Copper in Arizona Drinking Water
Ranked by 90th percentile copper level (mg/L) · Data from EPA SDWIS & UCMR
Copper in Arizona: what the data shows
Arizona has 30 cities with copper monitoring data. The state average 90th percentile copper level is 6.216 mg/L, compared to 28.808 mg/L nationally — better than the national average. 30 cities exceed the EPA action level of 1.3 mg/L. Copper in drinking water typically comes from corrosion of copper pipes and plumbing fixtures, particularly in older homes. The EPA action level of 1.3 mg/L is the 90th percentile threshold — if more than 10% of tap samples exceed it, utilities must take corrective action including adjusting water chemistry to reduce corrosivity. Short-term copper exposure above the action level can cause gastrointestinal distress. Long-term exposure at elevated levels is associated with liver and kidney damage. Flushing your tap for 30 seconds before use and using an NSF 53-certified filter can reduce copper exposure.
Cities exceeding 1.3 mg/L EPA Action Level
Copper data across Arizona
Each dot is a city, colored by overall water quality grade. Cities with copper levels above the 1.3 mg/L EPA action level are highlighted. Size reflects population served.
Top 10 cities by copper level in Arizona
All Arizona cities ranked by copper level
| # | City | Level | Level | Exceeds? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Gilbert | 135.500 mg/L | Yes | 11 | F | |
| 2 | Florence | 4.000 mg/L | Yes | 60 | F | |
| 3 | Yuma | 2.700 mg/L | Yes | 318 | F | |
| 4 | Houck, Querino Canyon | 2.330 mg/L | Yes | 3 | A- | |
| 5 | Fountain Hills | 2.255 mg/L | Yes | 21 | F | |
| 6 | Prescott | 2.080 mg/L | Yes | 33 | F | |
| 7 | Cameron | 1.910 mg/L | Yes | 38 | D | |
| 8 | Phoenix | 1.900 mg/L | Yes | 59 | F | |
| 9 | Aneth | 1.900 mg/L | Yes | 52 | D | |
| 10 | Sawmill (East And South), Upper Buell Pa | 1.900 mg/L | Yes | 0 | A- | |
| 11 | Pine | 1.760 mg/L | Yes | 10 | F | |
| 12 | Fort Defiance | 1.680 mg/L | Yes | 1 | F | |
| 13 | Parker | 1.620 mg/L | Yes | 148 | F | |
| 14 | Duncan | 1.600 mg/L | Yes | 8 | F | |
| 15 | Cave Creek | 1.590 mg/L | Yes | 25 | C- | |
| 16 | Peridot | 1.520 mg/L | Yes | 1 | B | |
| 17 | Page | 1.500 mg/L | Yes | 8 | F | |
| 18 | Big River | 1.500 mg/L | Yes | 7 | D | |
| 19 | Big River | 1.500 mg/L | Yes | 7 | D | |
| 20 | Tonopah | 1.500 mg/L | Yes | 42 | D+ | |
| 21 | Lukachukai | 1.490 mg/L | Yes | 4 | A- | |
| 22 | Crystal, Yazzie Springs, Crystal Junctio | 1.490 mg/L | Yes | 0 | A- | |
| 23 | Crystal, Yazzie Springs, Crystal Junctio | 1.490 mg/L | Yes | 0 | A- | |
| 24 | Payson | 1.430 mg/L | Yes | 60 | F | |
| 25 | Nogales | 1.400 mg/L | Yes | 39 | F | |
| 26 | Mohave Valley | 1.400 mg/L | Yes | 14 | F | |
| 27 | Ft. Wingate High School | 1.400 mg/L | Yes | 0 | B | |
| 28 | Ft. Wingate High School | 1.400 mg/L | Yes | 0 | B | |
| 29 | Wickenburg | 1.370 mg/L | Yes | 21 | F | |
| 30 | Black Canyon City | 1.350 mg/L | Yes | 16 | F |
Frequently asked questions about copper in Arizona
Is copper in Arizona drinking water safe?
30 cities in Arizona exceed the EPA action level of 1.3 mg/L for copper. The state average is 6.216 mg/L. Copper levels are highest in homes with copper plumbing, particularly when water sits in pipes overnight. Flushing the tap before use significantly reduces copper in drinking water.
What causes high copper levels in Arizona tap water?
Copper typically leaches from copper pipes and brass fittings within homes, not from the water source itself. Corrosive (low pH or soft) water accelerates this leaching. Water utilities with high copper readings are required to adjust water chemistry to reduce corrosivity. You can reduce exposure by flushing your tap for 30 seconds before use.