Endothall is a selective contact herbicide that is being applied to the Cayuga Inlet in the continued effort to eradicate Hydrilla. Endothall kills the growing green vegetation that it contacts in the water by disrupting photosynthesis. Hydrilla is much more sensitive to the effects of endothall than most native plants. The chemical degrades naturally by bacterial action in the water and has a half-life ranging from 5 to 8 days. The commerical name is Aquathol K (active ingredient dipotassium endothall 40.3%). We obtain Aquathol K from United Phosphorous, a company based in Pennsylvania. Read more about endothall and view the Aquathol K label providing information about its legal use.
During the 2011 treatment season through the 2015 treatment season, endothall was applied in the Cayuga Inlet, the Flood Control Channel, Treman Marina and the lower reaches of Cascadilla and Six Mile Creeks. Endothall has been applied to Fall Creek starting from the 2013 treatment season to the 2016 treatment season. Licensed herbicide applicators apply the herbicide using a boat where possible and backpack sprayers in less accessible areas. The application equipment uses hoses and nozzles to inject the herbicide application below the surface of the water for the entire treatment.
During the application process a cloud or mist may be seen behind the air boat. It is known as "prop wash," which refers to the column of air and water emitted rearward from an air boat by the propeller. It is not related to the herbicide chemicals or application in any way.
Drinking water quality is closely monitored.
Swimming is prohibited in the treatment area until one day after the endothall application.
Endothall is poorly absorbed through the skin. Minor skin and eye irritations have been reported in people who are regularly exposed to concentrated levels of endothall in the course of their work, but no effects have been observed as a result of occasional exposure. Swimming outside of the treatment area is not affected.
Fishing is unrestricted.
Use of lake water for irrigation restricted.
Because endothall is an herbicide, do not use lake water for irrigation or spraying of grass or agricultural crops until at least 7 days after the application.
Water use restrictions were supplied along the water with the yellow herbicide warning signs.
Last updated October 20, 2016