Ajo Improvement Company

PWS ID# AZ0410-001

As the owner and operator of this drinking water system, Ajo Improvement Company (AIC) is committed to providing a safe supply of drinking water to our customers. We issue this report by July 1sl 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.

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Information About Your Drinking Water

The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.

AIC's water source is groundwater that is obtained from the Childs Well Field located approximately six miles to the north of Ajo, Arizona.

In order to ensure that tap water is safe to drink, the Environmental Protection Agency (EPA) prescribes regulations that limit the amount of certain constituents in water provided by public water systems. The Food and Drug Administration (FDA) regulations establish limits for constituents in bottled water which must provide the same protection for public health.

Contaminants that may be present in source water include the following:

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA's Safe Drinking Water Hotline at 1-800-426-4791. Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV-AIDS or other immune system disorders, some elderly, and infants can be particularly at risk of infections. These people should seek advice about drinking water from their health care providers. EPA and the U.S. Centers for Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbiological contaminants are available from the EPA Safe Drinking Water Hotline at 1-800-426-4791.

Source Water Assessment:

The Source Water Assessment (SWA) Program, developed and implemented by the Arizona Department of Environmental Quality (UADEQ") under EPA guidance, was created to promote community awareness of water quality issues and to encourage the protection of drinking water sources at the community level. ADEQ gathers information on drinking water sources including wells, surface water intakes, and springs and evaluates the extent to which the water source is vulnerable to natural or man-made contamination from sources such as gas stations, landfills, dry cleaners, agriculture fields, waste water treatment plants, and mining activities.

ADEQ has evaluated the source water areas in Pima County including the source waters for the AIC drinking water system. The SWA for the AIC drinking water system has been designated as low risk.

The complete SWA report is available for inspection at the ADEQ, 1110 W. Washington, Phoenix, Arizona 85007, between the hours of 8:00 am and 5:00 pm. Further source water assessment documentation can be obtained by contacting ADEQ, 602-771-4641 or visit ADEQ's Source Water Assessment Protection Unit website at: www.azdeg.gov/environ/water/dw/swap.html.

Water Quality Data:

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

Violations, if any:

Type / Description Length of Violation Corrective Actions taken by PWS
None NA NA


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

Table for Reporting Constituents

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 0.91 0.02 - 0.91 2012 Water additive used to control microbes
Disinfection By-Products
Haloacetic Acids (HAA5) (ppb) 60 n/a N <1 n/a 8/2012 Byproduct of drinking water disinfecton
Total Trihalomethanes (TTHM) (ppb) 80 n/a N 22 n/a 8/2012 Byproduct of drinking water disinfecton
Lead & Copper
Copper (ppm) AL = 1.3 ALG = 1.3 N 90th Percentile = 0.02
# Samples over AL = 0
<0.01 - 0.03 8/2012 Corrosion of household plumbing systems;erosion of natural deposits
Lead (ppb) AL = 15 0 N 90th Percentile = 1.6
# Samples over AL = 0
<1.0 - 2.2 8/2012 Corrosion of household plumbing systems;erosion of natural deposits
Alpha emitters (pCi/L) 15 0 N 1.5 n/a 11/2009 Erosion of natural deposits
Arsenic (ppb) 10 0 N RAA = 5.5 2.2 - 11 2012 Erosion of natural deposits, runoff from orchards, runoff from glass and electronics production wastes
Asbestos (MFL) 7 7 N <0.01 n/a 12/2012 Decay of asbestos cement water mains; Erosion of natural deposits
Fluoride (ppm) 4 4 N 0.94 n/a 12/2012 Erosion of natural deposits; water additive which promotes strong teeth; discharge from fertilizer and aluminum factories
Sodium (ppm) No MCL No MCLG N 210 n/a 12/2012 Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Synthetic Organic Contaminats                
Di(2-ethylhexyl) phthalate (ppb) 6 0 N <6 n/a 12/2012 Discharge from rubber and chemical factories

NOTE: Data presented in the tables above 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.

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