The harmful algal bloom that was identified on Lake George and confirmed by the state Department of Environmental Conservation earlier this month was likely triggered by a combination of warm temperatures and calm conditions, a DEC scientist said during Tuesday’s meeting of the Lake George Park Commission. Still, several commissioners and members of the public remained concerned about the nutrient levels in the lake.
During Tuesday’s meeting, held via Zoom videoconference, DEC Bureau of Water Assessment Management director Jackie Landrum said the bloom diminished after the initial period when it was identified Nov. 7 by the Lake George Association.
“It did diminish after that initial very still, very warm period,” Landrum said, “but there did seem to be very small, residual sorts of blooms the following weekend.”
Landrum also said that after the bloom was initially reported, DEC has received photographic evidence of a bloom found two weeks earlier on Oct. 23.
Samples from the bloom were sent to three different labs for toxin analysis, which determined the toxin level was below the EPA’s 10-day drinking water health advisory level of 0.30 micrograms per liter for sensitive populations.
Still, Lendrum advocated a cautious approach.
“Every scientific method can only measure to a certain level,” she said. “To say that something is ‘absolute zero’ is really impossible. Although we didn’t detect toxins, we’re being very careful about messaging, because not being able to detect toxins should not give people false comfort that it’s therefore safe to drink untreated lake water, or safe to let your dog go swim, or if you’re swimming or boating at this time of year.
“We continue to be really careful to message to folks to know what a harmful algal bloom looks like, even the small, shoreline scums. Know what they look like, keep your animals out of them, take a picture and send it to us so that we can know what’s happening.”
Lake George Park Commission Executive Director Dave Wick said the commission has been concerned about a potential harmful algal bloom since one was confirmed in fall 2017 on Skaneateles Lake, considered a “sister” lake to Lake George because of the similar conditions.
Lendrum said the conditions that preceded the bloom, especially the calmness of the lake in the days leading up to it, were largely similar to the conditions on Skaneateles Lake in 2017.
“What we are focused on was understanding where the lake was from a stratification perspective,” she said. “Was it turned over, looking at temperatures in the lake and air temperatures. Also, the stillness that was happening on the lake at that time. It was a particularly calm period of a couple of days.”
Board of Commissioners member Cathy LaBombard questioned how the nutrient level in the lake, especially in regard to septic systems, could have helped trigger the bloom.
“It’s feeding on something,” LaBombard said. “It just upsets me to a point where nobody wants to bring up the word ‘nutrients’ from septic systems that aren’t working properly on the lake. The FUND [for Lake George] has done a study, and it’s almost like two-thirds of them aren’t working like they should be. Maybe they are failing. To me, it just would not have been a very difficult thing to have taken some kinds of readings to find out if there is indeed an overload of nutrients in some of those areas.”
Lendrum said that while the nutrient level likely was a factor, testing an isolated sample for nutrient levels would not help in formulating a hypothesis, as a longer time scale would be needed for comparison and analysis.
“Anything you can do to keep nutrients out of Lake George will benefit the lake — not just from a harmful algal bloom perspective, but regular green algae or clarity, any of those things that are going to keep your lake the beautiful water body that it is,” she said.
Carol Collins, one of the leaders of the Assembly Point Water Coalition, echoed Lendrum’s sentiment.
“It’s important to realize that nutrients play an important part in this,” Collins said. “It’s also important to understand that these type of algae have this internal storage capacity for holding onto nutrients for such a time that they will bloom. These are all factors that are part of this.”