Activated sludge and clarifiers: wastewater treatment plants in Alaska
8 plants · 22% of the state · 9 MGD combined
Klarifi identifies 8 publicly owned wastewater treatment plants with activated sludge and clarifiers in Alaska, 22% of the 36 plants in the state (9 MGD combined). The largest is Mendenhall Valley WWTP in Juneau at 2.15 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 Alaska
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Mendenhall Valley WWTP | Juneau | 2.15 | AK0022951 | May 2025 | 63 |
| 2 | Kodiak Wastewater Treatment Facility | Kodiak | 1.78 | AK0021555 | May 2029 | 2 |
| 3 | Charcoal Point WWTP | Ketchikan | 1.61 | AK0021440 | Oct 2030 | 10 |
| 4 | Eagle River WWTP | Eagle River | 1.39 | AK0022543 | Jan 2031 | 1 |
| 5 | Juneau Douglas Wastewater Treatment Plant | Juneau | 0.96 | AK0023213 | Feb 2026 | 25 |
| 6 | Girdwood WWTP | Girdwood | 0.47 | AK0047856 | Oct 2005 | 6 |
| 7 | Kenai STP | Kenai | 0.44 | AK0021377 | May 2026 | 1 |
| 8 | Auke Bay Wastewater Treatment Facility | Juneau | 0.05 | AKG572004 | Dec 2027 | 12 |
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 |
|---|---|---|---|---|
| Mendenhall Valley WWTP | Juneau | 2.15 | AK0022951 | May 2025 |
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 Alaska
Activated sludge and clarifiers in other states
Activated sludge and clarifiers in Alaska: 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 · Sludge dewatering · Tertiary treatment · all terms