(1) are—
(1)
installed and integrated into the air quality monitoring system established pursuant to sections 110(a)(2)(B) and 319 of the Clean Air Act (42 U.S.C. 7410(a)(2)(B), 7619); and
(2)
after installation, operated and maintained on a continuing basis.
(c)

Monitoring results
Monitoring results from NCore multipollutant stations required to be deployed under subsection (a)(1) shall be used for—
(1)
assessments of the compliance of areas with national ambient air quality standards;
(2)
integrated science assessments in reviews of national ambient air quality standards established under section 109 of the Clean Air Act (42 U.S.C. 7409);
(3)
evaluating disparities of pollution exposures within metropolitan areas; and
(4)
such other purposes as the Administrator determines will promote the protection of public health from air pollution.
(d)

Locations
(1)

Vulnerable populations
(A)

In general
The Administrator shall ensure that not fewer than 40 of the NCore multipollutant monitoring stations required to be deployed under subsection (a)(1)—
(i)
are not limited to metropolitan statistical areas with populations of 50,000 or greater; and
(ii)
meet the requirement described in subparagraph (B).
(B)

Requirement described
The requirement referred to in subparagraph (A)(ii) is that the NCore multipollutant monitoring stations shall be sited in census tracts that each meet 1 or more of the following criteria, with the specific site selected consistent with Appendix D to part 58 of title 40, Code of Federal Regulations (as in effect on the date of enactment of this Act), except that where the provisions of this Act conflict with that appendix, the provisions of this Act shall control:
(i)
The rates of childhood asthma, adult asthma, chronic obstructive pulmonary disease, heart disease, or cancer are not less than 5 percent higher than the national average for that condition in the census tract.
(ii)
The percentage of people living below the poverty level, that are above age 18 without a high school diploma, or that are unemployed, is higher than the national average in the census tract.
(iii)
2 or more major sources (as defined in section 501 of the Clean Air Act (42 U.S.C. 7661)) are located within the census tract or adjacent census tracts combined.
(iv)
There is a higher-than-national-average population in the census tract of vulnerable or sensitive individuals who may be at greater risk than the general population of adverse health effects from exposure to 1 or more air pollutants for which national ambient air quality standards have been established under section 109 of the Clean Air Act (42 U.S.C. 7409).
(2)

Siting determinations
In determining and approving sites for NCore multipollutant monitoring stations required to be deployed under subsection (a)(1), the Administrator shall—
(A)
invite proposals from or on behalf of residents of any community for the siting of the stations in that community, which may include inviting proposals through regional or virtual meetings;
(B)
prioritize siting of the stations in census tracts or counties based on—
(i)
the potential for the levels of 1 or more air pollutants to be monitored by the stations to reach or exceed the level of the applicable national ambient air quality standard established under section 109 of the Clean Air Act (42 U.S.C. 7409), including evidence of relevant industrial activity or nearby exceedances;
(ii)
the number of people who live, work, attend school, or recreate in the area or areas for which monitoring by the stations is reasonably anticipated to be representative with respect to air quality and the proportion of those people who are at higher risk than the general population of adverse health effects from the air pollutants monitored;
(iii)
the lack or inadequacy of existing air quality monitors for providing representative air quality data for the affected area or areas for the pollutants to be measured by the station; and
(iv)
the current designation of the area in which the monitoring station would be located as unclassifiable or in attainment for 1 or more of the pollutants to be monitored by that station; and
(C)
prior to making siting determinations—
(i)
hold at least 1 public hearing in or near each proposed siting location;
(ii)
provide public notice of the proposed siting locations and the hearings required under clause (i)—
(I)
in the Federal Register;
(II)
by email to persons who have requested notice of proposed siting determinations;
(III)
by news release; and
(IV)
by posting on the public website of the Environmental Protection Agency;
(iii)
provide an opportunity for public comment for not less than 60 days after the date of publication of the notice required under clause (ii) in the Federal Register; and
(iv)
publish online an explanation and record for the siting decisions of the Administrator.
(3)

Reliance on hybrid methods
In determining under paragraph (2)(B)(i) the potential for an air pollutant to reach or exceed the level of the applicable standard, the Administrator may rely on hybrid methods that combine information from multiple sources, including monitors, sensors, modeling, and satellites.
(e)

Additional ambient monitors
(1)

In general
The Administrator shall deploy not fewer than 100 additional Federal reference method monitors or Federal equivalent method monitors for 1 or more air pollutants for which national ambient air quality standards have been established under section 109 of the Clean Air Act (42 U.S.C. 7409) in areas—
(A)
that are unmonitored or undermonitored, as determined by the Administrator; and
(B)
within which the Administrator determines, after public notice and comment, that adding those monitors is warranted—
(i)
to detect whether the area is in nonattainment of the applicable national ambient air quality standards; and
(ii)
to improve the publicly available data on air quality for 1 or more of those air pollutants (or precursors to those air pollutants).
(2)

Siting determinations
In approving sites for new Federal reference method monitors or Federal equivalent method monitors required under this subsection, the Administrator shall prioritize siting of the stations in census tracts or counties in accordance with subsection (d)(2)(B).
(3)

Relation to previously deployed or planned monitors
The Federal reference method monitors required under this subsection shall be in addition to, and not in lieu of, any monitors already deployed or planned for deployment by the Administrator, any State, any other governmental entity, or any other entity prior to the date of enactment of this Act.
(f)

Report
Not later than 2 years after the date of enactment of this Act, the Administrator shall—
(1)
in coordination with the States, complete an assessment, which includes public input, on the status of all ambient air quality monitors that are part of Federal, State, or local networks and used for determining compliance with national ambient air quality standards, which shall identify—
(A)
each monitor that is not operating properly and that needs to be repaired or replaced; and
(B)
each monitor that is past the end of its ordinary useful life; and
(2)
submit to Congress and make available on the public website of the Environmental Protection Agency a report that includes—
(A)
a list of all monitors identified under paragraph (1); and
(B)
a schedule and plan to restore to proper operation or replace all monitors included in the list under paragraph (1)(A) and to replace all monitors included on the list under paragraph (1)(B), with all restorations and replacements to be completed not later than 40 months after the date of enactment of this Act, except that the schedule and plan shall not apply to monitors—
(i)
that have been discontinued in accordance with section 58.14(c) of title 40, Code of Federal Regulations (as in effect on the date of enactment of this Act); and
(ii)
(I)
for which such discontinuation is not subject to a judicial challenge; or
(II)
for which a judicial challenge described in subclause (I) has been fully resolved by a settlement or order that authorizes discontinuation of the monitor.
(g)

Designations
Not later than 2 years after the date on which data are received from a monitor sited pursuant to this section that demonstrate that an area designated by the Administrator pursuant to paragraph (1) of section 107(d) of the Clean Air Act (42 U.S.C. 7407(d)) as in attainment or unclassifiable for an air pollutant is not meeting or is contributing to air quality in a nearby area that does not meet 1 or more applicable national ambient air quality standards, the Administrator shall redesignate pursuant to paragraph (3) of that section that area as in nonattainment for that pollutant unless the designation is otherwise precluded under this Act.
(h)

Satellite monitoring
(1)

Definition of design value
In this subsection, the term design value means, for each pollutant, the air quality statistic the Administrator defines in part 50 (including appendices) of title 40, Code of Federal Regulations (as in effect on the date of enactment of this Act), for comparison with the relevant national ambient air quality standard established under section 109 of the Clean Air Act (42 U.S.C. 7409), regardless of whether the regulation (including appendices) in part 50 of title 40, Code of Federal Regulations (as in effect on the date of enactment of this Act), uses the term design value.
(2)

Satellite monitoring data
(A)

Provision of satellite data
The Administrator shall consult with the Administrator of the National Aeronautics and Space Administration on methods to facilitate the use of data from the satellites of the National Aeronautics and Space Administration or other entities for use in calculating design values under any national ambient air quality standards for PM_{10}, PM_{2.5}, ozone, and oxides of nitrogen for purposes of determining compliance or noncompliance with the national ambient air quality standards for those pollutants.
(B)

Regulations required
Not later than 18 months after the date of enactment of this Act, the Administrator shall, after public notice in the Federal Register and a public comment period of not less than 60 days, promulgate regulations to specify procedures (including any modeling techniques) for using data described in subparagraph (A) in combination with information from multiple sources, including monitors and modeling, to calculate the expected number of exceedances per year and the design values for PM_{10}, PM_{2.5}, ozone, and oxides of nitrogen for purposes of determining compliance or noncompliance with the national ambient air quality standards for those pollutants.
(3)

National Academy of Sciences report
(A)

In general
The Administrator may enter into an arrangement with the National Academy of Sciences under which the National Academy of Sciences agrees to submit a report that describes the actions necessary, including new science and satellite assets, to enable the contribution of satellite monitoring to the calculation of design values and nonattainment determinations under any national ambient air quality standards for ozone and oxides of sulfur established under section 109 of the Clean Air Act (42 U.S.C. 7409).
(B)

Regulations required
(i)

In general
Not later than 18 months after the date of enactment of this Act, the Administrator, in coordination with the Administrator of the National Aeronautics and Space Administration and the Administrator of the National Oceanic and Atmospheric Administration, shall, after public notice in the Federal Register and a public comment period of not less than 60 days, promulgate regulations that provide a plan for the use of satellite monitoring data in calculating design values for the pollutants described in subparagraph (A).
(ii)

Requirement
Not later than January 1, 2028, the Administrator shall implement the plan required by clause (i) and provide for use of satellite data in calculating design values for the pollutants described in subparagraph (A).
(i)

Monitoring plans
Notwithstanding any other provision of law, the Administrator may not approve a State monitoring plan under section 58.10 of title 40, Code of Federal Regulations (or successor regulations), unless—
(1)
the State provided, with respect to the State monitoring plan—
(A)
public notice of the proposal of the plan in a highly accessible format in multiple languages, including a publicly accessible web page address where members of the public can at any time view the entire proposed plan and supporting materials;
(B)
not less than 45 days for public comment; and
(C)
an opportunity for public hearing; and
(2)
the Administrator—
(A)
proposes in the Federal Register to approve or disapprove of the State monitoring plan;
(B)
provides not less than 45 days for public comment on the proposal described in subparagraph (A); and
(C)
after consideration of any comments received pursuant to subparagraph (B), publishes in the Federal Register the final action on the proposal described in subparagraph (A).
(j)

Funding
(1)

Authorization of appropriations
There is authorized to be appropriated to carry out this section $75,000,000 for fiscal year 2026.
(2)

Uses
The Administrator—
(A)
may use the amounts made available to carry out this section—
(i)
to directly deploy new or replacement NCore multipollutant monitoring stations required to be deployed under subsection (a)(1); or
(ii)
to make grants under section 103 or 105 of the Clean Air Act (42 U.S.C. 7403, 7405) to State and local governments for deployment and operation of the NCore multipollutant monitoring stations required to be deployed under subsection (a)(1); and
(B)
shall use not less than 5 percent, but not more than 10 percent, of the amounts made available to carry out this section to perform the maintenance and repairs necessary to restore to operation NCore multipollutant monitoring stations that are—
(i)
as of the date of enactment of this Act, nonoperational; and
(ii)
located in areas that are designated as in nonattainment of national ambient air quality standards established under section 109 of the Clean Air Act (42 U.S.C. 7409) for ozone or particulate matter.
6.

Community air quality system monitoring
(a)

Deployment of air quality systems
(1)

In general
Not later than 2 years after the date of enactment of this Act, the Administrator—
(A)
shall deploy, in accordance with the prioritization criteria described in section 5(d)(2), not fewer than 1,000 air quality systems, each of which shall cost not more than $5,000;
(B)
shall deploy those air quality systems in clusters of not fewer than 5 in each of the census tracts or counties selected;
(C)
before determining and approving sites for those air quality systems, shall invite, through public notice and other means designed to reach communities disproportionately impacted by air pollution, proposals from or on behalf of residents of any community for the sites;
(D)
may contract with nonprofit organizations (including academic institutions) and State and local air pollution control agencies to conduct air quality system monitoring and report the results; and
(E)
shall make data from air quality systems installed pursuant to this section public on an easily accessible data platform.
(2)

Requirement
In carrying out paragraph (1), the Administrator shall select systems for deployment that—
(A)
are available on the market at the time of purchase;
(B)
the Administrator determines will provide data of sufficient accuracy to provide a reasonable basis for determining whether the location in which the air quality system is sited is or may be at risk of exceeding 1 or more national ambient air quality standards established under section 109 of the Clean Air Act (42 U.S.C. 7409); and
(C)
are the lowest cost available that meet the standards described in subparagraph (B).
(3)

Exception to cost limitation
Notwithstanding paragraph (1), if the Administrator determines in writing that a system to measure a particular pollutant is not available on the market at a price at or below $5,000 each, the Administrator may spend an amount above $5,000 to acquire that system so long as the Administrator complies with subparagraphs (B) and (C) of paragraph (2).
(b)

Pollutants
(1)

In general
(A)

List
Not fewer than 500 air quality systems deployed pursuant to subsection (a) shall measure 1 or more of the following pollutants:
(i)
Ozone.
(ii)
PM_{2.5}.
(iii)
Oxides of nitrogen.
(iv)
Sulfur dioxide.
(B)

Required sensors
All air quality systems deployed pursuant to subsection (a) may include sensors to measure wind speed, wind direction, relative humidity, carbon dioxide and carbon monoxide, and other inputs that aid with source identification.
(2)

Determination
The Administrator shall determine which air pollutant or air pollutants an air quality system deployed pursuant to subsection (a) shall monitor based on the pollution sources affecting the area in which the air quality system is to be deployed.
(c)

Determination and installation
(1)

In general
Not later than 18 months after the date on which an air quality system deployed pursuant to subsection (a) has been monitoring air quality data for 1 year, the Administrator shall determine whether the air quality systems deployed in the applicable census tract or county reported air pollution levels over the 1-year period ending on the date of the determination that reached or exceeded 98 percent of the level of any applicable national ambient air quality standard established under section 109 of the Clean Air Act (42 U.S.C. 7409) for any air pollutant.
(2)

Requirement
If the Administrator makes a determination under paragraph (1) that an air pollutant described in subsection (b)(1) met or exceeded the threshold described in that paragraph, the Administrator shall, not later 180 days after the date of the determination, ensure that Federal reference method monitors or Federal equivalent method monitors are installed and in operation within that census tract or county for each pollutant that met or exceeded the threshold.
(3)

Exceptions
The Administrator shall waive the requirement of paragraph (2) if the Administrator finds, within the 180-day period described in that paragraph, and after providing notice and an opportunity for public comment, that based on clear and convincing evidence—
(A)
the measurements from the systems supporting the determination described in paragraph (2) were so inaccurate as to provide no reasonable basis for finding that levels of the relevant pollutant reached 98 percent of the level of the national ambient air quality standard established under section 109 of the Clean Air Act (42 U.S.C. 7409) for the relevant pollutant; or
(B)
complementary data, such as information on the ambient matric, meteorology, measurements from other nearby systems or ambient monitors, modeling, satellite data, or other relevant and reliable information, demonstrate that levels of the relevant pollutant could not have plausibly reached 98 percent of the level of that standard.
(d)

Report
Not later than 1 year after the date of enactment of this Act, and after public notice and a public comment period of not less than 60 days, the Administrator shall make publicly available online a report describing additional areas in which data from low-cost air quality systems may be relevant or useful for decisionmaking or for the purpose of increasing public access to information.
(e)

Authorization of appropriations
There is authorized to be appropriated to carry out this section $6,000,000 for fiscal year 2026.
7.

Hazardous air pollutant monitoring
(a)

In general
Not later than 2 years after the date of enactment of this Act, for the purposes of improving the quality of the national emissions inventory and advancing public access to information, the Administrator shall, after public notice and a public comment period of not less than 60 days, amend subpart A of part 51 of title 40, Code of Federal Regulations, to update and expand the requirements under that subpart to require all major and non-major sources to report additional emissions data, including emissions of hazardous air pollutants, perfluoroalkyl substances, and polyfluoroalkyl substances.
(b)

Minimum requirements
The amendment required under subsection (a) shall, at a minimum—
(1)
contain all amendments described in the proposed rule of the Environmental Protection Agency entitled “Revisions to the Air Emissions Reporting Requirements” (88 Fed. Reg. 54118 (August 9, 2023));
(2)
ensure reporting of emissions during periods of malfunction of the source; and
(3)
consistent with the proposal to require reporting of emissions of perfluoroalkyl substances and polyfluoroalkyl substances in the rule described in paragraph (1), require, in the reporting cycle immediately following the date on which a pollutant is listed as a hazardous air pollutant, the reporting of emissions of that pollutant.
(c)

Effective date
The amendment required under subsection (a) shall take effect for the first inventory year that begins after that amendment is finalized.
8.

Data requirement
To the extent practicable, the Administrator shall—
(1)
(A)
restore for public access the EJSCREEN mapping tool of the Environmental Protection Agency; or
(B)
create a relevant, nationwide geospatial mapping and screening tool similar to and providing, at minimum, all of the data previously included in the EJSCREEN mapping tool that the Administrator, acting through the Assistant Administrator for Research and Development, shall make available online for public comment not later than 270 days after the date of enactment of this Act; and
(2)
integrate into the applicable tool restored or created under paragraph (1) the data collected through the programs established under this Act.
9.

Rule of construction
Nothing in this Act amends any other statute or revises or alters any duty or authority of the Administrator under any other applicable law.