Living in Selden, NY: what to set up and who to call
Selden has no town government of its own, so Suffolk County runs its elections and most services, and its children attend Middle Country Central School District. Power in Selden comes from PSEG Long Island, a state utility rather than a private company.
I’m new in town
What to set up in Selden, and who provides it. Tap an answer for the details and where they come from.
Power, water and internet
Who to call to start service at a new address in Selden.
Power comes from PSEG Long Island
PSEG Long Island (Long Island Power Authority), a state utility, serves all of Selden. Its homes paid an average of 26.2¢ per kWh in 2025, about $195 a month (its average across New York, for customers on its standard service). New York lets you buy power from another supplier; 0% of PSEG Long Island’s home customers do, and PSEG Long Island still delivers it.
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Suffolk County Water Authority
Suffolk County Water Authority supplies almost all of Selden. It draws ground water and serves 1,100,000 people in all.
No health-based violations reported to EPA in the five years to October 2026, like 82% of the 27 systems serving more than 1,000,000 people.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2025–Dec 2027, was 1.2 ppb, below the 15 ppb action level that applied. The highest in five years was 2.3 ppb. That’s lower than 60% of similar systems’ latest results.
The system’s full record: EPA ECHO report
EPA SDWIS via Envirofacts (violations pulled Oct 9, 2026) and ECHO (lead samples, 2026Q3); service area: EPA Community Water System Service Area Boundaries v3.0. Violations are counted by the start of their compliance period. NY5110526.
3 home internet providers serve Selden
99% of 6,080 addresses can get 100/20 Mbps; 91% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Optimum | Cable, Fiber | 98% | 8,000/8,000 |
| Verizon | Fiber, Fixed wireless | 93% | 980/880 |
| T-Mobile | Fixed wireless | 33% | 100/20 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Selden’s trash rules yet
Pickup rules, the dump and recycling in Selden.
Where your child goes to school
Public school districts and the school path by grade.
Most of Selden (92%) is in Middle Country Central School District; parts are in Sachem Central School District (5%) and Brookhaven-Comsewogue Union Free School District (3%).
Test scores and every school: see Schools →U.S. Department of Education, NCES Common Core of Data, 2024–25. Enrollment rules and registration are the district’s.
No town hall: the county runs things
Selden is unincorporated, so Suffolk County is the local government.
Election office: FVAP local election office directory, updated Sep 2024; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Aug 3, 2026.
Selden spans 3 ZIP codes
ZIP codes where Selden residents live, with the share of the town in each.
| ZIP | Post office name | Share of Selden | ZIP’s residents in Selden |
|---|---|---|---|
| 11784 | Selden, NY | 94% | 80% |
| 11776 | Port Jefferson Station, NY | 5% | 5% |
| 11720 | Centereach, NY | 1% | 1% |
Census 2020 ZIP Code Tabulation Areas, by census block; post office names: GeoNames (CC BY 4.0). ZIPs created since 2020 are missing.
Getting around, the ER and the library
One line each; the subject pages have the rest.
ER: CMS hospital data. Library: IMLS Public Libraries Survey, FY2024.
Questions about living in Selden
Who supplies Selden’s drinking water, and has it had violations?
Suffolk County Water Authority (EPA ID NY5110526). It reported no health-based violations to EPA in the five years to October 2026; 82% of systems its size had none. Its latest lead 90th percentile was 1.2 ppb (Jan 2025–Dec 2027), against a 15 ppb action level.
Who provides electricity in Selden?
PSEG Long Island (Long Island Power Authority), a state utility. Its homes paid about 26.2¢ per kWh in 2025 (EIA).
What internet providers serve Selden?
Optimum, Verizon, T-Mobile (FCC, as of December 2025).
What ZIP codes are in Selden?
11784 (94%), 11776 (5%), 11720 (1%), by share of residents. Census 2020 ZIP Code Tabulation Areas.
What school district is Selden in?
Middle Country Central School District. Parts of the city are in Sachem Central School District and Brookhaven-Comsewogue Union Free School District.
How do I register to vote in Selden?
In New York you can register online until 10 days before Election Day, in person until 10 days before Election Day, or by mail (postmarked 15 days before and received 10 days before). Elections here are run by the Suffolk County Board of Elections. Check your registration at voterlookup.elections.ny.gov.
Sources & dates
Every answer above names its source. Here they are with their dates.
- Water: EPA SDWIS (Envirofacts, pulled Oct 9, 2026), ECHO SDWA 2026Q3, EPA CWS Service Area Boundaries v3.0.
- Power: HIFLD Electric Retail Service Territories (map Aug 2023); EIA-861 final 2025.
- Trash: OpenStreetMap, Geofabrik extract of Oct 9, 2026. © OpenStreetMap contributors (ODbL).
- ZIP codes: Census 2020 ZCTA relationship files; GeoNames postal codes (CC BY 4.0).
- Schools: NCES Common Core of Data, 2024–25.
- Registration: vote.gov, updated Aug 3, 2026 (read Oct 10, 2026). Official sites and area codes: Wikidata.
- Election office: FVAP local election office directory (fetched Oct 10, 2026; each record dated), EAC EAVS 2024 jurisdictions; registration and lookup links from vote.gov’s state data, checked Oct 10, 2026.
- Internet: FCC National Broadband Map, as of December 2025.