2020 Water Quality Report EnglishDenton 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 Abbigayle Otteson, Water Regulation Compliance Coordinator, at (940) 349-7477.
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 Abbigayle Otteson, Water Regulation Compliance Coordinator, at
(940) 349-7477. 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/publicmeetings.
EN ESPAÑOL: Este reporte incluye información importante sobre el agua para tomar. Para asistencia en español o para recibir una copia de
esta información o una traducción en español de estos datos, por favor llame a Servicio al Consumidor al (940) 349-8700.
IMPORTANT SPECIAL NOTICE: 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 INFORMATION: 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
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.
• 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 were found.
• Level 2 Assessment - A Level 2 assessment is a very detailed study of the water system to identify potential problems and determine (if possible) why an
Escherichia coli (E. coli) maximum contaminant level (MCL) violation has occurred and/or why total coliform bacteria were found on multiple occasions.
• 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 10-12 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.
The City of Denton’s goal is to achieve
a higher level of water quality than that
required by state and federal rules and
regulations.
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 2020. 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 2020.
Water
Quality
Report
Secondary and Other Constituents Not Regulated
Constituent Date Tested Unit Average Level Minimum Level Maximum Level Major Sources Violation
Sodium 3/04/20 ppm 23.90 20.50 27.30 Erosion of natural deposits; By-product of oil field activity No
Unregulated Contaminants
Constituent Date Tested Unit Average Level Minimum Level Maximum Level Major Sources Violation
Chloroform 2020 ppb 1.59 0.00 3.18 By-product of drinking water chlorination No
Bromodichloromethane 2020 ppb 2.84 2.19 3.49 By-product of drinking water chlorination No
Dibromochloromethane 2020 ppb 3.17 3.07 3.27 By-product of drinking water chlorination No
Bromoform 2020 ppb 0.71 0.00 1.41 By-product of drinking water chlorination No
Regulated Inorganic Contaminants
Constituent Date Tested Unit Average Level Minimum Level Maximum Level MCL MCLG Major Sources Violation
Barium 2/27/20 ppm 0.040 0.039 0.04 2 2 Discharge of drilling wastes; Discharge from metal refineries; Erosion of natural deposits No
Fluoride 2/27/20 ppm 0.196 0.171 0.22 4 4 Erosion of natural deposits; Water additive which promotes strong teeth; Discharge from fertilizer and aluminum factories No
Cyanide 2/27/20 ppb 10.100 0.0 20.2 200 200 Discharge from steel/metal factories; Discharge from plastic and fertilizer factories No
Nitrate 2/27/20 ppm 0.563 0.516 0.61 10 10 Runoff from fertilizer use; Leaching from septic tanks, sewage; Erosion of natural deposits No
Chromium 2/27/20 ppb 1.250 1.20 1.30 100 100 Discharge from steel and pulp mills; Erosion of natural deposits No
Constituent Date Tested Unit Action Level 90th Percentile Number of Sites Exceeding AL MCLG Major Sources Violation
Lead 2019 ppb 15 1.2 0 0 Corrosion of household plumbing systems;Erosion of natural deposits; Leaching from wood preservatives No
Copper 2019 ppm 1.3 0.49 0 1.3 Corrosion of household plumbing systems;Erosion of natural deposits; Leaching from wood preservatives No
Regulated Synthetic Organic Contaminants Including Pesticides and Herbicides
Constituent Date Tested Unit Average Level Minimum Level Maximum Level MCL MCLG Major Sources Violation
Atrazine 2/27/20 ppb 0.1 0.1 0.10 3 3 Runoff from herbicide used on row crops No
Simazine 2/27/20 ppb 0.045 0 0.09 3 3 Runoff from herbicide used on row crops No
Regulated Disinfectants and Disinfection By-Products
Constituent Date Tested Unit Average Level Minimum Level Maximum Level MCL MCLG Major Sources Violation
TOC1 (Total Organic Carbon)
Treated Water
2020 ppm 2.34 1.70 2.68 TT N/A Naturally present in the environment No
TOC1 (Total Organic Carbon) Raw Water 2020 ppm 5.03 3.47 6.07 TT N/A Naturally present in the environment No
1Total 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 Tested Unit Average Level Minimum Level Maximum Level MRDL MRDLG Major Sources Violation
Chloramines2 2020 ppm 3.53 0.40 4.80 4 4 Disinfectant used to control microbes No
2Compliance is based on the average level of Chloramines not exceeding the MRDL of 4 ppm.
Constituent Date Tested Unit Average Level Minimum Level Maximum Level MCL MCLG Major Sources Violation
Bromate 2020 ppb 1 0 3.20 10 0 By-product of drinking water disinfection No
Constituent Date Tested Unit LRAA Max Minimum Level Maximum Level MCL MCLG Major Sources Violation
TTHM (Total Trihalomethanes)2020 ppb 14 6.60 16.10 80 N/A By-product of drinking water chlorination No
HAA5 (Haloacetic Acids)2020 ppb 7 3 8.70 60 N/A By-product of drinking water chlorination No
Regulated Microbiological Contaminants
Constituent Date Tested Unit Highest Monthly Percentage of Positive Samples Action Level MCLG Major Sources Violation
Total Coliform 2020 Samples 0.00 > 5%0 Naturally present in the environment No
Constituent Date Tested Unit Highest Single Measurement % of samples <0.3 NTU Turbidity Limits MCLG Major Sources Violation
Turbidity3 June 2020 NTU 0.28 100.00 0.3 N/A Soil runoff No
Water Quality Table
Produced 04/21 by the City of Denton | ADA/EOE/ADEA | TDD (800) 735-2989 | www.cityofdenton.com
Water Quality Report