Suffolk County Cesspool Rules: Replacements, Renovations, New Homes and Selling

Article 6 of the Suffolk County Sanitary Code sets the rules for home wastewater systems. Two changes matter most to homeowners: the end of in-kind cesspool replacement in 2019, and the I/A requirement for new and expanded homes in 2021. Here is what each one means, in plain terms.

Quick facts. Cesspools have been banned for new construction in Suffolk since 1973. Since July 1, 2019, every replacement needs county approval and at least a septic tank. Since July 1, 2021, new homes, many additions, and major reconstructions need an I/A system. Only a contractor with a Suffolk County Liquid Waste License can replace or retrofit a system.

If your cesspool fails: no more in-kind replacement

Since July 1, 2019, no property owner or contractor can replace or retrofit an existing cesspool or septic system without approval from the Suffolk County Department of Health Services. The new system must meet the county's current standards and the state minimums. The county's guidance at the time put it simply: you can no longer replace a cesspool with a cesspool. At a minimum, a septic tank has to sit in front of the leaching structure.

A few more points from the code and the county's guidance:

• Licensed contractors only. The work must be done by a contractor holding an active Liquid Waste License from the Suffolk County Department of Labor, Licensing and Consumer Affairs.
• How approval works for a straight swap. For a replacement with no other changes, the licensed contractor files the registration with the county online. The county's Office of Wastewater Management says emergency replacement applications are typically reviewed the same day, and other submissions take 2 to 4 weeks.
• An upgrade isn't forced just because a cesspool fails. The 2019 changes required a code-compliant system when you replace, but they did not require an I/A system. Many owners choose I/A anyway, because the county and state grants are aimed at I/A systems.
• Sewer districts are different. These requirements exclude parcels inside a proposed sewer district approved by the county.

Your town or village can have stricter rules. In Brookhaven, for example, homes within 500 feet of surface water need an I/A system for new construction and certain additions.

Renovating, adding bedrooms or building new: when I/A is required

For applications submitted to the Office of Wastewater Management on or after July 1, 2021, Article 6 requires an I/A system when a project is permitted to use an onsite system and is one of these:

• A new single-family home
• An expanded single-family home. This includes an addition that requires new or changed sewage facilities, and adding bedrooms beyond the number the county previously approved.
• A major reconstruction. That means rebuilding or modifying an existing structure where the cost is more than 50% of the structure's market value, as set by a New York State certified appraiser. Land, landscaping, pools, fences and detached structures don't count toward either number.

The code also exempts some projects on an existing home. It doesn't apply if the work is not a major reconstruction and doesn't add bedrooms beyond the county's approved count. A second exemption covers work that is not a major reconstruction, doesn't change the square footage or footprint, and keeps the home at five bedrooms or fewer. When bedrooms are added, a conforming conventional septic system is still the minimum. Similar I/A rules apply to new commercial and multi-family projects.

These definitions are technical. Your design professional should confirm how the county will treat your project before you finalize plans.

New construction and the grants

New construction on a vacant lot is not eligible for the county SIP grant or the state fund. Construction projects on an existing home may still be eligible for the county grant, according to the county's FAQ. Shelter Island's town rebate does not cover a system that the county or town code requires, except after a catastrophic cesspool failure. Check your town's rules before you count on a rebate for a required system.

Selling or buying a home with a cesspool

The Article 6 rules above are triggered by replacing a system, retrofitting one, or building. They are not triggered by a sale. When the 2019 changes took effect, the county's FAQ said it was not requiring homeowners to replace their system when a property changes hands. A cesspool can still affect a sale, though, because a buyer, lender or attorney may ask for an inspection, a price credit, or a replacement as part of the contract.

Two practical points for sellers and buyers:

• The grant follows the application, not the sale. The county checks the recorded deed, the tax bill and the Certificate of Occupancy for the property. If you are buying, ask whether the seller has already applied, and plan to apply yourself after closing if not.
• A grant-funded I/A system comes with duties. It must be maintained every year and can't be removed without county approval. A buyer should ask for the maintenance contract and the county registration.

For legal questions about disclosure or contract terms, talk with a New York real estate attorney.

See also: costs and grants and how to apply.