Truesdale Lake  

South Salem, New York


In 2021, the Town of Lewisboro received a grant from the New York City Department of Environmental Protection (NYC DEP) to perform engineering studies on three of our lakes—Waccabuc, Truesdale and Kitchawan—to assess the impacts of septic systems and identify potential solutions.  The studies confirmed what decades of lake sampling data and previous research had long suggested: septic pollution is the primary contributor to the lakes’ phosphorus load, and phosphorus is the primary agent accelerating our lakes’ eutrophication (the process by which lakes age and die).

Image: one of twelve pages of detail from the linked and downloadable PDF viewable below.

These three studies conducted by independent firms (Barton & Loguidice-WaccabucRamboll Engineering-TruesdaleWoodard & Curran-Kitchawan) went beyond diagnosis to research and recommend the most feasible and effective wastewater treatment solutions—a sewer system for the four lakes in the center of Lewisboro and enhanced septic treatment units for Lake Kitchawan further south.

Following the release of the three individual reports lake residents from all seven of the town’s lakes rallied together and formed the Lewisboro Lakes Coalition (LLC) to enlist the support of town, county and state elected officials in applying for funding to implement these proposed wastewater solutions.  Lewisboro’s lakes are eligible for funding as part of the Croton watershed, one of three reservoir systems providing drinking water to the 10 million residents of New York City. 

At the moment, New York City’s Department of Environmental Protection is particularly interested in cleaning up the Croton system’s water BEFORE it reaches down-county filtration and treatment facilities, so it is an opportune moment to act.

The offices of Chris Burdick (NY Assembly) and Pete Harckham (NY Senate) were instrumental, working with Sue Enos of the LLC and Jan Andersen of the Three Lakes Council (TLC), in securing a $3mm East of Hudson Watershed Corporation grant to engage the engineering firm of Woodard & Curran to lay out the recommended sewer and septic districts. Other key contributors to the unprecedented progress so far are: Tony Gonçalves, Lewisboro Town Supervisor, Erika Pierce, Westchester County Legislator, Millie Magraw, Westchester County Planning Dept Coordinator, and Tom Snow, NYC Watershed Coordinator, NYS DEC.

On June 8, 2023, Woodard & Curran issued their report:

A low-pressure sewer collection system and central wastewater treatment plant located at the Main Street town campus is proposed for densely populated communities around Truesdale Lake and the Three Lakes (Waccabuc, Oscaleta, and Rippowam) at an estimated cost of $40 million. The Town is currently applying for grants from New York State to cover these capital costs.

Since Lake Kitchawan is a substantial distance from these other four eastern lakes, connecting residences around this lake to a central sewage treatment plant would be prohibitively expensive.

The best solution for mitigating pollution in this lake is replace inadequate septic systems with “enhanced treatment systems” at a cost of $6.25 million. As this is a far less complex undertaking and funding is already allocated (if not awarded), it is likely that Kitchawan may be designated as the first phase in remediating septic pollution in our lakes.

The Town of Lewisboro continues to study alternatives for mitigating septic pollution in the remaining Lewisboro lakes — Lake Katonah and Timber Lake (The Colony) — which are in the Croton River basin to the west. In that effort, it has engaged Westchester County and NY State officials, as well as the NYC DEP. To determine the best solution for each of the lakes and explore funding opportunities, further research will need to be conducted.

The Lewisboro Lakes Coalition, representing all seven lakes, has formed a Community Outreach group to update residents on continued progress. Information will be available through individual lake associations, on lake association websites, and in other publications. The Community Outreach group will work closely with Tony Gonçalves, Lewisboro Town Supervisor, to keep everyone informed.

Here is the latest memo in PDF format. View or download it:

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