Coachella Valley Contingency Measure State Implementation Plan (SIP) Revision for the 2008 8-Hour Ozone Standard

Coachella Valley Contingency Measure State Implementation Plan (SIP) Revision for the 2008 8-Hour Ozone Standard

Description of Nature, Purpose, and Beneficiaries of Project: The most recent comprehensive SIP for the 2008 ozone National Ambient Air Quality Standard in the Coachella Valley was submitted as part of the 2016 Air Quality Management Plan. The SIP included Reasonable Further Progress (RFP) contingency measures which relied upon surplus emission reductions achieved from previously implemented control measures, consistent with U.S. EPA’s previous guidance. However, court decisions held that RFP contingency measures cannot rely on surplus emission reductions from ongoing programs and instead, must rely on additional measures to achieve emission reductions with automatically implemented triggering mechanisms once an area has failed to achieve attainment or a major milestone in the RFP contingency measure has been missed. In absence of revised guidance from U.S. EPA about what would suffice as an approvable contingency measure, South Coast AQMD withdrew the RFP contingency measure on August 8, 2022. On March 17, 2023, U.S. EPA released Draft Guidance on the Preparation of SIP Provisions that Address the Nonattainment Area Contingency Measure Requirements for Ozone and Particulate Matter (Draft Guidance) which outlines the requirements to conduct a robust infeasibility justification to demonstrate the scarcity of available, alternative control measures capable of achieving surplus emission reductions. Consequently, South Coast AQMD has prepared the Coachella Valley Contingency Measure SIP Revision for the 2008 8-Hour Ozone Standard which contains the following contingency measures applicable to stationary and mobile sources and which address ozone precursors including nitrogen oxides (NOx) and volatile organic compounds (VOC). Stationary Source Contingency Measure: South Coast AQMD commits to developing proposed amendments to Rule 463 – Organic Liquid Storage, to introduce a contingency measure that would require more frequent Optical Gas Imaging (OGI) inspections for certain storage tanks to facilitate leak detection and repair. VOC emission reductions would be achieved by identifying and repairing leaks sooner. Rule development is currently underway, and a public hearing is tentatively scheduled for summer 2024. Mobile Source Contingency Measure: In October 2023, CARB adopted a SIP revision with the California Smog Check Contingency Measure for which the U.S. EPA issued a proposed approval in December 2023. Under the current California Smog Check Program, new vehicles are exempt from having to undergo an emissions test for the first eight years. However, if the contingency measure is triggered the first time, new vehicles will only be exempt from the emissions test requirement for the first seven years. Similarly, if the contingency measure is triggered a second time, new vehicles will only be exempt for the first six years. Implementation of the continency measure, if triggered, will assist with detecting failures of emission control equipment on new vehicles one to two years sooner, so that the leaks can be quickly repaired and mitigated thereby preventing excess vehicle emissions. Implementation of the mobile source contingency measure is estimated to reduce 0.008 ton per day of NOx and 0.003 ton per day of VOC.

Los Angeles, Orange, Riverside, San Bernardino

Countywide

Los Angeles, Orange, Riverside, San Bernardino