2017 Water Quality Report English Our goal is not only to meet,but to achieve higher
water quality results than all state and federal
standards;and our superior rating and awards for
best-tasting drinking water are clear indications
of our ability to deliver superior drinking water.
V Because of the high quality of our water,there are no
V VVV t
health-based advantages to purchasing bottled water,
filtration systems,or any other point-of-use devices.
City of Denton
To learn more about our water and how it is supplied,
please read the following water quality report.This
report includes water quality information from 2017.
As you can see from the Water Quality Table on
the next page,we have continued our commitment
to providing you and your family with safe drinking
-
_ water by having no violations in contaminant level or
water quality standards.
Denton uses surface water from Lake Lewisville and Lake Ray Roberts for its water supply. Drinking water,both tap and bottled,can come from
a variety of sources including rivers, lakes,streams,reservoirs,and springs.As water travels over the land's surface or through the ground,it dissolves
naturally occurring minerals and radioactive material and can be polluted by animal or human activity.
Contaminants that might be expected in untreated water include: microbial contaminants,such as viruses and bacteria; inorganic contaminants,such as
salts and metals; pesticides and herbicides;organic chemicals from industrial processes or petroleum use;and radioactive materials.
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 risk.More information about contaminants and potential health effects can be obtained by
calling the Safe Drinking Water Hotline at(800)426-4791 or visiting www.epa.gov/ground-water-and-drinking-water.
Water,whether tap or bottled,is regulated for safety.The U.S. Environmental Protection Agency regulates water provided by public water systems
while the Food and Drug Administration establishes regulations for bottled water.
Contaminants may be found in drinking water that may cause taste,color,or odor problems.These types of problems are not necessarily causes for
health concerns. For more information on taste,odor,or color of drinking water, please call Water Production at(940) 349-7525.
It is more responsible,and cheaper and easier,to keep contaminants out of our lakes than it is to remove them once they get in. Excessive or improper
use of pesticides/herbicides,improper disposal of used oil and antifreeze,and littering are just a few activities that can lead to pollution in our drinking
water supply. Learn more about protecting our water on the following pages,and please do your part to stop pollution.
The Texas Commission on Environmental Quality completed an assessment of your source water and results indicate that some of our sources are
susceptible to certain contaminants.The sampling requirements for your water system are based on this susceptibility and previous sample data.Any
detections of these contaminants may be found in this report. For more information about source water assessments and protection efforts at our system,
contact Kathy Gault,SCADA/Regulatory Supervisor,at(940) 349-7525.
There are a number of options available to learn more about Denton Water Utilities or to participate in decision-making processes.For questions
about this report or the quality of our drinking water,call Kathy Gault,SCADA/Regulatory Supervisor,at(940) 349-7525. For participation
opportunities,call Utilities Administration at(940) 349-7154 for the Public Utilities Board meeting times and locations.
Visit our website at www.cityofdenton.com.
Important 1ecial Noticeuwwuwwwwuwwwuiuwwwuwwwwuwwwwuwwwuwwwwuwwwwuwwwwuwwwuwwwwuwwwwuwwwuiuwmmnnuui
You may be more vulnerable than the general population to certain microbial contaminants,such as Cryptosporidium,in drinking water. Infants,some
elderly,or Immuno-compromised persons such as those undergoing chemotherapy for cancer;those who have undergone organ transplants;those who are
undergoing treatment with steroids; and people with HIV/AIDS or other immune system disorders can be particularly at risk from infections.You should
seek advice about drinking water from your physician or health care provider.Additional guidelines on appropriate means to lessen the risk of infection
by Cryptosporidium are available from the Safe Drinking Water Hotline at(800)426-4791 or www.epa.gov/ground-water-and-drinking-water.
Lead/Copper 1 1 uwwuwwwuwwwuiuwwwuwwwuwwwwuwwwuwwwuwwwwuwwwuwwwwuwwwuwwwuwwwwuwwwuwwwuiuwi
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.This water supply 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 two 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 www.epa.gov/safewater/lead.
En Espaiftol
Este reporte incluye informacion importance sabre el agua para tomar. Para asistencia en espanol a para recibir una copia de
esta informacion a una traducci6n en espanol de estos datos,par favor Ilame a Servicio al Consumidor al (940) 349-8700.
Listed on the back of this report are the regulated and unregulated contaminants detected in Denton's drinking water.All are below allowed levels.Not listed here
are hundreds of contaminants for which we tested that were not detected.This report is based upon the most recent data available to Denton Water Utilities.Terms
used in the Water Quality Table and in other parts of this report are defined here.
• Action Level (AL)-The concentration of a contaminant which,if exceeded,triggers a treatment or other requirements which a water system must follow.
• LRAA- Locational Running Annual Average.
• Maximum Contaminant Level(MCL)-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.
• Maximum Contaminant Level Goal(MCLG)-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.
• Maximum Residual Disinfectant Level(MRDL)-The highest level of a disinfectant allowed in drinking water.There is convincing evidence that addition of a
disinfectant is necessary for control of microbial contaminants.
• Maximum Residual Disinfectant Level Goal(MRDLG)-The level of a drinking water disinfectant below which there is no known or expected risk to health.
MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
• NTU-Nepholometric turbidity units.This is the unit used to measure water turbidity.
• pCi/L- Picocuries per liter is a measure of radioactivity in water.A picocurie is 10`curies-the quantity of radioactive material producing 2.22 nuclear
transformations per minute.
• ppb-Parts per billion.One part per billion is equal to one packet of artificial sweetener sprinkled into an Olympic-size swimming pool.
• ppm-Parts per million.One part per million is equal to one packet of artificial sweetener sprinkled into 250 gallons of iced tea.
• Treatment Technique(TT)-A required process intended to reduce the level of a contaminant in drinking water.
• Turbidity-A measure of water's clarity.How clear the water is can indicate how many particles are in it.The goal is to produce water with turbidity levels as
low as possible.
WATER QUALITY
6
Constituent Date
Tested Unit Average
Minimum Level Maximum Level MCL MCLG Major Sources Violation
Discharge of drilling wastes;Discharge
Barium 1/31/17 ppm 0.042 0.038 0.045 2 2 from metal refineries;Erosion of natural NO
deposits
Erosion of natural deposits;Water additive
Fluoride 1/31/17 ppm 0.284 0.142 0.425 4 4 which promotes strong teeth;Discharge NO
from fertilizer and aluminum factories
Chromium 1/31/17 ppb 1.5 1.4 1.6 100 100 Discharge from steel and pulp mills; NO
Erosion of natural deposits
Discharge from steel/metal factories;
Cyanide 1/31/17 ppb 88.35 84.6 92.1 200 200 Discharge from plastic and fertilizer NO
factories
Runoff from fertilizer use;Leaching from
Nitrate 1/31/17 ppm 0.369 0.351 0.387 10 10 septic tanks,sewage;Erosion of natural NO
deposits
Date Action Number of Sites
Constituent Tested Unit Level 90th Percentile Exceeding AL MCLG Major Sources Violation
Corrosion of household plumbing systems;
Lead 2016 ppb 15 1 0 0 Erosion of natural deposits;Leaching from NO
wood preservatives
Corrosion of household plumbing systems;
Copper 2016 ppm 1.3 0.501 0 1.3 Erosion of natural deposits;Leaching from NO
rTT
wood reservatives
1 i i i•
Constituent Date
Unit Average Minimum Level Maximum Level MCL MCLG Major Sources Violation
Atrazine 1/31/17 ppb 0.15 0.1 0.20 3 3 Runoff from herbicide used on row crops NO
Simazinc 1/31/17 ppb ND 0 0 3 3 Runoff from herbicide used on row crops NO
1 I CM1 igo P
Constituent Dted te Unit Average Level Minimum Level Maximum Level MCL MCLG I rMajjSources Violation
TOC'(Total
Organic Carbon) 2017 ppm 2.52 2.20 2.89 TT N/A Naturally present in the environment NO
Treated Water
TOC'(Total
Organic Carbon) 2017 ppm 4.87 3.69 6.46 TT N/A Naturally present in the environment NO
Raw Water
Total organic carbon(TOC)has no health effects.The disinfectant can combine with TOC to form disinfection by-products.Disinfection is necessary to ensure that water does not have unacceptable levels of pathogens.
By-products of disinfection include trihalomethanes(THMs)and haloacetic acids(HAA),which are reported elsewhere in this report.
Constituent Date Unit Average Level Minimum Level Maximum Level MRDL MRDLG Major Sources Violation
Tested
Chloramines` 2017 ppm 1 3.24 0.70 4.30 4 4 Disinfectant used to control microbes NO
ZCompliance is based on the average level of Chloramines not exceeding the MRDL of 4 ppm.
Constituent Date Unit Average Level Minimum Level Maximum Level MCL MCLG Major Sources Violation
Tested
Bromate 2017 ppb 2.49 0 6.40 10 0 By-product of drinking water disinfection NO
Constituent Date Unit LRAA Max Minimum Level Maximum Level MCL MCLG Major Sources Violation
Tested
TTHM(Total 2017 ppb 12.29 5.92 14.80 80 N/A By-product of drinking water chlorination NO
Trihalomethanes)
HAA5(Haloacetic 2017 ppb 7.73 4.20 12.50 60 N/A By-product of drinking water chlorination NO
Acids)
Date Highest Monthly
Constituent Tested Unit Percentage of Action Level MCLG Major Sources Violation
Positive Samples
Total Coliform Aug.2017 Samples 0.90 >5% 0 Naturally present in the environment NO
Constituent Date Unit Highest Single %of samples Turbidity Limits MCLG Major Sources Violation
Tested Measurement <0.3 NTU
Turbidity' June 2017 NTU 0.29 100% 0.3 N/A I Soil runoff NO
'Turbidity:Must be less than 0.3 NTU in 95 percent of monthly samples.The 0.29 level was the highest single reading for 2017.
ContaminantsUnregulated
Constituent Date Tested 1 Unit Average Level Minimum eve IMaximum Level Major Sources Violation
Chloroform 2017 ppb 1.57 1.03 2.25 By-product of drinking water chlorination NO
Bromodichloromethane 2017 ppb 3.01 2.28 3.55 By-product of drinking water chlorination NO
Dibromochloromethane 2017 ppb 3.89 2.70 5.45 By-product of drinking water chlorination NO
Bromoform 2017 ppb 1.34 0.00 2.47 By-product of drinking water chlorination NO
SecondaryOther Constituents Not
Constituent Date Tested Unit Average Level Minimum Level Maximum Level Major Sources Violation
Sodium 1/31/17 ppm 20.20 15.40 25.00 Erosion of natural deposits;By-product of oil NO
field activity
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CITY , (,(, e City of Denton
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DENTON
Produced 04/1 8 by the City of Denton Communications Office I ADA/EOE/AREA I TDD(800)735-2989 1 www.cityofdenton.com