A California appellate court affirmed in part and reversed in part a lower court decision granting an environmental group's petition for writ of mandamus challenging a county's approval of a mixed-use development project under the California Environmental Quality Act (CEQA).

The Seventh Circuit denied various states' motion to issue a preliminary injunction compelling the U.S. Army Corps of Engineers to prevent the emigration of invasive silver and bighead carp through the Chicago Area Waterway System into Lake Michigan.

A district court held that an energy company did not violate the CAA when it failed to obtain a new source review (NSR) permit prior to renovating electric utility steam generating units at its Monroe, Michigan, power plant.

A district court enjoined the U.S. Army Corps of Engineers from continuing with its Industrial Canal Lock Replacement Project in New Orleans until it complies with NEPA and the CWA.

A district court held that environmental groups are entitled to injunctive relief and civil penalties in their CWA citizen suit against a coal company for violating the water quality standards for selenium set forth in its permit.

A district court held that a railroad company that operates a railroad-transportation facility in Seattle, Washington, violated the terms of its NDPES permit in violation of CWA §402 and discharged pollutants into U.S. waters in violation of CWA §301.

The Tenth Circuit held that Oklahoma statutes that favor in-state water appropriation permit applicants over out-of-state permit applicants do not violate the Commerce Clause. The case arose after a Texas water district sought permits to appropriate water from Oklahoma for use in Texas.

The Tenth Circuit held that an Oklahoma city and a Texas city that entered into water contracts with one another lack standing to challenge Oklahoma's water appropriation permitting process as unconstitutional under the Commerce Clause.