Photo: Marine 69-71 · CC BY-SA 4.0Living in Sonoita, AZ: what to set up and who to call
An EPA health-based violation from 2019 is still open for Sonoita Valley (South) Water Company, and its latest lead result (8.0 ppb) was higher than 96% of similar systems’, though under the 15 ppb action level. Sonoita has no town government of its own, so Santa Cruz County runs its elections and most services, and its children attend Patagonia Union High School District.
I’m new in town
What to set up in Sonoita, 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 Sonoita.
Power comes from Sulphur Springs Valley E C
Sulphur Springs Valley E C (Sulphur Springs Valley E C Inc), a cooperative utility, serves all of Sonoita. Its homes paid an average of 14.6¢ per kWh in 2025, about $107 a month (its average across Arizona).
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Sonoita Valley (South) Water Company
Sonoita Valley (South) Water Company supplies Sonoita: about 20% of residents live in its service area. Sonoita Valley (North) Water Company serves another 15%. Casas Arroyo Association Inc serves another 13%. About 51% of homes are outside any mapped community water system, most likely on private wells, which EPA doesn’t regulate. It draws ground water and serves 169 people in all.
1 health-based violation reported to EPA in the five years to October 2026: a lead and copper treatment requirement (Lead and Copper Rule Revisions), beginning Oct 2024. 77% of the 15,074 systems serving 101–500 people had none. 1 older violation is still open, since 2019: a bacteria testing requirement (Revised Total Coliform Rule), per EPA’s records.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2022–Dec 2024, was 8.0 ppb, below the 15 ppb action level that applied. That’s higher than 96% 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. AZ0412005.
5 home internet providers serve Sonoita
95% of 506 addresses can get 100/20 Mbps; 0% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| CenturyLink | DSL | 53% | 10/1 |
| Verizon | Fixed wireless | 88% | 300/20 |
| Tristate Wi-Fi by Wi-Fiber | Fixed wireless | 77% | 100/20 |
| T-Mobile | Fixed wireless | 61% | 100/20 |
| Bluespan Wireless | Fixed wireless | 16% | 1,000/1,000 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Sonoita’s trash rules yet
Pickup rules, the dump and recycling in Sonoita.
Where your child goes to school
Public school districts and the school path by grade.
Sonoita is in two districts that split the grades: Patagonia Union High School District and Sonoita Elementary 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.
No town hall: the county runs things
Sonoita is unincorporated, so Santa Cruz 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 Sep 12, 2025.
Sonoita is in ZIP code 85637
ZIP codes where Sonoita residents live, with the share of the town in each.
| ZIP | Post office name | Share of Sonoita | ZIP’s residents in Sonoita |
|---|---|---|---|
| 85637 | Sonoita, AZ | 100% | 64% |
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 Sonoita
Who supplies Sonoita’s drinking water, and has it had violations?
Sonoita Valley (South) Water Company (EPA ID AZ0412005). It reported 1 health-based violation to EPA in the five years to October 2026: a lead and copper treatment requirement (Lead and Copper Rule Revisions). 77% of systems its size had none. Its latest lead 90th percentile was 8.0 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in Sonoita?
Sulphur Springs Valley E C (Sulphur Springs Valley E C Inc), a cooperative utility. Its homes paid about 14.6¢ per kWh in 2025 (EIA).
What internet providers serve Sonoita?
CenturyLink, Verizon, Tristate Wi-Fi by Wi-Fiber, T-Mobile, Bluespan Wireless (FCC, as of December 2025).
What ZIP codes are in Sonoita?
85637. Census 2020 ZIP Code Tabulation Areas.
What school district is Sonoita in?
Patagonia Union High School District and Sonoita Elementary District.
How do I register to vote in Sonoita?
In Arizona you can register online until 29 days before Election Day, in person until 29 days before Election Day, or by mail (postmarked 29 days before). Elections here are run by the Santa Cruz County Recorder. Check your registration at my.arizona.vote.
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 Sep 12, 2025 (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.