ZIP 78640 falls in Hays County, Texas, where we hold 56,993 parcels measured as septic county-wide and 32,829 on sewer. We do not have a per-ZIP parcel count for this county, so this is the county total, not a count specific to ZIP 78640.
ZCTA 78640 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) |
|---|---|---|---|---|
| Hays County, Texas | 84% | 2 | 56,993 | 32,829 |
| Caldwell County, Texas | 15% | 8 | — | — |
| Travis County, Texas | 1% | 164,420 | 34,543 | 337,990 |
1 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 |
|---|---|---|---|
| B & G Septic | Kyle | (512) 268-5302 | — |
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 hold 56,993 parcels measured as septic for Hays County, Texas as a whole, not broken out by ZIP.
ZIP 78640 spans 3 counties: Hays County, Texas, Caldwell County, Texas, Travis County, Texas.