Clean Water Act discharge permit · NPDES AZ0024031
CITY OF MESA - NORTHWEST WRP, Mesa, AZ: NPDES AZ0024031 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MajorDischarger class
- 17Pollutants under a numeric limit
- 8Pollutants with an effluent exceedance
- 1Inspections on file
- 0Formal enforcement actions
CITY OF MESA - NORTHWEST WRP, held by City Of Mesa - Water Resources, holds NPDES permit AZ0024031. EPA’s file records it issued November 20, 2024 and expiring November 19, 2029.
CITY OF MESA - NORTHWEST WRP, Mesa, Arizona: Individual permit AZ0024031, held by City Of Mesa - Water Resources; Publicly owned treatment works; Effective; issued November 20, 2024, term to November 19, 2029.
- Chlorine, total residual: 4 limits, 112 violations of any kind, 6 effluent exceedances, latest October 31, 2023, largest 16,567% over the limit.
- E. coli, colony forming units [CFU]: 2 limits, 41 violations of any kind, 3 effluent exceedances, latest May 31, 2009, largest 320% over the limit.
- Solids, total suspended: 6 limits, 120 violations of any kind, 2 effluent exceedances, latest March 31, 2006, largest 178% over the limit.
- BOD, 5-day, 20 deg. C: 6 limits, 127 violations of any kind, 1 effluent exceedance, latest March 31, 2012, largest 1,687% over the limit.
- pH: 2 limits, 41 violations of any kind, 1 effluent exceedance, latest February 29, 2012.
- Nitrogen, ammonia total [as N]: 4 limits, 1 violation of any kind, 1 effluent exceedance, latest May 31, 2021, largest 8% over the limit.
- TU Static Renewal 7-Day Chronic Pimphales promelas: 1 limit, 1 violation of any kind, 1 effluent exceedance, latest June 30, 2010, largest 33% over the limit.
- TU Static 7Day Chronic Ceriodaphnia dubia: 0 limits, 1 violation of any kind, 1 effluent exceedance, latest June 30, 2010, largest 33% over the limit.
- Selenium, total recoverable: 4 limits, 110 violations of any kind, 0 effluent exceedances.
- Cyanide, total [as CN]: 0 limits, 110 violations of any kind, 0 effluent exceedances.
- Sulfide, total [as S]: 0 limits, 110 violations of any kind, 0 effluent exceedances.
- Hexachlorocyclopentadiene: 0 limits, 107 violations of any kind, 0 effluent exceedances.
- Beryllium, total recoverable [as Be]: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Silver total recoverable: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Cadmium, total recoverable: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Lead, total recoverable: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Chromium, total recoverable: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Benzo[a]pyrene: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Bis[2-chloroethyl] ether: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- 1,2-Diphenylhydrazine: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Hexachlorobutadiene: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Phenanthrene: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- 2,4,6-Trichlorophenol: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- 4-Bromophenyl phenyl ether: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Benzidine: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- 4-Chloro-3-methylphenol: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- Mercury, total recoverable: 0 limits, 106 violations of any kind, 0 effluent exceedances.
- 2-Methyl-4,6-dinitrophenol: 0 limits, 102 violations of any kind, 0 effluent exceedances.
- Copper, total recoverable: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- Endosulfan sulfate: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- N-Nitrosodimethylamine [NDMA]: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- 2,4-Dinitrophenol: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- 3,3'-Dichlorobenzidine: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- Pentachlorophenol: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- Polychlorinated biphenyls [PCBs]: 0 limits, 94 violations of any kind, 0 effluent exceedances.
- Endosulfan, total: 0 limits, 72 violations of any kind, 0 effluent exceedances.
- Hardness, total [as CaCO3]: 0 limits, 38 violations of any kind, 0 effluent exceedances.
- Flow, in conduit or thru treatment plant: 2 limits, 34 violations of any kind, 0 effluent exceedances.
- Chromium, hexavalent dissolved [as Cr]: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- BOD, 5-day, percent removal: 1 limit, 11 violations of any kind, 0 effluent exceedances.
- Solids, suspended percent removal: 1 limit, 10 violations of any kind, 0 effluent exceedances.
- Chromium, trivalent [as Cr]: 0 limits, 10 violations of any kind, 0 effluent exceedances.
- Benzene: 0 limits, 7 violations of any kind, 0 effluent exceedances.
- TU Static 4 Day Chronic Raphidocelis subcapitata (formerly Selenastrum capricornutum): 2 limits, 2 violations of any kind, 0 effluent exceedances.
- TU Static Renewal 7-Day Chronic Ceriodaphnia dubia: 2 limits, 2 violations of any kind, 0 effluent exceedances.
- Tributyltin: 0 limits, 1 violation of any kind, 0 effluent exceedances.
- Mirex: 0 limits, 1 violation of any kind, 0 effluent exceedances.
- Oil & Grease: 2 limits, 0 violations of any kind, 0 effluent exceedances.
- Temperature, water deg. centigrade: 1 limit, 0 violations of any kind, 0 effluent exceedances.
- Pass/Fail Static Renewal 96Hr Acute Ceriodaphnia dubia: 1 limit, 0 violations of any kind, 0 effluent exceedances.
- Pass/Fail Static Renewal 96Hr Acute Pimephales Promelas: 1 limit, 0 violations of any kind, 0 effluent exceedances.
- April 30, 2026: Evaluation (S).
Arizona holds 91 Publicly owned treatment works coverages of this permit type in EPA’s file; 79 were issued before AZ0024031. City Of Mesa - Water Resources holds 3 permits in Arizona.
Other permits held by City Of Mesa - Water Resources
- CITY OF MESA - GREENFIELD WATER RECLAMATION PLANT, Gilbert: AZ0025241, issued December 26, 2019
- CITY OF MESA - GREENFIELD WATER RECLAMATION PLANT, Gilbert: AZPT00005, issued July 13, 1983
Coverages issued nearest AZ0024031
- June 12, 2023: CITY OF GOODYEAR - 157TH AVE WWTP, Goodyear, AZPT00010, held by City Of Goodyear
- August 15, 2023: CITY OF YUMA - FIGUEROA AVE WPCF, Yuma, AZ0020443, held by City Of Yuma - Department Of Public Works
- November 9, 2023: AMERICAN RANCH DWID, Prescott, AZ0026522, held by American Ranch Dwid
- January 18, 2024: AZ STATE PKS PATAGONIA LAKE, Nogales, AZ0026620, held by Arizona State Parks
- April 3, 2024: CITY OF BUCKEYE - SUNDANCE WRF, Buckeye, AZ0024881, held by City Of Buckeye
- December 2, 2024: CITY OF PHOENIX - CAVE CREEK WATER RECLAMATION PLANT, Phoenix, AZ0026727, held by City Of Phoenix
- March 13, 2025: CITY OF TOLLESON - WWTP, Tolleson, AZPT00017, held by City Of Tolleson
- June 6, 2025: SIX MILE LAGOON WASTEWATER TREATMENT FACILITY, Peridot, AZ0024640, held by San Carlos Apache Tribe Water Distribution and Wasteater Treatment Facilities Pr
CITY OF MESA - NORTHWEST WRP among its neighbors
EPA’s permit file holds 133 discharge permits in the Salt River-Tempe Town Lake subwatershed (HUC 150601060304), AZ0024031 among them. Its county holds 618, 31 of them major permits; AZ0024031 is a major permit.
Other permits in the Salt River-Tempe Town Lake subwatershed (HUC 150601060304)
- 202 VAL VISTA, Unknown: AZC103138, minor permit, permit term to June 30, 2025
- 4051101 COT DOWNTOWN STREETSCAPE: MILL AVE, Tempe: AZC115861, minor permit, discharging to Tempe Town Lake | AT MILL AVENUE BRIDGE @ 33°, permit term to August 28, 2030
- 7357 THOMAS ROAD SEWER, Unknown: AZC113735, minor permit, discharging to Unnamed ephemeral tributary, permit term to August 28, 2030
- 7TH STREET RESIDENTIAL, Tempe: AZC112163, minor permit, discharging to Hayden Canal | Tempe Canal - SAN FRANCISCO CAN, permit term to August 28, 2030
- 8TH ST; RURAL RD TO MCCLINTOCK DR, TEMPE, AZ, Unknown: AZC109871, minor permit, permit term to June 30, 2025
- 8TH ST; RURAL RD TO MCCLINTOCK DR, TEMPE, AZ, Unknown: AZC115467, minor permit, discharging to Hayden Canal | Tempe Canal - SAN FRANCISCO CAN, permit term to August 28, 2030
- ABC SUPPLY CO. INC., Mesa: AZC115219, minor permit, discharging to Tempe Cross Cut Canal | South Canal - CANAL @, permit term to August 28, 2030
- ABLE STEEL FABRICATORS, Mesa: AZI108613, minor permit, discharging to Roosevelt Canal, permit term to January 15, 2030
- ADVANCED AIR AT PHX, Phoenix: AZI107713, minor permit, discharging to Salt River | TEMPE TOWN LAKE DAM - I-10 BRIDGE, permit term to January 15, 2030
- AGRITAINMENT DISTRICT AT PIONEER CROSSING, Mesa: AZC105416, minor permit, permit term to June 30, 2025
Identity
| Facility as filed | CITY OF MESA - NORTHWEST WRP |
|---|---|
| Permittee as filed | City Of Mesa - Water Resources |
| NPDES ID | AZ0024031 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | November 20, 2024 |
| Expiration date | November 19, 2029 |
| Address | Mesa, AZ 85201 |
| Subwatershed | Salt River-Tempe Town Lake (HUC 150601060304) |
| Program components on file | POTW, Pretreatment |
| SIC | 4952 – Sewerage Systems |
Effluent limits and exceedances
- 51Pollutants on file
- 17Under a numeric limit
- 47With a violation of any kind
- 8With an effluent exceedance
An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.
| Pollutant or measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Chlorine, total residual | 4 | 112 | 6 | October 31, 2023 | 16,567% over the limit |
| E. coli, colony forming units [CFU] | 2 | 41 | 3 | May 31, 2009 | 320% over the limit |
| Solids, total suspended | 6 | 120 | 2 | March 31, 2006 | 178% over the limit |
| BOD, 5-day, 20 deg. C | 6 | 127 | 1 | March 31, 2012 | 1,687% over the limit |
| pH | 2 | 41 | 1 | February 29, 2012 | |
| Nitrogen, ammonia total [as N] | 4 | 1 | 1 | May 31, 2021 | 8% over the limit |
| TU Static Renewal 7-Day Chronic Pimphales promelas | 1 | 1 | 1 | June 30, 2010 | 33% over the limit |
| TU Static 7Day Chronic Ceriodaphnia dubia | 0 | 1 | 1 | June 30, 2010 | 33% over the limit |
| Selenium, total recoverable | 4 | 110 | 0 | ||
| Cyanide, total [as CN] | 0 | 110 | 0 | ||
| Sulfide, total [as S] | 0 | 110 | 0 | ||
| Hexachlorocyclopentadiene | 0 | 107 | 0 | ||
| Beryllium, total recoverable [as Be] | 0 | 106 | 0 | ||
| Silver total recoverable | 0 | 106 | 0 | ||
| Cadmium, total recoverable | 0 | 106 | 0 | ||
| Lead, total recoverable | 0 | 106 | 0 | ||
| Chromium, total recoverable | 0 | 106 | 0 | ||
| Benzo[a]pyrene | 0 | 106 | 0 | ||
| Bis[2-chloroethyl] ether | 0 | 106 | 0 | ||
| 1,2-Diphenylhydrazine | 0 | 106 | 0 | ||
| Hexachlorobutadiene | 0 | 106 | 0 | ||
| Phenanthrene | 0 | 106 | 0 | ||
| 2,4,6-Trichlorophenol | 0 | 106 | 0 | ||
| 4-Bromophenyl phenyl ether | 0 | 106 | 0 | ||
| Benzidine | 0 | 106 | 0 | ||
| 4-Chloro-3-methylphenol | 0 | 106 | 0 | ||
| Mercury, total recoverable | 0 | 106 | 0 | ||
| 2-Methyl-4,6-dinitrophenol | 0 | 102 | 0 | ||
| Copper, total recoverable | 0 | 94 | 0 | ||
| Endosulfan sulfate | 0 | 94 | 0 | ||
| N-Nitrosodimethylamine [NDMA] | 0 | 94 | 0 | ||
| 2,4-Dinitrophenol | 0 | 94 | 0 | ||
| 3,3'-Dichlorobenzidine | 0 | 94 | 0 | ||
| Pentachlorophenol | 0 | 94 | 0 | ||
| Polychlorinated biphenyls [PCBs] | 0 | 94 | 0 | ||
| Endosulfan, total | 0 | 72 | 0 | ||
| Hardness, total [as CaCO3] | 0 | 38 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 34 | 0 | ||
| Chromium, hexavalent dissolved [as Cr] | 0 | 12 | 0 | ||
| BOD, 5-day, percent removal | 1 | 11 | 0 | ||
| Solids, suspended percent removal | 1 | 10 | 0 | ||
| Chromium, trivalent [as Cr] | 0 | 10 | 0 | ||
| Benzene | 0 | 7 | 0 | ||
| TU Static 4 Day Chronic Raphidocelis subcapitata (formerly Selenastrum capricornutum) | 2 | 2 | 0 | ||
| TU Static Renewal 7-Day Chronic Ceriodaphnia dubia | 2 | 2 | 0 | ||
| Tributyltin | 0 | 1 | 0 | ||
| Mirex | 0 | 1 | 0 | ||
| Oil & Grease | 2 | 0 | 0 | ||
| Temperature, water deg. centigrade | 1 | 0 | 0 | ||
| Pass/Fail Static Renewal 96Hr Acute Ceriodaphnia dubia | 1 | 0 | 0 | ||
| Pass/Fail Static Renewal 96Hr Acute Pimephales Promelas | 1 | 0 | 0 |
Inspections, violations and enforcement
- 0Single-event violations
EPA’s single-event violation file, as loaded, holds no violation for NPDES AZ0024031.
Inspections
| Date | What EPA recorded | Agency |
|---|---|---|
| April 30, 2026 | Evaluation | S |
Formal enforcement and penalties
0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.
Informal enforcement
EPA’s informal enforcement file holds no action for NPDES AZ0024031.
Watch this permit
One permit holder, $99/month. Watch the register for one permit holder and the places and receiving waters tied to its permits. Choose “One permit holder” and enter this permit’s NPDES ID, AZ0024031.
Start the watch
- One permit holder — $99/month
- One watershed — $2,990/year
- One state — $4,990/year
- The whole register — $18,000/year
How we handle your data → Privacy
Nearby on the register
- Discharge permits in Mesa
- Every permit record in Mesa, A to Z
- Discharge permits in Arizona
- Every permit record in Arizona, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.