Sandpoint activists are sounding the alarm now that the Bonner County Commissioners have made their decision. They want to bomb the stuff with granules of plant poison. That means dumping 200,000 pounds of herbicides into the lake and the Pend Oreille River. Treatments are scheduled to start on July 10.
Steve Holt of the Sandpoint group Citizens for Sustainable Solutions says the plan is neither sustainable nor a solution.
"The issue is that herbicides are not the long-term answer," he says. "Milfoil is in 48 states, and we're dumping millions of dollars of herbicides on it, yet it's not working. It keeps coming back."
But milfoil is a menace. It can form mats of vegetation on top of the water that can ruin the ecosystem below, snag your propeller or muck up intakes for hydropower plants. Bonner County Commissioner Karl Dye says there are even reports of kids drowning in milfoil while swimming.
Milfoil is managed all over the nation in different ways -- through herbicide, underwater rototilling and even by having divers actually pull individual plants. Obviously that won't work on a lake the size of Pend Oreille Lake. So County Commissioners hired Aquatechnix of Centralia, Wash., to study the lake and make recommendations. They found that between Pend Oreille and a couple of smaller lakes, there are nearly 4,000 acres of Eurasian milfoil in Bonner County -- more than half the milfoil in the entire state of Idaho. They recommended a $1.6 million application of herbicide to tame or eradicate the weed, and Dye says with the help of state Rep. Eric Anderson, Bonner County got the state to pick up the tab for almost all of it.
"We're following the treatment regimen that has worked successfully in other bodies of water around the U.S.," says Dye. "It's the same treatment, and it has not caused harm to humans." Dye adds that near the City Beach and water system intakes, they'll follow the recommendation to use a different substance -- called Sonar -- than the 2,4-D herbicide that will be used everywhere else.
"We don't want any of it," says Holt. "We'd like to make the City Beach a chemical-free zone -- to do anything to keep our kids from swimming in fluridone" [an element of Sonar].
Holt says underwater harvesting or even the use of the milfoil weevil, a bug that stunts the weed's growth, would work better than chemicals as a long-term management approach. He's particularly concerned about the 2,4-D herbicide, which, he says, has been banned in parts of Europe.
So is 2,4-D herbicide safe? It's among the most widely used herbicides in the world, and it is also among the most heavily studied. It's used in everyday lawn herbicide and was part of the mix used as Agent Orange in Vietnam. Since it kills plants, it is toxic, but last August, the EPA released its formal finding that, after 17 years of study, the substance does not put human health at risk when used properly. Some of those studies have shown 2,4-D can damage human eyes and skin, and it has been found to be dangerous to birds and fish. Some have argued there are links between 2, 4-D and cancer, specifically non-Hodgkin's lymphoma, but the studies have been contradictory, and the EPA's finding dismisses the link.
For Holt and others in his group, that's more than enough uncertainty to question dumping 100 tons of the stuff in the lake. "There are a lot of questions, and all should be well considered," Holt says, "but at this point, that hasn't happened."
Dye says the risks of leaving the milfoil alone are greater than the tried-and-true herbicide. He also says that follow-up treatments will not rely on chemicals.
"This has been ongoing for the past eight years," says Dye. "Lots of people want to get rid of the milfoil. We have a vocal minority and a silent majority, and the silent majority wants to get rid of the milfoil."