GARDINER, Mont. (AP) — Officials from Yellowstone National Park and a Montana water district have scheduled a settlement conference over claims of excessive arsenic from the park's sewage.

Talks are scheduled for May 9 between the park and the Gardiner-Park County Water and Sewer District with the goal of keeping a lawsuit from reaching trial.

A 2016 suit filed by the district says the park did not address complaints that heightened arsenic in Gardiner's sewage ponds resulted from faulty manholes or pipes delivering wastewater from the park's headquarters at Mammoth Hot Springs in Wyoming.

Wastewater tests found the park's arsenic levels were 40 times higher than those from Gardiner.

Arsenic is prevalent in Yellowstone's thermal pools and geysers and ingestion in large quantities can cause various ailments.