Travis County, TX
Septic systems in unincorporated Travis County
Updated · Editorial team; not yet technically reviewed
Short answer
Outside city limits, Travis County permits septic systems (OSSFs). An application includes a soil evaluation, and systems with aerobic or advanced treatment, or surface or drip irrigation, also need a recorded affidavit and a maintenance contract with a licensed provider.
What Travis County handles
A residential OSSF permit application in Travis County includes an OSSF checklist and soil evaluation form. [1]
Systems with aerobic or advanced treatment, or surface or drip irrigation, need an Affidavit to the Public for an OSSF requiring maintenance, plus a maintenance contract. [1]
An Affidavit Linking Properties is required if the system crosses property lines. [1]
Under state rules, homeowners may maintain some secondary treatment systems themselves two years after installation, but local permitting authorities can adopt stricter requirements. [2]
Why so many aerobic systems
Thin soil over limestone across western Travis County limits how much treatment a conventional drain field can do, so many homes use aerobic units that treat wastewater and spray or drip it. They depend on air pumps, chlorinators and controls, which is why the county requires a maintenance contract.
Aerobic system warning signs
- Alarm light or buzzer on the control panel.
- Strong odor near the spray heads or tank.
- Spray heads running during the day when they're set for night.
- Drains slowing across the house. See drain cleaning only after ruling out the system.
Chlorine tablets
Aerobic systems that spray need chlorine tablets made for wastewater; pool tablets are a different chemical and shouldn't be used. Your maintenance provider checks the chlorinator on each visit.
Further reading: How sewer camera inspections work.
City-specific guides in Travis County
Common questions
Who permits septic systems in unincorporated Travis County?
Travis County's Transportation and Natural Resources department.
What evaluation does a Travis County septic permit need?
A soil evaluation, submitted with the OSSF checklist.
Do aerobic septic systems in Travis County need a maintenance contract?
Yes, along with a recorded affidavit for systems requiring maintenance.
Can I maintain my own aerobic system in Travis County?
State rules allow it for some systems after two years, but local authorities may be stricter; check with the county.
What if my Travis County septic system crosses a property line?
An Affidavit Linking Properties is required.
Why are aerobic systems common west of Austin?
Thin soil over limestone limits conventional drain fields.
What does an aerobic alarm mean?
Usually an air pump, high water or control fault; cut water use and call your provider.
Can I use pool chlorine in my aerobic system?
No. Use tablets made for wastewater chlorinators.
Do Austin homes need county septic permits?
Homes on city sewer don't; the county permit applies to on-site systems outside city jurisdiction.
Why do my spray heads run during the day?
A timer or control fault, or a high-water condition forcing a dose; have it checked.
Cities and services in Travis County
- Plumbing services in AustinAustin has some of the newest housing of any large US city, since much of it was built in the last few decades. Its plumbing questions lean toward new…
- Backflow Testing in TexasBackflow testing in Texas: the TCEQ tester license anyone testing or repairing assemblies must hold, test-at-install and annual rules, and gauge accuracy checks.
- Water Heater Replacement in TexasTexas law on water heater swaps: cities over 5,000 regulate water heaters and require permits beyond simple repairs, and the homestead exemption for owners.
- Plumbing in TexasStatewide code, licensing and climate for Texas.
Other Texas counties
- Plumbing and septic in unincorporated Harris CountySeptic in unincorporated Harris County: the County Engineer's OSSF permit, the site evaluation and design, the installer inspection, and who to call.
- Septic (OSSF) permits in Tarrant CountyTarrant County permits septic systems in unincorporated areas and 23 contract cities. When a permit is needed, repair permits, and the ETJ around nearby cities.
- Septic systems and aerobic maintenance in Bexar CountyBexar County septic rules: every on-site system must be permitted, aerobic permits last two years, then owners keep a service contract with quarterly reports.
Sources (2)
- Travis County TNR, Residential OSSF (septic) permit · checked 2026-10-03
- TCEQ, OSSF maintenance · checked 2026-10-03