In a public forum on March 13th, from 5:30-7:30 p.m. at the Bonner County Administration Building, the public will be updated on plans to combat invasive aquatic species in Lake Pend Oreille—and be provided with the chance to voice concerns. Bonner County is hosting the forum, which will also include the Idaho State Department of Agriculture (ISDA) and the Army Corps of Engineers. The county and agencies will highlight efforts to kill aquatic invasive weeds and prevent the introduction of quagga mussels.
Despite good intentions, efforts to control aquatic weeds with chemical herbicides are fraught with problems. These chemical herbicides are toxic substances, and pose their own threats to both human health and aquatic life.
These herbicides can potentially harm native plant species growing in or near the application sites. Plus, killing the “bad” weeds all at once can negatively impact water quality—by creating vast amounts of decomposing plant matter, dissolved oxygen in the water can be depleted, which fish need to survive. The decomposing plant matter also releases nutrient pollution into the water, feeding the next generation of weeds and increasing the chances of toxic algae outbreaks.
In past years, diquat dibromide (a.k.a. Reward), endothall (a.k.a. Aquastrike), glyphosate (a.k.a. Rodeo) and florpyrauxifen-benzyl (a.k.a.ProcellaCOR) have been used in attempts to control or eradicate invasive weeds in Lake Pend Oreille, along the shoreline, and on breakwaters.
Since these herbicides are pollutants, and are discharged from a specific point, they are called ‘point source’ pollution—and are therefore regulated under the Clean Water Act. As part of this regulatory process, discharges must adhere to stipulations in the Idaho Department of Environmental Quality’s (IDEQ) Pesticide General Permit. This permit currently allows an exemption for herbicide discharges that are under 80 acres. Eighty acres is pretty big… roughly equivalent to 60 football fields! This means that herbicide applications that cover less than 60 football fields are not regulated or coordinated.
In addition to agencies applying these pollutants, homeowners associations and individuals can also hire private companies to apply herbicides to the water near their shorelines. This means that several herbicide applications could happen in the same part of the lake without anyone knowing about the duplicative applications and oversaturation of the chemicals. Therefore the chemical labeling requirements on these chemicals, designed to protect human health and aquatic life by specifying the concentration of chemicals that are allowable, are undermined and ineffective.
The good news is that IDEQ is working to update the Pesticide General Permit, and the Idaho Conservation League (ICL) is urging them to close this loophole! While ICL and IDEQ hoped the new permit would be completed this winter, they are behind schedule. We now understand that the new permit will be published for public comments in the late summer or early fall. ICL will certainly be weighing in, and urging our concerned community members to do so as well.
In the meantime, we can all advocate that herbicide applicators and the agencies, homeowners associations, and individuals that hire them take extra precautions to ensure no duplicative chemical applications occur this year. Not only would it waste their money, duplicative herbicide discharges can harm people, fish, and other aquatic life.
The ISDA has responded to past public pressure and agreed to avoid discharging chemicals to areas near public drinking water intakes. They also employ hand pulling at City Beach and in Sand Creek. They have honored this agreement for many years and deserve our gratitude for that!
Hand pulling and bottom barriers are very effective ways to control weeds in specific areas like boat paths, docks, and swimming areas. These methods pose no risk to human health or water quality, and we encourage their prioritization by agencies and private entities alike. Since it is impossible to eradicate these weeds from a system as large and complex as Lake Pend Oreille, we need to learn to live with them outside of our immediate surroundings, and use these non-toxic methods in our immediate surroundings.
In the face of ongoing challenges with water quality and invasive species in Lake Pend Oreille, it’s crucial that we carefully consider the methods used to control them. The forum on March 13th is an excellent opportunity to learn more, share concerns, and advocate for solutions that prioritize the health of our lake and its ecosystem. We encourage everyone to attend and make their voices heard!