Verified as of September 11, 2026. We re-check these pages quarterly.
The short version
- Texas regulates on-site sewage facilities (OSSFs) under 30 TAC Chapter 285. Licences sit in 30 TAC Chapter 30, Subchapter G.
- A permit and an approved plan are required to construct, alter, repair, extend and operate a system.
- TCEQ is usually not your permitting authority. Local programs act as authorised agents, and a local program may be more stringent than the state minimum.
- An aerobic unit must be under contract with a licensed maintenance provider — an individual person. TCEQ no longer registers maintenance companies.
- That provider must report to both the permitting authority and you, at least once every four months.
- Routine pumping of a conventional tank needs no permit.
The four things worth knowing
Your aerobic maintenance contract — what it actually requires Tags, visit records, component checks, testing, and a report filed every four months. What the provider owes you, and what happens when a contract lapses.
The 10-acre rule: when a permit is not required Seven conditions, all of which must hold. Most owners who believe they qualify have missed at least one — usually the 100-foot setback or the single-dwelling requirement.
Emergency repairs and the 72-hour rule Some repairs can begin immediately without a permit. They still have to be reported in writing within 72 hours of starting, and the list of what counts is specific.
Limestone, spray fields and why your options are narrow Why a gravity drain field often cannot be permitted in the western county, and what that means for cost and siting.
If your system predates the rules
A system can be grandfathered if it was installed before a local authorised program existed, or before September 1, 1989 — whichever is earlier. That protection is conditional, not permanent. It holds only while the system is not creating a nuisance, is not in need of repair, and has not had a significant increase in use or been otherwise altered.
Adding a bedroom, a casita or a pool house is exactly the kind of change that ends it.
The honest caveat
Every statement above comes from TCEQ's own published rules and guidance. None of it overrides your local permitting authority, which is entitled to be stricter and frequently is. Before you spend money on the strength of an exemption, confirm it with the county in writing.