The Tenth Circuit held that FWS has the authority under the Commerce Clause to regulate the take of the Utah prairie dog. A group of property owners challenged FWS's authority to use the ESA to prohibit take of the Utah prairie dog, an intrastate species, on nonfederal land.

The Ninth Circuit rejected challenges to EPA's interpretation of the Tribal Authority Rule under the CAA in a case concerning a coal-fired power plant on Navajo land.

A district court denied a winery's motion to strike claims by EPA under CERCLA, the CAA, and other statutes in connection with a release of ammonia that claimed the life of one worker. In 2012, the winery experienced a 284-pound release of anhydrous ammonia from its refrigeration system.

A district court ordered EPA to complete overdue assessments of 13 sources of hazardous air pollutants.

The Colorado Court of Appeals ruled against the state Oil and Gas Commission's narrow interpretation of its authority to readjust the balance of state oil and gas conservation regulations between the development of oil and gas resources and protection of public health, safety, and welfare.

A district court upheld the Delaware River Basin Commission's fracking ban against a challenge from a energy company.

A district court held it had no authority to impose municipal penalties in a case involving a Kansas city's groundwater contamination claims against an oil company.

A district court held that defendants responsible for dumping hazardous waste in a town park were not liable under CERCLA because they did not know of the hazardous nature of the material dumped.

The New Jersey Supreme Court held that the state hazardous waste spill law, which waives state immunity for hazardous waste suits, does not apply to spills that predate the law. In 1968, a development corporation built a seawall on state-owned land.

A district court held that cow manure can be a hazardous substance under CERCLA. A citizen group sued a dairy farm for its part in contaminating Lake San Marcos. The dairy farm moved for judgment on the pleadings on the grounds that no actionable hazardous release was claimed.