On June 26, 2025, the California Air Resources Board adopted Resolution 25-4, formally repealing the In-Use Locomotive Regulation that was originally adopted on April 27, 2023. The regulation had been designed to reduce toxic air contaminants and greenhouse gas emissions from locomotives operating in California. The repeal removes compliance obligations for locomotive operators in California.
CARB implemented amended Low Carbon Fuel Standard (LCFS) regulations effective July 1, 2025. The amendments establish carbon intensity reduction targets of 30% by 2030 and 90% by 2045, introduce amended 2025 CI benchmarks applicable to Q3 2025 quarterly reporting (with different benchmarks applying to Q1-Q2 vs Q3-Q4), add new sustainability requirements under subsection 95488.9(g), require biomass attestation letters beginning with 2026 data year, and mandate third-party certification starting in 2028. Credit true-up provisions apply to all 2025 transactions.
CARB reached a $137,900 settlement with the Los Angeles Department of Water and Power (LADWP) for violations of the Regulation for Reducing Sulfur Hexafluoride (SF6) Emissions from Gas Insulated Switchgear. The regulation, codified in California Code of Regulations, Title 17, addresses emissions of this potent greenhouse gas from electrical equipment.
CARB published a Questions and Answers document resulting from March 2025 public workshops on SB 1137 oil and gas emissions regulations. The guidance addresses stakeholder comments received by the April 30, 2025 deadline and provides clarification on performance standards for emissions detection systems required under leak detection and response plans. Facilities subject to SB 1137 should review this Q&A for implementation guidance.
CARB announced it is pausing development of the Mobile Source Strategy and reconsidering the approach. The strategy, required by SB 44 (2019) to be updated every 5 years following the 2016 Strategy, guides mobile source emissions reduction planning. The pause reflects ongoing evaluation of opportunities amid evolving vehicle markets and policy priorities.
CARB's Enforcement Division issued a memorandum increasing maximum penalties for violations based on the 2024 California Consumer Price Index adjustment. The increased penalty amounts apply to violations occurring on or after February 21, 2025. This represents a routine but required adjustment to penalty structures to maintain their deterrent effect. Compliance teams should reference the updated penalty tables when assessing potential violation settlements.
CARB issued an Enforcement Division memo increasing maximum penalty amounts based on the 2024 California Consumer Price Index (CPI). The memo states the updated maximum penalties are effective immediately for settling violations occurring on and after February 21, 2025, and provides updated penalty tables. Compliance and legal teams should use the updated maximum penalty amounts when assessing enforcement exposure and settlement posture for applicable CARB violations.
CARB updated the Clean Truck Check compliance fee to $32.13, reflecting a CPI adjustment, effective January 1, 2026. The fee applies to almost all non-gasoline heavy-duty vehicles with a gross vehicle weight rating greater than 14,000 pounds operating in California. This replaces the previous fee of $31.18.
On November 21, 2024, CARB exercised enforcement discretion for the Heavy-Duty Engine and Vehicle Omnibus and Advanced Clean Fleets Regulations. The action responds to concerns raised by upfitters, dealers, and tow truck fleets regarding their inability to purchase heavy-duty vehicles due to supply chain restrictions and insufficient compliant engine availability. This enforcement discretion provides temporary relief for affected entities while supply chain issues are resolved.