PWS ID# AZ0410-001

Ajo Improvement Company, (AIC) is committed to providing a safe supply of drinking water to our customers. We issue this report by July 1st of every year describing the quality of your drinking water to comply with state and U.S. Environmental Protection Agency (EPA) regulations. Much of the language used is mandated by regulations. This report provides valuable information about your drinking water, including information about its source and quality.

If you would like more information on the quality of your drinking water, have questions regarding this report, or require additional copies, please contact AIC at 520-387-2001. AIC recommends that customers serving more than one housing unit post a copy of this report in a conspicuous place.


The data in the accompanying tables are from water samples that have been analyzed by independent laboratories, which are certified by the Arizona Department of Health Services.

Constituents Units MCL MCLG Violation
Highest Level Detected or Running Annual Average Range Detected Sample Month/Year Likely Source of Detected Constituent
Chlorine (ppm) MRDL = 4 MRDLG = 4 N 0.72 0.22 - 0.72 2011 Water additive used to control microbes
Disinfection By-Products
Haloacetic Acids (HAA5) (ppb) 60 n/a N ND ND 8/2011 Byproduct of drinking water disinfecton
Total Trihalomethanes (TTHM) (ppb) 80 n/a N 11.0 NA 8/2011 Byproduct of drinking water disinfecton
Lead & Copper
Copper (ppm) AL = 1.3 ALG = 1.3 N 90th Percentile = 0.11
# Samples over AL = 0
NA 8/2011 Corrosion of household plumbing systems;erosion of natural deposits
Lead (ppb) AL = 15 0 N 90th Percentile = 0
# Samples over AL = 0
NA 8/2011 Corrosion of household plumbing systems;erosion of natural deposits
Alpha emitters (pCi/L) 15 0 N 1.5 NA 11/2009 Erosion of natural deposits
Arsenic (ppb) 10 0 N RAA = 1.7 1.2 - 2.0 2011 Erosion of natural deposits, runoff from orchards, runoff from glass and electronics production wastes
Chromium (ppb) 100 100 N 19 NA 11/2009 Discharge from steel and pulp mills, erosion of natural deposits
Fluoride (ppm) 4 4 N 0.35 NA 11/2009 Erosion of natural deposits; water additive which promotes strong teeth; discharge from fertilizer and aluminum factories
Nitrate (ppm) 10 10 N 3.6 NA 2011 Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Selenium (ppb) 50 50 N 2.2 NA 11/2009 Discharge fro petroleum and metal refineries; erosion of natural deposits; discharge from mines

NOTE: Data presented in the above tables are from the most recent testing done in accordance with applicable regulations. Some constituents are monitored less frequently than once per year because either their concentrations do not change frequently, or they are not likely to be detected. Therefore, some of the water quality testing data contained herein, although representative, may be more than one year old. The Environmental Protection Agency requires monitoring of over 80 drinking water contaminants. Those listed above are the only contaminants detected in your drinking water. For a complete list of all contaminants monitored please contact ADEQ.


Action Level (AL) The concentration of a contaminant that, if exceeded, triggers treatment or other requirements that a community water system shall follow.
Inorganic Chemicals Chemical substances of mineral origin, such as lead and copper.
Maximum Contaminant Level (MCL) The highest level of a constituent that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.
Maximum Contaminant Level Goal (MCLG) The level of a constituent in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
Microbiological Contaminants Very small organisms, such as bacteria, algae, plankton and fungi.
Maximum Residual Disinfectant Level (MRDL) The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
Maximum Residual Disinfectant Level Goal (MRDLG) The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
Organic Contaminants Naturally occurring or synthetic substances containing mainly carbon, hydrogen, nitrogen and oxygen. This includes most pesticides and industrial chemicals.
pCi/L Picocuries per liter.
Point-of-Entry The point at which water is discharged into the distribution system from a well, storage tank, pressure tank, or water treatment plant.
ppb Parts per billion, or one microgram per liter (µg/l)
ppm Parts per million, or one milligram per liter (mg/l)
Radionuclides Contaminants giving off ionizing radiation.
Treatment Technique A required process intended to reduce the level of a contaminant in drinking water

Index of CCRs




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