May 2005 • Special Edition
Annual Water Quality Report for 2004
The U.S. Congress revised the federal government’s Safe Drinking Water Act in 1996. One requirement mandates that all public water supply systems send annual water quality reports to each of their customers. The purpose of this report is to advance consumers’ understanding of drinking water and to heighten awareness of the need to protect precious water resources. The report you are reading summarizes the results of monitoring done on Woodbury drinking water for the period from Jan. 1 to Dec. 31, 2004. In addition to the water quality report, this special newsletter contains information about Woodbury’s water conservation regulations.
Why this report?
Department of Health has determined that one or more of the sources of water is potentially susceptible to contamination. The city’s wells are not susceptible because they meet all construction standards and do not present a pathway for contamination to readily enter the water supply. The aquifer is considered to exhibit a high sensitivity to contamination because of the local geological setting. The city’s operating procedures include daily monitoring of well sites and frequent water testing that would help identify, detect and contain any contaminant spill before it could enter the water supply. If you wish to obtain the entire source water assessment regarding your drinking water, please call (651) 215-0800 or 1-800-818-9318 (and press 5) during regular
Continued page 2
How much water does Woodbury use?
In 2004, residents and businesses in Woodbury used approximately 2.1 billion gallons of water. This works out to an average of about 5.64 million gallons of water per day. A typical Woodbury family consumes approximately 26,500 gallons of water each quarter of the year, on average. Water use is higher than the average during the summer months and lower in the winter. The City of Woodbury provides safe drinking water to its residents and businesses by pumping water from a groundwater source: the Jordan St. Peter and the Prairie Du ChienJordan aquifers. The Jordan aquifer is a vast underground lake that supplies all the water distributed by the city to its residents. The city currently has 15 wells ranging from 405 to 517 feet deep. Well 16 is under construction and is expected to be completed in fall 2005. The water provided to customers meets drinking water standards. However, the Minnesota
Your drinking water is certified safe
The City of Woodbury’s goal is to provide you with high quality, safe, reliable drinking water that surpasses every federal and state requirement. Test results, from monitoring done in 2004, show that we are doing that very well. The United States Environmental Protection Agency and the Minnesota Department of Health have identified many chemicals and other substances that may pose a risk to humans. When a contaminant is thought to pose a risk, these agencies set upper limits for safe human consumption. We are proud to report that no contaminants were detected at levels that violated federal drinking water standards. This special newsletter contains the city’s annual water quality report, which includes complete information on the monitoring done on Woodbury drinking water during 2004. Please review the report and, if you have questions, contact Dan Hansen, utilities supervisor, at (651) 714-3720.
Where does the city get its water?
Woodbury City Update • 2004 Drinking Water Report • page 2
Substances detected in Woodbury water
Detected SubstanceUnit of Measure Alpha Emitters-(radioactive substances)-in pCi/L. Test date: 6-15-2001 Arsenic-in ppb Barium-in ppm Meets Amount Detected Standard (average)* 3.1 4 Allowed Max. (MCL) 15.4 Ideal Max. (MCLG) 0 Range Detected (2004) N.A. Typical Source in Drinking Water Erosion of natural deposits.
2.44
4
50
0
nd-2.44
Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes.
0.04
4
2
2
nd-0.0428
Discharge of drilling wastes; discharge from metal refineries; erosion from natural deposits. State of Minnesota requires all municipal water systems to add fluoride to the drinking water to promote strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories. By-product of drinking water disinfection (chlorination). Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits. By-product of drinking water disinfection (chlorination).
Fluoride-ppm
1.18
4
4
4
1.1-1.3
Haloacetic Acids (HAA5)-in ppb Nitrate (as Nitrogen)-in ppm TTHM (Total trihalomethanesproduced as a by-product of chlorination)-in ppb
1.4
4
60
0
0.6-1.4
1.9
4
10
10
0.07-1.9
4.15
4
80
0
3-5.7
*This is the value used to determine compliance with federal standards. It sometimes is the highest value detected and sometimes is an average of all the detected values. If it is an average, it may contain sampling results from the previous year.
Annual Water Quality...from page 1
business hours. Also, you can view it online at www.health.state.mn.us/divs/eh/water/swp/swa. Call Dan Hansen, utilities supervisor, at (651) 714-3720 if you have questions about the City of Woodbury drinking water or would like information about opportunities for public participation in decisions that may affect the quality of the water. The city tests the water in Woodbury on a daily basis. An outside testing laboratory and the State of Minnesota both conduct additional testing on monthly and quarterly schedules. Daily readings of flow and chemical usage verify that proper ratios of fluoride and chlorine are used. More than 2,200 individual tests are performed annually to ensure that water quality remains at the highest possible level. The entire water distribution system is cleaned when fire hydrants are flushed twice a year. Flushing removes sediment from the underground lines, moves freshly chlorinated water through all lines, and verifies the operational reliability of the fire hydrants. Chlorine samples are tested from different areas of the city to verify that the disinfection properties are carried throughout the entire system to the ends of the lines. In addition,
Woodbury’s water quality monitoring
the city tests for lead and copper under Department of Health guidelines by collecting water samples from selected households in the city. No contaminants were detected at levels that violated federal drinking water standards. Some contaminants were detected in trace amounts that were always below the maximum allowed in drinking water. The table above shows the contaminants that were detected in trace amounts in 2004. (Some contaminants are sampled less frequently than once a year; as a result, not all contaminants were sampled for 2004. If any of these contaminants were detected the last time they were sampled for, they are included in the table along with the date that the detection occurred.)
Monitoring results
Water treatment process
Because Woodbury’s source water is very clean to begin with, only minimal treatment is required by the State of Minnesota for its use as drinking water. Treatment includes the addition of fluoride to meet Department of Health requirements and the recommended addition of chlorine to protect the system from biological growth or bacteria. These additives are metered into the water as the water is pumped from our deep wells so that no untreated water is ever added to the water system.
Woodbury City Update • 2004 Drinking Water Report • page 3
Chlorine testing
Substance (unit of measure) MRDLG
Chlorine is added to protect the system from biological growth or bacteria. Chlorine samples are tested from different areas of the city to verify that the disinfection properties are carried throughout the entire system to the ends of the lines.
MRDL Highest and Lowest Monthly Average 0.5-0.9 Highest Quarterly Average 0.72 Typical Source of Contaminant
Chlorine-in ppm
4
4
Water additive used to control microbes.
Radon is a radioactive gas that is naturally occurring in some groundwater. It poses a lung cancer risk when gas is released from water into air (as occurs during showering, bathing, or washing dishes or clothes) and a stomach cancer risk when it is ingested. Because radon in indoor air poses a much greater health risk than radon in drinking water, an Alternative Maximum Contaminant Level (AMCL) of 4,000 picoCuries per liter may apply in states that have adopted an Indoor Air Program, which compels citizens, homeowners, schools, and communities to reduce the radon threat from indoor air. For states without such a program, the Maximum Contaminant Level (MCL) of 300 pCi/l may apply. Minnesota plans to adopt an Indoor Air Program once the Radon Rule is finalized by the federal government.
Substance (unit of measure) Radon-in pCi/L Amount Range Meets Detected Standard Detected (average) (2004) 659.5* 4 613-723 Typical Source of Contaminant Erosion of natural deposits.
Radon testing
Glossary of abbreviations:
AL - Action Level: The concentration of a contami-
nant which, if exceeded, triggers treatment or other requirements which a water system must follow.
90% Level: This is the value obtained after dis-
regarding 10 percent of the samples taken that had the highest levels. (For example, in a situation in which 10 samples were taken, the 90th percentile level is determined by disregarding the highest result, which represents 10 percent of the samples.) Note: In situations in which only five samples are taken, the average of the two with the highest levels is taken to determine the 90th percentile level.
MCL - Maximum Contaminant Level: The highest
* This is the value used to determine compliance with federal standards. It sometimes is the highest value detected and sometimes is an average of all the detected values. If it is an average, it may contain sampling results from the previous year.
level of a contaminant that is allowed in drinking water. MCLs are set as close to the ideal maximums (MCLGs) as feasible using the best available treatment technology.
MCLG - Maximum Contaminant Level Goal: The
Tests for PFCs reveal no concerns
The Minnesota Department of Health recently sampled six of the city’s wells for perfluorochemicals (PFCs). PFCs have been used for many years by 3M and other companies in products that resist heat, oil, grease, stains and water. Testing was completed in January 2005 and no trace of these chemicals was found in Woodbury.
level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
MRDL: Maximum Residual Disinfectant Level. MRDLG: Maximum Residual Disinfectant Level
Goal.
N.A. - Not applicable: Does not apply. nd: No detection. pCi/L: PicoCuries per liter (a measure of radioac-
Other substances
tivity in water).
ppb: Parts per billion: The number of units of the
Some contaminants do not have Maximum Contaminant Levels (MCLs) established for them. These “unregulated contaminants” are assessed using state standards known as health risk limits to determine if they pose a threat to human health. If unacceptable levels of an unregulated contaminant are found, the response is the same as if an MCL (the allowed maximum) has been exceeded; the water system must inform its customers and take other corrective actions. In the table that follows are the unregulated contaminants that were detected. Based on state standards, none of the substances detected pose health risks.
Substance (units) Average/ Result 16.4 6.1 23 Meets Standard 4 4 4 Range (2004) nd-16.4 2.7-6.1 9.1-23 Typical Source of Contaminant Erosion of natural deposits; discharge from industrial sites. Erosion of natural deposits. Erosion of natural deposits.
substance, in its pure form, found in every billion units of water. Can also be expressed as micrograms per liter.
ppm: Parts per million: The number of units of the substance, in its pure form, found in every million units of water. Can also be expressed as milligrams per liter. Range Detected: Minimum and maximum levels of
Nickel-in ppb Sodium-in ppm Sulfate-in ppm
substance detected from all samples taken from all wells (in samples where any level of contaminant was detected).
Source of Contaminant: Erosion of natural deposits
occurs as groundwater has slowly flowed through different rock formations before reaching the aquifer from which Woodbury’s drinking water is pumped.
Monitoring for unregulated contaminants as required by U.S. Environmental Protection Agency rules (40 CFR 141.40) was conducted in 2004.
Woodbury City Update • 2004 Drinking Water Report • page 4
Rehabilitation work on well No. 5
Well rehabilitation work, which generally is needed about every 10 years, is currently taking place on well No. 5, located north of Valley Creek Road and east of Tower Drive. Left: An air compressor (the large red machine on left) pumps air into the well cavity through a large yellow hose. The air forces sand to be pumped out of the well cavity through an inner pipe (inside the tall blue object). Work involves blasting to enlarge the well cavity, bailing sand out of the cavity, and pump and pipe activity. The result will be better water flow and less possibility of sand entering the system. The work will also upgrade the well to current design specifications. Rehabilitation projects are typically completed during the spring season, when water demand is relatively low.
Lead and copper testing
This is a specialized testing program to identify the potential for a homeowner’s internal plumbing to impact his/her drinking water. Woodbury drinking water does not contain lead or copper; however, these substances might be detected in household drinking water primarily as a result of the plumbing system that has been installed. Common sources of lead and copper are lead solder and copper pipe fittings. (Lead in solder was banned after 1985.) The city tests for lead and copper every three years by collecting water samples from households in the city. The City of Woodbury is required by the Minnesota Department of Health to test 30 samples for lead and copper. This required sampling was incomplete for the monitoring period between June 1, 2004, and September 30, 2004. The city inadvertently submitted just 29 samples for testing. However, all 29 samples taken by the city met acceptable limits. Based on these test results, the city believes your water supply to be safe to use and no extraordinary measures by the city or yourself are necessary. The city will continue to test the water to ensure all safe drinking water standards are met. Because of the city’s failure to have 30 samples successfully tested, the city is required by the Minnesota Department of Health to issue the following statement. However, in spite of this required statement, the city feels there is no need to be alarmed or to use an alternate source of water. During 2004, the city had a violation for failure to take a sample and/or submit information on lead and copper by the required date. Because we did not monitor, or failed to monitor completely during the compliance period, we did not know whether lead and copper were present in your drinking water, and we are unable to tell you whether your health was at risk during that time. The chart below shows the results of tests performed during 2004. No contaminants were detected at levels that violated federal drinking water standards.
Substance (Units) Copper-in ppm Lead-in ppb Action Level (AL) 1.3 90% Level 0.12 # sites over AL 0 out of 29* 0 out of 29* Meets Standard 4 Maximum Contaminant Level Goal (MCLG) Not Applicable Typical Source of Contaminant Corrosion of household plumbing systems; erosion of natural deposits. Corrosion of household plumbing systems; erosion of natural deposits.
15
5
4
Not Applicable
* The City of Woodbury is required to test 30 samples for lead and copper. This required sampling was incomplete for the monitoring period beginning June 1, 2004, and ending September 30, 2004. The city inadvertently submitted just 29 samples for testing. However, all 29 samples taken by the city met acceptable limits.
Woodbury City Update • 2004 Drinking Water Report • page 5
Contaminants and drinking water
The sources of drinking water in the United States (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.
z Organic chemical contaminants, including
Contaminants that may be present in source water include:
synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and can also come from gas stations, urban storm water runoff, and septic systems. z Radioactive contaminants, which can be naturally-occurring or be the result of oil and gas production and mining activities. In order to ensure that tap water is safe to drink, the U. S. Environmental Protection Agency (EPA) prescribes regulations that limit the amount of certain contaminants in water provided by public water systems. Food and Drug Administration regulations establish limits for contaminants in bottled water which must provide the same protection for public health. 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 1-800426-4791.
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 from infections. These people should seek advice about drinking water from their health care providers. EPA/Center for Disease Control guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline at 1-800-426-4791. Cryptosporidium is a microscopic organism that, when ingested, can result in diarrhea, fever and other gastrointestinal symptoms. Woodbury does not have a potential for Cryptosporidium contamination, because the city uses only deep wells for its water source. The city’s water supply is not impacted from field runoff that introduced the parasite to some surface water sources. Recent changes in the law assure that all cities, regardless of their water source, will eliminate the chance for such a contaminant entering the drinking water system.
Water and health
z Microbial contaminants, such as viruses
and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife. z Inorganic contaminants, such as salts and metals, which can be naturally-occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming. z Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban storm water runoff, and residential uses.
Want to know more about water?
If you have any questions about Woodbury’s drinking water or would like information about opportunities for public participation in decisions that may affect water quality, call Dan Hansen, utilities supervisor, at (651) 714-3720. Regular hours are 7 a.m. to 3:30 p.m., Monday through Friday. Additional information, including links to sites that focus on water, also is available on the Woodbury Web site at: www.ci.woodbury.mn.us.
The City of Woodbury is a member of the American Water Works Association, an international nonprofit scientific and educational society dedicated to the improvement of drinking water quality and supply.
Be aware of Woodbury’s lawn watering restrictions
The Woodbury City Council reaffirmed the city’s odd/even watering policy and added new restrictions in 2001 that prohibit lawn watering altogether between noon and 5 p.m. every day. The watering restrictions are designed to encourage conservation, maintain adequate water pressure, and ensure fire-fighting reserves. Before turning on your sprinkler . . . 1. Check the clock. Lawn sprinkling is permitted only before noon and after 5 p.m. 2. Determine if it's “your day” to water the lawn. Woodbury’s odd/even schedule means: z If your home or business address ends in an odd number (i.e. 1, 3, 5, etc.) you may water your lawn only on odd-numbered calendar days. z If your address ends in an even number (0, 2, 4, etc.) you may sprinkle only on evennumbered days. The watering regulations are enforced year round and no warnings are issued. Automatic sprinkling systems must be set to comply with both the odd/even schedule and the hours of the day when lawn watering is allowed. Residents and businesses violating Woodbury’s watering ordinance will receive a
CITY OF
Lawn watering tips
z Do your lawn sprinkling early in the
z
z
z
citation that carries a fine. The watering restrictions apply only to lawn watering and not to incidental uses such as washing cars or filling pools. Permits allowing 14 continuous days of watering for areas of new seed and sod are available at the Public Works Building, 2301 Tower Drive. For more information, call Public Works at (651) 714-3720.
z
z
morning, between 4 and 6 a.m., when water demand is low. After about 10 a.m., both heat and evaporation go up, robbing the lawn of moisture. Water only when your lawn needs it, rather than on a set schedule. One sign that a lawn needs water is when it lacks enough moisture to spring back after you walk on it. If it stays flat, it’s time to water. Watering twice a week is usually enough to keep a healthy lawn growing. In general, your lawn needs about one inch of water per week, including rainfall, to keep it green during the growing season. Water deeply and infrequently. Deep watering promotes a deep root system, while over-watering promotes shallow root growth, making your lawn less hardy. Adjust lawn watering to the weather. Following a heavy rain, for instance, skip your regular watering day until the grass needs it again. Teach the family how to turn off an automatic sprinkler system in case a storm comes up during the sprinkling cycle. Delay regular lawn watering during the first cool weeks of spring. This encourages deeper rooting and makes your lawn healthier for the rest of the summer. It also delays the first time you have to mow the grass.
Information sources: “55 Facts, Figures & Follies of Water Conservation,” published by the American Water Works Association and originally published by the Denver Water Department, Denver, Colo. Also: “40 Ways to Save Water in Your Yard and Garden,” by L. Ken mith, Landscaping Architect.
Woodbury • May 2005 Special Edition
ECRWSS PRST STD U.S. Postage
The Woodbury Water Report is published annually by the City of Woodbury and mailed to all water customers. Comments are welcomed. Send to: Woodbury City Hall, 8301 Valley Creek Road, Woodbury, MN 55125-3330. Phone: (651) 714-3500. email: jlehr@ci.woodbury.mn.us Mayor: William Hargis. Council Members: Cheryl Hurst, Michael Madigan, Paul Rebholz, Amy Scoggins. City Administrator: Clinton Gridley. Communications Coordinator: Julie Lehr. The City of Woodbury is subject to Title II of the Americans with Disabilities Act. In accordance with the act, the Water Report is available in other formats. Call Julie Lehr, 714-3500; TDD: 714-3568.
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