91st Avenue WWTP
Tolleson, AZ · Maricopa County · Publicly Owned Treatment Works
- Average flow
- 78.71 MGD
- Design flow
- 230 MGD
- NPDES permit
- AZ0020524
- Effective
- Permit expires
- April 2028
- Population served
- —
- CWNS 2022
91st Avenue WWTP is a publicly owned wastewater treatment works in Tolleson, Maricopa County, Arizona treating an average of 78.71 million gallons per day against a permitted design capacity of 230 MGD. Treatment on site includes clarifiers, uncovered lagoons, carrousels / oxidation ditches, biogas silos. It discharges under NPDES permit AZ0020524 (effective), which expires in April 2028, with 2 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Clarifiers
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Uncovered lagoons
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Carrousels / oxidation ditches
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Biogas silos
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Compliance snapshot (last 3 years)
- Total violations
- 2
- Effluent violations
- 2
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
3 verified contacts for 91st Avenue WWTP, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at 91st Avenue WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Arizona
Tolleson · 3 mi away
—
Phoenix · 8 mi away
35.67 MGD
Goodyear · 9 mi away
2.5 MGD
Goodyear · 14 mi away
—
Buckeye · 16 mi away
2.02 MGD
Buckeye · 20 mi away
0.28 MGD
Buckeye · 20 mi away
1.38 MGD
Peoria · 23 mi away
0.23 MGD
91st Avenue WWTP: frequently asked 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; facility record last updated May 10, 2025.