2000 Water Quality Report
(published May 2001)
Click here for the 2001 Water Quality Report
|
Community Water Company of Green Valley, Arizona is pleased to present you with its third annual Water Quality Report. Information contained in this report reflects the 2000 calendar year. Two years ago community water systems nationwide began providing their customers with annual water quality reports. These reports are designed to help you, the water user, make informed decisions regarding your drinking water. Within this report, you will find information about:
We hope that you will find this 2000 Water Quality Report informative and enlightening. Above all, we hope to maintain your confidence in our efforts to provide you with safe, clean water.
Community Water Company of Green Valley
Community Water Company is a member-owned, non-profit water utility existing in unincorporated Pima County and Sahuarita. We serve an average of 2 million gallons of water per day to approximately 15,000 people. Our service area is approximately eight square miles, existing roughly between Duval Mine Road to the north, the Santa Cruz River to the east, Cyprus Sierrita to the west, and Mission Twin Buttes Road to the south. We currently have fifteen full-time and three part-time employees who work hard to ensure you receive safe, clean water. Our Water Source Community Water Company’s water source is the Tucson Basin Aquifer. An aquifer is a saturated permeable geologic unit that can transmit groundwater. In our region water is typically removed or withdrawn from the aquifer by municipal, agricultural and industrial users. Water can be added or recharged to the aquifer naturally from rain and snow or incidentally through agricultural and industrial runoff or by artificial recharge from sources such as the Central Arizona Project (CAP) and wastewater treatment facilities. The general direction of flow of groundwater in the aquifer around Green Valley is from south to north. This same aquifer is the water supply source for all of Green Valley, part of Tucson, and the surrounding communities. Community Water Company pumps groundwater from the aquifer using four wells and stores it in three one-million gallon reservoirs. The water is delivered to the community through our water distribution system. Plans call for the construction of a new two million gallon reservoir and for the drilling a new production well in the fall of 2001. The Source Water Assessment Plan According to information from the Arizona Department of Environmental Quality (ADEQ) website, “The [Source Water Assessment Plan] SWAP will result in an evaluation of each source water that provides drinking water to each [Public Water System] PWS in Arizona. This evaluation will determine the degree to which a PWS is protected, or at risk from contamination. Once completed, SWAP reports will be used to assist local communities in implementing protection measures such as Wellhead Protection. In addition, specific monitoring requirements can be tailored for each system. For example, if a PWS has no history of a particular chemical, as well as no potential for future contamination (based on land use practices and the risk they might pose to water sources), then monitoring relief or reduced monitoring for that chemical(s), would be granted for that PWS. If a different PWS has a history of problems with that same chemical(s), then monitoring would still be required.” For more information, please contact ADEQ toll free at 1-800-234-5677 extension 4425 or (602) 207-4644. ADEQ plans to conduct the Source Water Assessment for Community Water Company in 2002. Ways to Protect Our Water Source All sources of drinking water are subject to potential contamination by substances that are naturally occurring or man made. These substances can be microbes, inorganic or organic chemicals, and radioactive substances. All 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 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 at 1-800-426-4791. Proper disposal of household chemicals and automotive waste can help minimize the risk of groundwater contamination by reducing the potential for runoff and leaching. The Sahuarita Landfill accepts paint, batteries, motor oil, anti-freeze, and other hazardous household items 7 days a week between 7:30 AM and 5:00 PM. Call 744-7649 for more information. A hazardous waste pickup occurs in Green Valley, usually two to four times each year. The Green Valley News and Sun typically announces the date, time, and location of the scheduled pickup. The Lyon’s Club collects recyclable paper, aluminum cans, and used eye glasses. They are located off Desert Bell Road near the Library. This site is open Monday, Tuesday, Thursday, Friday, and Saturday from 9:00 AM to 1:00 PM (Summer) and 9:00 AM to 3:00 PM (Winter). General recycling information may be obtained by contacting the Pima County Recycling Hotline at 791-5000. Hardness and Sodium Over time, we have noticed some questions and comments that tend to be raised more frequently than others. The most common pertain to the hardness and sodium content of the water. Below are a few of the typical comments along with our responses. We are grateful for the input and suggestions we have received from many of you. “My dishwasher leaves white stuff all over my dishes.” - We suspect that this is caused by the hardness of the water. As a service to our customers, Community Water Company now samples annually for hardness levels. Current hardness levels range between 13.2 and 30.4 grains per gallon. Some of our customers have suggested the following methods to minimize deposits: use detergent additives (some report that adding these during the rinse cycle yields the best results), reduce the temperature of your hot water heater (based on inquiries we receive, those with newer dishwashers tend to notice more deposits - one customer suggested that this may be due to the temperature boosters in the newer dishwashers - if you’ve lowered the temperature of your hot water heater, you may want to check your dishwasher), and/or allow your dishes to air dry. Your dishwasher manufacturer may be able to give you additional suggestions. “My doctor wants me to reduce my sodium intake. What is the sodium content of the water?” - Community Water Company now samples annually for sodium. Current sodium levels range between 38 and 70 milligrams per liter (mg/L), which is approximately 8.9 to 16.5 milligrams of sodium in an 8-ounce glass of water. One liter is approximately equal to 33.82 ounces. “I’ve noticed a white residue around my plants.” - In 1999, one of our customers submitted water and soil samples to a lab to determine if this residue is harmful to plants. According to reports he obtained, the irrigation water quality is very good. His soil fertility reports concluded that the salinity is high and will cause slow growth, foliar burn, or death of sensitive species. The consultant suggested that some of the salts are native to the soil, but additional salts may have been deposited by light, frequent irrigation through the drip system. The consultant’s recommendation was to apply 3 to 4 cycles of heavy irrigation (12 to 24 hours with a drip system) to leach the excess salts down and out of the root zone, allowing the soil to dry between cycles. Please be sure to consult with your landscape expert to determine the appropriate watering methods for your plants. Once plants mature, they typically require less water. Community Water Company conducts routine maintenance on its wells to ensure they are working properly and to extend their useful life. In 2000, three of our wells were temporarily taken out of service for maintenance. All of the wells have varying levels of hardness. Some customers noticed water hardness fluctuations while wells were put in or taken out of service for well maintenance. 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, persons 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. United States Environmental Protection Agency and Center for Disease Control guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbiological contaminants are available from the Safe Drinking Water Hotline at 1-800-426-4791. Definitions Action Level (AL) - The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow. Maximum Contaminant Level Goal (MCLG) - The “Goal” (MCLG) is the level of contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety. Maximum Contaminant Level (MCL) - The “Maximum Allowed” (MCL) is the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology. MCLs are set at very stringent levels. To understand the possible health effects described for many regulated constituents, a person would have to drink 2 liters of water every day at the MCL level for a lifetime to have a one-in-a-million chance of having the described health effect. Non-Detects (ND) - The laboratory analysis indicates that the constituent is not present. Parts Per Million (ppm) or Milligrams Per Liter (mg/l) - one Part Per Million corresponds to one minute in two years, or a single penny in $10,000. Parts Per Billion (ppb) or Micrograms Per Liter (ug/l) - one Part Per Billion corresponds to one minute in 2,000 years, or roughly 1-1/2 inches in your travels around the world. Picocuries Per Liter (pCi/l) - The measure of the radioactivity in water. Summary of Sampling Results
We are pleased to report that our water met all federal and state standards for drinking water during 2000. We routinely monitor for constituents in drinking water according to federal and state laws and are required to test the water for more than 100 constituents at intervals determined by the state. These intervals, or compliance periods, differ depending on the type of contaminant and the likelihood of variation in sample results from year to year. Regulated synthetic organic chemicals, volatile organic chemicals, and inorganic chemicals are sampled every three years. Unregulated synthetic organic chemicals, volatile organic chemicals, and inorganic chemicals are sampled every five years. Samples for radiochemicals are required every four years. Lead and copper are sampled every three years. Asbestos samples are required every nine years. Sampling for other contaminants, such as total trihalomethanes and bacteria, occurs more frequently. Table 1 on the following page identifies constituents that were detected during the required compliance period. As noted in Table 1, some data is from the most recent compliance period which may not have occurred in 2000. All data included in Table 1 is from testing done within the last five years. The constituents that were detected were within state and federal standards. It is important to remember that the presence of these constituents does not necessarily pose a health risk. Table 2 identifies constituents that were tested for, but not detected in your water.
|
Table 1—Detected Contaminants
|
Contaminant |
MCLG |
MCL |
Unit Meas. |
Highest Level Detected |
Violation Yes/No |
Likely Source of Contamination |
|
|
Microbiological
Contaminants (Samples were
collected in 2000.) |
|||||||
|
Coliform1 |
0 |
Presence of coliform bacteria in more than one (1)
monthly sample |
- |
Presence
of coliform bacteria in one (1) sample in one month Repeat samples taken
within 24 hours of detection showed no coliform were present in the system |
Yes |
Naturally
present in the environment |
|
|
|
Highest |
Range |
|||||
|
Inorganic
Contaminants (Unless noted, our
compliance period was 1998 as determined by EPA. Our next compliance period will occur in 2001.) |
|||||||
|
Arsenic |
N/A |
50 |
ppb |
12 |
9 - 12 |
No |
Erosion
of natural deposits; runoff from orchards; runoff from glass and electronics
production wastes |
|
Barium |
2 |
2 |
ppm |
0.05 |
0.02 - 0.05 |
No |
Discharge
of drilling wastes; discharge from metal refineries; erosion of natural
deposits |
|
Chromium |
100 |
100 |
ppb |
10 |
5 - 10 |
No |
Discharge
from steel and pulp mills; erosion of natural deposits |
|
Fluoride |
4 |
4 |
ppm |
0.8 |
0.6 - 0.8 |
No |
Erosion
of natural deposits; water additive which promotes strong teeth; discharge
from fertilizer and aluminum factories |
|
Mercury |
2 |
2 |
ppb |
0.6 |
N/A |
No |
Erosion
of natural deposits; discharge from refineries and factories; runoff from
landfills; runoff from cropland |
|
Nitrate (as Nitrogen)2 (2000 data) |
10 |
10 |
ppm |
7.5 |
1.3 - 7.5 |
No |
Runoff
from fertilizer use; leaching from septic tanks, sewage; erosion of natural
deposits |
|
Volatile
Organic Contaminants (Unless noted, our
compliance period was 1998 as determined by EPA.) Our next compliance period will occur in 2001. |
|||||||
|
TTHMs (2000 data) |
N/A |
100 |
ppb |
12.0 |
0.5 - 12.0 |
No |
By-product
of drinking water chlorination |
|
Radioactive
Contaminants (Samples were
collected in 1999.) Next compliance period will occur in 2003. |
|||||||
|
Alpha Emitters |
0 |
15 |
pCi/L |
7.3 |
ND - 7.3 |
No |
Erosion
of natural deposits |
|
Radium 226 |
0 |
5 |
pCi/L |
0.4k |
0.2 - 0.4 |
No |
Erosion
of natural deposits |
|
Unregulated
Synthetic Organic Contaminants (Unless noted, our
compliance period was 1995 as determined by EPA.) Our next compliance period will occur in 2005. |
|||||||
|
Sulfate (1998 data) |
N/A |
N/A |
ppm |
456 |
58 - 456 |
No |
Naturally
present in the environment |
|
Lead &
Copper (Samples were collected
in 1999.) Our next compliance period will occur in 2002. |
|||||||
|
Contaminant |
Action Level (AL) |
Samples Exceeding AL |
Unit Meas. |
90th %Value |
Range |
Violation Yes/No |
Likely Source of Contamination |
|
Lead |
15 |
0 |
ppb |
6 |
0 - 8 |
No |
Corrosion
of household plumbing systems; erosion of natural deposits |
|
Copper |
1.30 |
0 |
ppm |
.189 |
0 - .32 |
No |
Corrosion
of household plumbing systems; erosion of natural deposits; leaching from
wood preservatives |
| Table 1 Notes | |
|
1 |
Coliform are bacteria that are naturally present in the environment and are used as an indicator that other bacteria may be present. Coliform was detected in one sample in December 2000 resulting in an MCL violation; however, repeat samples, all taken within 24 hours of detection, showed that no coliform were present in the system. |
|
2 |
Nitrate
in drinking water at levels above 10 ppm is a health risk for infants of less
than six months of age. High nitrate levels in drinking water can cause blue
baby syndrome. Nitrate levels may rise quickly for short periods of time
because of rainfall or agricultural activity. If you are caring for an infant,
you should ask advice from your health care provider. Nitrate was detected
above 5 ppm (EPA’s AL) at Well 5, therefore, we monitor this well annually
for nitrate. All water samples have been below 10 ppm for nitrate. |
|
Changes in Water Quality
Regulations
You may have noticed recent media coverage of EPA’s proposed changes in water quality regulations and other water quality issues. The EPA welcomes public comments and we encourage you to become involved in issues affecting your water. Below is a brief summary of some changes and information on water quality issues affecting Community Water Company.
RadionuclidesOn December 7, 2000, EPA published their Final Rule setting new standards for radionuclides in drinking water (65 FR 76708). This rule has an effective date of December 8, 2003. Originally proposed in 1991, the final rule sets Maximum Contaminant Levels (MCLs) for the following:
As known or suspected carcinogens, all of the radionuclides have a maximum contaminant level goal (MCLG) of zero. The rule applies to all 55,000-community water systems in the U.S., and impacts primarily groundwater systems. The Agency estimates that 800 systems will need to install removal treatment. Radium is naturally occurring and is found in groundwater in the Upper Mid-west while uranium occurs in the mountainous areas in the West as well as Nebraska and Texas. For more information, please visit the EPA Office of Water website at http://www.epa.gov/safewater/ and type radon in the search window.
ArsenicUnder a final rule signed by the US Environmental Protection Agency on January 16, 2001 and by President Clinton on the following day, a revised arsenic maximum contaminant level (MCL) of 10 parts per billion was to become effective on March 23, 2001 with full implementation five years from promulgation and would apply to all community and non-transient-noncommunity water systems. On March 23, 2001 the EPA said it would extend the rule’s effective date until May 22 based on the Bush administration’s directive to review regulations. Arsenic is an element that is present in the earth’s crust and may enter the water supply through the weathering of rocks and erosion. As noted in Table 1, arsenic levels for Community Water Company ranged between 9 and 12 ppb during the 1998 compliance period. Because the new MCL is at or below existing arsenic levels, we anticipate that future water treatment will be required to remove arsenic. EPA and others have prepared national cost predictions for arsenic treatment which range from $400 million to $1.3 billion annually. Community Water Company is currently participating in an American Water Works Association Research Foundation (AWWARF) study that will create a decision tree enabling water utilities to select the most appropriate treatment options based on physical constraints and costs. A January 20 order by the Bush administration to hold for review certain late-hour rulemakings by the outgoing Clinton administration has clouded the fate of several Safe Drinking Water Act rules, including the arsenic rule, which was published in the January 22 Federal Register. For more information, please visit the EPA Office of Water website at http://www.epa.gov/safewater/ and type arsenic in the search window. MTBEMethyl Tertiary Butyl Ether (MTBE) is a gasoline additive that oxygenates fuel. A requirement of the Clean Air Act included the reduction of smog through the use of oxygenates which help fuel burn more efficiently. Contamination of water supplies in many communities is attributed to leaking underground storage |
||||
Table 2
Constituents Tested For, But
Not Detected
|
Regulated Contaminants |
Unregulated Contaminants |
||
|
Inorganic Contaminants |
Volatile Organic Contaminants |
Synthetic Organic Contaminants |
|
|
Antimony Asbestos Beryllium Cadmium Cyanide Nickel Nitrite Selenium Thallium |
Benzene Carbon Tetrachloride cis-1,2-Dichloroethylene Dichloromethane 1,2-Dichloroethane 1,1-Dichloroethylene 1,2-Dichloropropane Ethylbenzene Monochlorobenzene o-Dichlorobenzene Para-Dichlorobenzene Styrene Tetrachloroethylene Toluene trans-1,2-Dichloroethylene 1,2,4-Trichlorobenzene 1,1,1-Trichloroethane 1,1,2-Trichloroethane Trichloroethylene Vinyl Chloride Xylenes (total) m-Xylene o-Xylene p-Xylene |
Alachlor Atrazine Benzo(a)pyrene Carbofuran Chlordane Dalapon 1,2-Dibromo-3-chloropropane Di(2-ethylhexyl)adipate Di(2-ethylhexyl)phthalate Dinoseb Diquat 2,4-D Endothall Endrin Ethylene Dibromide Glyphosate Heptachlor Heptachlor Epoxide Hexachlorobenzene Hexachlorocyclopentadiene Lindane Methoxychlor Oxamyl Picloram Polychlorinated Biphenyls Pentachlorophenol Simazine Toxaphene 2,3,7,8-TCDD (Dioxin) 2,4,5-TP
(Silvex) |
Aldicarb Aldicarb Sulfone Aldicarb Sulfoxide Aldrin Aroclor Screening Bromobenzene Bromodichloromethane Bromoform Bromomethane Butachlor Carbaryl Chlorodibromomethane Chloroethane Chloroform Chloromethane o-Chlorotoluene p-Chlorotoluene Dibromomethane Dicamba m-Dichlorobenzene 1,1-Dichloroethane 2,2-Dichloropropane 1,3-Dichloropropane 1,1-Dichloropropene 1,3-Dichloropropene Dieldrin 3-Hydroxycarbofuran Methomyl Metolachlor Metribuzin Propachlor Sodium 1,1,1,2-Tetrachloroethane 1,1,2,2-Tetrachloroethane 1,2,3-Trichloropropane |
|
All samples for constituents listed in Table 2 were collected during the 1998 compliance period and will be tested in 2001 except for the unregulated contaminants (column 4). which were collected for compliance in 2000. Asbestos and Dioxin samples were collected in 1995. Asbestos is sampled every 9 years. Dioxin and glyphosate sampling requirements were waived by ADEQ from 1995 through 2001. Samples were collected in 1999 for Dichloromethane, Toluene, 1,1,1-Trichloroethane, and Di(2-ethylhexyl)phthalate.
Do You Want to Receive e-mail Notices?
We
are compiling a distribution list for sending out water related notices via
e-mail. These notices will include: Annual water quality reports Annual financial reports Notices of water meetings Information on local water programs
or other water related notices If you would like to receive water related notices send an e-mail request to: and
include the words SIGN ME UP in the subject line.
Contact Information We would be happy to answer any questions you may have about this report. Please contact David Pfordt at 625-8409, Monday through Friday, between 9:00 AM and 4:00 PM. We encourage you to attend our annual Board Meeting held on the first Monday in May. The meeting was held at the Green Valley Library on May 7, 2001 at 10:00 A.M. A special notice is published in the Green Valley News and Sun. Members will also be notified by mail in April.
|