PWSID# 10-001

The Ajo Improvement Company, (AIC) is committed to providing a safe supply of drinking water to our customers. We issue this report annually 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. We are proud to report that AIC's water meets or exceeds all health standards set by the state and federal government for 2009.

Additional copies of the report are available at the AIC office located on Elota Avenue in Ajo, Arizona; via mail by sending a request to AIC, PO Drawer 9, Ajo, Arizona 85321; or by calling 520-387-2001. Ajo Improvement Company recommends that customers serving more than one housing unit post a copy of this report in a conspicuous place. If you have questions regarding this report or if you require this report in Spanish please contact AIC at (520) 387-2001. Si tiene usted alguna pregunta sobre este informe de Calidad de Ia Agua, o require este informe en espãnol, favor de escribir a Ajo Improvement Company, PO Drawer 9, Ajo, AZ 85321 o llame por telefono a (520) 387-2001.


Ajo Improvement Company's water source is groundwater which is obtained from an underground well field located approximately six miles to the north of Ajo, Arizona. The groundwater is delivered from the well field to holding tanks. The water is then routed through a Water Treatment Plant for the removal of naturally occurring arsenic and fluoride and chlorinated before it is delivered to the community through the water distribution system.


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

The sources of drinking 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.

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 the 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 (800-426-4791). Information on bottled water can be obtained from the FDA.

Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, persons with HIV, AIDS, or immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA and Centers for Disease Control guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the EPA Safe Drinking Water Hotline (800-426-4791).

Lead and Copper Testing

Federal regulations require that AIC test for lead and copper at selected customer's taps every year. AIC last conducted lead and copper tap sampling during the summer of 2009 with the concentrations of lead and copper well below regulatory limits.

If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. AIC is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline or at http://www.epa.gov/safewater/lead.


Backflow Prevention

AIC has a backflow prevention program that ensures proper installation and maintenance of backflow prevention devices throughout its water system. These devices ensure hazards originating on customer's property and from temporary connections do not impair or alter the water in AIC's water distribution system by minimizing the return of any water to AIC's water distribution system after the water has been used for any purpose on the customer's premises or within the customer's piping system. Backflow prevention devices range from vacuum breakers on household hose bibs to large commercial reduced-pressure principal devices.

Source Water Assessment Plan:

The Source Water Assessment Program (SWAP), 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 facilitate and encourage the protection of drinking water sources at the community level. Under SWAP, ADEQ evaluates all sources of water including wells, surface water intakes, and springs that provide drinking water to public water systems throughout Arizona. ADEQ gathers information on drinking water sources for a public water system 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. If a risk of contamination exists, protection measures can be implemented at the local level. ADEQ has evaluated the source water areas in Pima County including the source waters for the AIC PWS. The SWAP for AIC PWS has been designated as low risk.

Residents can help protect sources by practicing good septic system maintenance, taking hazardous household chemicals to hazardous material collection sites, and limiting pesticide and fertilizer use.

The complete SWAP report is available for inspectioD at the ADEQ, 1110 W. Washington, Phoenix, Arizona 85007, between the hours of 8:00 am and 5:00 pm. Electronic copies are available from ADEQ at dml@azdeq.gov. For more information, visit ADEQ's Source Water Assessment Protection Unit website at: www.azdeq.gov/environ/water/dw/swap.html.


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.

Water Quality Constituent Units MCL MCLG Highest Level Detected Range of Levels Detected Sample Year Likely Source of Detected Constituent
1. Arsenic ppm 0.010 0 0.00033 0.00033 2009 Erosion of natural deposits; runoff from orchards
2. Chromium ppm 0.1 0.1 0.019 0.019 2009 Erosion of natural deposits
3. Fluoride ppm 4.0 4.0 0.35 0.35 2009 Erosion of natural deposits; water additive which promotes strong teeth
4. Nitrate ppm 10.0 10.0 3.9 3.9 2010 Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
5. Selenium ppm 0.05 0.05 0.0022 0.0022 2009 Erosion of natural deposits


Water Quality Constituent Units MCL MCLG Highest Level Detected Range of Levels Detected Sample Year Likely Source of Detected Constituent
6. Gross Alpha pCi/L 15.0 0 1.5 1.5 2009 Erosion of natural deposits


Water Quality Constituent Units MRDL MRDLG Highest Average Range of Levels Detected Sample Year Likely Source of Detected Constituent
7. Chlorine ppm 4.0 4.0 0.36 0.27-0.36 2010 Water additive used to control microbes


Water Quality Constituent Units MCL MCLG Highest Level Detected Range of Levels Detected Sample Year Likely Source of Detected Constituent
8. Total Trihalomethanes (TTHM) ppm 0.08 None 0.0123 .0.0082-0.023 2010 By-product of drinking water disinfection


Water Quality Constituent Units Action Level 90th Percentile of Sample Results Number of Samples That Exceeded the Action Level Sample Year Likely Source of Detected Constituent
9. Lead ppm 0.015 0 0 2010 Corrosion of household plumbing systems; erosion of natural deposits
10. Copper ppm 1.3 0.03 0 2010 Corrosion of household plumbing systems; erosion of natural deposits


Water Quality Constituent Units Highest Level Detected Range of Levels Detected Sample Year Likely Source of Detected Constituent
11. Sodium ppm 220 220 2009 Unknown

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 AIC.

Information on Violations/Public Notifications: AIC received a violation for not having all backflow prevention devices tested within one year of their last test, however no public notifications were required during the year 2010.


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

Ajo Water Index




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