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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Analysis of nitrates contamination levels across Arizona cities
Complete list of cities where nitrates has been detected, sorted by level
| City | Level | EPA Limit | % of Limit | Status |
|---|---|---|---|---|
| PrescottGrade C- | 4.93 mg/L | 10.00 mg/L | 49.3% | Safe |
| NogalesGrade D | 0.452 mg/L | 1.00 mg/L | 45.1% | Safe |
| ScottsdaleGrade D | 0.422 mg/L | 1.00 mg/L | 42.3% | Safe |
| Paradise ValleyGrade C- | 4.02 mg/L | 10.00 mg/L | 40.2% | Safe |
| Prescott ValleyGrade B- | 0.391 mg/L | 1.00 mg/L | 39.1% | Safe |
| El MirageGrade C- | 0.390 mg/L | 1.00 mg/L | 39.0% | Safe |
| MaranaGrade C+ | 0.370 mg/L | 1.00 mg/L | 37.0% | Safe |
| TucsonGrade C+ | 0.365 mg/L | 1.00 mg/L | 36.5% | Safe |
| SomertonGrade B+ | 2.99 mg/L | 10.00 mg/L | 29.9% | Safe |
| BuckeyeGrade B | 2.96 mg/L | 10.00 mg/L | 29.6% | Safe |
| MesaGrade C+ | 0.268 mg/L | 1.00 mg/L | 26.8% | Safe |
| SurpriseGrade C+ | 0.263 mg/L | 1.00 mg/L | 26.3% | Safe |
| SahuaritaGrade B- | 0.240 mg/L | 1.00 mg/L | 24.1% | Safe |
| AvondaleGrade B- | 0.238 mg/L | 1.00 mg/L | 23.8% | Safe |
| GoodyearGrade C+ | 0.203 mg/L | 1.00 mg/L | 20.3% | Safe |
| KingmanGrade B- | 2.00 mg/L | 10.00 mg/L | 20.0% | Safe |
| GilbertGrade B+ | 1.81 mg/L | 10.00 mg/L | 18.1% | Safe |
| DouglasGrade B+ | 1.75 mg/L | 10.00 mg/L | 17.5% | Safe |
| YumaGrade B+ | 1.60 mg/L | 10.00 mg/L | 16.0% | Safe |
| Casa GrandeGrade A | 1.42 mg/L | 10.00 mg/L | 14.2% | Safe |
| Fountain HillsGrade B+ | 0.139 mg/L | 1.00 mg/L | 13.9% | Safe |
| FlagstaffGrade A- | 1.34 mg/L | 10.00 mg/L | 13.4% | Safe |
| Lake Havasu CityGrade A- | 0.132 mg/L | 1.00 mg/L | 13.2% | Safe |
| Sierra VistaGrade A | 0.125 mg/L | 1.00 mg/L | 12.5% | Safe |
| ChandlerGrade A+ | 0.117 mg/L | 1.00 mg/L | 11.7% | Safe |
Showing 25 of 40 cities. View individual city pages for detailed reports.
Nitrates pose the greatest risk to infants under six months of age. High nitrate levels can cause methemoglobinemia, also known as "blue baby syndrome," which reduces the blood's oxygen-carrying capacity. Pregnant women are also at risk as nitrate exposure has been linked to neural tube defects, preterm birth, and low birth weight. IMPORTANT: Boiling water does NOT remove nitrates - it concentrates them.
Runoff from fertilizer use; leaching from septic tanks; erosion of natural deposits; agricultural runoff
Based on our analysis of EPA Safe Drinking Water Information System (SDWIS) data and local water utility reports,nitrates has been detected in 40 Arizona water systems. The average level across all tested cities is 19% of the EPA Maximum Contaminant Level (MCL), with the highest detection at 49.3% of the limit.
The EPA MCL for nitrate is 10 mg/L measured as nitrogen. The EPA MCL for nitrates is 10 mg/L. This limit is set to protect public health based on available scientific evidence about the contaminant's health effects.
40 Arizona cities have nitrates detected in their water supply. All tested cities are within EPA safety limits.
Blue baby syndrome in infants, pregnancy complications, potential cancer risk. The most vulnerable groups include infants under 6 months and pregnant women.
The most effective methods for removing nitrates include Reverse Osmosis, Ion Exchange, Distillation. Look for filters certified by NSF/ANSI for nitrates reduction.
The EPA Maximum Contaminant Level (MCL) for nitrates is 10 mg/L.The EPA MCL for nitrate is 10 mg/L measured as nitrogen.
Recommended filtration methods for nitrates removal:
Removes 83-92% of nitrates
Specifically designed for nitrate removal
Effective but energy-intensive