Arsenic in Arizona Drinking Water
Ranked by arsenic violation count · Data from EPA SDWIS & UCMR
Arsenic in Arizona: what the data shows
Arizona has 222 cities with arsenic-related violations on record. Arsenic contamination is a federal MCL violation at levels above 10 µg/L (10 ppb). The state has 222 cities with at least one arsenic violation. Arsenic enters drinking water primarily through erosion of natural deposits, particularly in western states with arsenite-bearing geology. Industrial sources include mining runoff, glass manufacturing, and semiconductor production. Groundwater systems are significantly more likely to have arsenic issues than surface water systems. Long-term arsenic exposure above the MCL increases the risk of bladder, lung, and skin cancer, as well as cardiovascular disease and diabetes. Reverse osmosis and specialized arsenic-removal media are the most effective point-of-use treatment options.
Cities exceeding 10 µg/L EPA MCL
Arsenic data across Arizona
Each dot is a city with arsenic violation data. Cities with at least one arsenic-related violation are highlighted. Size reflects population served.
Top 10 cities by arsenic level in Arizona
Highest Arsenic levels (violations)
All Arizona cities ranked by arsenic level
| # | City | Level | Level | Violations? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Cottonwood | 279 violations | Yes | 184 | D | |
| 2 | Yuma | 253 violations | Yes | 318 | F | |
| 3 | Camp Verde | 242 violations | Yes | 149 | D | |
| 4 | Sedona | 221 violations | Yes | 174 | F | |
| 5 | Tucson | 123 violations | Yes | 150 | F | |
| 6 | Kingman | 110 violations | Yes | 110 | D | |
| 7 | Maricopa | 107 violations | Yes | 228 | D | |
| 8 | First Mesa Consolidated Villages | 92 violations | Yes | 74 | D | |
| 9 | Flagstaff | 84 violations | Yes | 74 | D | |
| 10 | Chino Valley | 81 violations | Yes | 48 | D+ | |
| 11 | Stanfield | 80 violations | Yes | 215 | D+ | |
| 12 | Rimrock | 77 violations | Yes | 53 | C- | |
| 13 | Casa Grande | 74 violations | Yes | 44 | F | |
| 14 | Shungopavi | 71 violations | Yes | 58 | D+ | |
| 15 | Douglas | 70 violations | Yes | 55 | D | |
| 16 | Nogales | 69 violations | Yes | 39 | F | |
| 17 | Clifton | 68 violations | Yes | 37 | D+ | |
| 18 | Pomerene | 68 violations | Yes | 19 | D+ | |
| 19 | Buckeye | 67 violations | Yes | 103 | F | |
| 20 | San Carlos | 66 violations | Yes | 140 | D | |
| 21 | Phoenix | 63 violations | Yes | 59 | F | |
| 22 | Surprise | 60 violations | Yes | 18 | F | |
| 23 | Black Canyon City | 60 violations | Yes | 16 | F | |
| 24 | Oak Creek Canyon | 60 violations | Yes | 43 | D+ | |
| 25 | Aneth | 57 violations | Yes | 52 | D | |
| 26 | Aneth | 57 violations | Yes | 49 | D+ | |
| 27 | Toadlena, Two Grey Hills | 56 violations | Yes | 51 | D | |
| 28 | Toadlena, Two Grey Hills | 56 violations | Yes | 51 | D | |
| 29 | Cornville | 54 violations | Yes | 21 | F | |
| 30 | Tubac | 53 violations | Yes | 44 | F | |
| 31 | Avra Valley | 52 violations | Yes | 32 | B- | |
| 32 | Show Low | 48 violations | Yes | 60 | D | |
| 33 | Tacna | 48 violations | Yes | 63 | D | |
| 34 | Green Valley | 47 violations | Yes | 9 | D | |
| 35 | Florence | 46 violations | Yes | 60 | F | |
| 36 | Tombstone | 45 violations | Yes | 26 | D | |
| 37 | Tonopah | 41 violations | Yes | 42 | D+ | |
| 38 | Hopi High School | 38 violations | Yes | 46 | D+ | |
| 39 | Red Mesa | 37 violations | Yes | 33 | D | |
| 40 | Cave Creek | 34 violations | Yes | 25 | C- | |
| 41 | Bullhead City | 33 violations | Yes | 57 | F | |
| 42 | Litchfield Park | 33 violations | Yes | 21 | F | |
| 43 | Globe | 32 violations | Yes | 46 | F | |
| 44 | Keams Canyon | 32 violations | Yes | 27 | B | |
| 45 | Chandler | 29 violations | Yes | 32 | F | |
| 46 | Middle Verde | 29 violations | Yes | 22 | B- | |
| 47 | Sierra Vista | 28 violations | Yes | 44 | D | |
| 48 | Prescott | 28 violations | Yes | 33 | F | |
| 49 | Parker | 28 violations | Yes | 148 | F | |
| 50 | Mayer | 26 violations | Yes | 24 | D+ | |
| 51 | Supai | 23 violations | Yes | 11 | D+ | |
| 52 | Payson | 22 violations | Yes | 60 | F | |
| 53 | Paulden | 22 violations | Yes | 3 | B | |
| 54 | Gilbert | 21 violations | Yes | 11 | F | |
| 55 | Glendale | 21 violations | Yes | 5 | F | |
| 56 | Pioneer | 21 violations | Yes | 16 | B | |
| 57 | Peoria | 20 violations | Yes | 13 | F | |
| 58 | El Mirage | 20 violations | Yes | 3 | D | |
| 59 | Fountain Hills | 20 violations | Yes | 21 | F | |
| 60 | Sweetwater, Red Mesa | 19 violations | Yes | 18 | C+ | |
| 61 | Wellton | 16 violations | Yes | 72 | D | |
| 62 | Eloy | 15 violations | Yes | 64 | D | |
| 63 | Red Mesa | 15 violations | Yes | 13 | B- | |
| 64 | White River | 15 violations | Yes | 20 | B- | |
| 65 | Sun City West | 13 violations | Yes | 3 | B+ | |
| 66 | Paradise Valley | 13 violations | Yes | 3 | C | |
| 67 | Scottsdale | 12 violations | Yes | 22 | F | |
| 68 | Whiteriver | 12 violations | Yes | 7 | D | |
| 69 | Salt River Indian Community | 11 violations | Yes | 22 | B | |
| 70 | Lakeside | 11 violations | Yes | 15 | D+ | |
| 71 | Humboldt | 11 violations | Yes | 10 | A- | |
| 72 | Tempe | 10 violations | Yes | 3 | D+ | |
| 73 | Pine | 10 violations | Yes | 10 | F | |
| 74 | Fredonia | 10 violations | Yes | 1 | C- | |
| 75 | Apache Junction | 9 violations | Yes | 18 | F | |
| 76 | Sun City | 9 violations | Yes | 1 | B | |
| 77 | Bonita | 9 violations | Yes | 4 | D | |
| 78 | Lake Havasu City | 8 violations | Yes | 5 | D | |
| 79 | Huachuca City | 8 violations | Yes | 12 | D | |
| 80 | Stotonic, Goodyear, Gila Butte, Sweetwat | 8 violations | Yes | 11 | B+ | |
| 81 | Rough Rock | 8 violations | Yes | 7 | B | |
| 82 | Mesa | 7 violations | Yes | 3 | F | |
| 83 | Sahuarita | 7 violations | Yes | 19 | F | |
| 84 | Safford | 7 violations | Yes | 9 | D | |
| 85 | Heber | 7 violations | Yes | 11 | F | |
| 86 | Buckeye-Sono | 7 violations | Yes | 2 | B- | |
| 87 | Vernon | 7 violations | Yes | 13 | D | |
| 88 | Wittmann | 7 violations | Yes | 5 | D+ | |
| 89 | Kearny | 7 violations | Yes | 14 | D | |
| 90 | Adaman | 7 violations | Yes | 9 | C- | |
| 91 | Grand Canyon | 6 violations | Yes | 11 | D | |
| 92 | Pinetop | 6 violations | Yes | 12 | D | |
| 93 | Clarkdale | 6 violations | Yes | 0 | B+ | |
| 94 | Tusayan | 6 violations | Yes | 18 | D+ | |
| 95 | Cameron | 6 violations | Yes | 38 | D | |
| 96 | Beaver Dam | 6 violations | Yes | 14 | D | |
| 97 | Red Valley | 6 violations | Yes | 5 | B+ | |
| 98 | San Luis | 5 violations | Yes | 8 | D | |
| 99 | Fort Huachuca | 5 violations | Yes | 9 | F | |
| 100 | Page | 5 violations | Yes | 8 | F | |
| 101 | Snowflake | 5 violations | Yes | 1 | C+ | |
| 102 | Topock | 5 violations | Yes | 13 | C | |
| 103 | Bagdad | 5 violations | Yes | 6 | A- | |
| 104 | Springerville | 5 violations | Yes | 16 | F | |
| 105 | Lukachukai | 5 violations | Yes | 4 | A- | |
| 106 | Oro Valley | 4 violations | Yes | 11 | D | |
| 107 | Marana | 4 violations | Yes | 13 | F | |
| 108 | Catalina | 4 violations | Yes | 2 | D | |
| 109 | Bisbee | 4 violations | Yes | 15 | F | |
| 110 | Winslow | 4 violations | Yes | 9 | D | |
| 111 | Wickenburg | 4 violations | Yes | 21 | F | |
| 112 | Benson | 4 violations | Yes | 29 | D | |
| 113 | Ajo | 4 violations | Yes | 0 | B- | |
| 114 | Quartzsite | 4 violations | Yes | 7 | D+ | |
| 115 | Williams | 4 violations | Yes | 14 | D+ | |
| 116 | Morenci | 4 violations | Yes | 15 | C- | |
| 117 | Bylas | 4 violations | Yes | 65 | D | |
| 118 | Ash Fork | 4 violations | Yes | 3 | B | |
| 119 | Star Valley | 4 violations | Yes | 9 | D+ | |
| 120 | San Xavier West | 4 violations | Yes | 3 | A- | |
| 121 | Round Rock | 4 violations | Yes | 12 | D+ | |
| 122 | Concho | 4 violations | Yes | 17 | D | |
| 123 | Ganado | 4 violations | Yes | 3 | D | |
| 124 | Coolidge | 4 violations | Yes | 18 | D+ | |
| 125 | Queen Creek | 3 violations | Yes | 14 | D | |
| 126 | Avondale | 3 violations | Yes | 13 | C+ | |
| 127 | Rio Rico | 3 violations | Yes | 4 | C | |
| 128 | Somerton | 3 violations | Yes | 17 | D | |
| 129 | Holbrook | 3 violations | Yes | 6 | F | |
| 130 | Superior | 3 violations | Yes | 0 | C- | |
| 131 | Willcox | 3 violations | Yes | 7 | D | |
| 132 | Fort Mohave | 3 violations | Yes | 19 | D | |
| 133 | Sr Boarding School, Sr Subdivision, Palo | 3 violations | Yes | 2 | A | |
| 134 | Linden | 3 violations | Yes | 3 | C- | |
| 135 | Tsaile, Dine College | 3 violations | Yes | 1 | A | |
| 136 | Spring Valley | 3 violations | Yes | 3 | A- | |
| 137 | Ehrenberg | 3 violations | Yes | 5 | B | |
| 138 | Three Points | 3 violations | Yes | 5 | D+ | |
| 139 | Wilhoit | 3 violations | Yes | 1 | A- | |
| 140 | Seligman | 3 violations | Yes | 0 | A- | |
| 141 | Hayden | 3 violations | Yes | 2 | D | |
| 142 | Wildhorse Pass Casino, St. Johns Komatke | 2 violations | Yes | 12 | B+ | |
| 143 | White Tanks | 2 violations | Yes | 1 | B+ | |
| 144 | Chinle, Many Farms, Del Muerto | 2 violations | Yes | 10 | B+ | |
| 145 | Sacaton, Sacaton Flats,Upper San Tan, Bl | 2 violations | Yes | 11 | B | |
| 146 | Peach Springs | 2 violations | Yes | 30 | C+ | |
| 147 | Taylor | 2 violations | Yes | 1 | D | |
| 148 | Mohave Valley | 2 violations | Yes | 14 | F | |
| 149 | Vail | 2 violations | Yes | 9 | F | |
| 150 | Casa Blanca,Bapchule,Wet Camp,Sacate,Wes | 2 violations | Yes | 10 | A- | |
| 151 | Clints Well | 2 violations | Yes | 1 | A- | |
| 152 | New Lands (Sanders) | 2 violations | Yes | 2 | A | |
| 153 | Upper Moenkopi | 2 violations | Yes | 8 | B- | |
| 154 | Cottonwood, Tselani | 2 violations | Yes | 4 | A | |
| 155 | Organ Pipe Nm | 2 violations | Yes | 1 | B | |
| 156 | Prescott Valley | 1 violations | Yes | 6 | D | |
| 157 | Goodyear | 1 violations | Yes | 3 | F | |
| 158 | Anthem | 1 violations | Yes | 1 | B | |
| 159 | Fort Defiance, Window Rock, St. Michaels | 1 violations | Yes | 22 | B- | |
| 160 | Tolleson | 1 violations | Yes | 1 | B+ | |
| 161 | Munds Park | 1 violations | Yes | 1 | A | |
| 162 | Kayenta | 1 violations | Yes | 0 | D | |
| 163 | Pinon, South Pinon, Burnt Corn, Blue Gap | 1 violations | Yes | 0 | A | |
| 164 | Eagar | 1 violations | Yes | 9 | C | |
| 165 | Pima | 1 violations | Yes | 11 | F | |
| 166 | Crownpoint, Littlewater, Three Mile Poin | 1 violations | Yes | 4 | A | |
| 167 | Crownpoint, Littlewater, Three Mile Poin | 1 violations | Yes | 4 | A | |
| 168 | Carefree | 1 violations | Yes | 0 | A- | |
| 169 | Big River | 1 violations | Yes | 7 | D | |
| 170 | Big River | 1 violations | Yes | 7 | D | |
| 171 | Saint Johns | 1 violations | Yes | 7 | C+ | |
| 172 | Silverbell | 1 violations | Yes | 0 | A | |
| 173 | Dolan Springs | 1 violations | Yes | 12 | C+ | |
| 174 | Bread Springs, Chichiltah | 1 violations | Yes | 3 | A | |
| 175 | Bread Springs, Chichiltah | 1 violations | Yes | 3 | A | |
| 176 | Kaibeto | 1 violations | Yes | 0 | B | |
| 177 | Sanostee, Tocito, Littlewater, Mittenroc | 1 violations | Yes | 0 | A | |
| 178 | Sanostee, Tocito, Littlewater, Mittenroc | 1 violations | Yes | 0 | A | |
| 179 | Joseph City | 1 violations | Yes | 0 | C+ | |
| 180 | Rock Point | 1 violations | Yes | 0 | B- | |
| 181 | Hotevilla, Hotevilla/Bacavi Community Sc | 1 violations | Yes | 1 | D+ | |
| 182 | Rock Springs | 1 violations | Yes | 0 | A | |
| 183 | Rock Springs | 1 violations | Yes | 0 | A | |
| 184 | Many Farms | 1 violations | Yes | 1 | B- | |
| 185 | St David | 1 violations | Yes | 22 | D+ | |
| 186 | Sunsites | 1 violations | Yes | 2 | B+ | |
| 187 | Dennehotso | 1 violations | Yes | 1 | B+ | |
| 188 | South Komelic, Choulic, Cold Fields, Top | 1 violations | Yes | 1 | A | |
| 189 | Kykotsmovi | 1 violations | Yes | 1 | A- | |
| 190 | Centennial Park | 1 violations | Yes | 21 | B- | |
| 191 | Mammoth | 1 violations | Yes | 2 | C- | |
| 192 | Naschitti, Bisola | 1 violations | Yes | 0 | A | |
| 193 | Naschitti, Bisola | 1 violations | Yes | 0 | A | |
| 194 | Bacavi | 1 violations | Yes | 0 | B+ | |
| 195 | Huerfano | 1 violations | Yes | 0 | A | |
| 196 | Huerfano | 1 violations | Yes | 0 | A | |
| 197 | Le Chee | 1 violations | Yes | 3 | A | |
| 198 | Ojo Encino, North Of | 1 violations | Yes | 0 | A- | |
| 199 | Ojo Encino, North Of | 1 violations | Yes | 0 | A- | |
| 200 | Nazlini | 1 violations | Yes | 1 | B | |
| 201 | Shonto | 1 violations | Yes | 0 | B+ | |
| 202 | Teec Nos Pos | 1 violations | Yes | 5 | B+ | |
| 203 | Alpine | 1 violations | Yes | 5 | B+ | |
| 204 | Aguila | 1 violations | Yes | 6 | B+ | |
| 205 | Hard Rock, Dinnebeto, Rocky Ridge | 1 violations | Yes | 2 | A | |
| 206 | Nageezi | 1 violations | Yes | 21 | D+ | |
| 207 | Ft. Wingate High School | 1 violations | Yes | 0 | B | |
| 208 | Ft. Wingate High School | 1 violations | Yes | 0 | B | |
| 209 | Fort Defiance | 1 violations | Yes | 1 | F | |
| 210 | Narbona Pass, Sheep Springs | 1 violations | Yes | 0 | A | |
| 211 | Narbona Pass, Sheep Springs | 1 violations | Yes | 0 | A | |
| 212 | Circle City | 1 violations | Yes | 1 | B+ | |
| 213 | Elfrida | 1 violations | Yes | 8 | D | |
| 214 | Iyanbito | 1 violations | Yes | 0 | A | |
| 215 | Iyanbito | 1 violations | Yes | 0 | A | |
| 216 | Nageezi | 1 violations | Yes | 2 | A | |
| 217 | Duncan | 1 violations | Yes | 8 | F | |
| 218 | Standing Rock | 1 violations | Yes | 0 | A- | |
| 219 | Standing Rock | 1 violations | Yes | 0 | A- | |
| 220 | Crystal, Yazzie Springs, Crystal Junctio | 1 violations | Yes | 0 | A- | |
| 221 | Crystal, Yazzie Springs, Crystal Junctio | 1 violations | Yes | 0 | A- | |
| 222 | Yarnell | 1 violations | Yes | 1 | B+ |
Frequently asked questions about arsenic in Arizona
Is arsenic in Arizona tap water a concern?
Yes — 222 cities in Arizona have arsenic-related violations on record. The EPA MCL for arsenic is 10 µg/L. Even at levels below the MCL, long-term arsenic exposure has been linked to cancer and cardiovascular disease.
How can I remove arsenic from my drinking water in Arizona?
Reverse osmosis (RO) systems are the most effective at removing arsenic, typically reducing it by 90% or more. Specialized arsenic-removal media (such as iron-based adsorption filters) are also highly effective. Standard carbon filters and pitcher filters do NOT effectively remove arsenic. If your water comes from a private well, have it tested for arsenic.
Where does arsenic in Arizona water come from?
Arsenic enters drinking water primarily through natural erosion of arsenic-bearing rock formations. It is most common in groundwater systems in the western United States, parts of the Midwest, and New England. Industrial sources include mining, smelting, and agricultural pesticide residues. Groundwater sources are far more likely to contain arsenic than surface water.