TEXAS · TCEQ REGION 04 · 19 COUNTIES
Aerobic septic systems in TCEQ Region 04 (DFW Metroplex)
TCEQ Region 04 office (Dallas/Fort Worth)
2309 Gravel Dr, Fort Worth TX 76118-6951
Main line: 817-588-5800
TCEQ does not permit septic systems in any of these 19 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 04 (DFW Metroplex) covers 19 Texas counties: Collin, Cooke, Dallas, Denton, Ellis, Erath, Fannin, Grayson, Hood, Hunt, Johnson, Kaufman, Navarro, Palo Pinto, Parker, Rockwall, Somervell, Tarrant and Wise.
All 19 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)). The filing channel is confirmed for 2 of the 19 counties. The rest have not published it, and their pages say so.
81,351 aerobic systems were authorized across the region from 2015 to 2025. In 2025, 8,307 of the region’s 9,407 on-site sewage facility authorizations were aerobic (88.3%).
Counties in TCEQ Region 04 (DFW Metroplex)
| COUNTY | PERMITTING AUTHORITY | HOW TO FILE | AEROBIC 2015–25 | AEROBIC 2025 | MPs |
|---|---|---|---|---|---|
| Collin | Collin County | web-form · Confirmed | 8,433 | 640 | 20 |
| Cooke | Cooke County | Not confirmed | 2,093 | 263 | 12 |
| Dallas | Dallas County | Not confirmed | 823 | 90 | 6 |
| Denton | Denton County | Not confirmed | 6,546 | 546 | 20 |
| Ellis | Ellis County | Not confirmed | 6,022 | 806 | 17 |
| Erath | Erath County | Not confirmed | 939 | 107 | 8 |
| Fannin | Fannin County | Not confirmed | 2,734 | 258 | 8 |
| Grayson | Grayson County | paper · Confirmed | 6,061 | 656 | 22 |
| Hood | Hood County | Not confirmed | 4,503 | 495 | 22 |
| Hunt | Hunt County | Not confirmed | 6,585 | 656 | 31 |
| Johnson | Johnson County | Not confirmed | 7,176 | 844 | 31 |
| Kaufman | Kaufman County | Not confirmed | 5,574 | 483 | 22 |
| Navarro | Navarro County | Not confirmed | 2,311 | 387 | 9 |
| Palo Pinto | Palo Pinto County | Not confirmed | 652 | 99 | 5 |
| Parker | Parker County | Not confirmed | 11,707 | 1,154 | 22 |
| Rockwall | Rockwall County | Not confirmed | 1,540 | 107 | 5 |
| Somervell | Somervell County | Not confirmed | 663 | 66 | 4 |
| Tarrant | Tarrant County | Not confirmed | 3,376 | 223 | 9 |
| Wise | Wise County | Not confirmed | 3,613 | 427 | 18 |
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 | 5,304 | 3,767 | 103 |
| 2016 | 6,478 | 4,777 | 137 |
| 2017 | 7,399 | 5,455 | 177 |
| 2018 | 8,266 | 6,128 | 295 |
| 2019 | 8,943 | 6,846 | 304 |
| 2020 | 9,927 | 7,687 | 500 |
| 2021 | 11,180 | 8,756 | 720 |
| 2022 | 12,040 | 9,351 | 828 |
| 2023 | 10,191 | 7,890 | 786 |
| 2024 | 9,788 | 7,689 | 848 |
| 2025 | 9,407 | 7,459 | 848 |
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 04 (DFW Metroplex)?
19 Texas counties: Collin, Cooke, Dallas, Denton, Ellis, Erath, Fannin, Grayson, Hood, Hunt, Johnson, Kaufman, Navarro, Palo Pinto, Parker, Rockwall, Somervell, Tarrant and Wise.
Who permits aerobic septic systems in TCEQ Region 04 (DFW Metroplex)?
All 19 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 DFW Metroplex region?
81,351 aerobic systems were authorized across the region from 2015 to 2025. In 2025, 8,307 of the region’s 9,407 on-site sewage facility authorizations were aerobic (88.3%).
When is an aerobic maintenance report due in TCEQ Region 04 (DFW Metroplex)?
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.