Lagoon systems: wastewater treatment plants in Texas
373 plants · 31% of the state · 692 MGD reported by 323 plants
Klarifi identifies 373 publicly owned wastewater treatment plants with lagoon systems in Texas, 31% of the 1,220 plants in the state (692 MGD reported by 323 plants). The largest is Dos Rios Water Recycling Center in San Antonio at 105.32 MGD.
Lagoon systems treat wastewater in large earthen ponds over weeks of retention time, with or without mechanical aeration. They serve thousands of small towns because they are cheap to run, but they struggle with ammonia and nutrient limits, fill with sludge over decades and are the plants most often converted or upgraded when a permit is renewed.
The largest lagoons in Texas
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Dos Rios Water Recycling Center | San Antonio | 105.32 | TX0077801 | Jun 2025 | 48 |
| 2 | City Of Dallas Central WWTP | Dallas | 104 | TX0047830 | Apr 2027 | 10 |
| 3 | Walnut Creek WWTP | Austin | 56.6 | TX0046981 | Mar 2025 | 0 |
| 4 | Hillebrandt WWTP | Beaumont | 47.3 | TX0046990 | Apr 2029 | 24 |
| 5 | Roberto R Bustamante WWTP | El Paso | 32.92 | TX0101605 | Apr 2030 | 35 |
| 6 | Waco Metropolitan Area Regional Sewarge System | Waco | 21.83 | TX0026506 | Jul 2030 | 48 |
| 7 | River Road Wastewater Treatment Plant | Wichita Falls | 16.92 | TX0047686 | Jul 2028 | 2 |
| 8 | Denton Creek Regional WWTF | Roanoke | 13.6 | TX0104957 | Apr 2029 | 0 |
| 9 | City Of Longview Main WWTP | Longview | 13.3 | TX0022217 | Sep 2026 | 11 |
| 10 | Dallas Salmon WWTP | League City | 11.35 | TX0085618 | Apr 2029 | 4 |
| 11 | City Of Texas City | Texas City | 10.53 | TX0023949 | Jul 2030 | 5 |
| 12 | City Of Nederland Wastewater Treatment Plant | Nederland | 9.82 | TX0026476 | Jan 2031 | 20 |
| 13 | South Mission 1 WWTP | Mission | 9.49 | TX0070017 | Apr 2028 | 0 |
| 14 | Conroe Southwest Regional WWTP | Conroe | 9.4 | TX0022268 | Oct 2029 | 9 |
| 15 | Bob Derrington Water Reclamation Plant | Odessa | 8.79 | TX0072800 | Jul 2025 | 92 |
| 16 | Cibolo Creek Municipal Authority WWTP | Schertz | 8.42 | TXR05FI55 | Aug 2026 | 1 |
| 17 | Harlingen WWTP | Harlingen | 6.61 | TX0047929 | Dec 2025 | 8 |
| 18 | River Road WWTP | Amarillo | 6.35 | TX0025801 | Mar 2027 | 1 |
| 19 | STP 2a WWTP | Nacogdoches | 6.2 | TX0055123 | Apr 2030 | 7 |
| 20 | City Of Sugar Land North Wastewater Treatment Plant | Sugar Land | 4.99 | TX0058114 | May 2030 | 9 |
| 21 | City Of Grapevine - Peach Street Plant WWTP | Grapevine | 4.56 | TX0032018 | Sep 2027 | 1 |
| 22 | Sulphur Springs WWTF | Sulphur Springs | 4.53 | TX0058955 | Jun 2030 | 1 |
| 23 | City Of Deer Park | Deer Park | 4.31 | TX0025321 | Jul 2029 | 15 |
| 24 | John Hargrove Water Reclamation Facility | Pearland | 3.98 | TX0116581 | Jun 2029 | 85 |
| 25 | City Of Pearland Barry Rose W. W. Treatment Plant | Pearland | 3.89 | TX0032735 | Apr 2030 | 28 |
Contacts and project signals for every plant on this list
Klarifi adds verified decision-maker contacts, permit limits, discharge monitoring data and the capital projects planned in each city, filterable by technology, size and compliance record.
Other technologies in Texas
Lagoon systems in other states
Lagoon systems in Texas: questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed September 11, 2026.