A portion of the state-owned Mason Valley Wildlife Management Area near here has been closed due to a potential public health risk, state officials said.
Terry Crawforth, director of the Nevada Division of Wildlife, announced the closure late last week of Cinnamon Pond.
He said the alleged improper treatment of sewage effluent that the city of Yerington discharges into the area is causing concern for the health of hunters.
For the last two years, an average of more than 180 hunters a day have used the area during the fall hunting season between October and January.
The 17,000-acre wildlife area is home to a variety of species, including ducks, geese, migratory birds, porcupine, mule deer and mountain lion. It's also a popular fishing area.
At least two separate discharges of improperly treated effluent have been reported in the area, one in July and another in October, officials said.
"Due to the reoccurring problem of improperly treated effluent, we felt it was prudent to close the affected portions of the management area," Crawforth said.
"In coordination with the Nevada Divison of Environmental Protection and state health officer, we determined that there may be a health hazard in the area, prompting the closure," he added.
In two separate inspections in July, Yerington's wastewater treatment facility was found to be in non-compliance with permitting requirements, officials said.
Later that month, state environmental regulators issued an order alleging violations of the city's groundwater discharge permit.
On Oct. 15, a follow-up inspection found that decomposed toilet paper, sanitary items and floating debris had again been discharged at Cinnamon Pond.
In late October, the state environmental protection division ordered the city of Yerington to complete designs for an automatic treatment system by Nov. 28 and to have the system in operation by Jan. 31.