Water Monitoring Post-herbicide Application 2011
NYS Dept. of Environmental Conservation, Tompkins County Soil and Water Conservation District, Tompkins County Dept. of Health (TCHD), and the Ithaca Area Wastewater Treatment Facility worked together to monitor the levels of endothall (trade name Aquathol-K) in and beyond the herbicide treatment area. The Dept. of Environmental Conservation (DEC) and Tompkins County Dept. of Health (TCHD) developed the monitoring protocol (500 kb pdf), which is part of the DEC permit to use the herbicide. TCHD and DEC worked in tandem to get the fullest picture of the spread of the herbicide. The collected water samples were shipped overnight to a lab in Florida for analysis. The test results (48 kb pdf) were sent to Tompkins County Soil and Water Conservation District.
DEC monitoring focused on environmental protection. On DEC’s behalf, the Tompkins County Soil and Water Conservation District collected water samples from the shore at six locations (green stars) adjacent to the area of herbicide treatment (yellow outline). See larger image of DEC monitoring locations for 2011. Their focus was upstream and downstream of treatment areas as well as upstream of Cascadilla and Sixmile Creek. .
Water samples required for DEC were taken 24, 48 and 72 hours after the first and second endothall applications (the afternoons of October 11 and 12, 2011). Since endothall was still present at detectable levels after 72 hours, sampling continued every seven days until there was a “no detect” reading. The laboratory used could detect endothall as low as 7 parts per billion (ppb).
TCHD efforts focus on protecting drinking water. On their behalf, the Ithaca Area Waste Water Treatment Facility (IAWWTF) took grab samples from a boat at six in-lake locations (yellow squares). See larger image of TCHD monitoring locations. IAWWTF collected water samples 24 and 72 hours after the second of two applications. Since lab results were not available for the 72 hours sampling, water samples were again taken from the lake and shoreline on Oct 19, 2011. Even though Oct 19 test results were "no detect" , samples were taken again on Oct. 26, 2011 as a precautious. Again there was "no detect".
The lab in Florida was chosen because of its experience, which includes work for the University of Florida, and its ability to rapidly provide test results. Since it is not a NYS approved lab, two water samples are going to a NYS-certified lab, which is located in Sayre, PA. This process is called a split sample since one water sample is split in two and sent to different laboratories. The test results from both labs should be the same. The split samples were done as an extra precaution at TCHD and DEC’s request. The split samples were taken from C5 and from within the treatment area. NYS law requires that endothall levels in drinking water be below 50 parts per billion (ppb).
Bolton Point collected a sample from their intake prior to the treatment and also on Oct 17, 2011. Results of Bolton Point post-endothall monitoring
Lab test results for 2011endothall monitoring
