EPA Approves Two Significant Air Quality Actions in Louisiana
DALLAS, TEXAS (June 30, 2025) –U.S. Environmental Protection Agency (EPA) approved two of the state of Louisiana’s clean air plans, known as State Implementation Plans (SIPs), addressing sulfur dioxide (SO2) pollution. The first approval applies to reducing emissions of SO2 Cabot Corporation’s Ville Platte carbon black plant in Evangeline Parish. EPA also approved the SIP for the interstate transport of SO2, known as the “good neighbor” provision of the Clean Air Act (CAA). Because the state submitted this revision in 2013, EPA’s approval also contributes to clearing the agency’s SIP backlog.
“EPA is working hard to implement Administrator Zeldin’s priority of eliminating the backlog of SIPs, and today’s announcement gets us one step closer to that goal. EPA worked with the state of Louisiana to reach consensus on plans that will improve air quality and comply with all Clean Air Act requirements,” said Regional Administrator Scott Mason. “In the spirit of cooperative federalism, EPA will continue working with our state counterparts to develop approvable plans for reducing pollution.”
The Louisiana Department of Environmental Quality (LDEQ) worked extensively with Cabot to develop the emissions limits and controls in the plan, which are largely required by a 2013 consent decree between Cabot, the state, and EPA. Modeling by LDEQ that was verified by EPA shows the emissions reductions will bring Evangeline Parish into attainment with the CAA’s National Ambient Air Quality Standard (NAAQS) for SO2. EPA worked closely with LDEQ and Cabot to support the State’s development of the modeling demonstration and SIP requirements.
In 2013, LDEQ submitted revisions to the SO2 transport SIP to address the “good neighbor” provision of the CAA NAAQS for SO2. EPA reviewed the state’s submission and considered additional information including available emissions data, monitoring data, and air quality modeling, in determining that the SIP complies with the Clean Air Act requirements. EPA proposed approval of LDEQ’s SO2 transport SIP in April 2025 and accepted public comments for 30 days.
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