The U.S. Supreme Court denied, 8-0, Texas' motion to review a river master's final determination in a long-running dispute over how Texas and New Mexico share water. Texas challenged the river master's determination that New Mexico was entitled to delivery credit for water that evaporated while it w...

The Fourth Circuit stayed a pipeline company's use of a nationwide permit, verified by the Army Corps of Engineers, to carry out construction of the Mountain Valley Pipeline in streams and rivers along the pipeline's route. Environmental groups argued the verification was unlawful because the Corps ...

The Montana Supreme Court affirmed vacatur of a Montana Pollutant Discharge Elimination System (MPDES) permit issued by the Montana Department of Environmental Quality (MDEQ) for a copper and silver mine in the Cabinet Mountains. Environmental groups argued, among other things, that MDEQ unlawfully ...

A district court denied mine owners' motion to dismiss a lawsuit alleging they were in violation of their NPDES permit. A conservation group and the state of Washington argued that the owners had violated the terms of their permit by discharging pollutants in excess of average monthly effluent limit...

A district court vacated EPA's 2019 determination that found no jurisdictional waters under the CWA at a salt production complex bordering the southwestern San Francisco Bay. The Agency argued that the CWA did not apply to the complex because it was converted to salt ponds prior to the Act's passage...

The Illinois Supreme Court dismissed a lawsuit concerning the city of Chicago's replacement of water meters and water main pipes as well as the partial replacement of lead service lines that run between water mains and residences throughout the city. City residents brought a negligence claim against...

The Tenth Circuit held, 2-1, that a sovereign must affirmatively act to extinguish aboriginal water rights in a lawsuit concerning water rights of the Pueblos of Jemez, Santa Ana, and Zia in the Jemez River Basin in New Mexico. The district court had concluded that the Pueblos' water rights were ext...

The Nevada Supreme Court held that the public trust doctrine did not permit reallocation of water rights already adjudicated and settled under the doctrine of prior appropriation in a lawsuit concerning established water rights for a deteriorating lake in western Nevada. The court found that while t...

A district court denied a motion to reconsider its 2018 ruling that gave EPA discretion as to how to establish a new TMDL for trash in the Anacostia River. An environmental group argued that little progress had been made since the 2018 ruling and that the court should require the Agency to establish...

In an unpublished opinion, the Ninth Circuit granted in part and denied in part an environmental group's petition to review EPA's approval of the Idaho Pollution Discharge Elimination System (IPDES). Specifically, the court denied the petition with respect to the group's challenges concerning the st...