Tarrant County, TX
Septic (OSSF) permits in Tarrant County
Updated · Editorial team; not yet technically reviewed
Short answer
Tarrant County is the septic (OSSF) permitting authority for the unincorporated county and 23 contract cities. A permit is needed for new construction and for renovations that significantly change square footage or water flow, and a repair permit for any change to an existing system. Nearly all unincorporated land sits in a city's extraterritorial jurisdiction, which can add city subdivision rules.
What Tarrant County handles
Tarrant County regulates OSSF inspection and permitting for 23 cities and the unincorporated parts of the county; OSSF review moved to Transportation Services on October 1, 2025. [1]
An OSSF permit is required for new construction and whenever renovations significantly change square footage or assigned water flow; a repair or remodel permit is required for any change to an existing system. [1]
Nearly all unincorporated land in Tarrant County lies within a city's extraterritorial jurisdiction, where the city can require subdivisions to meet minimum city requirements. [2]
When a remodel triggers a septic permit
| Project | Permit? |
|---|---|
| New house on septic | OSSF permit |
| Adding bedrooms or a big addition | Likely, if water flow or square footage changes significantly |
| Replacing a failed field or tank | Repair permit |
| Converting a home to a business use | Yes, if wastewater type or strength changes |
Cities
Fort Worth and Arlington run their own sewer and water systems; see Fort Worth water lines and Fort Worth backflow testing. For clay-soil plumbing problems across the county, see signs of a slab leak.
City-specific guides in Tarrant County
Common questions
How many cities use Tarrant County for septic permits?
23 contract cities, plus the unincorporated county.
Does a Tarrant County remodel need a septic permit?
If it significantly changes square footage or water flow, yes.
Is a permit needed to repair a Tarrant County septic system?
Yes; any change to an existing system needs a repair or remodel permit.
Which county office handles OSSF permits now?
Transportation Services, since October 1, 2025.
What is the ETJ in Tarrant County?
Land outside city limits where a nearby city can require subdivisions to meet its minimums; it covers nearly all unincorporated land.
Does converting a home to a business affect septic permits?
Yes, if the wastewater type or strength changes from residential.
Does Fort Worth follow county septic rules?
Fort Worth homes are mostly on city sewer; county rules cover unincorporated areas and contract cities.
Which Texas law governs Tarrant County OSSF permits?
Texas Health and Safety Code Chapter 366.
Why do Tarrant County lines crack?
Expansive clay soil shrinks and swells with drought and rain.
Do I need a permit to replace a septic tank lid?
Minor maintenance may not, but changes to the system need a repair permit; ask the county.
Cities and services in Tarrant County
- Plumbing services in Fort WorthFort Worth has grown fast, and its housing is newer on average than Dallas's, but the city still has older neighborhoods with aging pipe and the same …
- Plumbing services in ArlingtonArlington sits between Dallas and Fort Worth and shares their clay soils and slab foundations. Most homes were built since 1980, so water heaters, sla…
- 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 systems in unincorporated Travis CountySeptic systems in unincorporated Travis County: the county OSSF permit, the soil evaluation and affidavits it needs, and maintenance contracts for aerobic systems.
- 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)
- Tarrant County, On-Site Sewage Facilities · checked 2026-10-03
- Tarrant County Public Health, Extra Territorial Jurisdiction · checked 2026-10-03