Anaerobic digester and biogas projects in US capital improvement plans
136 planned projects · $946M · 84 cities in 30 states
In short
How many digester and biogas projects are in US city capital plans?
Klarifi’s extraction of published capital improvement plans finds 136 digester and biogas projects in 84 cities across 30 states, with a combined budget of $946M. The largest is Re-Gen Phase III in Arlington, VA, at $210M.
Digester tank rehabilitation, covers, mixing and heating systems, and biogas use from flares to combined heat and power and renewable natural gas. Concentrated at plants above 5 MGD. The list below ranks the 10 largest by budget; every city links to its full capital plan page. What is an anaerobic digester? →
The largest digester and biogas projects
| # | Project | City | Budget | Years |
|---|---|---|---|---|
| 1 | Re-Gen Phase III | Arlington, VA | $210M | 2025–2029 |
| 2 | West Boise Water Renewal Facility | Boise, ID | $128M | 2026–2030 |
| 3 | Disinfection and Digestion Upgrade | Mankato, MN | $80M | 2025–2026 |
| 4 | Patapsco Sludge Digestion Facilities | Baltimore, MD | $69M | 2031 |
| 5 | R.M. Clayton Digester Improvements | Atlanta, GA | $54M | 2026–2030 |
| 6 | Digester No. 4 | Longmont, CO | $30M | 2027–2029 |
| 7 | WPCP | Digester Rehabilitation Project | Davenport, IA | $27M | 2026–2028 |
| 8 | Bio Solids Facilities Enhancements | Fallston, MD | $27M | 2025–2029 |
| 9 | Digesters (2-years) | Jackson, MI | $24M | 2027–2029 |
| 10 | Wastewater OWTP: Digester/Cogeneration Improvements | Oxnard, CA | $17M | 2025–2029 |
All 136 digester and biogas 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 digester and biogas projects
| City | Projects | Budget |
|---|---|---|
| Hanover, NH | 11 | $814K |
| Lincoln, NE | 6 | $18M |
| Spokane, WA | 6 | $17M |
| Midland, MI | 4 | $3M |
| Alpena, MI | 4 | $386K |
| Antioch, IL | 4 | $80K |
| Saint Petersburg, FL | 3 | $26M |
| Mankato, MN | 2 | $80M |
| Baltimore, MD | 2 | $72M |
| Orlando, FL | 2 | $22M |
| Portland, OR | 2 | $12M |
| Wooster, OH | 2 | $7M |
States with the most digester and biogas projects
| State | Projects | Budget |
|---|---|---|
| Michigan | 28 | $36M |
| Washington | 12 | $55M |
| New Hampshire | 11 | $814K |
| California | 9 | $31M |
| Iowa | 7 | $40M |
| Illinois | 7 | $2M |
| Nebraska | 6 | $18M |
| Minnesota | 5 | $82M |
| Florida | 5 | $48M |
| Ohio | 5 | $24M |
| Oregon | 4 | $18M |
| Wisconsin | 4 | $5M |
Planned spend by start year
Before 2026
$500M
51 items
2026
$286M
40 items
2027
$69M
11 items
2028
$11M
14 items
2029
$8M
6 items
2030
$3M
4 items
2031
$69M
1 items
2032 and later
$732K
9 items
Other project types
Questions about digester and biogas 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 · Activated sludge · Oxidation ditch · all terms