Living in Twain Harte, CA: what to set up and who to call
Twain Harte has no town government of its own, so Tuolumne County runs its elections and most services, and its children attend Summerville Union High School District. Tap water in most of Twain Harte comes from Twain Harte Community Services District, which has a clean five-year EPA record (about 22% of systems its size had a health-based violation) and a latest lead result below detection.
I’m new in town
What to set up in Twain Harte, 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 Twain Harte.
Power comes from PG&E
PG&E (Pacific Gas & Electric Co.), an investor-owned utility, serves all of Twain Harte. Its homes paid an average of 37.5¢ per kWh in 2025, about $174 a month (its average across California, for customers on its standard service). California lets you buy power from another supplier; 66% of PG&E’s home customers do, and PG&E still delivers it.
Start or move service: pgecorp.com
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Twain Harte Community Services District
Twain Harte Community Services District supplies Twain Harte: about 55% of residents live in its service area. Tud - Upper Basin Water System serves another 40%. Twain Harte Valley Mwc serves another 5%. About 7% of homes are outside any mapped community water system, most likely on private wells, which EPA doesn’t regulate. It draws surface water and serves 2,378 people in all.
No health-based violations reported to EPA in the five years to October 2026, like 78% of the 7,966 systems serving 1,001–3,300 people.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2022–Dec 2024, was 0.0 ppb, below the 15 ppb action level that applied. Results below detection are reported as 0, so 0 doesn’t mean no lead at any tap.
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. CA5510005.
6 home internet providers serve Twain Harte
100% of 2,077 addresses can get 100/20 Mbps; 0% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Xfinity | Cable | 95% | 2,000/250 |
| AT&T | DSL | 59% | 10/1 |
| Cal.net | Fixed wireless | 100% | 100/20 |
| T-Mobile | Fixed wireless | 89% | 25/3 |
| Conifer Communications | Fixed wireless | 65% | 100/10 |
| Verizon | Fixed wireless | 58% | 300/20 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Twain Harte’s trash rules yet
Pickup rules, the dump and recycling in Twain Harte.
Where your child goes to school
Public school districts and the school path by grade.
Twain Harte is in two districts that split the grades: Summerville Union High School District and Twain Harte School District.
B+School gradeSee 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
Twain Harte is unincorporated, so Tuolumne County is the local government.
Election office: FVAP local election office directory, updated Jul 2021; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 18, 2024.
Twain Harte spans 2 ZIP codes
ZIP codes where Twain Harte residents live, with the share of the town in each.
| ZIP | Post office name | Share of Twain Harte | ZIP’s residents in Twain Harte |
|---|---|---|---|
| 95383 | Twain Harte, CA | 85% | 49% |
| 95370 | Sonora, CA | 15% | 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 Twain Harte
Who supplies Twain Harte’s drinking water, and has it had violations?
Twain Harte Community Services District (EPA ID CA5510005). 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 0.0 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in Twain Harte?
PG&E (Pacific Gas & Electric Co.), an investor-owned utility. Its homes paid about 37.5¢ per kWh in 2025 (EIA).
What internet providers serve Twain Harte?
Xfinity, AT&T, Cal.net, T-Mobile, Conifer Communications, Verizon (FCC, as of December 2025).
What ZIP codes are in Twain Harte?
95383 (85%), 95370 (15%), by share of residents. Census 2020 ZIP Code Tabulation Areas.
What school district is Twain Harte in?
Summerville Union High School District and Twain Harte School District. Parts of the city are in Sonora Union High School District and Soulsbyville Elementary School District.
How do I register to vote in Twain Harte?
In California you can register online until 15 days before Election Day, in person up to and including Election Day, or by mail (postmarked 15 days before). Elections here are run by the Tuolumne County Clerk - Elections. Check your registration at voterstatus.sos.ca.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 18, 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.