Low levels of harmful algal bloom toxins were detected in the city of Auburn's drinking water, which comes from Owasco Lake, on Friday, Sept. 22, according to the latest results posted Monday on the Cayuga County Department of Health's website.
The department reported levels of 0.17 micrograms per liter, which is still considered safe to drink.
The U.S. Environmental Protection Agency's 10-day health advisory guideline for vulnerable populations is 0.3 micrograms per liter of microcystin, the toxin most commonly found in Owasco Lake's harmful algal blooms. Should drinking water levels be detected at 0.3 or higher, local municipalities who purchase water from Auburn have emergency plans in place to provide water to residents.
Despite the result for treated water, the untreated lake water entering the plant showed no signs of toxins in the Friday morning test. Cayuga County Health Department Director Kathleen Cuddy said based on the EPA's guidelines for detection, test results are considered more accurate at 0.3 micrograms per liter or greater.
As a result of the Friday morning result, a second sample was taken in the afternoon and results showed toxins came back with non-detect levels in the raw and drinking water. Cuddy said results from the Friday morning test came in around 5 p.m. that same day, and to make sure it was a likely anomaly, the department took a second sample. Results from the state Department of Health's Wadsworth Center in Albany came back Saturday morning showing no detection.
"The two samples were taken within 12 hours of each other," Cuddy said. "It just reinforces what we suspected was likely an anomaly."
Harmful algal blooms are a kind of bacteria that usually crop up in water bodies during late…
With state funding, the city installed a temporary powder activated carbon treatment system, which is supposed to keep algae toxins at bay. The system is still up and running, Cuddy said.
The town of Owasco's water treatment plant continues to show no signs of toxins in the untreated and treated water. It too, has been running its algae toxin treatment system, which uses granular activated carbon.
The department will continue its testing of the water three times per week.
"We certainly would give consideration to doing more if the information appeared some sort of a detection or more frequent detection, but even the raw water has been really good for non-detect in microcystin," Cuddy said.
Meanwhile Skaneateles Lake water continues to be clean. Test results released on Sunday and Monday showed no detection of toxins "at all points of sampling including those that are representative of drinking water reaching customers of the system," according to a joint statement from the Onondaga County Health Department and the City of Syracuse Department of Water.
State and local officials will continue daily testing of the Skaneateles Lake water until samples return non-detect consistently.