TEXAS · TCEQ REGION 11 · 10 COUNTIES
Aerobic septic systems in TCEQ Region 11 (Austin)
TCEQ Region 11 office (Austin)
12100 Park 35 Circle, Bldg A, Rm 179, Austin TX 78753
Main line: 512-339-2929
TCEQ does not permit septic systems in any of these 10 counties. For an OSSF permit or a maintenance report, use the county's authorized agent in the table below.
From TCEQ's regional office directory, read Oct 31, 2026.
TCEQ Region 11 (Austin) covers 10 Texas counties: Bastrop, Blanco, Burnet, Caldwell, Fayette, Hays, Lee, Llano, Travis and Williamson.
All 10 counties permit on-site sewage facilities through a local authorized agent (a county), and maintenance reports go to that agent.
Reports are due within 14 days after the test (30 TAC §285.7(e)(1)(B)). No county in this region has published how maintenance providers submit the report, so every county page here says so rather than guessing.
28,477 aerobic systems were authorized across the region from 2015 to 2025. In 2025, 1,988 of the region’s 3,115 on-site sewage facility authorizations were aerobic (63.8%).
Counties in TCEQ Region 11 (Austin)
| COUNTY | PERMITTING AUTHORITY | HOW TO FILE | AEROBIC 2015–25 | AEROBIC 2025 | MPs |
|---|---|---|---|---|---|
| Bastrop | Bastrop County | Not confirmed | 7,337 | 597 | 25 |
| Blanco | Blanco County | Not confirmed | 790 | 61 | 4 |
| Burnet | Burnet County | Not confirmed | 1,935 | 220 | 4 |
| Caldwell | Caldwell County | Not confirmed | 1,963 | 41 | 12 |
| Fayette | Fayette County | Not confirmed | 1,296 | 129 | 9 |
| Hays | Hays County | Not confirmed | 5,183 | 143 | 32 |
| Lee | Lee County | Not confirmed | 907 | 79 | 4 |
| Llano | Llano County | Not confirmed | 352 | 51 | 5 |
| Travis | Travis County | Not confirmed | 5,065 | 287 | 22 |
| Williamson | Williamson County | Not confirmed | 3,649 | 380 | 23 |
MPs are licensed OSSF maintenance providers whose license mailing address is in the county. Each provider is counted once, where it is based; many also work in neighboring counties.
Permits across the region, 2015–2025
| YEAR | ALL OSSF | SURFACE (SPRAY) | DRIP |
|---|---|---|---|
| 2015 | 3,443 | 1,175 | 518 |
| 2016 | 3,762 | 1,399 | 552 |
| 2017 | 4,129 | 1,493 | 594 |
| 2018 | 4,428 | 1,651 | 669 |
| 2019 | 4,766 | 1,901 | 649 |
| 2020 | 5,636 | 2,205 | 805 |
| 2021 | 6,266 | 2,760 | 1,093 |
| 2022 | 5,782 | 2,602 | 1,041 |
| 2023 | 4,813 | 1,843 | 886 |
| 2024 | 4,144 | 1,760 | 893 |
| 2025 | 3,115 | 1,300 | 688 |
Authorizations to Construct from the eleven annual TCEQ “Types of Systems Installed” reports, summed over the region’s counties. Surface irrigation and drip both require aerobic pretreatment. The statewide dataset has the CSV, and the 2025 report compares the regions.
The rules are the same in every county
- · An aerobic system with surface application is tested every four months (30 TAC §285.91(4), Table IV). How often systems are inspected.
- · Each report goes to the permitting authority and the owner within 14 days of the test (30 TAC §285.7(e)(1)(B)). The deadline rule.
- · A new aerobic system starts with a two-year service policy (30 TAC §285.7(c)). After that the owner renews the maintenance contract or, for a single-family home, may maintain the system themselves where local rules allow (§285.7(d)(4)). What the contract must say.
Common questions
Which counties are in TCEQ Region 11 (Austin)?
10 Texas counties: Bastrop, Blanco, Burnet, Caldwell, Fayette, Hays, Lee, Llano, Travis and Williamson.
Who permits aerobic septic systems in TCEQ Region 11 (Austin)?
All 10 counties permit on-site sewage facilities through a local authorized agent (a county), and maintenance reports go to that agent.
How many aerobic septic systems were permitted in the Austin region?
28,477 aerobic systems were authorized across the region from 2015 to 2025. In 2025, 1,988 of the region’s 3,115 on-site sewage facility authorizations were aerobic (63.8%).
When is an aerobic maintenance report due in TCEQ Region 11 (Austin)?
Within 14 days after the date the test is performed, everywhere in Texas. 30 TAC §285.7(e)(1)(B) requires the report to go to the permitting authority and to the system owner.
The other fifteen TCEQ regions
Data as of Oct 5, 2026, from the TCEQ authorized-agent register, the OSSF license register, the annual “Types of Systems Installed” reports and the counties’ own pages. How we research and check this. Not legal advice. Verify with your permitting authority.