Photo: Barney, Paul · Public domainLiving in Castle Rock Township, MN: what to set up and who to call
Power in Castle Rock Township comes from Dakota Electric Association, a cooperative utility rather than a private company. The closest ER is Northfield Hospital, 9.6 miles away.
I’m new in town
What to set up in Castle Rock Township, 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 Castle Rock Township.
Power comes from Dakota Electric Association
Dakota Electric Association (Dakota Electric Association), a cooperative utility, serves 96.2% of Castle Rock Township residents. Its homes paid an average of 15.6¢ per kWh in 2025, about $116 a month (its average across Minnesota).
Start or move service: dakotaelectric.com · (800) 874-3409
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Farmington water system
The Farmington water system supplies Castle Rock Township: about 4% of residents live in its service area. About 96% 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 23,534 people in all.
No health-based violations reported to EPA in the five years to October 2026, like 83% of the 3,525 systems serving 10,001–50,000 people.
The latest lead result on file, the 90th percentile of homes sampled in Jul–Dec 2025, 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. MN1190008.
12 home internet providers serve Castle Rock Township
100% of 634 addresses can get 100/20 Mbps; 23% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| JTN Communications | Fixed wireless, Fiber | 81% | 1,000/1,000 |
| Frontier | DSL, Fiber | 49% | 7,000/7,000 |
| Spectrum | Cable, Fiber | 13% | 1,000/1,000 |
| CenturyLink | DSL | 8% | 60/5 |
| HBC | Fiber, Fixed wireless | 4% | 5,000/5,000 |
| Midco | Fixed wireless | 100% | 100/20 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Castle Rock Township’s trash rules yet
Pickup rules, the dump and recycling in Castle Rock Township.
Where your child goes to school
Public school districts and the school path by grade.
Most of Castle Rock Township (70%) is in Farmington Public School District; parts are in Randolph Public School District (24%) and Northfield Public School District (7%).
BSchool gradeSee 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 Aug 2015; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 18, 2024.
Castle Rock Township spans 4 ZIP codes
ZIP codes where Castle Rock Township residents live, with the share of the town in each.
| ZIP | Post office name | Share of Castle Rock Township | ZIP’s residents in Castle Rock Township |
|---|---|---|---|
| 55024 | Farmington, MN | 61% | 2% |
| 55057 | Northfield, MN | 18% | 1% |
| 55065 | Randolph, MN | 11% | 12% |
| 55031 | Hampton, MN | 10% | 7% |
55010 is P.O. box or single-organization ZIP with no homes.
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 Castle Rock Township
Who supplies Castle Rock Township’s drinking water, and has it had violations?
The Farmington water system (EPA ID MN1190008). It reported no health-based violations to EPA in the five years to October 2026; 83% of systems its size had none. Its latest lead 90th percentile was 0.0 ppb (Jul–Dec 2025), against a 15 ppb action level.
Who provides electricity in Castle Rock Township?
Dakota Electric Association (Dakota Electric Association), a cooperative utility. Its homes paid about 15.6¢ per kWh in 2025 (EIA).
What internet providers serve Castle Rock Township?
JTN Communications, Frontier, Spectrum, CenturyLink, HBC, Midco (FCC, as of December 2025).
What ZIP codes are in Castle Rock Township?
55024 (61%), 55057 (18%), 55065 (11%), 55031 (10%), by share of residents. Census 2020 ZIP Code Tabulation Areas.
What school district is Castle Rock Township in?
Farmington Public School District. Parts of the city are in Randolph Public School District and Northfield Public School District.
How do I register to vote in Castle Rock Township?
In Minnesota you can register online until 21 days before Election Day, in person up to and including Election Day, or by mail (received 21 days before). Elections here are run by the Dakota County Elections. Check your registration at mnvotes.sos.state.mn.us.
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.