After a "quiet" week with minimal harmful algal bloom reports from volunteers and the public, activity picked back up again today, with several reports and samples collected from the west side of the lake. Photos coming in show areas of surface streaking and shoreline accumulations of algae from several spots around the lake. We are also starting to get more algae bloom reports from the southern half of the lake.

And while the sunny, calm, warm weather forecasted for the next several days will be great for those end-of-summer activities, it is also ideal conditions for blue green algae (cyanobacteria) to pop up. As we cannot predict when or where blooms may appear, please continue to use your visual indicators before recreating in the lake.

September has been the month when we have experienced our most significant bloom events, and last year was no exception, with many blooms being designated as "Confirmed with High Toxins". This year, the DEC will not be releasing toxin (microcystin) values associated with the samples collected until the end of the season, but is updating the  NYHABS webpage when a bloom is confirmed with high toxins.

What does this mean for our drinking water?

The six Canandaigua Lake water purveyors (the City of Canandaigua, the Village of Newark, the Village of Palmyra, the Village of Rushville, the Town of Gorham, and Bristol Harbour) 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. Samples of the public drinking water are collected twice a week and sent to a State approved laboratory to determine if toxins are present. To date, all finished water samples have been non-detectable for the microcystin toxin. If there is a detectible value in the finished drinking water (above 0.3 micrograms per liter), the DOH, in cooperation with the affected public water system, will notify the public when alternative water should be used for drinking, making infant formula, making ice, brushing teeth and preparing food. CLWA and the Canandaigua Lake Watershed Council will strive to assist in getting the word out from the DOH in the event that this situation arises.

Users of private water systems (those not on municipal water, who are using a surface water intake or nearshore well) face further challenges when there are high levels of blue green algae and cyanotoxins present in the lake due to the varying capabilities of household treatment units to remove cyanotoxins. Private system users are encouraged to actively monitor their waterfront and pay close attention to the HAB reports in their area in an effort to make informed decisions on their drinking water source.  With the increased reports of algae in the southern half of the lake, where there are private water supply systems- individuals need to be cautious and work with their water treatment system company to determine if their system will be sufficient.