By Michelle Calvi

The aging sewer system in Westchester County is causing significant environmental damage to local waterways, with over 1.2 billion gallons of untreated or partially treated sewage flowing into local waters last year alone. This sobering statistic was shared at the March 11th meeting of the Larchmont-Mamaroneck Local Summit, where leaders in clean water advocacy, Tracy Brown, President of Riverkeeper, and Nancy Seligson, former Mamaroneck Town Supervisor and NY Co-chair of the Long Island Sound Study Citizens Advisory Committee presented on behalf of the Westchester Coalition for Clean Water.

Much of Westchester’s sewer infrastructure dates back 80-100 years. Cracked pipes and failing systems abound. When it rains, groundwater infiltrates these damaged pipes, overwhelming treatment plants and causing sewage overflows that discharge directly into local waterways.

Seligson reported, just last week, heavy rains released over 5 million gallons of partially treated or untreated sewage into Long Island Sound and Larchmont Harbor. After a deluge, she warned, “It’s not a good time to jump in the water.”

The impact of these overflows is evident in water quality monitoring data. Both Riverkeeper and Save the Sound regularly test for fecal bacteria levels, finding that tributaries where sewer lines are leaking consistently fail swimming criteria, often by a factor of ten or more.

These sewage discharges have direct consequences for residents, causing beach and shellfish bed closures, and health risks for swimmers. Last summer alone, 49 beaches closed due to high fecal bacteria levels in Westchester County.

Beyond closing beaches, sewage pollution harms marine ecosystems by degrading habitats and triggering algae blooms that deplete oxygen and cause fish die-offs, explained Brown. Untreated sewage also introduces pharmaceutical and toxic chemicals into waterways, affecting marine life reproduction and overall ecosystem health.

Part of the problem is that the sewer collection system is fragmented, with three different owners: private property owners, municipalities, and the county. While the county is required to inspect and maintain its trunk lines, the other sections often receive attention only when they break.

The Mamaroneck treatment plant is particularly problematic with too much rainwater getting in. Thanks to the NY Sewage Right to Know Law, we learned that last year over 357 million gallons of partially treated sewage were released, primarily from this facility.

Despite these challenges, local municipalities have made substantial investments in repairs. The Town of Mamaroneck has spent over $6million and the Village of Larchmont over $2million in the past seven years to fix failing pipes. “We should feel proud of our communities that we are taking care of these issues,” Seligson said.

The Westchester Coalition for Clean Water proposes creating a unified county sewer district as a solution. This would provide economies of scale, allow for consistent and proactive maintenance, and create a more focused approach to investment in the entire collection system.

A pilot model for this approach has already taken shape: the Town of Mamaroneck, Village of Larchmont, Village of Pelham Manor, and City of New Rochelle have formed the New Rochelle sewer district to address their problems.

The creation of a countywide sewer district requires both state and county legislation. There are also concerns about equitable distribution of costs, as some communities have already invested heavily in repairs while others have not.

To address these concerns the proposed consolidation would include a “firewall” so that each individual community’s capital needs would be isolated. The district would also be opt-in rather than mandated.

The coalition is seeking public support to encourage elected officials at all levels to prioritize this issue. Residents can help by signing up for sewage alert notifications, joining the coalition’s mailing list, and speaking to their elected officials about the importance of investing in sewer infrastructure.

“A good sewer system is the hallmark of a civilized society,” Seligson concluded. “We want to support the county in order to consolidate the sewer districts, and we want to support the municipalities in joining that consolidation and improving their sewer pipes.”

The Larchmont/Mamaroneck Local Summit is an informal community council that seeks to make a better life for the community by keeping it informed of major issues of concern. On April 8th the Local Summit will host the Superintendents of the Mamaroneck and Rye Neck School Districts to discuss current programs, accomplishments, issues and the school budget. For more information: https.//www.localsummitlm.org/ . To view recorded programs on LMCMedia: https.//lmcmedia.org/ .