Short answer: About 6% of the Town of Brookhaven's land is inside an active sewer district on the county map, mostly Selden Sewer District; about 109,618 of 121,196 one-family lots in the town's hamlets and villages sit outside any active sewer district. There is no town septic rebate, so the county and state grants are the funding.
Last updated: November 2026. Data computed 2026-11-07 from Suffolk County GIS; rules and programs re-read November 7, 2026.
Town of Brookhaven in numbers
| Land in active sewer districts | 6% |
|---|---|
| Land in proposed districts | 4% |
| Under feasibility study (not a district) | under 1% |
| Places with ~0% active sewer | 28 of 46 hamlets and villages |
| One-family lots outside active districts | about 109,618 of 121,196 |
| Groundwater zones (land share) | Zone III about 48%; Zone VI about 27%; Zone I about 11%; Zone VIII about 10% |
| I/A systems installed (Oct 2024) | about 730, 14% of the county's 5,344; 3rd of the ten towns |
| Town septic rebate | No |
| Town code on I/A systems | None found beyond the county rules |
Sewer districts and where the cesspools are
- Active districts (11): Selden Sewer District (about 2%), Medford Sewer District (about 1%), SUNY Stony Brook Sewer District (about 1%), Stony Brook Sewer District (about 1%), plus 7 smaller.
- Proposed districts (11 polygons): Forge River Watershed Sewer District Phases III & IV (about 2%), Middle Country Road (about 1%), Proposed SCCRI Forge River Sewage Treatment Plant Expansion (about 1%), plus 8 smaller. Homes inside a proposed district are excluded from the county and state septic grants.
- Feasibility-study areas (not districts): Stonybrook/Setauket Study Area 1 (under 1%). A study area does not by itself affect grant eligibility.
By one-family lot count, the most lots outside an active district are in Shirley (about 7,570), Centereach (about 7,466), Selden (about 4,957), East Patchogue (about 4,892), Lake Ronkonkoma (about 4,834). Median one-family lots run from 0.14 acres in Fire Island to 2.07 acres in Old Field. In 38 of 46 places the median lot is smaller than Article 6's minimum for a new home on an on-site system in its main zone. Across the town, about 7% of the land is in FEMA's 1%-annual-chance flood zone; 42% is in a Special Groundwater Protection Area; 39% is in the Central Pine Barrens (core plus compatible growth area).
What the Town of Brookhaven adds
- Rebate: none listed by the county as of November 7, 2026.
- Town code: no town-wide I/A mandate found beyond the county rules as of November 7, 2026.
- Building department: Town of Brookhaven; villages with their own: Belle Terre, Bellport, Lake Grove, Old Field, Patchogue, Poquott, Port Jefferson, Shoreham.
Every hamlet and village in the Town of Brookhaven
Land-area shares inside county sewer-district polygons; zone = main Article 6 groundwater zone; flood = FEMA 1%-annual-chance zone; lot = median one-family lot (acres). Linked names have their own page. Some village-run systems are missing from the county layer. Full table: sewer coverage by hamlet.
| Hamlet / village | Active sewer | Proposed sewer | Feasibility study | Zone | Flood | Median lot (ac) |
|---|---|---|---|---|---|---|
| Belle Terre (village) | under 1% | 0% | 0% | Zone VIII | 3% | 1.13 |
| Bellport (village) | 0% | 3% | 0% | Zone VI | 11% | 0.34 |
| Blue Point | 0% | 0% | 0% | Zone VI | 17% | 0.28 |
| Brookhaven | 0% | 0% | 0% | Zone VI | 23% | 0.51 |
| Center Moriches | 0% | 0% | 0% | Zone VI | 12% | 0.45 |
| Centereach | 8% | 6% | 0% | Zone I | 0% | 0.31 |
| Coram | 22% | 3% | 0% | Zone III | 0% | 0.36 |
| East Moriches | 0% | 0% | 0% | Zone VI | 16% | 0.53 |
| East Patchogue | 8% | 0% | 0% | Zone VI | 10% | 0.30 |
| East Setauket | 0% | 0% | 4% | Zone I | under 1% | 0.45 |
| East Shoreham | under 1% | 0% | 0% | Zone VIII | 3% | 0.55 |
| Eastport | 0% | 0% | 0% | Zone III | 4% | 0.63 |
| Farmingville | 3% | 9% | 0% | Zone III | 0% | 0.28 |
| Fire Island | 0% | 0% | 0% | Zone IV | 89% | 0.14 |
| Gordon Heights | 0% | 0% | 0% | Zone III | 0% | 0.29 |
| Holtsville | 8% | under 1% | 0% | Zone VI | 1% | 0.34 |
| Lake Grove (village) | 4% | 1% | 0% | Zone I | 0% | 0.30 |
| Lake Ronkonkoma | 0% | 7% | 0% | Zone I | 0% | 0.23 |
| Manorville | 0% | 0% | 0% | Zone III | 2% | 0.92 |
| Mastic | 0% | 32% | 0% | Zone VI | 2% | 0.23 |
| Mastic Beach | 0% | 98% | 0% | Zone VI | 36% | 0.23 |
| Medford | 7% | 7% | 0% | Zone III | 0% | 0.34 |
| Middle Island | 2% | 0% | 0% | Zone III | 1% | 0.52 |
| Miller Place | 3% | 0% | 0% | Zone III | 1% | 0.51 |
| Moriches | 0% | 0% | 0% | Zone VI | 8% | 0.51 |
| Mount Sinai | 24% | under 1% | 0% | Zone III | 4% | 0.55 |
| North Bellport | 21% | 10% | 0% | Zone VI | 0% | 0.24 |
| North Patchogue | 0% | 0% | 0% | Zone VI | 7% | 0.20 |
| Old Field (village) | 0% | 0% | 0% | Zone VIII | 24% | 2.07 |
| Patchogue (village) | 17% | 0% | 0% | Zone VI | 20% | 0.22 |
| Poospatuck Indian Reservation | 0% | 100% | 0% | Zone VI | 22% | 0.27 |
| Poquott (village) | 0% | 0% | 0% | Zone VIII | 9% | 0.46 |
| Port Jefferson (village) | 21% | 0% | 0% | Zone VIII | 2% | 0.40 |
| Port Jefferson Station | 0% | 5% | 0% | Zone I | 0% | 0.34 |
| Ridge | 8% | 0% | 0% | Zone III | 1% | 0.48 |
| Rocky Point | 0% | 0% | 0% | Zone III | under 1% | 0.23 |
| Selden | 5% | 8% | 0% | Zone III | 0% | 0.22 |
| Setauket | 0% | 0% | 3% | Zone VIII | 6% | 0.59 |
| Shirley | 0% | 16% | 0% | Zone VI | 15% | 0.26 |
| Shoreham (village) | 0% | 0% | 0% | Zone VIII | 2% | 0.76 |
| Sound Beach | 0% | 0% | 0% | Zone VIII | 1% | 0.20 |
| Stony Brook | 28% | 1% | 2% | Zone VIII | 6% | 0.39 |
| Stony Brook University | 97% | 0% | 0% | Zone I | 0% | 0.46 |
| Terryville | 4% | 0% | 0% | Zone III | 0% | 0.27 |
| Upton | 0% | 0% | 0% | Zone III | 2% | 1.00 |
| Yaphank | under 1% | 0% | 0% | Zone III | 2% | 0.69 |
County rules apply on top: no cesspool-for-cesspool replacement since July 1, 2019, and an I/A system for new homes and major reconstruction since July 1, 2021. Details, licensing and grants: Suffolk County overview.
Frequently asked questions
How much of the Town of Brookhaven is on sewer?
About 6% of the land in the town's hamlets and villages is inside an active county sewer district, and 4% inside proposed districts; about 109,618 of 121,196 one-family lots in the town's hamlets and villages sit outside any active sewer district. A district boundary is not a connection.
Does the Town of Brookhaven have a septic rebate?
No town rebate is listed by Suffolk County as of November 7, 2026. Brookhaven homeowners use the county grant (up to $20,000) and the state grant (up to $25,000); the town had about 730 I/A systems by October 2024.
Who issues building permits for septic work in Brookhaven?
The Town of Brookhaven building department, except in the incorporated villages (Belle Terre, Bellport, Lake Grove, Old Field, Patchogue, Poquott, Port Jefferson, Shoreham), which run their own. SCDHS approves the sanitary system itself.
Sources
Each source was re-read on November 7, 2026. Program amounts and rules change; the agency page is the authority.
- Suffolk County GIS Viewer map service (hamlets, villages, sewer districts, groundwater zones, flood zones, tax parcels)
- Suffolk County DHS presentation, 11/19/2024 (hosted by the Town of Shelter Island)
- Suffolk County DHS: Changes to wastewater practices effective July 1, 2019
- Suffolk County: Septic Improvement Program information
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