Lagoon systems: wastewater treatment plants in Kansas
284 plants · 80% of the state · 69 MGD reported by 37 plants
Klarifi identifies 284 publicly owned wastewater treatment plants with lagoon systems in Kansas, 80% of the 355 plants in the state (69 MGD reported by 37 plants). The largest is Joco Mill Creek Regional Wtf in Shawnee at 11.46 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 Kansas
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Joco Mill Creek Regional Wtf | Shawnee | 11.46 | KS0088269 | Jan 2030 | 0 |
| 2 | Joco Douglas Smith Mid Basin | Overland Park | 10.79 | KS0119601 | Feb 2027 | 0 |
| 3 | Lawrence, City Of | Lawrence | 7.45 | KS0038644 | Jul 2029 | 14 |
| 4 | Joco Blue River District #1 | Stanley | 6.3 | KS0092738 | Dec 2027 | 0 |
| 5 | Olathe (cedar Creek) Wastewater Plant | Olathe | 4.47 | KS0081299 | Dec 2029 | 0 |
| 6 | Hutchinson, City Of | Hutchinson | 3.3 | KS0036188 | Dec 2028 | 17 |
| 7 | City Of Coffeyville WTP | Coffeyville | 2.38 | KS0050733 | Dec 2026 | 20 |
| 8 | Wichita - Four Mile Creek - New | Wichita | 2.38 | KS0100790 | Dec 2026 | 9 |
| 9 | Fort Scott, City Of (new Plant) | Fort Scott | 2.33 | KS0095923 | Oct 2028 | 35 |
| 10 | Lawrence, City Of (wakarusa) | Lawrence | 1.97 | KS0099031 | Aug 2029 | 0 |
Plants planning lagoon systems upgrades
These plants report lagoon systems as a planned process in the EPA Clean Watersheds Needs Survey: the earliest public signal of a project.
| Facility | City | Avg flow (MGD) | NPDES permit | Expires |
|---|---|---|---|---|
| Hanston Waste Water Treatment Plant | Hanston | 0.01 | KS0031143 | Dec 2026 |
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 Kansas
Lagoon systems in other states
Lagoon systems in Kansas: 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 · Tertiary treatment · Significant industrial user · all terms