U.S. EPA Sets Stricter National Ambient Air Quality Standards for Particulate Matter

On February 7, 2024, the U.S. Environmental Protection Agency (EPA) issued a final rule under the Clean Air Act lowering the primary (health-based) annual National Ambient Air Quality Standard (NAAQS) for fine particulate matter 2.5 micrometers in diameter or smaller (PM2.5) from 12 to 9 micrograms per cubic meter (µg/m3). EPA asserts that the stricter standard is based on scientific evidence showing that the current PM2.5 standard (12 µg/m3), which was established in 2012 and retained in 2020, does not sufficiently protect human health. According to EPA, based on air monitoring data from 2020-22, 119 counties would not meet the new standard of 9 µg/m3.


D.C. Circuit Upholds U.S. EPA’s 2021 Interstate Ozone Transport Rule

On March 3, 2023, the D.C. Circuit Court of Appeals rejected an industry challenge to the April 2021 Revised Cross-State Air Pollution Rule (CSAPR) Update Rule from the Environmental Protection Agency (EPA or Agency), which required power plants in 12 “upwind” states to reduce nitrogen oxide (NOx), an ozone precursor, emissions such that those states did not inhibit downwind states’ ability to comply with the 2008 Ozone National Ambient Air Quality Standard (NAAQS).


EPA Acts on Interstate Transport Requirements for Ozone Under State Implementation Plans

On Tuesday, January 31, EPA Administrator Michael Regan finalized EPA’s disapproval of State Implementation Plan (SIP) submissions for 19 states regarding the interstate transport of ozone under the 2015 eight-hour ozone national ambient air quality standards (NAAQS) of 70 parts per billion. Under the Clean Air Act, states were required to submit SIPs for the 2015 eight-hour ozone standard by October 1, 2018. The Clean Air Act required the SIPs to include “good neighbor” provisions, which prohibit emissions that either significantly contribute to nonattainment in a neighboring state or interfere with maintenance of the NAAQS in a neighboring state.


EPA Proposes “Good Neighbor” Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air Quality Standard

On April 6, 2022, the U.S. Environmental Protection Agency (EPA) is scheduled to publish its proposed Federal Implementation Plan Addressing Ozone Transport for the 2015 Ozone National Ambient Air Quality Standards (NAAQS), otherwise known as the latest iteration of EPA’s Cross-State Air Pollution Rule or “Good Neighbor” Plan. The proposal would subject 26 upwind states to the “good neighbor” or “interstate transport” provision of the Clean Air Act because EPA is proposing to find that nitrogen oxide (NOx) emissions, which are a precursor to ozone formation, from the upwind states significantly contribute to downwind states’ attaining and maintaining the 2015 ozone NAAQS.


Texas Challenges EPA’s Ozone Nonattainment Designation for El Paso County

On Friday, the state of Texas and Texas Commission on Environmental Quality filed a petition for review in the U.S. Court of Appeals for the District of Columbia Circuit challenging the Environmental Protection Agency (EPA) November 2021 designation of El Paso County as a nonattainment area for ozone. (more…)