Ajo Arizona Fact Sheet

Ajo Arizona Water Quality
Water Quality

Water is a hot topic in Ajo. The municipal water is pumped from a deep volcanic source which maintains the water at a hot 106° F. The temperature of the water drops somewhat during the trip from the well to the treatment plant and then to the consumers, however during the summer months, the water temperature at the shower head is over 90°, allowing us to turn off the water heater for many weeks. More importantly, however, is the presence of Arsenic and Fluorine in the source water. Ajo tap water is treated with activated alumina to reduce Arsenic and Fluorine, but not all is removed. For this reason many residents do not drink water taken directly from the tap. Others point to the fact that many generations of Ajo residents have drunk the city water, even before it was treated to reduce Arsenic and Fluorine, with "no ill effects." So, how do you find out what is in the drinking water, and what do the "experts" have to say about the water quality? The water providers in Ajo, Ajo Domestic WID, Ajo Improvement Co and Arizona Water Co-Ajo will provide a copy of the Consumer Confidence Report upon request, or you can read it here. This is a government mandated report of the quality of the municipal water. Ajo Domestic WID and Arizona Water Co-Ajo purchase their treated water from Ajo Improvement Co, a division of Freeport McMoRan Corporation, so the water quality is the same from all three providers.

After reading several articles about the long term effects of Arsenic in drinking water, I decided to investigate drinking water options. The Brita filter, which I had used previously for drinking water, did a good job of improving the taste of the water, but past chemical analysis revealed that the Brita filter is not effective at removing inorganic chemicals, such as Sodium and Chlorine. Next, I tried bottled water, but it varied in taste and was expensive. Eventually I learned of the Reverse Osmosis water purification kiosk at the Shell Food Mart Ajo. The water tasted good, but was it really pure? I had it tested, so you can be the judge.

Independent Test of Water Samples collected in Ajo on July 8, 2002.

* Reverse Osmosis Water Purification Kiosk located at the Shell Food Mart, Ajo

Test Results
Arsenic (AS) Sodium (NA) Chlorine (CL) Bromine (BR)
Sample 1 <7 PPB 6.15 PPM 3.81 PPM <51.3 PPB
Sample 2 <6 PPB 6.07 PPM 3.75 PPM <66.7 PPB
Sample 3 <48 PPB 174 PPM 149 PPM 231 PPB
Sample 4 48.6 PPB 209 PPM 167 PPM 441 PPB
17 PPB 180 PPM    
The Arsenic detection limits reported in this summary table were manually calculated,
as opposed to the very conservative computer generated results reported in the
Multi-Element Survey Analysis reports, referred to below.

Notes: The symbol < stands for "less than." Elements with results preceded by "<" were not detected in the sample, however the element may be present in a quantity that is less than this detection limit.

Units of Measure
1 PPM 1 Part Per Million 0.001 gram / liter 1 mg / liter
1 PPB 1 Part Per Billion 0.000001 gram / liter 1 µg / liter

These samples were tested by General Activation Analysis, Inc., using neutron activation analysis. The Multi-Element Survey Analysis reports are available, Sample 1, Sample 2, Sample 3, Sample 4


Total Dissolved Solids Test Results

Test Method - Hand-Held Total Dissolved Solids Meter

Raw Well Water435 PPM
Tap Water400 PPM
RO Purified Water*15 PPM



More information on Water Quality

Arsenic in Drinking Water

Technical Fact Sheet: Arsenic in Drinking Water

Safe Water - General Interest

Overview of the Safe Drinking Water Act



Current Consumer Confidence Report for Ajo, Arizona

Previous Consumer Confidence Reports: 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2014, 2015, Current


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