Around this time of year folks are usually enjoying one last dip in Lake Lincolndale.

But this Labor Day weekend, that was simply not an option at the Somers waterfront community.

The culprit? Floating scums of blue-green meanies.

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Blue-green algae (BGA), aka photosynthesizing organisms known as cyanobacteria, are not in themselves harmful, but some strains can produce toxins that can affect the liver, kidneys, or nervous system.

These particular blooms appear to be dissipating at the 20-acre manmade lake and while tests have showed no toxins present, the Westchester County Health Department decided to temporarily prohibit swimming there just to be on the safe side, said Michael O’Keefe, who chairs the board of the Lake Lincolndale Property Owners Association (LLPOA).

Harmful Algae Blooms (HABs) can cause rashes, eye irritation, and nausea in humans. The toxins, when present, can be fatal to pets, livestock, and waterfowl.

The smelly and unsightly intruders can appear suddenly and without warning, resemble floating pea soup, and also be white, brown, red or blue.

Small BGA blooms in past seasons were spotted in the cove adjacent to Lakeshore Drive South, near Lovell Street.

They didn’t impact the lake in general and “were well away from the swim area. 2019 was different,” the LLPOA said.

“We’ve had them come and go, but never as widespread as this, or seen them stick around this long,” O’Keefe said, adding that this was the first time he knew of the lake being closed to swimmers.

In late May, the association began its bi-weekly Citizens’ Statewide Lake Assessment Program (CSLAP) testing. Things looked great for the upcoming summer season. However, in mid-June a suspicious bloom was spotted near the cove, sampled and found negative for toxins. It waxed and waned throughout July—declared by the National Oceanic and Atmospheric Administration (NOAA) as the hottest month on record—until much larger blooms were detected in “numerous areas around the lake.” They also tested negative for toxins, but, the LLPOA reported “it was obvious” there was a larger problem brewing.

In early August, tests confirmed a BGA of the species Anabaena (also called Dolichospermum) although, again, no toxins were discovered.
As a precaution, swimming was banned and the LLPOA Beach Committee, Lake Management Committee, and the county have been keeping a close eye on the situation. Hence, the decision to keep the status quo as the swimming season drew to a close.

The Lake Purdys community stepped up with an offer of swimming for heartbroken would-be waders.

(Taking a stroll, or walking the dog, on the lakeshore is still fine just so long as you—or Fido—don’t play in the water. Warning signs have been posted to that effect. As usual, no pooches are allowed on the sanded beach.)


Like Somers’ Lake Shenorock, Lake Lincolndale has fallen prey to eutrophication, a process that, over time, turns lakes more shallow and prone to harboring weeds and algae.

Climate change could be a factor, but Lake Lincolndale’s algae and weed woes are more likely due to stormwater runoff, which contains loads of phosphorus and nitrogen—key components in lawn and garden fertilizer.

The LLPOA had tried to combat this by stocking weed-eating carp. Unfortunately, the hungry fishies did such a good job decimating the weeds that the lake’s ecosystem got off-kilter, allowing algae to proliferate.

The carp have now died off and some weeds are returning.

Because of the rise in BGA blooms in the past few decades worldwide, there has been increased awareness—and tracking—of the problem.


The association treats the lake with Cutrine algicide about once a month to reduce filamentous algae mats and takes other proactive measures such as the removal of cattails, a wetland plant with a unique flowering spike found in marshes and the edges of ponds. “Cutrine is also usually effective against BGA blooms, but conditions were right for a very aggressive bloom,” the LLPOA reported.

The organization has created a plan to mitigate nutrient loading because, it reported “using algicides to control algae only address the symptoms and not the problem. In fact, as the algae dies it releases more nutrients into the water, exacerbating the problem.”

That plan will require “the support of LLPOA members and lake residents, as well as cooperation with the town of Somers,” the organization said.
It is already aerating the water to de-stratify and bind phosphorus to the lake’s sediment.

In order to enforce aquatic buffers around the lake, the LLPOA plans to ask adjacent homeowners to stop mowing within 25 feet of the shoreline to allow aquatic plants to grow. This should slow runoff and absorb some nutrients. Home drainage, directed into the lake, would also be removed under the proposed measures.

The LLPOA is also encouraging homeowners to test their septic systems and remove “any now-illegal dry wells for their graywater.” Graywater is relatively clean wastewater from sinks, baths, washing machines and kitchen appliances.

The group has already earmarked areas around the lake where the effects of excessive nutrient loading can be seen and promised to assist homeowners in identifying malfunctioning septics.

The county regularly tests Lake Lincolndale for signs of septic seepage. The good news is that E. Coli bacteria levels are currently so negligible that they’re “not even on the map,” O’Keefe said.

However, with 400 homes in the community—and their aging septic fields and cesspools—it’s probably just a matter of time before that becomes a problem too, according to town officials.

A public hearing on the creation of a sewer district that would incorporate the R10 areas of both Lake Lincolndale and Lake Shenorock was held in August. It is to be continued on Thursday, Sept. 5, and Thursday, Sept. 12. Town Board meetings take place at 7 p.m. at Town Hall on Route 202.

The town says the infrastructure is needed because both hamlets started as summer retreats in the 1930s and 1940s and have since developed into year-round residential communities.

Because of the age of septic systems there and “limiting site conditions such as small lot sizes/high density, poor soil and shallow depth to bedrock and groundwater, many of these onsite systems are beyond their useful lives,” the town said on its website.

Decades of these conditions have affected water quality and limited recreation opportunities. 

Lake Shenorock, which was taken over by the town, “is no longer open to swimming, and has been designated as an at-risk waterbody by the NYS Department of Environmental Conservation due to high level of pollutants.”

“Although not as severe, Lake Lincolndale is also showing signs of deterioration, including algae blooms, despite the best efforts of the Lake Lincolndale Property Owners Association,” the town said.

Moving away from septic systems, the town contended, “lifts home expansion limitations, resulting in potentially higher property values and an enhanced tax base.”

According to O’Keefe, the majority of Lake Lincolndale property owners are in favor of the multi-million dollar project, which depends on whether

Westchester County allows the town to send sewage to its treatment plant in Peekskill. 

The town is pursuing $10 million in funding earmarked for sewering Lake Lincolndale and Lake Shenorock as well as other grants.

The former’s BGA blooms, based on testing, don’t appear to have anything to do with septic situation, and O’Keefe wouldn’t characterize the algae bloom’s appearance as good timing, but he did allow that “it further illustrates the need for public sewers.”

Calling it “vital,” the LLPOA said it is working with the town to seek funds and enact a stormwater management plan and system like the one recently installed at Lake Shenorock.

It is also asking folks not to use fertilizers, saying “If it goes on your lawn, it will certainly end up in the lake.”

Finally, it is asking all Lake Lincolndale residents to support efforts “to keep the lake clean and beautiful” by joining the association.

At present, only 25 percent of Lake Lincolndale homeowners pay dues to maintain what the LLPOA calls “the centerpiece of our community.”

“It’s not enough,” the organization said.

For more information, or to join the LLPOA, contact O’Keefe at 914-310-6628, or email him at; or LLPOA President Rebecca Wintle, 914-519-7244,