Multi-state lawsuit challenging EPA failure to act on petition requesting that the agency regulate ozone pollution from sources in upwind states.

Multi-state settlement of consumer-protection claims against car manufacturers that overstated their vehicles’ fuel efficiency.

Twelve states joined in defense of EPA’s new source performance standards for methane and VOC emissions from the oil and gas sector.

California AG, working with the federal EPA, entered into two related settlements over Volkswagen’s use of defeat devices to evade emissions testing.

Settlement of consumer protection claims raised by a multi-state coalition of state attorneys general against Volkswagen for selling vehicles equipped with “defeat device” software intended to circumvent emissions standards and concealing this software from regulators and the public.

Multiple states intervened in lawsuit to defend EPA standards regulating mercury and other air pollutants from the power sector.

Illinois AG co-authored legislative proposal to regulate bulk materials storage facilities that handle petroleum coke and other refinery production materials in response to air pollution violations linked to several facilities on Chicago’s southeast side.

Michigan AG brought enforcement action against waste management companies to reduce foul odor emanating from the United States’ largest waste incineration facility.

Multiple states intervened in lawsuit to support EPA rule on cross-state air pollution against state and industry challenge.

Multi-state suit to compel EPA to review and revise New Source Performance Standards for wood burning devices.

California AG filed an amicus brief in a case involving the Port of Los Angeles “Clean Trucks Program,” which was designed to improve diesel emissions and air quality.

California AG intervened in and helped to settle litigation surrounding an industrial project that was expected to increase diesel truck traffic in a predominantly Latino residential area.

Multi-state lawsuit to force EPA to comply with Clean Air Act requirement to update and revise National Ambient Air Quality Standards (NAAQS) every five years.

Multi-state lawsuit challenging the adequacy of EPA’s 2006 revision to the National Ambient Air Quality Standards (NAAQS) regulating soot pollution under the Clean Air Act.

Multi-state challenge to EPA decision to remove fossil fuel-fired power plants from list of sources regulated under CAA section 112 (hazardous air pollutants) and to establish new performance standards for mercury emissions from these plants under CAA section 111.

Multi-state litigation under Clean Air Act alleging violations of New Source Review permitting process to reduce sulfur dioxide emissions in coal-fired power plants.

Multi-state challenge to 2002 EPA rule amending and expanding the routine maintenance, repair and replacement exceptions to the New Source Review program.

Multi-state challenge to 2002 EPA rule amending the New Source Review (NSR) program and narrowing the definition of “modification” to exclude certain sources from NSR requirements.