EPA proposes approving California's Coachella Valley ozone reasonable further progress plan

SAN FRANCISCO, Oct 19 — The U.S. Environmental Protection Agency (EPA) proposed approving California's reasonable further progress plan for the Coachella Valley, according to a proposed rule dated Oct 19, which addresses "Extreme" nonattainment area requirements for the 2008 ozone standard.

The proposal covers the plan's reasonable further progress demonstration and its associated emissions inventory and motor vehicle emissions budgets. Under the Clean Air Act, reasonable further progress is defined as annual incremental reductions in emissions of the relevant air pollutant that are required to ensure the area meets the standard by the applicable date, according to the proposed rule. The budgets are the limits that on-road vehicle emissions in transportation plans are checked against, the agency said.

The plan's 2011 base year inventory lists 16.3 tons per day of volatile organic compounds (VOC) and 27.5 tons per day of oxides of nitrogen (NOX). VOC and NOX are the pollutants that form ozone, according to the proposed rule.

EPA said it proposes to determine that the state has demonstrated reasonable further progress in each milestone year and in the 2031 attainment year. The plan substitutes NOX reductions for VOC reductions beginning in 2017.

EPA will accept public comments for 30 days after the proposal is published in the Federal Register. The agency said it will consider the comments before taking final action.

The California Air Resources Board submitted the plan on Dec 7, 2022. On March 8, 2023, EPA granted the state's request to reclassify the Coachella Valley as Extreme. The agency said it plans to act at a later date on other elements the state submitted on Oct 30, 2024.