SAN FRANCISCO (AP) – A federal appeals court in San Francisco on Monday heard arguments in a case challenging the planned use of treated wastewater for snowmaking at a northern Arizona ski resort.

Attorney Howard Shanker, representing the Save the Peaks Coalition and a group of citizens, argued before the 9th Circuit U.S. Court of Appeals that the U.S. Forest Service needs to do a more thorough environmental analysis on the health and safety risks of using the wastewater for artificial snow.

No studies have considered the impacts that could come from ingesting such snow that is sprayed on the San Francisco Peaks in Flagstaff, Ariz., that at least a dozen American Indian tribes consider sacred, Shanker told the three-judge panel.

“There’s got to be a reasonably thorough discussion,” Shanker said. “There’s been no full discussion on this.”

Lane McFadden, an attorney with the U.S. Department of Justice, told the judges that the plaintiffs are “engaging in a delay tactic,” while arguing a need for more information without providing specifics.

The owners of the Arizona Snowbowl plan to begin making snow for skiing and snowboarding for the 2012-13 season after years of legal wrangling with tribes and critics.

The three judges repeatedly referred to a 2010 ruling by Arizona U.S. District Judge Mary Murguia that stated the Forest Service adequately considered the impacts of the snowmaking plan and that the record supported the agency’s decision to allow it.

The Forest Service said 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 Snowbowl resort.

On Monday, Judge John Noonan told Shanker that he disagreed that the issued has not been fully discussed.

American Indian tribes had argued unsuccessfully in a separate case that the plan violated religious freedom. Since then, some tribal members have continued protesting the plan by chaining themselves to construction equipment at the ski resort, and one tribe recently lost its own lawsuit to keep the city of Flagstaff from selling treated wastewater to the Snowbowl.

Shanker said after the hearing that he was disappointed by the judges’ reaction, especially after another panel of the appeals court sided with tribes who asserted in the previous lawsuit that drinking water tainted by runoff from the man-made snow could pose health risks.

The full court later overturned the decision, saying the plaintiffs never properly raised the issue in the lower court.

“I don’t feel confident, but I think we did the best we could,” Shanker said. “We’ll see what happens.”