Tucson Water

Some Things You Might Want To Know...

Whether you've just relocated to Tucson, Arizona, or you were born and raised here, water is a primary concern. Tucson lies in the Sonora Desert region, and as in the Mojave Desert, water is scarce. For this reason, Tucson residents should consider taking an active part in water conservation and water quality monitoring. With this in mind, the following information is presented.

You can find volumes of additional information on the Tucson water supply at sources such as the Metropolitan Domestic Water Improvement District, P.O. Box 36870 Tucson, Arizona 85740 www.metrowater.com, www.watercasa.org. Sources abound on this critical topic for desert dwellers.

A statement from Metropolitan Domestic Water Improvement District:

Metro Water is committed to providing information about your water supply. We believe customers who are well informed are our best allies in supporting improvements necessary to maintain the highest drinking water standards. This is the seventh annual water quality report required by the federal government under the Safe Drinking Water Act.

Where does your water come from? The Metro Water District uses groundwater from the northwest portion of the Tucson Basin aquifer. The water in our aquifer was created primarily from mountain runoff and storm water infiltrating beneath the ground along the Cañada del Oro Wash and Rillito River. Our 29 active wells pump water from the local aquifer. Depth to water is 148 to 358 feet. Water from wells is placed in storage tanks or reservoirs. Either by gravity or pressurized, it is moved underground through pipes to reach your home. While water is made up of hydrogen and oxygen, this life-giving liquid also contains many naturally occurring minerals. Such minerals affect the taste and hardness of your water. The make-up of water varies greatly from one well to another in the District’s 11 integrated service areas. Unfortunately, human-caused and bacterial contaminants can also be found in water. This is why the Safe Drinking Water Act exists.

How do you know your water is safe? Metro Water District regularly checks its water for contaminants. The District monitors water from its source to your tap for 115 regulated constituents during the year to meet federal and state regulations as well as to test for constituents that may be regulated in the near future. This was accomplished at a cost of $66,000.

How is your water tested? Approximately 1,068 water samples were collected and tested in 2004. Samples are collected from wells, storage facilities, and points in the distribution system. The samples are taken to a state licensed laboratory for analysis. The test results are reported to the District and the State of Arizona. The District works closely with the Arizona Department of Environmental Quality to ensure all water quality standards are met.

What happens if the water tested indicates contamination? If a constituent is found that does not comply with safe drinking water standards, the District is required by federal and state regulation to notify customers within the affected service area. Notification may be made by a letter or through the media. If a serious situation occurs that may affect the health and well being of our customers, the District would do whatever is necessary to warn you and provide an alternate source of safe drinking water.

What contaminants might be detected? 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 U.S. Environmental Protection Agency’s Safe Drinking Water Hotline at 1-800-426-4791. The source of our tap drinking water is from wells. As water travels through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can pick up dissolved substances resulting from the presence of plants, animals or from human activity. Contaminants that may be present in our water include microbial, such as viruses and bacteria; inorganics, such as salts and metals; pesticides & herbicides; organic chemical contaminants, both synthetic and volatile; and radioactive contaminants. These above-noted contaminants can be man-made or naturally-occurring. Microbial contaminants may come from sewage treatment plants, septic systems, residential uses, agricultural livestock operations, and wildlife. Inorganic contaminants can result from urban storm water runoff, industrial or domestic wastewater discharges, or mining. Pesticides & herbicides may come from many sources, such as agriculture, urban runoff and residential use. Radioactive contaminants can be naturally-occurring or from mining activities. Organic chemical contaminants can come from landfills, gas stations, urban runoff and septic systems. In order to ensure that tap water is safe to drink, the EPA prescribes regulations which limit the amount of certain contaminants in water provided by public water systems.

Is your water treated? Metro Water District does treat its water with chlorine. It began to add chlorine in 1994. Metro Water adds chlorine to eliminate any type of bacterial contamination that could occur in the water pipes. If you detect a chlorine taste or odor, leave a container of water in the sunlight for two hours or try storing water overnight in the refrigerator. Additionally, a water treatment system was operational at the South Shannon service area until April 2004. The District is currently making upgrades to make that treatment system even more effective.

EPA nationally warns that:

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, people with HIV/AIDS or other 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 Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (1-800-426-4791).

Metro Water takes hundreds of samples each year to ensure you have safe drinking water. You can help protect our drinking supply by correctly disposing of hazardous waste at a free disposal site. The collection site is open the first Saturday of each month at the Park & Ride parking lot on Ina & Oracle west of the Wild Oats Market. For more information, you can call 690-5749.

Arsenic

EPA requires that water providers ensure by January 2006 that no more than 10 parts per billion (ppb) of arsenic be found in the water delivered. At present, 50 ppb of arsenic is allowed by the Safe Drinking Water Rules. All of Metro-Main’s wells are 5 ppb or under and do not require any treatment. Arsenic is a naturally-occurring mineral known to cause some forms of cancer, particularly bladder cancer, in humans at high level over long periods of exposure.

Source Water Assessment

In 2004, the Arizona Department of Environmental Quality (ADEQ) completed a source water assessment for the 27 wells used in Metro-Main. The Assessment reviewed if adjacent land uses may pose a potential risk to groundwater sources. Land uses such as gas stations and a state superfund site were found near seven of the water sources. Since ADEQ identified adjacent land uses, the risk to the source water was ranked high by ADEQ from land uses that could potentially affect the water source. The sources are currently protected by the State’s underground storage tank (UST) and groundwater clean up programs. The UST program funds the clean up of leaking tanks at gas stations, while groundwater clean up from landfills is completed under the State Superfund. Residents can help further protect the water sources by taking hazardous household chemicals to hazardous material collection centers and limiting pesticide and fertilizer use. Electronic copies of the Assessment are available from ADEQ at dml@azdeq.gov. For more information, call the District Hydrologist with Metro Water District at 575-8100 or visit the ADEQ’s Source Water Assessment and Protection Unit website at: www.azdeq.gov/environ/water/dw/swap.html.

Additional Information about Table of Detected Regulated Contaminants:
Total Coliform Bacteria Metro Water District exceeded the maximum contaminant level for total coliform bacteria in March 2004 during its monthly testing. Immediately, repeat samples were taken; all of which showed no detection of total coliform. Specifically, six of the 31 initial samples taken were positive for total coliform. Repeat samples from the same six sites were taken right after the District was made aware of the initial positive results. All of the repeat samples returned negative for coliforms. A public notice to all customers was mailed in March 2004. Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other, potentially harmful, bacteria may be present. If it had been an emergency, customers would have been notified immediately. Although the District suspected an anomaly with the sample protocol, proactive measures were immediately implemented to mitigate the possible coliform problem. Again, subsequent testing did not find harmful bacteria to be present in your water. Tetrachloroethylene The Tetrachloroethylene (PCE) detection occurred at the South Shannon storage tank in March 2004. The detection of 5.6 parts per billion (ppb) was above the allowed level of 5.0 ppb. The exceedence of the maximum contaminant level happened due to a failure of the wellhead treatment system. Metro Water immediately took the well offline when the detection occurred. South Shannon well will not be returned to service until a new treatment system is in place. The well requires a treatment system for removing industrial solvents due to its location within an active state superfund cleanup site. Lead In June 2004, one of the 30 distribution system samples taken for lead exceeded the EPA action level. EPA sets the value at 15 ppb but this sample was at a value of 32 ppb. A second or confirmation sample was immediately taken with a value of 7 ppb, which is well below the action level. The second sample indicates that the original sample may have been a laboratory/ sampling error. The District remains in compliance with all drinking water standards as compliance is based on a 90th percentile calculation of all of the distribution system samples collected in June 2004. The 90th percentile value was less than 5 ppb. Cyanide A detection of 220 parts per billion (ppb) for cyanide occurred on October 1, 2003 at the Hardy well. A confirmation sample was taken on November 10, 2003 and the result was a concentration of less than 100 ppb. According to ADEQ, an average of the two sample results are used to determine compliance. Therefore, the average is well below the MCL of 200 ppb and is in compliance with ADEQ regulations. The original detection may have been due to a laboratory/sampling error.

National Secondary Drinking Water Regulations

National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. However, states may choose to adopt them as enforceable standards.

List of Contaminants & their Maximum Contaminant Level

Contaminant

Aluminum

Chloride

Color

Copper

Corrosivity

Fluoride

Foaming Agents

Iron

Manganese

Odor

Silver

Sulfate

Total Dissolved Solids

Zinc

Secondary Standard

0.05 to 0.2 mg/L

250 mg/L

15 (color units)

1.0 mg/L

noncorrosive

2.0 mg/L

0.5 mg/L

0.3 mg/L

0.05 mg/L

3 threshold odor number

6.5-8.5

0.10 mg/L

250 mg/L

500 mg/L

5 mg/L

Many people living in the Tucson area get their water from a private well. That's okay, there are provisions for ensuring the safety of your private water supply. If you have a well in Tucson, or the surrounding communities, the following will be of use to you.

How can I test the quality of my private drinking water supply?

Consider testing your well for pesticides, organic chemicals, and heavy metals before you use it for the first time. Test private water supplies annually for nitrate and coliform bacteria to detect contamination problems early. Test them more frequently if you suspect a problem. Be aware of activities in your watershed that may affect the water quality of your well, especially if you live in an un-sewered area.

Reasons to Test Your Water

The chart below will help you spot problems. The last five problems listed are not an immediate health concern, but they can make your water taste bad, may indicate problems, and could affect your well long term.

Conditions or Nearby Activities: Test for:
Recurring gastro-intestinal illness Coliform bacteria
Household plumbing contains lead pH, lead, copper
Radon in indoor air or region is radon rich Radon
Corrosion of pipes, plumbing Corrosion, pH, lead
Nearby areas of intensive agriculture Nitrate, pesticides, coliform bacteria
Coal or other mining operations nearby Metals, pH, corrosion
Gas drilling operations nearby Chloride, sodium, barium, strontium
Dump, junkyard, landfill, factory, gas station, or dry-cleaning operation nearby Volatile organic compounds, total dissolved solids, pH, sulfate, chloride, metals
Odor of gasoline or fuel oil, and near gas station or buried fuel tanks Volatile organic compounds
Objectionable taste or smell Hydrogen sulfide, corrosion, metals
Stained plumbing fixtures, laundry Iron, copper, manganese
Salty taste and seawater, or a heavily salted roadway nearby Chloride, total dissolved solids, sodium
Scaly residues, soaps don’t lather Hardness
Rapid wear of water treatment equipment pH, corrosion
Water softener needed to treat hardness Manganese, iron
Water appears cloudy, frothy, or colored Color, detergents

For more information on what human activities can pollute ground water see:

Drinking Water From Household Wells (EPA 816-K-02-003 January 2002)

If you use a private laboratory to conduct the testing, nitrate and bacteria samples will typically cost between $10 and $20 to complete. Testing for other contaminants will be more expensive. For example, testing for pesticides or organic chemicals may cost from several hundred to several thousand dollars. Only use laboratories that are certified to do drinking water tests. To find a certified laboratory in your state, you can contact:

A State Certification Officer to get a list of certified water testing labs in your state (www.epa.gov/safewater/privatewells/labs.html), or your local health department may also test private well water for free. Phone numbers for your local, county, or state health department are available under the "health" or "government" listings in your phone book.

Most laboratories mail back the sample results within a week or two. If a contaminant is detected, the results will include the concentration found and an indication of whether this level exceeds a drinking water health standard.

See the List of Drinking Water Contaminants and their Maximum Contaminant Levels for information on Drinking Water Contaminants. If a standard is exceeded in your sample, retest the water supply immediately and contact your public health department for assistance. Some problems can be handled quickly. For example, high bacteria concentrations can sometimes be controlled by disinfecting a well. Filters or other on-site treatment processes may also remove some contaminants. Other problems may require a new source of water, or a new, deeper well. If serious problems persist, you may need to rely on bottled water until a new water source can be obtained.

You should test private water supplies annually for nitrates, coliform bacteria, total dissolved solids, and pH levels to detect contamination problems early. Test more frequently if a problem was found in earlier tests. For more information, read Home Water Testing..

What concerns should I have after a flood if I have a private well?

Stay away from the well pump while flooded to avoid electric shock, AND . . .

Do not drink or wash from the flooded well to avoid becoming sick.
Get assistance from a well or pump contractor to clean and turn on the pump.
After the pump is turned back on, pump the well until the water runs clear to rid the well of flood water.
If the water does not run clear, get advice from the county or state health department or extension service.

How can I protect my private water supply?

Protect your water supply by carefully managing activities near the water source. For households using a domestic well, this includes keeping contaminants away from sinkholes and the well itself. Keep hazardous chemicals out of septic systems.

Periodically inspect exposed parts of the well for problems such as:

cracked, corroded, or damaged well casing
broken or missing well cap
settling and cracking of surface seals.

Also:

Slope the area around the well to drain surface runoff away from the well.
Install a well cap or sanitary seal to prevent unauthorized use of, or entry into, the well.
Have the well tested once a year for coliform bacteria, nitrates, and other constituents of concern.
Keep accurate records of any well maintenance, such as disinfection or sediment removal, that may require the use of chemicals in the well.
Hire a certified well driller for any new well construction, modification, or abandonment and closure.
Avoid mixing or using pesticides, fertilizers, herbicides, degreasers, fuels, and other pollutants near the well.
Do not dispose of wastes in dry wells or in abandoned wells.
Do not cut off the well casing below the land surface.
Pump and inspect septic systems as often as recommended by your local health department.
Never dispose of harsh chemicals, solvents, petroleum products, or pesticides in a septic system or dry well.

End Notes

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seventh annual water quality report: See the report at: www.metrowater.com

Safe Drinking Water Act: The Safe Drinking Water Act (SDWA) was originally passed by Congress in 1974 to protect public health by regulating the nation's public drinking water supply. The law was amended in 1986 and 1996 and requires many actions to protect drinking water and its sources: rivers, lakes, reservoirs, springs, and ground water wells. (SDWA does not regulate private wells which serve fewer than 25 individuals.) For more information see: http://www.epa.gov/safewater/sdwa/index.html

Coliform Bacteria Metro Water District: Coliform bacteria are used as a barometer for the quality of water. These bacteria are in water and flora.