Photo: Larry D. Moore · CC BY 4.0Living in San Marcos, TX: what to set up and who to call
San Marcos runs its own electric utility, City of San Marcos; its homes paid 12.7¢ per kWh in 2025. The City of San Marcos water system reported one health-based violation to EPA in the last five years: disinfection byproducts (TTHM), beginning Oct 2025.
I’m new in town
What to set up in San Marcos, 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 San Marcos.
Power comes from City of San Marcos
City of San Marcos (City of San Marcos - (TX)), a municipal utility, serves 85.0% of San Marcos residents. Its homes paid an average of 12.7¢ per kWh in 2025, about $116 a month (its average across Texas).
Start or move service: ci.san-marcos.tx.us · (512) 393-8309
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from City of San Marcos water system
The City of San Marcos water system supplies San Marcos: about 90% of residents live in its service area. Texas State University - San Marcos serves another 7%. It draws surface water (EPA lists Alliance Regional Water Authority 1b as seller) and serves 72,970 people in all.
1 health-based violation reported to EPA in the five years to October 2026: disinfection byproducts (TTHM), beginning Oct 2025. 90% of the 597 systems serving 50,001–100,000 people had none.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2022–Dec 2024, was 1.6 ppb, below the 15 ppb action level that applied. The highest in five years was 1.9 ppb. That’s higher than 62% 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. TX1050001.
8 home internet providers serve San Marcos
98% of 16,156 addresses can get 100/20 Mbps; 29% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Spectrum | Cable, Fiber | 90% | 1,000/1,000 |
| Astound Broadband | Cable, Fiber | 60% | 1,500/1,500 |
| Brightspeed | DSL, Fiber | 30% | 940/940 |
| Verizon | Fixed wireless | 65% | 300/20 |
| T-Mobile | Fixed wireless | 58% | 100/20 |
| VTX1 | Fixed wireless | 52% | 400/50 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
Trash day in San Marcos depends on your street
Pickup days, the drop-off and recycling in San Marcos, from the town’s own site.
Your pickup week
- TrashEvery week, on your street’s dayFind your street’s day on sanmarcostx.gov →
- RecyclingEvery other week, day by addressCheck which week on sanmarcostx.gov →
Household Hazardous Waste (HHW) Drop-Off
634 E. Hopkins, San Marcos, TX 78666
- Frinoon–3:30 pm
- Sat8 am–noon
Single-stream recycling
All your recyclables go in one bin, no sorting.
From sanmarcostx.gov, the town’s official site, checked Oct 21, 2026; pages dated 2026-10-01. Rules change: the town’s page is the last word. .
Where your child goes to school
Public school districts and the school path by grade.
Most of San Marcos (91%) is in San Marcos Consolidated Independent School District; parts are in Hays Consolidated Independent School District (9%).
DSchool 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 Jun 2025; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 18, 2024.
San Marcos is in ZIP code 78666
ZIP codes where San Marcos residents live, with the share of the town in each.
| ZIP | Post office name | Share of San Marcos | ZIP’s residents in San Marcos |
|---|---|---|---|
| 78666 | San Marcos, TX | 100% | 78% |
A few homes fall in 78656. 78667 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.
Train: OpenStreetMap (© OpenStreetMap contributors). ER: CMS hospital data. Library: IMLS Public Libraries Survey, FY2024.
Questions about living in San Marcos
Who supplies San Marcos’ drinking water, and has it had violations?
The City of San Marcos water system (EPA ID TX1050001). It reported 1 health-based violation to EPA in the five years to October 2026: disinfection byproducts (TTHM). 90% of systems its size had none. Its latest lead 90th percentile was 1.6 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in San Marcos?
City of San Marcos (City of San Marcos - (TX)), a municipal utility. Its homes paid about 12.7¢ per kWh in 2025 (EIA).
What internet providers serve San Marcos?
Spectrum, Astound Broadband, Brightspeed, Verizon, T-Mobile, VTX1 (FCC, as of December 2025).
What ZIP codes are in San Marcos?
78666. Census 2020 ZIP Code Tabulation Areas.
What school district is San Marcos in?
San Marcos Consolidated Independent School District. Parts of the city are in Hays Consolidated Independent School District.
How do I register to vote in San Marcos?
Texas has no online registration; you can register in person until 30 days before Election Day or by mail (postmarked 30 days before). Elections here are run by the Hays County Early Voting Clerk. Check your registration at teamrv-mvp.sos.texas.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: San Marcos’ own website (sanmarcostx.gov), read Oct 21, 2026, pickup and drop-off facts extracted and checked against the page they came from.
- 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.