Fluridone is a selective systemic herbicide that is being applied to the Cayuga Inlet in the continued effort to eradicate Hydrilla. Fluridone has been used to control invasive plants, including Hydrilla where it has shown up in New York lakes and other parts of the United States. The chemical is a slow-acting herbicide, effective over long time periods at very low concentrations. It is absorbed through submersed shoots and roots, and is then transported throughout the plant, where it acts by inhibiting photosynthesis. Evidence of plant damage may appear within 7-10 days of application, but 30-90 days of continuous application is required to kill the plants.

Health Impacts

There are no restrictions on drinking, fishing, swimming, boating, or domestic use of fluridone-treated water at the concentrations to be applied in the inlet.

  • Fluridone will be maintained at a concentration of 3-5 ppb (parts per billion) in the treatment area. This application rate is far below the maximum contaminant level (MCL) of 50 ppb allowable for fluridone in drinking water in the state of New York.
  • The Bolton Point Water Treatment Plant is located 3 miles away from the treatment area. Samples from the water supply intake are being analyzed regularly thrughout the treatment period, but concentrations of the chemical are not expected to approach the MCL. Analytical results are posted here and at www.tompkinscountyny.gov/health.
  • Note: water taken directly from the lake, like other surface waters, should never be used for drinking.
  • Fish and birds tested have not shown any negative health effects as a result of acute or long-term exposure to fluridone. The chemical is absorbed into the tissues of some fish, up to the concentration in the surrounding water, but not to levels toxic to humans. Fluridone levels in fish will decrease after the herbicide treatment ends.

Fluridone is not considered a carcinogen or mutagen, or to impact immune or endocine functions

  • However, fluridone can cause mild to moderate skin and eye irritation at high concentrations.

Treated water may be toxic to domestic plants.

  • While fluridone is not equally effective on all plants, it can still inhibit photosynthesis in plants other than hydrilla, so you should not use water taken directly from the inlet to water plants until after the end of the fluridone treatment.

Restrictions can be found along the water on the yellow and white herbicide warning signs.

Last updated May 29, 2015