TEXAS · TCEQ REGION 16 · 10 COUNTIES
Aerobic septic systems in TCEQ Region 16 (Laredo)
TCEQ Region 16 office (Laredo)
707 E Calton Rd, Ste 304, Laredo, TX 78041-3887
Main line: 956-791-6611
This office permits septic systems and takes maintenance reports for the 1 county without a local authorized agent; the other 9 permit locally.
From TCEQ's regional office directory, read Oct 31, 2026.
TCEQ Region 16 (Laredo) covers 10 Texas counties: Dimmit, Duval, Kinney, La Salle, Maverick, McMullen, Val Verde, Webb, Zapata and Zavala.
9 of the 10 counties permit on-site sewage facilities through a local authorized agent (a county). The remaining county has none, so the TCEQ Region 16 (Laredo) office (956-791-6611) permits systems and takes maintenance reports there.
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.
324 aerobic systems were authorized across the region from 2015 to 2025. In 2025, 22 of the region’s 173 on-site sewage facility authorizations were aerobic (12.7%).
Counties in TCEQ Region 16 (Laredo)
| COUNTY | PERMITTING AUTHORITY | HOW TO FILE | AEROBIC 2015–25 | AEROBIC 2025 | MPs |
|---|---|---|---|---|---|
| Dimmit | Dimmit County | Not confirmed | 0 | 0 | 0 |
| Duval | Duval County | Not confirmed | 0 | 0 | 0 |
| Kinney | Kinney County | Not confirmed | 4 | 0 | 0 |
| La Salle | TCEQ Region 16 - Laredo | Not confirmed | 0 | 0 | 1 |
| Maverick | Maverick County | Not confirmed | 0 | 0 | 0 |
| McMullen | Mcmullen County | Not confirmed | 3 | 0 | 0 |
| Val Verde | Val Verde County | Not confirmed | 301 | 20 | 2 |
| Webb | Webb County | Not confirmed | 15 | 2 | 1 |
| Zapata | Zapata County | Not confirmed | 0 | 0 | 0 |
| Zavala | Zavala County | Not confirmed | 1 | 0 | 0 |
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 | 140 | 21 | 1 |
| 2016 | 145 | 21 | 0 |
| 2017 | 174 | 25 | 4 |
| 2018 | 139 | 30 | 1 |
| 2019 | 161 | 25 | 3 |
| 2020 | 204 | 23 | 0 |
| 2021 | 218 | 40 | 0 |
| 2022 | 212 | 37 | 3 |
| 2023 | 192 | 33 | 1 |
| 2024 | 187 | 33 | 1 |
| 2025 | 173 | 20 | 2 |
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 16 (Laredo)?
10 Texas counties: Dimmit, Duval, Kinney, La Salle, Maverick, McMullen, Val Verde, Webb, Zapata and Zavala.
Who permits aerobic septic systems in TCEQ Region 16 (Laredo)?
9 of the 10 counties permit on-site sewage facilities through a local authorized agent (a county). The remaining county has none, so the TCEQ Region 16 (Laredo) office (956-791-6611) permits systems and takes maintenance reports there.
How many aerobic septic systems were permitted in the Laredo region?
324 aerobic systems were authorized across the region from 2015 to 2025. In 2025, 22 of the region’s 173 on-site sewage facility authorizations were aerobic (12.7%).
When is an aerobic maintenance report due in TCEQ Region 16 (Laredo)?
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.