State conducts water tests in response to Priest Lake stench

Complaints of an unusually foul stench coming off Priest Lake last month have prompted a round of water tests by the Idaho Department of Environmental Quality.

The results aren’t expected until late next week at the earliest. Many suspect the stench could be coming from a naturally occurring form of algae or zooplankton.

Reginald Unterseher, whose family has a summer home on the lake, said the smell was strongest in mid-June, as surface water temperatures skyrocketed from 52 degrees to 74 degrees in less than two weeks during a heat wave. Unterseher suspects the heat wave combined with a high amount of snowmelt this year had something to do with the rank odor.

“I’ve been coming up here since the late 1950s, and this was the worst kind of fishy algae smell I have ever smelled up here,” said Unterseher, who spends cooler months in Kennewick.

Unterseher and others also wonder if booming real estate development and logging practices on the east side of the lake might have something to do with the odor.

“The smell is getting a little bit worse every year,” he said. “This lake is a system that can absorb a certain amount of stuff, but I’m concerned we’re approaching that limit.”

The odor is “90 percent gone,” Unterseher said, but the water continues to have a slightly greener tinge than usual.

Mark Sprengel, with the Selkirk Conservation Alliance, said his group has received many complaints and phone calls from worried residents because of the smell. The Mosquito Bay area on the far northern end of the lake had some of the strongest of the reported odors.

“No one in their recollection could ever recall a previous year that even approximated what they were sensing this year,” Sprengel said.

The Department of Environmental Quality recently sent water samples from the lake for analysis at an independent lab, said Ed Tulloch, regional water quality manager for the agency. Although nothing is certain until the results are returned, Tulloch said agency officials say such scent events are not unusual and are often the result of algae blooms or zooplankton. “We’re leaning towards it being a natural occurrence.”

Although strong pondlike odors during summer months are not uncommon at freshwater lakes, Unterseher said, Priest Lake’s cool, deep waters are usually crystal clear and relatively free of plant or fish smells. The lake is one of the most pristine large water bodies in the lower 48 states, he said. That’s why people become alarmed when they smell something fishy.

“The water quality is the basic economic engine up here. So many people’s livelihoods depend on the pristine quality of the lake,” he said.