The South Coast Air Basin is classified as an "extreme" nonattainment area for the 1997 8-hour ozone NAAQS. As required by the federal Clean Air Act, South Coast AQMD adopted a Contingency Measure Plan for the 1997 ozone standard on December 6, 2019 and subsequently submitted to U.S. EPA. On February 2, 2024, U.S. EPA proposed disapproval of that plan. If the proposed disapproval were finalized, it would have resulted in economic impacts to our region, including sanctions.
Over the past several months, South Coast AQMD, the California Air Resources Board (CARB), and U.S. Environmental Protection Agency (U.S. EPA) have met frequently to discuss actions each agency can take to attain all ozone standards in the South Coast Air Basin, including the 1997 standard. The result of this effort is memorialized in a Joint Statement on Advancing Emissions Reductions. U.S. EPA, CARB and South Coast AQMD also developed Letters of Intent that detail specific actions each agency will take to reduce emissions. These actions require involvement from multiple agencies – demonstrating the need for continued cooperation moving forward.
Joint Statement on Advancing Emissions Reductions
Letters of Intent
As part of this joint agency effort, South Coast AQMD and CARB determined that the most prudent path forward was to withdraw the 2019 Contingency Measure Plan from U.S. EPA’s consideration (AQMD, and CARB letters). It is South Coast AQMD’s understanding that all three agencies intend to pursue the actions in their respective Letters of Intent, and that by withdrawing this plan, U.S. EPA will not impose a sanctions clock for this action.
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