Plan to allow pesticides at Lake Tahoe criticized

RENO (AP) - Lake Tahoe's leading conservation organization is criticizing a regional board's vote to allow the use of pesticides to combat non-native aquatic species at the Sierra Nevada lake.

The Lahontan Regional Water Quality Control Board's unanimous vote Wednesday to lift a ban on the use of pesticides at Tahoe and other lakes under its jurisdiction now goes to the California State Water Resources Control Board for action.

Carl Young, interim executive director of the League to Save Lake Tahoe, said the plan poses a threat to the lake's water quality and the public's health, and he's concerned visitors and residents could be exposed to pesticides through Tahoe's fish and drinking water.

The league is urging regulators to fight invasive species such as Asian clams and the underwater weed Eurasian watermilfoil with non-chemical methods, including "bottom barriers" that involve the use of large mats to starve the species of sunlight and oxygen.

"I think honestly this is coming down to human health issues," Young told The Associated Press. "They can say all they want that it won't harm people, but it's poison and it can kill things."

Dan Sussman, an environmental scientist with the Lahontan water board, said pesticides are "one more tool in the toolbox" to fight non-native species, and they would only be used under strict controls.

Asian clams are blamed for contributing to algae growth at Tahoe and diminishing its famed clarity, while officials are trying to snuff out watermilfoil before it clogs water intakes for the region's primary water supply system.

The use of pesticides to fight such invasive species was identified as an option in a plan signed by the governors of California and Nevada, and was endorsed by the national Aquatic Nuisance Species Task Force, Sussman added.

"There are circumstances where they (Lahontan board) believe pesticides could be justified to promote the ecological integrity of a lake, and the public health and safety," he said. "It's really not a promotion of pesticide use, but allowing more information to come forward and allowing our board to have discretion to decide."

Greg Reed, chairman of the Tahoe Water Suppliers Association board, told the Lahontan board that he's concerned about the effect aquatic pesticides could have on drinking water at the lake, the Tahoe Daily Tribune reported.

Many providers draw drinking water from Tahoe and would be unable to filter out any pesticides that reach their intake pipes, he said.

Reed called for a five-year moratorium on the use of pesticides, saying the issue should receive further study at less pristine lakes before being allowed at Tahoe.

The Lahontan board rejected his recommendation, but added language that would require notification of affected water providers and users as well as California and Nevada health officials.

"We really tried to cover our bases, and our board felt comfortable that the protection of drinking water could be maintained," Sussman said.

But water purveyors and conservationists remained skeptical.

"The best thing for the environment and human health is to treat it with non-chemical methods," Young said, adding his group only supports the use of pesticides to control mosquitoes and to fight quagga or zebra mussels in the event they spread to Tahoe and their eradication is probable.

The proposal also must be approved by the California Office of Administrative Law and U.S. Environmental Protection Agency before taking effect. The process could take until July, Sussman said.