Short answer: Sewers barely reach Calverton: about 6% of the land is inside Calverton Sewer District, Riverhead Sewer District, so most homes depend on a cesspool, septic tank or I/A system.
Calverton in numbers
| Town | Town of Riverhead (Brookhaven 18% elsewhere) |
|---|---|
| Area | 26.43 sq mi |
| In active sewer district | 6% · Calverton Sewer District, Riverhead Sewer District |
| In proposed district | 0% |
| Groundwater zone | Zone III 100% |
| FEMA flood zone | 4% |
| One-family lots / median | 915 / 0.55 ac |
| One-family lots outside active sewer districts | about 914 |
Computed 2026-11-07 from Suffolk County GIS (hamlet boundaries, sewer districts, groundwater management zones, FEMA flood zones, protection areas, tax parcels). Shares are of land area; a district boundary is not a hookup, and some village-run systems are missing from the county layer. Method and full table.
Sewer coverage
Sewers barely reach Calverton: about 6% of the land is inside Calverton Sewer District, Riverhead Sewer District, so most homes depend on a cesspool, septic tank or I/A system. Counting lots instead of land: about 914 of the 915 one-family lots touching Calverton lie outside any active sewer district, and those homes rely on on-site systems. Next door: Wading River (0% sewered, median lot 0.58 ac); Manorville (0% sewered, median lot 0.92 ac); Baiting Hollow (0% sewered, median lot 0.53 ac). By active-sewer share Calverton ranks 41 of the 165 Suffolk hamlets and villages we measured.
Groundwater, lots and flood exposure
Groundwater management Zone III: Article 6's minimum lot for a new home on an on-site system here is 40,000 sq ft, unless the density is met another way or an exemption applies. County parcel records show 915 one-family lots touching Calverton, with a median of 0.55 acres (about 23,900 sq ft), below that minimum and the 44th-largest median lot in our Suffolk table. Also mapped: 4% of the land is in FEMA's 1%-annual-chance flood zone; 98% is in a Special Groundwater Protection Area; 42% is Pine Barrens Core; 21% is Pine Barrens Compatible Growth Area.
For most Calverton homes the main running cost is pumping; when a cesspool fails, the replacement must include at least a septic tank, and grants can cover most of an I/A system.
Who handles what in Calverton
- Building and electrical permits: Town of Riverhead
- Sewer: Calverton Sewer District
- System approvals and grants: SCDHS, 631-852-5700 (permits) / 631-852-5811 (grants)
Frequently asked questions
Is Calverton on public sewer?
Partly: about 6% is inside Calverton Sewer District; the other 94% relies on cesspools, septic tanks and I/A systems.
Can Calverton homeowners get septic grants?
Yes, if the home isn't sewered and isn't in a proposed sewer district: up to $20,000 from Suffolk and up to $25,000 from the state.
County rules, licensing and grant steps: Town of Riverhead overview, septic grants, replacement rules. More in Riverhead: Wading River, Riverhead.
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 Sanitary Code, Article 6 (amended 12/1/2020)
- Suffolk County: Septic Improvement Program information
- Suffolk County: SIP property eligibility lookup
Need cesspool or septic work in Calverton?
Submit a request with your address. We match it to an independent, licensed Suffolk County operator who serves that address; the operator confirms the time and price with you.
Request Service →