The D.C. Circuit clarified an earlier ruling vacating portions of a 2015 rule that defined when certain hazardous materials were deemed discarded—as opposed to legitimately recycled—and therefore subject to EPA's oversight under RCRA.

A Pennsylvania appellate court reversed and remanded a lower court's decision that the owner of an oil and gas company should be liable for failing to plug 47 abandoned oil and gas wells located in Erie and Crawford Counties.

The U.S. Supreme Court held that the United States may pursue claims against New Mexico for violating the Rio Grande Compact, which Colorado, New Mexico, and Texas entered into in the 1930s to resolve disputes over water rights.

In a 259-page opinion, a federal claims court held that the U.S. Army Corps of Engineers is responsible for causing recurrent flooding along the Missouri River.