Hydrilla, an extremely aggressive aquatic plant, was found in the Cayuga Lake Inlet in Ithaca in early August 2011. National experts on Hydrilla and local resource managers/stewards agree that an approach including the use of herbicides is the best method to achieve eradication of Hydrilla. Total eradication of the plant is expected to take 5-8 years.
The herbicides endothall and fluridone are being applied to Cayuga Inlet during the summer of 2012. Endothall was applied in a one-day treatment on June 26th, 2012. Fluridone application began on July 12th and will continue for at least 30-90 days for effective destruction of the Hydrilla plants.
Water quality monitoring is conducted during the herbicide application periods. Water samples are being collected in the treatment area and at selected sites in the lake, as well as at the Bolton Point water intake. Monitoring results are updated online each time new sampling results are available.
The herbicide endothall was also applied in October 2011.
Fluridone, a selective systemic herbicide, is the second part of the 2012 Hydrilla treatment strategy in Cayuga Inlet. The chemical is delivered by continuous drip metering equipment at three upstream locations (map), and by a one-time deployment of pellets in shallow water areas (map), with the intention of maintaining a concentration of 3-5 ppb (parts per billion) of fluridone in the inlet for at least 30-90 days.
Monitoring Results (PDF, 15KB, 17" x 11"; Final update 11/28/2012)
Health Effects Information (PDF, 80KB)
PDF Maps: Cayuga Inlet Treatment Area and Monitoring (PDF files, 8.5" x 11", 580KB each)
Larger Image PDF | Larger Image PDF
Endothall Application, June 2012
PDF Downloads: Monitoring Results | Health Effects Information | Treatment Map
What is Endothall?
Endothall is a selective contact herbicide that has been applied to the Cayuga Inlet in the continued effort to eradicate Hydrilla. Endothall kills the growing green vegetation that it contacts in the water. Hydrilla is much more sensitive to the effects of endothall than most native plants.
The chemical is applied below the surface of the water. Licensed herbicide applicators Allied Biological deployed the chemical throughout the marked treatment area on June 26, 2012, completing the application in one day. The chemical degrades naturally by bacterial action in the water, and has a half-life ranging from 5 to 8 days.
Water samples are being collected in the treatment area and at selected sites in the lake, as well as at the Bolton Point water intake and distribution system entry point. The Monitoring Results spreadsheet is updated each time new sampling results are available. The New York State Drinking Water Maximum Contaminant Level (MCL) for endothall is 50 ppb (parts per billion); however, taking water directly from the lake for drinking is never recommended. Swimming was prohibited for 24 hours after the application, but there is no ongoing restriction.
Monitoring Results (PDF, 48KB; 8.5"x14")
Health Effects Information (PDF, 63KB)
Cayuga Inlet Treatment Area map (PDF, 807KB)