You need a permit for a septic system in unincorporated Smith County

Outside city sewer lines, a septic tank is an OSSF, or on-site sewage facility. Texas wants that system approved before the digging starts. In most cases, you need the permit first, not after the tank is already in the ground.

There is a narrow break for large lots. If you hold 10 acres or more and meet the setback rules, you may not need the permit. Even then, a licensed professional still has to check the site and soil. Smith County or TCEQ can tell you who handles the address. A lot that will not perc can stop a house plan cold.