Activated sludge and clarifiers: wastewater treatment plants in Vermont
22 plants · 29% of the state · 17 MGD combined
Klarifi identifies 22 publicly owned wastewater treatment plants with activated sludge and clarifiers in Vermont, 29% of the 76 plants in the state (17 MGD combined). The largest is Bennington Wastewater Treatment Facility in Bennington at 3.62 MGD.
Activated sludge is the standard mechanical process for cities: aeration basins where bacteria consume organic matter, followed by clarifiers that settle the biomass out. These plants are identified by their circular or rectangular clarifiers and by the suspended-growth process code, and they are the main market for blowers, diffusers, clarifier mechanisms and instrumentation.
The largest activated sludge plants in Vermont
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Bennington Wastewater Treatment Facility | Bennington | 3.62 | VT0100021 | Jun 2029 | 7 |
| 2 | St Albans City | St Albans | 3.2 | VT0100323 | Sep 2022 | 18 |
| 3 | Essex Junction Wastewater Treatment Facility | Essex Junction | 2.07 | VT0100111 | Jun 2026 | 2 |
| 4 | Montpelier Wastewater Treatment Facility | Montpelier | 1.92 | VT0100196 | Sep 2022 | 0 |
| 5 | Brattleboro Wastewater Treatment Facility | Brattleboro | 1.28 | VT0100064 | Sep 2021 | 10 |
| 6 | St Johnsbury | St Johnsbury | 0.9 | VT0100579 | Mar 2023 | 18 |
| 7 | Springfield Wastewater Treatment Facility | Springfield | 0.8 | VT0100374 | Sep 2020 | 18 |
| 8 | Winooski Sewage Treatment Plant | Winooski | 0.64 | VT0100510 | Jun 2026 | 0 |
| 9 | Bellows Falls Waste Water Treatment Facility | Bellows Falls | 0.55 | VT0100013 | Sep 2021 | 59 |
| 10 | Burlington Riverside Wastewater Treatment Plant | Burlington | 0.55 | VT0100307 | Sep 2009 | 86 |
Plants planning activated sludge and clarifiers upgrades
These plants report activated sludge and clarifiers 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 |
|---|---|---|---|---|
| Middlebury Wastewater Treatment Facility | Middlebury | 1.13 | VT0100188 | Sep 2013 |
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 Vermont
Activated sludge and clarifiers in other states
Activated sludge and clarifiers in Vermont: 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: Activated sludge · Biological nutrient removal · Equalization tank · Lift station · Inflow and infiltration · all terms