2011 Drinking Water ReportCONSUMER CONFIDENCE REPORT
PWSID: 1270051
City of Shorewood
2011 Drinking Water Report
The City of Shorewood is issuing the results of monitoring done on its drinking water for the period from
January 1 to December 31, 2011. The purpose of this report is to advance consumers' understanding of
drinking water and heighten awareness of the need to protect precious water resources.
Source of Water
The City of Shorewood provides drinking water to its residents from the following groundwater sources:
• Purchases treated water from the City of Chanhassen which obtains its water from wells in the Prairie Du
Chien - Jordan and Prairie Du Chien - Galesville aquifers
• Six wells ranging from 326 to 640 feet deep, that draw water from the Prairie Du Chien - Jordan, Prairie Du
Chien Group, and Franconia - Ironton - Galesville aquifers.
The water provided to customers may meet drinking water standards, but the Minnesota Department of Health
has also made a determination as to how vulnerable the source of water may be to future contamination
incidents. If you wish to obtain the entire source water assessment regarding your drinking water, please call
651 - 201 -4700 or 1- 800 - 818 -9318 (and press 5) during normal business hours. Also, you can view it on line at
www.health.state.mn.us/divs/eh/water/swp/swa.
Call 952 - 960 -7913 if you have questions about the City of Shorewood drinking water or would like information
about opportunities for public participation in decisions that may affect the quality of the water.
Results of Monitoring
No contaminants were detected at levels that violated federal drinking water standards. However, some
contaminants were detected in trace amounts that were below legal limits. The table that follows shows the
contaminants that were detected in trace amounts last year. (Some contaminants are sampled less frequently
than once a year; as a result, not all contaminants were sampled for in 2011. 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.)
Key to abbreviations:
MCLG— Maximum Contaminant Level Goal: The 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.
MCL— Maximum Contaminant Level: 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.
MRDL— Maximum Residual Disinfectant Level
MRDLG— Maximum Residual Disinfectant Level Goal.
AL— Action Level: The concentration of a contaminant which, if exceeded, triggers treatment or other
requirement which a water system must follow.
90th Percentile Level —This is the value obtained after disregarding 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
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PWSID: 1270051
situations in which only 5 samples are taken, the average of the two with the highest levels is taken to
determine the 90th percentile level.
pCi /I— PicoCuries per liter (a measure of radioactivity).
ppm —Parts per million, which can also be expressed as milligrams per liter (mg /1).
ppb —Parts per billion, which can also be expressed as micrograms per liter (pg /1).
nd —No Detection.
N/A —Not Applicable (does not apply).
*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.
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, which is a
mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as
skin damage and circulatory problems.
Contaminant
(units) MRDLG MRDL * * ** * * * ** Typical Source of Contaminant
2
Level Found
Contaminant
MCLG
MCL
Typical Source of Contaminant
Range
Average
(units)
(2011)
/Result*
Alpha Emitters
0
15.4
N/A
8
Erosion of natural deposits.
(pCi /I)
(07/07/2009)
Arsenic (ppb)
0
10
1 -6.87
6.87
Erosion of natural deposits; Runoff from
orchards; Runoff from glass and electronics
production wastes.
Barium (ppm)
2
2
.0586-
.23
Discharge of drilling wastes; Discharge from
.231
metal refineries; Erosion of natural deposits.
Combined
0
5.4
N/A
3.8
Erosion of natural deposits.
Radium (pCi /1)
(07/07/2009)
Fluoride (ppm)
4
4
.64 -1.3
1.09
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.
Haloacetic Acids
0
60
N/A
2.8
By- product of drinking water disinfection.
(HAAS) (ppb)
TTHM (Total
0
80
N/A
1.9
By- product of drinking water disinfection.
trihalomethanes)
(ppb)
*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.
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, which is a
mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as
skin damage and circulatory problems.
Contaminant
(units) MRDLG MRDL * * ** * * * ** Typical Source of Contaminant
2
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PWSID: 1270051
Contaminant
Level Found
Typical Source of Contaminant
90%
# sites
Sodium (ppm)
(units)
MRDLG
MRDL
* * **
* * * **
Typical Source of Contaminant
Chlorine
4
4
.2 -2
1.04
Water additive used to control microbes.
(ppm)
20
Erosion of natural deposits.
* ** *Highest and Lowest Monthly Average.
* * ** *Highest Quarterly Average.
Contaminant
Level Found
Typical Source of Contaminant
90%
# sites
Sodium (ppm)
(units)
MCLG
AL
Level
over AL
Typical Source of Contaminant
Copper (ppm)
1.3
1.3
.59
0 out of
Corrosion of household plumbing systems;
20
Erosion of natural deposits.
Lead (ppb)
0
15
13.5
2 out of
Corrosion of household plumbing systems;
20
Erosion of natural deposits.
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. City of Shorewood 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.
Some contaminants do not have Maximum Contaminant Levels 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 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:
Contaminant (units)
Level Found
Typical Source of Contaminant
Range
(2011)
Average/
Result
Sodium (ppm)
4.26 -21.2
21.2
Erosion of natural deposits.
Sulfate (ppm)
nd -19.5
19.5
Erosion of natural deposits.
Compliance with National Primary Drinking Water Regulations
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 activity.
Contaminants that may be present in source water include:
Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants,
septic systems, agricultural livestock operations, and wildlife.
Inorganic contaminants, 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]
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PWSID: 1270051
Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban
stormwater runoff, and residential uses.
Organic chemical contaminants, including synthetic and volatile organic chemicals, which are
by- products of industrial processes and petroleum production, and can also come from gas stations, urban
stormwater runoff, and septic systems.
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 which 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 Environmental
Protection Agency's Safe Drinking Water Hotline at 1- 800 - 426 -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 /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 at 1- 800 426 4791.
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