ALBUQUERQUE, N.M. — The New Mexico Court of Appeals has sided with a coalition of environmental groups that had repeatedly sought a public hearing related to the cleanup of chromium contamination at one of the nation’s premier federal laboratories.

The court in a ruling issued last week found there was no evidence to support the decision by state regulators to deny requests for a public hearing.

At issue is a permit granted by the state Environment Department that allows Los Alamos National Laboratory to release thousands of gallons of treated wastewater as part of its efforts to address groundwater pollution.

The coalition, Communities for Clean Water, has concerns that discharging the treated water could end up pushing the plume of chromium closer to drinking water wells.

Rachel Conn with Amigos Bravos, one of the groups involved in the legal battle, called the ruling a victory for clean water.

“The court has ensured that the public’s concerns must be heard before discharges of pollution into our state’s waters are authorized,” she said.

The state Environment Department did not return messages seeking comment on the ruling.

The permit was finalized in 2015 following a public comment period. Then-Environment Secretary Ryan Flynn denied the request for a public hearing, saying his agency had accepted comments and that the permit was in the public interest.

The state Water Quality Control Commission backed up Flynn’s decision, saying concerns raised by the coalition had already been addressed by the Environment Department in a private meeting.

The commission said that allowing for a public hearing would delay the lab’s cleanup efforts. The appellate court disagreed, finding that denying a hearing because public health and environmental issues are so grave actually weighs in favor of there being substantial public interest.

“If anything, this factor supports a conclusion that the public interest in the permit would be heightened, rather than lessened, mandating the hearing under the regulation,” the judges wrote.

Under the permit, the lab is allowed to discharge up to 350,000 gallons a day of treated water associated with pumping tests, well development and groundwater remediation. This included work related to the preliminary investigations of the extent, location and migration of the chromium plume.

At a legislative meeting in November, lab officials testified that new mapping shows the plume is larger than previously thought. They said cleanup could take decades.