FLAGSTAFF, Ariz. (AP) – Plaintiffs in a lawsuit challenging the health effects of making snow with treated wastewater grossly abused the judicial process, a federal appellate judge wrote in a ruling that upholds a northern Arizona ski resort's snowmaking plan.

The 9th U.S. Circuit Court of Appeals ruled Thursday that the U.S. Forest Service adequately considered the health impacts of snowmaking at Arizona Snowbowl. The plaintiffs' claims should have and would have been decided in a previous but related lawsuit involving the Navajo Nation had their attorney properly raised them, Judge Milan Smith Jr. wrote in the 9th Circuit's ruling.

“The Navajo Nation plaintiffs, in effect, got a second bite at the apple through their surrogates, the Save the Peaks plaintiffs,” Smith wrote for the San Francisco-based court.

The plaintiffs' attorney, Howard Shanker, denied that the lawsuit was meant to delay development at the ski resort. He said he wasn't surprised by the decision but it was inconsistent with the court's prior decisions.

A three-judge panel of the appellate court had sided with American Indian tribes in the previous lawsuit, which asserted that drinking water tainted by runoff from the man-made snow could pose health risks. But Smith wrote Thursday that the decision could not be cited as precedent because the full court later overturned it, saying the plaintiffs – also represented by Shanker – never properly raised the issue in the lower court.

“It doesn't diminish the fact that it happened,” Shanker said. “It doesn't say much for our judicial system when you have something like that going on.”

He said his clients likely would appeal.

The owners of the 770-acre Arizona Snowbowl want to spray artificial snow, add a fifth chairlift and clear about 100 acres of forest to extend the ski season on the western flank of the San Francisco Peaks, which have spiritual and religious significance to 13 Southwestern tribes. The ski area, which opened in 1937, gets about 135,000 visitors during the ski season.

Snowbowl hasn't been fully operational this winter because of the lack of snow. Crews have had to move snow onto the trails to keep them open, but coverage on the beginner area is thin and one of the two lifts there is closed, said Snowbowl owner Eric Borowsky.

Some of the pipeline for the snowmaking project has been laid and the rest should be complete by November, he said.

“Howard Shanker can continue to waste money filing appeals, but we're moving forward,” Borowsky said.

A spokesman for the Forest Service said it is reviewing the ruling. The agency has said that while the use of reclaimed water for snowmaking is not considered hazardous for recreational skiing and snow play, signs will be posted to urge people not to intentionally ingest snow at the resort.