Senate Bill 24-165: Air Quality Improvements

• Air Quality Control Commission must adopt rules by December 31, 2028 for in-use, off-road diesel-fueled fleets, including idling limits, vehicle reporting requirements, restrictions on adding older engines, emission reduction targets through engine retirement/replacement/repowering or emission control retrofits, and renewable diesel procurement requirements.

• Commission must adopt rules by December 31, 2025 controlling emissions from indirect sources (facilities, buildings, parking, highways, warehouses, airports, etc.) in the Denver metro/North Front Range ozone nonattainment area, including emission reduction targets and alternative compliance approaches allowing funding of voluntary programs and emission reduction efforts in disproportionately impacted communities.

• Oil and gas preproduction activities (drilling, hydraulic fracturing, flowback) must pause during ozone season (May 1-September 30) beginning in 2025, with exceptions for grid-powered electric drill rigs and hydraulic fracturing engines, continuing until the area is redesignated as a maintenance area.

• Oil and gas operators must submit annual emission inventory reports by June 30 each year starting 2024, and operators in the nonattainment area must submit nitrogen oxides emission estimates by November 30; the Energy and Carbon Management Commission must develop ozone season nitrogen oxides emission budgets capped at 31.71 tons per day for 2025-2029 and 22.65 tons per day for 2030 onward.

• Department of Transportation must establish vehicle miles traveled reduction targets for the Denver metro/North Front Range nonattainment area and develop policies and programs to assist metropolitan planning organizations in meeting those targets, with presentation to legislative committees in January 2025.