Fort Constitution · Photo: AlexiusHoratius · CC BY-SA 3.0Living in New Castle, NH: what to set up and who to call
New Castle runs its own elections, so the town clerk of New Castle, not a county office, keeps the voter rolls. The closest public drop-off to New Castle is Portsmouth Recycling Center, 3 miles out; the town decides whether residents may use it.
I’m new in town
What to set up in New Castle, 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 New Castle.
Power comes from Eversource
Eversource (Public Service Co. of New Hampshire), an investor-owned utility, serves all of New Castle. Its homes paid an average of 24.2¢ per kWh in 2025, about $150 a month (its average across New Hampshire, for customers on its standard service). New Hampshire lets you buy power from another supplier; 43% of Eversource’s home customers do, and Eversource still delivers it.
Start or move service: eversource.com · (800) 662-7764
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from New Castle Water Works
New Castle Water Works supplies almost all of New Castle. It buys treated surface water (EPA lists Portsmouth Water Works as seller) and serves 910 people in all.
No health-based violations reported to EPA in the five years to October 2026, like 78% of the 5,327 systems serving 501–1,000 people.
The latest lead result on file, the 90th percentile of homes sampled in Jan–Dec 2007, was 17.0 ppb, above the 15 ppb action level that applied. It’s from 2007: EPA has no newer result for this system.
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. NH1661010.
4 home internet providers serve New Castle
100% of 523 addresses can get 100/20 Mbps; 72% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Xfinity | Cable | 99% | 2,000/250 |
| Fidium Fiber | Fiber | 70% | 1,000/1,000 |
| Verizon | Fixed wireless | 4% | 300/20 |
| AT&T | Fixed wireless | 3% | 25/3 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
The nearest public drop-off is 3 miles away
Pickup rules, the dump and recycling in New Castle.
Portsmouth Recycling Center
· run by City of Portsmouth
This isn’t New Castle’s own facility. Whether New Castle residents may use it is the town’s rule: check newcastlenh.org.
OpenStreetMap, as of Oct 9, 2026. © OpenStreetMap contributors.
Where your child goes to school
Public school districts and the school path by grade.
New Castle is in New Castle School District.
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.
Town hall and registering to vote
Who to call, and how to register.
Election office: FVAP local election office directory, updated Sep 2025; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 19, 2024.
New Castle is in ZIP code 03854
ZIP codes where New Castle residents live, with the share of the town in each.
| ZIP | Post office name | Share of New Castle | ZIP’s residents in New Castle |
|---|---|---|---|
| 03854 | New Castle, NH | 100% | 100% |
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 New Castle
Who supplies New Castle’s drinking water, and has it had violations?
New Castle Water Works (EPA ID NH1661010). It reported no health-based violations to EPA in the five years to October 2026; 78% of systems its size had none. Its latest lead 90th percentile was 17.0 ppb (Jan–Dec 2007), against a 15 ppb action level.
Who provides electricity in New Castle?
Eversource (Public Service Co. of New Hampshire), an investor-owned utility. Its homes paid about 24.2¢ per kWh in 2025 (EIA).
What internet providers serve New Castle?
Xfinity, Fidium Fiber, Verizon, AT&T (FCC, as of December 2025).
What ZIP codes are in New Castle?
03854. Census 2020 ZIP Code Tabulation Areas.
What school district is New Castle in?
New Castle School District.
How do I register to vote in New Castle?
New Hampshire has no online registration; you can register in person up to and including Election Day or by mail only in special circumstances (received 13 days before). Elections here are run by the Town Clerk of New Castle. Check your registration at app.sos.nh.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 Nov 19, 2024 (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.