Cleaning Up Our Lakes: Septics & Sewers

In 2021, the New York City Department of Environmental Protection awarded the Town of Lewisboro three grants to perform engineering studies on three specified lakes —Waccabuc, Truesdale and Kitchawan—to assess the negative 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 a 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).

These three studies conducted by independent firms (Barton & Loguidice-Waccabuc, Ramboll Engineering-Truesdale, Woodard & 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 seven of the town’s lakes in the Lewisboro Lakes Coalition (LLC) enlisted the support of town, county, and state elected officials to explore and implement these proposed wastewater solutions.

Chris Burdick, our NY State Assembly Representative, Tony Gonçalves, our Town Supervisor, and Ken Kohlbrenner from Woodard and Curran assessed the three engineering studies and came up with a proposal to size an initial project to the potentially available funding and define a possible future expansion.  Other key contributors include: Peter Harckham, NY State Senator; Erika Pierce, Westchester County Legislator; Millie Magraw, Westchester County Planning Dept. Coordinator; Tom Snow, NYS DEC; Janet Andersen, Three Lakes Council; Sue Enos, Jonathan Peter, Tadeusz Rajwer, Carol Sherwood, Susan Allport, Allison Setteneri, John Gusmano, Leah Graygor, Catherine Marino, and Tara A. Owen, Lewisboro Lakes Coalition.  

On June 8, 2023, Woodard & Curran issued their report: 2023-6-8-Lewisboro PROPOSED Sewer and Septic Plan Memo 

For densely populated communities around Truesdale Lake and the Three Lakes (Waccabuc, Oscaleta, and Rippowam), the report proposes a low-pressure sewer collection system and central wastewater treatment plant located at the Main Street town campus. The estimated cost is $40 million.  To cover these capital costs, the Town is applying for two grants from New York State and is pursuing funds from Westchester County and NYC DEP. Homeowners in the proposed sewer district would have to approve a taxing district to cover ongoing operations and maintenance costs. 

Connecting residences around Lake Kitchawan to this central wastewater treatment plant would be prohibitively expensive because of its distance from the proposed plant. The proposed solution for remediating pollution at Lake Kitchawan is to replace inadequate septic systems with “enhanced treatment units” (ETUs) at a cost of $6.25 million. This capital cost is expected to come from allocated NYC DEP funds, and, again, will necessitate the creation of a tax district to cover ongoing costs.

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.