🌫️EPA Approves Washington Regional Haze SIP
The Environmental Protection Agency (EPA) is approving the regional haze State implementation plan (SIP) revision, submitted by Washington on January 28, 2022, to address applicable requirements under the Clean Air Act (CAA) and the EPA's Regional Haze Rule (RHR) for the regional haze program's second implementation period.
Learn More🌬️EPA Proposes Redesignation of Indiana's Sulfur Dioxide Standards
The Environmental Protection Agency (EPA) is proposing to find that Huntington Township, Indiana (referred to in this proposed rule as the Huntington County, Indiana area) is attaining the 2010 sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS) and to propose approval of Indiana's request to redesignate the area to attainment for the 2010 SO<INF>2</INF> NAAQS, because the request meets the statutory requirements for redesignation under the Clean Air Act (CAA). EPA is also proposing to approve Indiana's maintenance plan for the area, which, once approved, will become part of Indiana's federally enforceable State Implementation Plan (SIP).
Learn More🌱EPA Proposes Renewable Fuel Standards Changes for 2026 and 2027
On June 17, 2025, the U.S. Environmental Protection Agency (EPA) proposed volumes and percentage standards for four categories of renewable fuel that would apply to obligated parties in 2026 and 2027 under the Renewable Fuel Standard (RFS) program. On August 22, 2025, the EPA issued decisions on 175 small refinery exemption (SRE) petitions under the RFS program. This supplemental proposal takes into consideration the expected impacts of the SRE decisions issued. Based on this information, the EPA is co-proposing additional volumes in 2026 and 2027 representing complete (100 percent) reallocation and 50 percent reallocation for SREs granted in full or in part for 2023 and 2024, as well as those projected to be granted for 2025, as part of the ongoing RFS rulemaking. The EPA is also providing more information on its projection of SREs to inform the calculation of the 2026 and 2027 percentage standards.
Learn More🌬️Final Rule on Clean Data Determination for Sulfur Dioxide in Guam
The Environmental Protection Agency (EPA) is taking final action on a clean data determination (CDD) for the Piti-Cabras, Guam sulfur dioxide (SO<INF>2</INF>) nonattainment area ("Piti-Cabras area") based on our determination that the area has attained the 2010 1-hour SO<INF>2</INF> National Ambient Air Quality Standard (NAAQS, "standard," or "2010 SO<INF>2</INF> NAAQS"). In designated nonattainment areas where air quality data demonstrate that a NAAQS has been attained, the EPA interprets certain requirements of the Clean Air Act (CAA) as no longer applicable for so long as air quality continues to meet the standard. Under this Clean Data Policy, the EPA may issue a determination of attainment, known as a CDD, that a nonattainment area is attaining the relevant NAAQS. This CDD suspends the obligation to submit certain attainment planning requirements for the Piti-Cabras area for as long as the area continues to attain the 2010 SO<INF>2</INF> NAAQS or until the area is formally redesignated. This CDD does not constitute redesignation of the area to attainment. This action is being taken under the CAA.
Learn More🌬️EPA Approves Guam Air Plan
The Environmental Protection Agency (EPA) is finalizing an approval of a revision to the Guam state implementation plan (SIP). This revision governs the Guam Environmental Protection Agency's (GEPA) issuance of permits for stationary sources and focuses on the preconstruction review and permitting of major sources and major modifications under the Clean Air Act (CAA or "the Act").
Learn More🌬️EPA Proposes Air Quality Rule for San Joaquin Valley Businesses
The Environmental Protection Agency (EPA) is proposing to approve a revision to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD or "District") portion of the California State Implementation Plan (SIP) concerning a rule submitted to address section 185 of the Clean Air Act (CAA or the "Act") with respect to the revoked 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS or "standard"). We are proposing action on this local rule that was submitted as an equivalent alternative to a statutory section 185 program. We are taking comments on this proposal and plan to follow with a final action.
Learn More🌫️EPA Proposes Updated VOC Regulations Affecting Maricopa Businesses
The Environmental Protection Agency (EPA) is proposing to approve revisions to the Maricopa County Air Quality Department (MCAQD) portion of the Arizona State Implementation Plan (SIP). These revisions concern rules that regulate volatile organic compounds (VOC) emissions from solvent cleaning operations. We are proposing to approve the revisions under the Clean Air Act (CAA or "Act"). We are taking comments on this proposal and plan to follow with a final action.
Learn More🌫️Proposed Air Quality Revisions in Maricopa County by EPA
The Environmental Protection Agency (EPA) is proposing an approval of revisions to the Maricopa County Air Quality Department (MCAQD) portion of the Arizona State Implementation Plan (SIP). These revisions concern emissions of particulate matter from incinerators, burn-off ovens, and crematories. We are proposing to approve revisions to a local rule that regulates these emissions sources under the Clean Air Act (CAA or "Act"). We are taking comments on this proposal and plan to follow with a final action.
Learn More🌁Montana's Regional Haze Plan
The Environmental Protection Agency (EPA) is proposing to approve the regional haze state implementation plan (SIP) submission submitted by the State of Montana on August 10, 2022, under the Clean Air Act (CAA) and the EPA's Regional Haze Rule (RHR) for the program's second implementation period. Montana's 2022 SIP submission addresses the requirement that states revise their long-term strategies every implementation period to make reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility, including regional haze, in mandatory Class I Federal areas. Montana's 2022 SIP submission also addresses other applicable requirements for the second implementation period of the regional haze program. The EPA is also proposing to approve the prong 4 visibility portion of Montana's October 1, 2018 Infrastructure SIP submission for the 2015 ozone National Ambient Air Quality Standards (NAAQS). The EPA is taking these actions pursuant to the CAA.
Learn More🌬️Proposed Revisions to Mojave Desert Air Quality Regulations
The Environmental Protection Agency (EPA) is proposing to approve revisions to the Mojave Desert Air Quality Management District (MDAQMD or "District") portion of the California State Implementation Plan (SIP). These revisions concern amended or rescinded prohibitory and administrative rules that regulate air pollutants under the Clean Air Act (CAA or "Act"). We are proposing to rescind numerous requirements from the District's portion of the California SIP because the requirements can be replaced by more current requirements. We are taking comments on this proposal and plan to follow with a final action.
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