Chlorine disinfection: wastewater treatment plants in Arizona
12 plants · 23% of the state · 74 MGD reported by 7 plants
Klarifi identifies 12 publicly owned wastewater treatment plants with chlorine disinfection in Arizona, 23% of the 53 plants in the state (74 MGD reported by 7 plants). The largest is 23rd Avenue Wastewater Treatment Plant in Phoenix at 35.67 MGD.
Chlorine or chloramine disinfection, often followed by dechlorination before discharge, remains the most common effluent disinfection in the United States. Plants on gas chlorine are candidates for conversion to hypochlorite or UV, a recurring capital project driven by safety rules and permit limits on residual chlorine.
The largest plants with chlorine disinfection in Arizona
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | 23rd Avenue Wastewater Treatment Plant | Phoenix | 35.67 | AZ0020559 | Jun 2029 | 2 |
| 2 | Pima County - Ina Road WWTP | Tucson | 31.89 | AZ0020001 | May 2027 | 3 |
| 3 | Casa Grande WRF | Casa Grande | 3.54 | AZ0025178 | Sep 2029 | 29 |
| 4 | Buckeye WWTP | Buckeye | 1.38 | AZ0025313 | Oct 2030 | 1 |
| 5 | Cottonwood WWTF | Cottonwood | 1.04 | AZ0024716 | Apr 2027 | 16 |
| 6 | City Of Safford - Gila Resources Wrp | Safford | 0.78 | AZ0024911 | Jun 2029 | 0 |
| 7 | Town Of Patagonia - WWTP | Patagonia | 0.05 | AZ0025011 | Jul 2030 | 0 |
| 8 | Agua Nueva WRF | Tucson | — | AZ0026107 | Apr 2028 | 0 |
| 9 | Apache Junction WWTP | Apache Junction | — | AZ0023931 | Jul 2029 | 0 |
| 10 | North Florence Wwtp, Town Of Florence | Florence | — | AZ0025194 | Nov 2025 | 11 |
| 11 | Pima County - Wwmd - Green Valley Bnro - WWTP | Sahuarita | — | AZ0024937 | Mar 2031 | 0 |
| 12 | Town Of Florence WWTP | Florence | — | AZ0025208 | Apr 2031 | 23 |
Plants planning chlorine disinfection upgrades
These plants report chlorine disinfection 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 |
|---|---|---|---|---|
| Town Of Prescott Valley - WWTP | Prescott Valley | 2.74 | AZ0025381 | Feb 2027 |
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 Arizona
Chlorine disinfection in other states
Chlorine disinfection in Arizona: 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 September 11, 2026.