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Facts on Skaneateles Lake Blue Green Algal Bloom (HAB or Harmful Algal Bloom) September 2017

A Report from the Skaneateles Lake Association (SLA)


1) Suspicious green algae were found suspended in water at the lakefront of a Skaneateles Lake Association (SLA) member at Widewaters, about 6 miles south on the East side of the lake on Tuesday, 9/12/17. This property owner notified the SLA by Email and a team of SLA Board members inspected the site.  This event did not appear very suspicious for a HAB as there was only a visible suspension of green particles in the water (this had been noticed before in recent years, but usually was short lived). However, this time a decision was made by Bob Werner and Buzz Roberts to go ahead and take samples just to be sure, since the SLA team had the equipment and expertise from participating in the statewide CSLAP lake monitoring program on a regular basis.

 2) The sample was sent to Greg Boyer’s Lab at ESF as directed by the DEC . Greg is a well-known expert on HABs and runs one of the few labs capable of such analysis in the state. On Friday 9/15 the results revealed a positive indication of a HAB with elevated levels of blue-green algae (60 ug BGA-chl/liter), well above the DEC alert level of 10-20 ug BGA chl/liter. This was immediately reported to SLA Board member, Dr. Bob Werner. Toxin testing available on Saturday, 9/16 showed an elevated microcystin level at 12 ug/L, at or slightly above the DEC alert threshold for recreational contact (swimming) and well above the level allowed in tap water.

 The same day there was widespread visible green scum along the lakeshore. This was quite worrisome since the original samples taken by the SLA appeared to be a dilute suspension of green particles in the water column which had not yet coalesced into a green scum or paint-like appearance on the surface of the water.

 Immediately, representatives from the SLA met with Rich Abbott at the City Water Dept. in Skaneateles and with the Skaneateles. Town Supervisor, Jim Lanning and Town Clerk, Janet Aaron. Microcystis colonies were again confirmed in the City Lab with both Rich Abbott and Bob Werner examining another sample under the microscope brought in from Bob’s waterfront about 4-5 miles down on the West side.

The County Health Dept. was notified along with the local media and Town and SLA websites to warn people not to swim or drink the lake water directly. Syracuse City residents and Skaneateles village residents that obtained their water through OCWA were told it was OK to drink their tap water, as posted on, that same day.

Additional samples were taken at the village pier and steps to the village swim area on Sat, 9/16 by the NY Federation of Lake Associations as directed by the DEC and were hand delivered to SUNY-ESF for testing. These samples also showed elevated levels of blue-green algae (400-600 ug BGA-chl/liter) and elevated levels of the liver toxin microcystins (120-170 ug/L). These numbers were reported in Sunday’s These microcystin levels were considerably higher than the original more dilute samples taken by the SLA team on Tuesday 9/12.  Algal neurotoxins, occasionally found in other blooms in New York State, were not present in any of the Skaneateles Lake samples. Combined, the results indicated the presence of a toxic blue-green algae bloom (HAB) in Skaneateles Lake, potentially being accumulated along the shore by wind and wave action.

 3) Sunday, 2/16, visible inspection of the lake showed resolution of the confluent areas of green scum along the shoreline, at least by this observer, along the west and east shorelines south to about 7 miles. However, heavy green particle suspension was present all over and in mid- lake about 5-6 miles down even in deeper offshore waters. There were visible streaks of greenish particles but not the actual layered scum on the surface that was visible just the day before. This had broken apart.

 Impacts of the bloom

Discussion with Dr. Greg Boyer 9/18 /17, Professor SUNY ESF

1) A toxic HAB event was confirmed for Skaneateles Lake. The algal species involved was 99% Microcystis aeruginosa and measured hepatotoxin (liver toxin) concentrations (microcystin) exceeded the levels for drinking water and recreational contact (swimming).

2) Drinking water obtained via OCWA via the tap was considered to be safe. The allowable levels in tap water for the liver toxins are <0.3 for children and <1.6 for adults (10 day average), OCWA has a number of options available, including using a deep water intake, mixing the water with Lake Ontario water, flocculation of the cells, or the use of activated carbon for removal of the toxins from the water.

 3) In contrast, residents who obtain their water directly from the lake should be using bottled water during the bloom event. Many local residents’ water intakes are located near shore, in shallow water (10 -20 feet) and do not have the technology to remove the cells and toxins from the water. Routinely, blooms mix at least to depths of 20 feet.

Residential UV light systems may kill the cells but not necessarily remove the toxins from the water. Residential activated carbon systems are also generally insufficient to remove the toxins unless the system is expensive (thousands of dollars) and properly maintained.  Point-of-use filters commonly found on sink taps are insufficient at removing the toxins. Filtration and reverse osmosis do not remove the toxins once they have been released from the cell but may be beneficial in keeping the cells (about 7 microns in size) themselves out of the residential system.

These toxins are not destroyed by heat (e.g., boiling water does not work) and use of chlorine is often complicated by the presence of other organic material in the water from the bloom. These microcystin toxins do linger in the lake water even after the visible bloom is gone but become more dilute and dissipate with time. They do not remain forever.

4) Special care needs to be taken with pets.  Levels above 100 ug/L in bloom events are in the “Dead Dog” range, according to Greg, where pets can die due to the toxins accumulating in the fur and the dog’s normal tendency to lick its fur to clean itself. Pet owners should wash off their pets with a garden hose if the animal has been swimming in green water.  For more information regarding pets see

5) Residents should avoid contact with all blooms and should not be swimming in any water where a bloom is present. The bloom will eventually go away and the water should be free of suspended green particles (usually weeks, not days) before resuming swimming or drinking the water.

A small fraction of the population (<1%) may also be allergic to contact with the bloom’s cells themselves (separate from the toxins). This may impact the use of the water for showering, washing of hands, dishes, or clothes using raw lake water during an active bloom event. The response is generally a skin rash.  Also, he does not recommend people who might be immunosuppressed from age, medication and/or disease use raw lake water for any of these activities during a time when a bloom might be present.

Discussion with Lisa Letteney, 9/18/17 Director of Environmental Health,                            Onondaga County Health Department:

 The City is actively monitoring the water at the intakes on Skaneateles Lake and also as the village trunk comes off the main after it exits the lake. She said if anything changes the County/City will alert the public.

 We discussed some of the same issues brought up with Greg Boyer and she agreed to send out another Alert to keep the public informed and advice people not only on municipal water but also those who live on the lakeshore and draw directly from the lake.

We also discussed the possibility of setting up a Hotline # so in the future they could be immediately notified of a suspicious algal bloom and it can be immediately tested by the County/City authorities- so HABs aren’t missed! We were fortunate this time to have the SLA act proactively and discover it before the nasty green bloom appeared!

We both agreed that it’s important for the County Health Dept. to stay in touch and advice accordingly since there seems to be much misinformation being dissipated along with misunderstanding of the issues involved with HABs.

 Lisa agreed that subsequent Informational Alerts from the County Health Dept. could be expected.

 Submitted by:   Paul F. Torrisi, MD, President, SLA


Potentially Toxic Algae Blooms

A potentially toxic strain of blue green algae has been confirmed on Skaneateles Lake.  Further tests will be completed next week to determine the level of toxicity.  People and their pets are cautioned about swimming or drinking the water until further testing is completed.