MAHOPAC, N.Y. - Imagine buying a lakefront home-paying extra for the privilege of living near a lake and all the amenities that come with it, only to discover the lake has become unusable thanks to an annual summertime invasion of toxic blue-green algae.

Such is the plight of residents in the Lake Casse Park District.

“For about two and a half years it’s been like this,” said Stacey Kelly, a member of the park district’s advisory board. “It came out of nowhere. Something has changed in the ecosystem or the area to cause this, but we haven’t been able to figure it out.”

Sign Up for Mahopac Newsletter
Our newsletter delivers the local news that you can trust.

Bill Siclary, another board member, said, “We want to get the lake clean so everyone can use it. It’s just a shame. We use it maybe two weeks out of the whole year.”

Last Wednesday, Aug. 7, local elected officials held a press conference on the Lake Casse beach, pledging to get to the bottom of the problem and calling on the federal government to step up and provide funding to help remedy the issue.

“The Putnam County Department of Health tests it weekly. If they come and it fails the test, we have to close it until they come back,” Kelly said. “They’ve taught the lifeguards what to look for. So, if the lifeguards get here and see that it looks a little iffy, they close it right down. They don’t want to take any chances. It was open two weeks in June, and then by the Fourth of July, it was closed again. Blue-green algae have been in bloom for the last month. It might get open for a day or two here and there and then it gets closed right back up.”

Blue-green algae can cause gastrointestinal distress, respiratory issues, and skin rashes. It can be deadly for pets. The cause of the outbreaks in Lake Casse remains a mystery.

“They don’t know what it is [that is causing it]. Bill [Siclary] has gone to a couple of training sessions about it but they haven’t been able to pinpoint it,” Kelly said. “We’ve been told it could be fertilizers, septic systems leaking into the lake, road runoff. Last year, all lakes in Putnam were closed with it at one time or another except for two.”

“The septic doesn’t help,” Siclary added. “The salt from the roads, everything is a contributor.”

County Executive MaryEllen Odell said that as of Aug. 7, Putnam County had more than 90 days of lost recreation due to blue-green closures at public beaches.

“In 2018, we had over 45 percent of the statewide totals for harmful algal blooms,” she said. “Putnam County has three lakes that were selected under Gov. Cuomo’s HABs initiative, where he funded this project with $64 million in order to get some studies done for the local beaches.  We here in Putnam County are looking at Lake Carmel, Palmer Lake and Putnam Lake-they’ve been targeted to receive funding. However, it’s not enough. So, we urge the federal government to continue funding this very important project. It’s a severe public health issue.”

County Legislator Neal Sullivan, who represents District 9, which includes Lake Casse, said the problem is especially troublesome for young children and pets.

“It can result in serious health concerns, especially for small children, and it can be deadly for dogs because they ingest more water and groom their coats after being in the water,” he said. “Common causes are untreated stormwater runoff and leaking septic systems. Weather can play an important role. We often see these large alga blooms after a period of drought followed by heavy storms. It’s unfortunate that Lake Casse has experienced this problem for such a long time, but I’m glad that we are bringing attention to it today.”

Town Supervisor Ken Schmitt said the best way to solve the problem is to get all levels of government to work together.

“It’s important that we continue to bring awareness,” Schmitt said. “This is a beautiful lake and we don’t want to lose it. We need to attack this collectively from the federal, state and local levels to identify the source of the problem and aggressively pursue whatever avenues we may have to address. Because if we lose this lake, we have 450 homes that are part of this association that will lose the opportunity to swim in it, to fish in it and to recreate around it.”

Siclary said the park district has tried several methods to eradicate the toxic algae blooms but nothing has worked.

“We started with an aeration system first. It didn’t work at all,” he said. “Then we went to copper sulfate. That worked for maybe a week or two and then we were right back to where we started.”

Odell said there have been a lot of mandates from the federal government to look at these problems.

“But there’s no funding to support it,” she said. “The state has funded some studies. There is one happening at Lake George. It’s become an international problem because it’s in Canada, too. It’s a very interesting topic, but also a very concerning one at the same time. If the money is spent in the right place in research, that will be very, very helpful. But it all starts at the federal level.”

Last year, the Mahopac Golf and Beach Club on Lake Mahopac was closed twice by the county health department due to blue-green algae scares, but Lake Mahopac Park District’s Advisory Board Chair Ed Barnett said it wasn’t the toxic algae people were seeing.

“They closed down the golf course [beach], but it wasn’t blue-green algae,” he said. “It was just regular seaweed growth at the beginning of the summer. I told [health department officials] to make sure before you drive everyone crazy.”

Barnett said there is a big difference between the two lakes. Lake Mahopac is a deep, natural lake (66 feet at its deepest), while the shallower, man-made Lake Casse waters get really warm in the summer and can become a natural breeding ground for the toxic blooms.

Barnett said blue-green algae has not been an issue in Lake Mahopac this summer.

“There’s been no indication,” he said. “So far, so good.”