Multi-state lawsuit challenging the federal government’s decision to delay the effective dates of final rules governing energy efficiency for six products.

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

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.

Multi-state lawsuit to compel the United States Army Corps of Engineers and the Metropolitan Water Reclamation District of Greater Chicago to take action to prevent Asian carp from crossing from the Mississippi River Basin into the Great Lakes.

Multiple states moved to intervene in litigation concerning the 2012–2016 light duty motor vehicle emissions standards.

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

Multi-state lawsuit challenging the Department of Energy (DOE)’s failure to create energy efficiency standards for consumer appliances according to the timeline established by the Energy Policy and Conservation Act (ECPA).

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.