Scientists Disagree on Source of Lake Tahoe Pollution

Top scientists studying Lake Tahoe disagree about whether hard-to-control pollution blown to Lake Tahoe from the California lowlands is contributing to the lake’s loss of clarity.

Growing air pollution in the California foothills and Stockton is playing a significant role in clarity loss, said Dennis Murphy, an environmental researcher at the University of Nevada, Reno.

The pollution combines with water to make nitrogen and phosphorus, which fuel the algae growth clouding the lake, Murphy said.

If pollution from outside the basin is a significant factor, it may be difficult to restore the alpine lake’s clarity, said Murphy, who led a federal team evaluating Tahoe’s environment. “Even if we do the most thorough job possible here in the basin, that’s not going to remove the source of some of these pollutants,” Murphy said.

Tom Cahill, an expert on Sierra air pollution at UC Davis, disagrees with Murphy.

Cahill, who is on the federal research team with Murphy, argues that the vast majority of pollution fueling the algae growth comes from the cars, road dust and wood smoke surrounding Lake Tahoe itself.