Ajo Improvement Company, (the "Company") has released its 2005 Water Quality Report (Consumer Confidence Report) for its Ajo water system, PWSID 10-001. The Company will not be mailing a copy of the report to its customers. Arizona Governor Jane Hull has granted a mailing waiver to small water systems with a population less than 10,000 people. Copies are now available at the Ajo Improvement Company office located in the Phelps Dodge office on Elota Avenue, Ajo, AZ; via mail by sending a request to Ajo Improvement Company, PO Drawer 9, Ajo, AZ 85321; or by calling 520-387-7151. The report is also printed in its entirety below. The Company recommends that customers serving more than one housing unit post a copy of the 2005 Water Quality Report in a conspicuous place. If you have questions about this water quality report or if you require this information in Spanish, please contact the Site Manager, Phelps Dodge Ajo, Inc. and Ajo Improvement Company, PO Drawer 9, Ajo, AZ 85321, telephone (520) 387-7151. Si tiene usted aiguna pregunta sobr-e este infortne de Calidad de el Agua, o require este infoane en espanol, favor de esciibir a Ajo Improvement Company, P 0 Drawer 9, Ajo, AZ 85321 o name por telefono a (520) 387-7151.


PWSID# 10-001

This report contains important information about your drinking water. Este informe contiene informacion muy importante sobre su agua para beber. Traduzcalo o hable con alguien que lo entienda bien.

Ajo Improvement Company provides groundwater to its Ajo customers from water purchased from Phelps Dodge Ajo, Inc, The primary source of water for Ajo is the underground well field which is located six miles to the north of town. This water is then pumped to town for both industrial and domestic consumption. The water contains quantities of fluoride and arsenic in an excess of the standards adopted by the state and local health departments for public drinking water. The water is delivered via two 500,000-gallon water storage tanks to a water treatment plant, which reduces the fluoride and arsenic below EPA drinking water standards. The water treatment plant is designed to process 1,008,000 gallons of water per day for public use.

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 MCLG MCL Highest Level Detected Range of Levels Detected Sample Year Likely Source of Detected Copnstituent
1. Arsenic ppb N/A 50 17 17 2003 Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes
2. Chromium ppb 100 100 21 21 2003 Discharge from steel and pulp mills; erosion of natural deposits
3. Fluoride Ppm 4 4 1.07 1.07 2003 Erosion of natural deposits; water additive which promotes strong teeth; discharge from fertilizer and aluminum factories
4. Nitrate
(As Nitrogen)
Ppm 10 10 0.55 0.55 2005 Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
5. Selenium Ppb 50 50 7.9 7.9 2003 Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
6. Lead Ppm AL
0 0.005 0.002-
2005 Corrosion of household plumbing systems;
Erosion of natural deposits.
7. Copper Ppm AL
1.3 0.46 0.01-0.46 2005 Corrosion of household plumbing systems;
Erosion of natural deposits;
Leaching from wood preservatives.
8. TRC Ppm Running
na na 2005 Sampled only at one (1) of the four (4) locations.
121 La Mina Avenue
9. DBP's Ppm TTHM-
na na 2004 Sampled in 2004, not sampled in 2005.


Water Quality Constituent Units Average Level Detected Range of Levels Detected Sample Year Likely Source of Detected Constituent
8. Bromoform ppb 3.5 3.5 2000 Unknown
9. Sodium Ppm 180 180 2003 Unknown
10. Sulfate Ppm 160 160 1998 Unknown

NOTE: Data presented are from the most recent testing done in accordance with applicable regulations. Some constituents are monitored less frequently than once a 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 EPA requires monitoring of over 80 drinking water contaminants. Those listed above are the only contaminants detected in your drinking water. For a complete list contact Ajo Improvement Company.


The EPA Requies that Ajo Improvement Company Provide the Following Information:

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of various 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 Environmental Protection Agency's Safe Drinking Water Hotline (800-4264791). Information on bottled water can be obtained from the United States Food and Drug Administration (FDA).

Some people may be more vulnerable to contaminants in drinking water than the general population. lmmuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people 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/CDC guidelines on appropriate means to lessen the risk of infection by Cryptsoporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791).

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 acivity.

Constituents that may be present in source water include: (A) Microbials, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife. (B) Inorganics, such as salts and metals, which can be naturally-occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming. (C) Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses. (D) Oganics, including synthetic and volatile runoff, and septic systems. (E) Radionuclides, which can be naturally-occurdng or be the result of oil and gas production and mining activities.

To ensure that tap water is safe to drink, EPA prescribes regulations, which limit the amount of certain constituents in water provided by public water systems. FDA regulations establish limits for constituents in boffled water, which must provide the same protection for public health.

While your drinking water meets EPA's standard for arsenic, it does contain low levels of arsenic. EPA's standard balances the current understanding of arsenic's possible health effects against the costs of removing arsenic from drinking water. EPA continues to research the health effects of low levels of arsenic. Some people who drink water containing arsenic in excess of the MCL over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer.

Source Water Assessment. In 2004, the Arizona Department of Environmental Quality has developed and implemented the Source Water Assessment Program (SWAP) to promote community awareness, and to facilitate and encourage source water protection at the community level. SWAP provides information on public water system drinking water sources by evaluating the hydrogeologic setting in which the source is located and any adjacent land uses that are in a specified proximity of the drinking water source. Theses risks included but are not limited to, gas stations, landfills, agriculture fields, waste water treatment plants, and mining activities. This information is evaluated to determine the extent to which the drinking water sources are vulnerable to natural or man-made contamination and are categorized as either high risk or low risk. ADEQ has evaluated the source water areas in Pima County including the source waters for the AIC PWS and has given a low risk designation for the degree to which the this PWS source water is protected. The complete SWAP is available for inspection at the Arizona Department of Environmental Quality, 1110 W. Washington, Phoenix, Arizona 85007, between the hours of 8:00 a.m. and 5:00 p.m. Electronic copies are available from ADEQ at dml@azdeq.gov.

Public Notice: The residual disinfection levels were only measured at one location within the distribution system and not at the same time and locations where the microbial samples are collected. Starting the month of July 2006, residual disinfectant levels will be measured at the same time microbial samples are collected and at the following locations:

In addition, the 2005 DBP monitoring was not completed. We will conduct the 2006 DBP annual monitoring during the month of August in accordance with the regulatory requirements. The Ajo Improvement Company will also perform public notification as required by Title 18, Chapter 4 of the Arizona Safe Drinking Water Regulations (R18-4-105(F)).


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.
NTU Nephelometric Turbidity Unit; a measure of particles in the water.
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.
µg/l Micrograms per liter; parts of contaminant per billion parts of water.
mg/l Milligrams per liter; parts of contaminant per million parts of water.
Radionuclides Contaminants giving off ionizing radiation.
Treatment Technique A required process intended to reduce the level of contaminant in drinking water.
DBPs Disinfection by-Products. (Total Trihalomethanes (TTHM) and Halo Acetic Acid 5 (HAA5))
TRCs Total Residual Chlorine
Variance (or Exemption) Permission of the Department (ADEQ) or the EPA not to meet a MCL or a treatment technique under certain conditions.

Index of CCRs

Ajo Water Index




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