ZIP 78121 falls in Wilson County, Texas, where we hold 1 septic-related documents. We have not classified septic-versus-sewer status for this county, and we do not have a per-ZIP parcel count -- see the county page for what we hold and where the records are kept.
ZCTA 78121 is not entirely inside one county. Land-area share is from the 2020 Census ZCTA-to-county relationship file.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Wilson County, Texas | 75% | 1 | — | — |
| Guadalupe County, Texas | 25% | 11 | 36,043 | 31,861 |
2 businesses on record with an address in this ZIP: pumping, installation, design, inspection and repair. Not an endorsement, and we take no fee.
| Company | City | Phone | Rating |
|---|---|---|---|
| C&D Outdoor Solutions | La Vernia | (830) 251-9368 | 5.0 (1) |
| 4B’s Welding and Septics | La Vernia | (361) 960-9235 | — |
Land-area overlap is from the 2020 Census Bureau ZCTA5-to-county relationship file, not an estimate of ours. Parcel and document counts are rows we hold, not a survey of every property in the ZIP. Last verified 2026-09-01.
We have not measured septic-versus-sewer status for this county yet.
ZIP 78121 spans 2 counties: Wilson County, Texas, Guadalupe County, Texas.