Manganese in Arizona Drinking Water
Ranked by max manganese detected (µg/L) · UCMR 4 data (2018–2020) · Data from EPA SDWIS & UCMR
Manganese in Arizona: what the data shows
Arizona has 58 cities with manganese data from the EPA's UCMR 4 program (2018–2020). Manganese exceeded the 50 µg/L EPA secondary MCL in 12 of those cities. The state average max detected level is 66.4 µg/L. Manganese occurs naturally in groundwater and surface water. Elevated levels are common in areas with iron-rich geology and in systems that draw from reservoirs with low dissolved oxygen. The secondary MCL of 50 µg/L is based on aesthetic concerns (taste, staining), but health-based guidelines suggest neurological effects at higher concentrations. Emerging research links chronic manganese exposure in drinking water to neurodevelopmental effects in children, including reduced IQ and behavioral issues. Oxidation filtration and water softeners are effective at removing manganese from household water.
Cities exceeding 50 µg/L EPA Secondary MCL
Manganese data across Arizona
Each dot is a city with UCMR 4 manganese testing data. Cities where manganese exceeds the 50 µg/L EPA secondary MCL are highlighted. Size reflects population served.
Top 10 cities by manganese level in Arizona
Highest Manganese levels (µg/L)
All Arizona cities ranked by manganese level
| # | City | Level | Level | Over SMCL? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Phoenix | 992.0 µg/L | Over SMCL | 59 | F | |
| 2 | Whiteriver | 920.0 µg/L | Over SMCL | 7 | D | |
| 3 | San Luis | 300.0 µg/L | Over SMCL | 8 | D | |
| 4 | Payson | 240.0 µg/L | Over SMCL | 60 | F | |
| 5 | Yuma | 220.0 µg/L | Over SMCL | 318 | F | |
| 6 | Chandler | 170.0 µg/L | Over SMCL | 32 | F | |
| 7 | Bullhead City | 140.0 µg/L | Over SMCL | 57 | F | |
| 8 | Fort Defiance, Window Rock, St. Michaels | 130.0 µg/L | Over SMCL | 22 | B- | |
| 9 | Tucson | 120.0 µg/L | Over SMCL | 150 | F | |
| 10 | Show Low | 87.0 µg/L | Over SMCL | 60 | D | |
| 11 | Tempe | 86.0 µg/L | Over SMCL | 3 | D+ | |
| 12 | Apache Junction | 51.0 µg/L | Over SMCL | 18 | F | |
| 13 | Eagar | 37.0 µg/L | No | 9 | C | |
| 14 | Cottonwood | 36.0 µg/L | No | 184 | D | |
| 15 | Litchfield Park | 32.0 µg/L | No | 21 | F | |
| 16 | Safford | 27.3 µg/L | No | 9 | D | |
| 17 | Somerton | 25.0 µg/L | No | 17 | D | |
| 18 | El Mirage | 23.0 µg/L | No | 3 | D | |
| 19 | Anthem | 23.0 µg/L | No | 1 | B | |
| 20 | Surprise | 22.0 µg/L | No | 18 | F | |
| 21 | Fountain Hills | 16.0 µg/L | No | 21 | F | |
| 22 | Oro Valley | 14.4 µg/L | No | 11 | D | |
| 23 | Kingman | 14.0 µg/L | No | 110 | D | |
| 24 | Green Valley | 14.0 µg/L | No | 9 | D | |
| 25 | Glendale | 12.0 µg/L | No | 5 | F | |
| 26 | Mesa | 10.0 µg/L | No | 3 | F | |
| 27 | Gilbert | 10.0 µg/L | No | 11 | F | |
| 28 | Rio Rico | 8.1 µg/L | No | 4 | C | |
| 29 | Sun City | 6.4 µg/L | No | 1 | B | |
| 30 | Lake Havasu City | 5.2 µg/L | No | 5 | D | |
| 31 | Pine | 4.8 µg/L | No | 10 | F | |
| 32 | Wildhorse Pass Casino, St. Johns Komatke | 4.2 µg/L | No | 12 | B+ | |
| 33 | Douglas | 4.2 µg/L | No | 55 | D | |
| 34 | Goodyear | 4.1 µg/L | No | 3 | F | |
| 35 | Johnson Ranch | 3.8 µg/L | No | 7 | D | |
| 36 | Prescott Valley | 3.4 µg/L | No | 6 | D | |
| 37 | Scottsdale | 3.3 µg/L | No | 22 | F | |
| 38 | Florence | 3.2 µg/L | No | 60 | F | |
| 39 | Nogales | 3.1 µg/L | No | 39 | F | |
| 40 | Queen Creek | 2.6 µg/L | No | 14 | D | |
| 41 | Catalina | 2.5 µg/L | No | 2 | D | |
| 42 | Sierra Vista | 2.0 µg/L | No | 44 | D | |
| 43 | Maricopa | 1.9 µg/L | No | 228 | D | |
| 44 | Flagstaff | 1.8 µg/L | No | 74 | D | |
| 45 | Casa Grande | 1.7 µg/L | No | 44 | F | |
| 46 | Fort Huachuca | 1.7 µg/L | No | 9 | F | |
| 47 | Peoria | 1.6 µg/L | No | 13 | F | |
| 48 | Heber | 1.6 µg/L | No | 11 | F | |
| 49 | Ak-Chin Village | 1.4 µg/L | No | 10 | A- | |
| 50 | Avondale | 1.3 µg/L | No | 13 | C+ | |
| 51 | Pinetop | 1.2 µg/L | No | 12 | D | |
| 52 | Upper Fruitland, Nenahnezad, San Juan, N | 1.1 µg/L | No | 9 | B+ | |
| 53 | Upper Fruitland, Nenahnezad, San Juan, N | 1.1 µg/L | No | 9 | B+ | |
| 54 | First Mesa Consolidated Villages | 0.9 µg/L | No | 74 | D | |
| 55 | Salt River Indian Community | 0.7 µg/L | No | 22 | B | |
| 56 | Buckeye | 0.7 µg/L | No | 103 | F | |
| 57 | Sedona | 0.6 µg/L | No | 174 | F | |
| 58 | Sun City West | 0.5 µg/L | No | 3 | B+ |
Frequently asked questions about manganese in Arizona
Is manganese in Arizona tap water harmful?
The EPA secondary MCL for manganese is 50 µg/L, set primarily for aesthetic reasons (taste, color, staining). 12 cities in Arizona exceed the secondary MCL. However, emerging research links chronic manganese exposure above 50–100 µg/L to neurodevelopmental effects in children, including reduced IQ.
How can I remove manganese from my drinking water?
Oxidation filtration (such as greensand or birm filters) is the most common and effective method for removing manganese from well water. Water softeners using ion exchange also work well. Standard carbon filters provide limited manganese removal. If your water has a metallic taste or brown/black discoloration, manganese may be the cause.
What causes high manganese in Arizona water?
Manganese occurs naturally in groundwater and surface water, particularly in areas with iron-rich geology. Low dissolved oxygen conditions (common in deep wells and reservoir bottom waters) increase manganese solubility. Industrial sources include mining, steel production, and battery manufacturing. Seasonal changes in reservoir water chemistry can cause manganese spikes.