HomeMy WebLinkAbout2016-CCR-LECONSUMER CONFIDENCE REPORT
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City of Lake Elmo
2016 Drinking Water Report
The City of Lake Elmo is issuing the results of monitoring done on its drinking water for the period from
January 1 to December 31, 2016. 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 Lake Elmo provides drinking water to its residents from a groundwater source: three wells ranging
from 285 to 805 feet deep, that draw water from the Jordan-Mt.Simon and Prairie Du Chien-Jordan aquifers.
The Minnesota Department of Health has made a determination as to how vulnerable our systems' source(s) 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 651-747-3940 if you have questions about the City of Lake Elmo 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 2016. 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
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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 5 samples are taken, the average of the two with the highest levels is taken to determine the 90th
percentile level.
ppm─Parts per million, which can also be expressed as milligrams per liter (mg/l).
ppb─Parts per billion, which can also be expressed as micrograms per liter (μg/l).
N/A─Not Applicable (does not apply).
TT-Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water.
Contaminant
(units)
MCLG
MCL
Level Found
Typical Source of Contaminant Range
(2016)
Average
/Result*
Fluoride (ppm) 4 4 .42-1 .95 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.
Nitrate (as
Nitrogen) (ppm)
10.4 10.4 .49-3.3 3.3 Runoff from fertilizer use; Leaching from
septic tanks, sewage; Erosion of natural
deposits.
TTHM (Total
trihalomethanes)
(ppb)
0 80 N/A 8 By-product of drinking water disinfection.
*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.
Contaminant (units) MCLG MCL # of TT
exceedances
Typical Source of
Contaminant
Total Coliform
Bacteria ‡
N/A TT 2 Naturally present in
the environment.
‡Beginning April 1, 2016
Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other,
potentially harmful, waterborne pathogens may be present or that a potential pathway exists through which
contamination may enter the drinking water distribution system. We found coliforms indicating the need to look
for potential problems in water treatment or distribution. When this occurs, we are required to conduct
assessment(s) to identify problems and to correct any problems that were found during these assessments.
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Level 1 Assessment: A Level 1 assessment is a study of the water system to identify potential problems and
determine (if possible) why total coliform bacteria have been found in our water system.
During the past year we were required to conduct two Level 1 assessments. Two Level 1 assessments were
completed. In addition, we were required to take zero corrective actions.
Contaminant
(units)
MRDLG
MRDL
****
*****
Typical Source of Contaminant
Chlorine
(ppm)
4 4 .3-1 .43 Water additive used to control microbes.
****Highest and Lowest Monthly Average.
*****Highest Quarterly Average.
Contaminant
(units)
MCLG
AL
90%
Level
# sites
over AL
Typical Source of Contaminant
Copper (ppm)
(06/19/2014)
1.3 1.3 .07 0 out of
10
Corrosion of household plumbing systems;
Erosion of natural deposits.
Lead (ppb)
(06/19/2014)
0 15 .6 0 out of
10
Corrosion of household plumbing systems;
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 Lake Elmo 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.
Monitoring may have been done for additional contaminants that do not have MCLs established for them and
are not required to be monitored under the Safe Drinking Water Act. Results may be available by calling 651-
201-4700 or 1-800-818-9318 during normal business hours.
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.
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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.
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.