LAKE TAHOE — Despite concerns from Lake Tahoe water providers, pesticides could soon be used to combat the lake’s aquatic weed problems.
The Lahontan Regional Water Quality Control Board approved rule changes last Wednesday that will allow the agency to permit the use of aquatic pesticides under certain conditions.
Existing rules effectively prohibit pesticide application to water within the agency’s jurisdiction, which includes Lake Tahoe and covers much of eastern California.
Projects related to public health and ecological preservation are eligible to use aquatic pesticides under the changes. Allowing chemical treatment at Lake Tahoe has attracted support from several agencies concerned with the threat invasive species pose to the lake.
About 20 nonnative species are established in the region. Economic impacts from introductions of new aquatic invasive species, like quagga or zebra mussels, and the expansion of existing species like Eurasian watermilfoil have been estimated at $417.5 million over 50 years.
The largest impacts would be to property values and lost tourism spending, according to a 2009 aquatic invasive species management plan for the region.
Greg Feet, general manager of the Tahoe Keys Property Owners Association, said he supports Lahontan’s changes, saying existing methods to control the spread of invasive species are ineffective.
The annual harvesting of milfoil at the keys does not kill the plant and actually contributes to its spread by creating fragments that float to other areas of the lake and take hold.
“Herbicide is not a good word in the U.S., but invasive species is becoming a bad word too, and I think that is a good thing,” Feet said.
But Greg Reed, general manager of Round Hill General Improvement District and Board Chairman of Tahoe Water Suppliers Associations, said he is “very concerned” about the impacts aquatic pesticides could have on drinking water at Lake Tahoe.
Many water providers draw drinking water directly from the lake and would be unable to filter out any pesticides that reach their intake pipes, Reed said.
He asked the board to impose a five-year moratorium on any chemical use on projects at Lake Tahoe, saying the use of pesticides should receive further study at less pristine water bodies before being used here.
Reed said he was appreciated of water board staff’s efforts to diminish any effects of pesticide use on water quality, but said the possibility of contaminated water is a frightening one.
“We’re still not comfortable this process is going to get us the protection we desire,” Reed said.
Water board member Peter Pumphrey questioned whether five years would resolve water purveyors’ concerns and said a moratorium could end up becoming indefinite.
The changes to the rules do not guarantee the water board will permit a project to use pesticides at Lake Tahoe, Pumphrey added.
“I think there’s enough safeguards in our plan that we can look at each project and really analyze it,” said water board member Jack Clarke.
Studying pesticide use at other water bodies may never yield result applicable to Tahoe because of the lake’s uniqueness, Clarke said.
According to an Associated Press article, Carl Young of the League to Save Lake Tahoe says his group wants to protect the health of visitors and residents, and is concerned they could be exposed to pesticides through drinking water and the lake’s fish.
Final approval of the changes by the U.S. Environmental Protection Agency is scheduled for July.