A dangerous toxin from blue-green algae made its way into treated drinking water in New York state for the first time ever.
“Cayuga County officials health and municipal officials reported [last month] that a dangerous toxin released by an algal bloom in Owasco Lake in the Finger Lakes region, had survived the treatment process in two different plants, and made it into the supplies being distributed to homes and businesses. Combined, the two systems serve more than 50,000 customers in Cayuga County,” the Democrat and Chronicle reported.
“The town of Owasco's treated drinking water had .16 micrograms per liter of toxins,” The Citizen reported, citing microcystins as the threat at hand. The county health department tested the water daily until toxins stopped showing up.
“All of the samples [were] below the U.S. EPA health advisory level for short-term exposure of 0.3 microgram per liter for the most sensitive population, which are pre-school age children,” Syracuse.com reported.
County health officials provided details on how the treatment facilities altered their processes to arrest the problem. One official said the plants “increased the chlorine amounts, which kills off the toxins. They've also increased the carbon dosage to the water, and have postponed or reduced their treatment to kill off zebra mussels. Typically zebra mussel treatment involves chlorine, and when chlorine is used outside of the water plant in the lake, the chlorine kills off the blue-green algae,” The Citizen reported.
“Toxins are inside the blue-green algae, and are only released when the algae dies off. [An official] said it's better to filter out the algae before it dies so it does not release the toxins,” the report continued.
Officials said the concentrations were so low that they did not pose a threat to public health, the Democrat and Chronicle reported. They added that the toxin is no longer detectable in water entering drinking water facilities.
Eileen O’Connor, director of environmental health for the Cayuga County Health Department, said water is drawn into treatment plants in the same area of the lake where an algal bloom had taken hold. Algal blooms are not uncommon on Owasko Lake.
“Possibly the conditions this year were better for a bloom,” O’Connor said, per the report. “There is still a lot the scientific community doesn’t know about blue-green algae blooms and what triggers them.”
Toxins produced by blue-green algae have prompted water bans in other cities, including Toledo, OH. Cyanotoxins are produced by blue-green algae. Algal blooms thrive in warm, slow bodies of water, including drought-plagued reservoirs.
“Evidence is mounting that harmful algal blooms (HABs) are increasing in both frequency and intensity. Drought conditions brought on by climate change can depress lake levels, concentrating nutrient-rich agricultural runoff in areas of low turbidity,” Scientific American reported last month.
To read more about harmful algal blooms visit Water Online’s Nutrient Removal Solutions Center.