Lagoon systems: wastewater treatment plants in Texas
339 plants · 27% of the state · 684 MGD reported by 303 plants
Klarifi identifies 339 publicly owned wastewater treatment plants with lagoon systems in Texas, 27% of the 1,244 plants in the state (684 MGD reported by 303 plants). The largest is Dos Rios Water Recycling Center in San Antonio at 124.77 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 | 124.77 | TX0077801 | Jun 2025 | 44 |
| 2 | City Of Dallas Central WWTP | Dallas | 118.1 | TX0047830 | Apr 2027 | 11 |
| 3 | Walnut Creek WWTP | Austin | 69.41 | TX0046981 | Mar 2025 | 0 |
| 4 | Hillebrandt WWTP | Beaumont | 34.23 | TX0046990 | Apr 2029 | 22 |
| 5 | Roberto R Bustamante WWTP | El Paso | 33.07 | TX0101605 | Apr 2030 | 35 |
| 6 | Waco Metropolitan Area Regional Sewarge System | Waco | 28.36 | TX0026506 | Jul 2030 | 48 |
| 7 | Washburn Tunnel Facility | Pasadena | 15.54 | TX0052591 | Apr 2019 | 11 |
| 8 | City Of Longview Main WWTP | Longview | 14.44 | TX0022217 | Sep 2026 | 11 |
| 9 | Denton Creek Regional WWTF | Roanoke | 14.01 | TX0104957 | Apr 2029 | 8 |
| 10 | Conroe Southwest Regional WWTP | Conroe | 10.4 | TX0022268 | Oct 2029 | 9 |
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 October 26, 2026.
Wastewater terms: WWTP · POTW · Biosolids · Equalization tank · Centrate · all terms