If the town’s application is approved, the herbicide triclopyr (trade name Renovate) will be used to aggressively stop the growth of Eurasian water milfoil in Cazenovia Lake. But some have voiced concerns: Is this chemical safe? Is this the best option?
According an intermunicipal council of town, village, and lake association officials, the answer to both questions is yes.
The EPA classifies Renovate as “practically non-toxic,” the lowest possible toxicity classification for an herbicide. This rating comes after over 20 years of testing.
“It’s a very rigorous process,” said Town of Cazenovia Supervisor Liz Moran. “All those tests have to be done using very specific protocols and laboratories that are certified and audited.”
According to a document on the town’s website, the EPA requires pesticide registrants to submit more than 100 different scientific studies and tests.
The document states that strict testing standards must be maintained by the EPA. This “helps ensure quality results in the way data is conducted, recorded and documented with appropriate quality control. These studies can also be audited by the EPA at any time to ensure data was generated and documented to support the results obtained.”
Triclopyr affects the growth of dicots, or broad-leaf plants. Of the plants most common in Cazenovia Lake, a minority are dicots. Of those dicots, one species besides Eurasian water milfoil, water marigold, is highly susceptible to the herbicide.
“The water marigold is distributed throughout the lake, so I think it will recolonize itself,” Moran said.
At several town and watershed council meetings, officials have said that native plants will grow to fill the niche vacated by the milfoil. Eurasian water milfoil is currently taking space and resources from native plant life.
The second most abundant dicot in the lake, coontail, has low susceptibility to Renovate.
The particular dilution of Renovate allowed by the EPA (2.5 parts per million) has resulted in no verified cases of toxicity to fish when triclopyr is used, according to the town’s Draft Environmental Impact Statement.
According to a document on the town’s website addressing submitted questions regarding triclopyr, the herbicide will not be harmful to humans.
“Triclopyr is not considered to be a cause of cancer, birth defects, or genetic mutations. Nor is it considered likely to cause systemic, reproductive, or developmental effects in mammals at or near concentrations encountered during normal human use,” the document states. “However, Washington State Department of Health considers it prudent public health advice to minimize exposure to pesticides regardless of their known toxicity.”
Possible alternatives:
The town of Cazenovia’s Draft Environmental Impact Statement lists several alternatives to herbicide and their reasons for not using them.
No action
If no action is taken, Eurasian watermilfoil will continue to dominate aquatic plantlife and recreational use will become increasingly impaired. This would damage the economy of the town as lake front properties lose value.
Mechanical harvesting
This solution provides a temporary reduction, but can actually spread the species as fragments become new plants in new areas of the lake.
Grass carp
While a sterile form of grass carp can be used to eat aquatic vegetation, this plant-eating fish prefers other native plants to Eurasian watermilfoil. This could result in a reduction in all plants in the lake, not just invasive species.
Suction dredging
This method, while practical for small areas, is slow, labor-intensive and prohibitively expensive for use in the entire lake. This option is still a valid possibility for lakefront property owners.
Benthic barriers
These barriers prevent light from reaching the sediment surface and crush vegetation underneath, preventing and stopping the growth of plant life. This is another method that individual homeowners might employ.
