Water Quality Update for September 22, 2023

Volunteers logged a total of 70 shoreline surveys this week (reporting week from 9/15 – 9/21), 13 of which were bloom reports. The vast majority of the bloom reports came through on Wednesday, 9/19 and Thursday, 9/20 and were reported as small to large localized blooms. Volunteers reported areas of surface streaking, in some cases rather heavy.

This is the time of year we may see isolated blooms when the conditions are just right – dead calm winds are an early indicator that cyanoHABs may pop up.
We received the certified toxin results from the blooms that were reported the week after Labor Day- when Canandaigua Lake had its first significant outbreak of the season. Analysis was run for microcystin (the toxin associated with cyanobacterial blooms) from several bloom samples collected on 9/6 an 9/7.

We do not run toxin analysis on every sample collected during HABs season, but we find value in running this analysis for the first major bloom of the season. We strive to get a variety of conditions, from open water to light blooms, to major pea soup-like conditions. Results from this sampling round in early September did have detectable toxins, in most cases the shoreline areas were over the DEC threshold for “high toxins.” This further reiterates that blooms should be avoided to protect public health.

Our municipal water purveyors have been routinely testing public drinking water supplies for the microcyston toxin and all results have come back as “Not Detect”. Please see write up below for further information on cyanoHABs and drinking water.
Please continue to use your visual indicators to look for signs of an active bloom situation before recreating in the lake- surface streaking, green, discolored water, or surface scums. Calm days (no wind) seem to be more favorable for the rapid proliferation of cyanobacteria and resulting blooms. Please email HABs@canandaigualakeassoc.org with any questions you have.

Drinking Water Testing
Our five municipal water purveyors (the City of Canandaigua, the Village of Newark, the Village of Palmyra, the Village of Rushville, the Town of Gorham) are working alongside the Geneva District Office of the Health Department and the New York State Department of Health to monitor the public drinking water for the presence of toxins associated with harmful algal blooms. Water quality information and data is exchanged between the water purveyors, health departments, and our local watershed groups (the Canandaigua Lake Watershed Council and CLWA) to keep all partners up to date on the current lake conditions. All results from this summer’s toxin testing of municipal systems have so far come back as non-detects. CLWA publishes the weekly results on our website, and the results can be found here. We also maintain a webpage with information for both municipal systems and for private water system users, which can be found here.
Read more about cyanoHABs and Drinking Water