Aeration and blower projects in US capital improvement plans
204 planned projects · $2.8B · 132 cities in 31 states
In short
How many aeration projects are in US city capital plans?
Klarifi’s extraction of published capital improvement plans finds 204 aeration projects in 132 cities across 31 states, with a combined budget of $2.8B. The largest is Sand Island Wastewater Treatment Plant Secondary Treatment in Honolulu, HI, at $2.0B.
Secondary treatment capacity and efficiency: blowers, diffusers, aeration basins, oxidation ditches, sequencing batch reactors and other biological process upgrades. Aeration is typically the largest energy cost at a plant. The list below ranks the 10 largest by budget; every city links to its full capital plan page. What is activated sludge? →
The largest aeration projects
| # | Project | City | Budget | Years |
|---|---|---|---|---|
| 1 | Sand Island Wastewater Treatment Plant Secondary Treatment | Honolulu, HI | $2.0B | 2025–2031 |
| 2 | CBWTP Secondary Treatment Expansion Program | Portland, OR | $84M | 2025–2027 |
| 3 | Membrane Bioreactor Plant | Creswell, OR | $65M | 2026–2029 |
| 4 | Secondary Treatment System Upgrades | Windsor, CA | $57M | 2023–2027 |
| 5 | NG - TSWRRF Growth Capacity Improvements | Lincoln, NE | $56M | 2025 |
| 6 | CBWTP Blower System/Building Improvements | Portland, OR | $50M | 2025–2030 |
| 7 | Jackson Pike WWTP Aeration Optimization | Columbus, OH | $48M | 2025–2027 |
| 8 | 23rd Avenue Wastewater Treatment Plant Process Blower Replacement | Phoenix, AZ | $46M | 2024–2029 |
| 9 | Arlington East Reclamation Facility Upgrades - Aeration Basin and Blowers | Jacksonville, FL | $41M | 2024–2028 |
| 10 | SWWTP Aeration Optimization | Columbus, OH | $37M | 2026–2028 |
All 204 aeration projects, with descriptions and contacts
Every line item with its description, page reference and source document, filterable by state, budget and start year, linked to the treatment plants and decision-makers in each city, and refreshed as new plans are adopted.
Cities with the most aeration projects
| City | Projects | Budget |
|---|---|---|
| Juneau, AK | 5 | $14M |
| Columbus, OH | 4 | $124M |
| Puyallup, WA | 4 | $1M |
| Cadillac, MI | 4 | $608K |
| Clare, MI | 4 | $205K |
| Antioch, IL | 4 | $190K |
| Wixom, MI | 4 | $140K |
| Kittery, ME | 4 | $103K |
| Saint Petersburg, FL | 3 | $5M |
| Webster, MA | 3 | $5M |
| Hanover, NH | 3 | $5M |
| Salem, OR | 3 | $3M |
States with the most aeration projects
| State | Projects | Budget |
|---|---|---|
| Michigan | 47 | $18M |
| California | 12 | $68M |
| Illinois | 12 | $16M |
| Iowa | 12 | $3M |
| Florida | 11 | $93M |
| Ohio | 10 | $131M |
| Washington | 10 | $15M |
| Oregon | 8 | $202M |
| Colorado | 8 | $10M |
| Alaska | 6 | $14M |
| New York | 6 | $10M |
| Missouri | 6 | $9M |
Planned spend by start year
Before 2026
$2.5B
74 items
2026
$196M
54 items
2027
$52M
25 items
2028
$21M
17 items
2029
$11M
12 items
2030
$4M
10 items
2031
$4M
2 items
2032 and later
$5M
9 items
Unscheduled
$110K
1 items
Other project types
Questions about aeration projects
Sources and methodology
Budgets and years are as published in each city’s capital improvement plan or adopted budget. Klarifi extracts the water, sewer and wastewater line items from the published document, keeps the page reference for each one, and assigns a project type from the title and description with a keyword classifier. Figures are planning budgets, not awarded contracts, and can change when a plan is re-adopted.
Data refreshed October 12, 2026.
Wastewater terms: Lift station · Inflow and infiltration · Sludge dewatering · WWTP · Oxidation ditch · Anaerobic digester · all terms