Is there a minimum lot size to use a septic system in Texas?

Yes, for new subdivisions. Texas OSSF rules require single-family lots in subdivisions created after the rule took effect to be at least one-half acre when served by a public water supply, and at least one acre when not served by public water, meaning the lot will likely have its own well. The rules also say a single-family system on a tract of ten acres or larger may not need a permit if certain conditions are met. Local permitting authorities can adopt stricter requirements, and the soil and setbacks still have to work on your lot, so check with your county or local septic authority early.

Check your local rule. This varies by state, county or city. Your permitting office has the final word; the official lookup pages below show you who that is.

Sources

• On-Site Sewage Facility Rules Compilation (RG-472)Texas Commission on Environmental Quality (TCEQ)
• Getting a Permit for an OSSF, Such as a Septic SystemTexas Commission on Environmental Quality (TCEQ)