Photo: Lights and freedom · CC BY-SA 4.0Living in Castro Valley, CA: what to set up and who to call
Castro Valley has no town government of its own, so Alameda County runs its elections and most services, and its children attend Castro Valley Unified School District. Tap water in Castro Valley comes from the East Bay Municipal Utility District (EBMUD), which has a clean five-year EPA record (about 18% 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 Castro Valley, 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 Castro Valley.
Power comes from PG&E
PG&E (Pacific Gas & Electric Co.), an investor-owned utility, serves all of Castro Valley. 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 East Bay Municipal Utility District (EBMUD)
The East Bay Municipal Utility District (EBMUD) supplies almost all of Castro Valley. It draws surface water (EPA lists Contra Costa Water District as seller) and serves 1,442,800 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 2022–Dec 2024, was 0.0 ppb, below the 15 ppb action level that applied. The highest in five years was 3.3 ppb. 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. CA0110005.
7 home internet providers serve Castro Valley
99% of 19,247 addresses can get 100/20 Mbps; 75% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Xfinity | Cable | 99% | 2,000/250 |
| AT&T | Fiber, DSL, Fixed wireless | 94% | 5,000/5,000 |
| Sonic Telecom | Fiber | 50% | 10,000/10,000 |
| Verizon | Fixed wireless | 64% | 300/20 |
| T-Mobile | Fixed wireless | 55% | 100/20 |
| Etheric Networks | Fixed wireless | 53% | 250/100 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Castro Valley’s trash rules yet
Pickup rules, the dump and recycling in Castro Valley.
Where your child goes to school
Public school districts and the school path by grade.
Most of Castro Valley (86%) is in Castro Valley Unified School District; parts are in San Lorenzo Unified School District (6%) and Hayward Unified School District (6%) and San Leandro Unified School District (2%).
ASchool 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
Castro Valley is unincorporated, so Alameda County is the local government.
Election office: FVAP local election office directory, updated Sep 2025; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 18, 2024.
Castro Valley spans 3 ZIP codes
ZIP codes where Castro Valley residents live, with the share of the town in each.
| ZIP | Post office name | Share of Castro Valley | ZIP’s residents in Castro Valley |
|---|---|---|---|
| 94546 | Castro Valley, CA | 69% | 98% |
| 94552 | Castro Valley, CA | 21% | 95% |
| 94578 | San Leandro, CA | 10% | 17% |
A few homes fall in 94577, 94541.
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 Castro Valley
Who supplies Castro Valley’s drinking water, and has it had violations?
The East Bay Municipal Utility District (EBMUD) (EPA ID CA0110005). 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 0.0 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in Castro Valley?
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 Castro Valley?
Xfinity, AT&T, Sonic Telecom, Verizon, T-Mobile, Etheric Networks (FCC, as of December 2025).
What ZIP codes are in Castro Valley?
94546 (69%), 94552 (21%), 94578 (10%), by share of residents. Census 2020 ZIP Code Tabulation Areas.
What school district is Castro Valley in?
Castro Valley Unified School District. Parts of the city are in San Lorenzo Unified School District and Hayward Unified School District and San Leandro Unified School District.
How do I register to vote in Castro Valley?
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 Alameda Registrar of Voters. 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.