Suffolk County Sewer Plan Advances for 539 West Islip Parcels

WEST ISLIP, NY — Suffolk County has completed an environmental-review milestone for a proposed sanitary sewer system serving approximately 539 existing parcels in a defined portion of West Islip. The action advances planning for the project, but it does not set a construction start date, homeowner connection deadline or confirmed connection cost.

What is proposed

The project is identified as West Islip Area 110-1 and is also labeled Carlls River-West Islip in county planning records. The service area is in the Town of Islip and covers property north and east of the intersection of Arbor Street and Kime Avenue, including lots south of Bay Shore Road and west of Udall Road.

County records describe a full gravity collection system for the primarily residential parcels. Wastewater collected in Area 110-1 would move through a new extension to the existing 110 Sewer District interceptor, connect with the existing Suffolk County Sewer District No. 3 Southwest Sewer District system and then be treated at the Bergen Point Wastewater Treatment Plant. The county says Bergen Point has permitted capacity for the additional flow and that plant upgrades are not expected as part of this project.

Why the county is pursuing it

The proposed project area currently relies on on-site wastewater systems, including cesspools and septic tanks. Suffolk County’s environmental-review documents say those systems contribute contaminants to groundwater, particularly in an area with closely situated homes and high groundwater tables.

The county says the sewer project is anticipated to mitigate associated water-quality concerns. That language describes expected environmental benefits and existing wastewater conditions; it does not establish legal liability for individual property owners.

April environmental action

The Suffolk County Council on Environmental Quality recommended on January 14, 2026, that the project be treated as an “Unlisted Action” under the State Environmental Quality Review Act and that it was not expected to have significant adverse environmental impacts. The CEQ recommendation was based on the county’s Environmental Assessment Form and project information presented to the council.

The Suffolk County Legislature then adopted Resolution 262-2026 on April 21, 2026, determining that the proposed West Islip Area 110-1 sewer system and its connection to Sewer District No. 3 would have no significant adverse environmental impacts. County Executive Edward Romaine approved the resolution on April 23, 2026.

This is an environmental-review milestone, not a construction contract award or documentation that construction has begun. The resolution states that required regulatory permits and approvals must be obtained before construction.

Planning and funding records show different figures

Suffolk County’s Subwatersheds Wastewater Implementation Plan lists project 8518, Carlls River-West Islip (110-1), with an estimated infrastructure cost of $52.4 million. The document identifies that figure as excluding individual connections. It lists January 2025 as an estimated design-start date and December 2028 as an estimated construction-completion date.

Separately, New York’s 2026 Clean Water State Revolving Fund Intended Use Plan lists project C1-5120-32-00 for West Islip collection work with a total cost of $40.01 million. That state document is a funding-program record. By itself, it does not show that all financing, permits, contracts or construction authorizations are complete.

The two records state different project figures and should not be treated as interchangeable. The documents reviewed do not explain the difference.

What remains unresolved for homeowners

Residents in the identified service area should not infer from the April action or funding listing that construction is underway or that service will begin by a fixed date. The records reviewed for this report do not document a construction start or establish a confirmed homeowner connection schedule, mandatory connection rule, private-property connection cost, assessment or household service date.

For now, the project remains in planning and implementation stages. Its practical significance is limited to the specifically identified West Islip Area 110-1 service area rather than the entire hamlet. The county’s December 2028 date remains a planning estimate subject to later approvals, funding and implementation.

Sources

• Suffolk County Legislature Resolution 262-2026
• Suffolk County Subwatersheds Wastewater Implementation Plan
• Final 2026 Clean Water State Revolving Fund Intended Use Plan
• Suffolk Lawmakers Approve $3B Capital Budget, Paving Way for Major Sewer Expansion