Consumer Confidence Report for 2016

Exactly as extracted, unformatted — for checking against the original. The readable version is easier to read.

ANNUAL DRINKING WATER QUALITY REPORT FOR 2016
TOWN OF CENTREVILLE
PWSID # 0170001
JUNE 2017
We are pleased to present to you this year's Annual Water Quality Report. This report is designed to inform you about the water quality and services we
deliver to you every day. Our constant goal is to provide you with a safe and dependable supply of drinking water. We would like you to understand the
efforts we make to continually improve the water treatment process and protect our water resources. We are committed to ensuring the quality of your
water. The Town’s water source is located in the Aquia formation from two wells within the town limits.
The Maryland Department of the Environment’s Water Supply Program completed a Source Water Assessment for the Town of Centreville in 2003. A
copy of that assessment can be reviewed at Town Hall.
We would like our valued customers to be informed about their water utility. If you would like to learn more, please attend any of our regularly
scheduled town meetings held on the first and third Thursday of each month at 7:00 pm at the Liberty building, 107 North Liberty Street.
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.
If you have any questions about this report or have questions concerning your water quality, please call Kip Matthews, Director of Public
Works at 410-758-1180
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 storm water 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 storm water 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 storm water runoff, and septic systems.
 Radioactive contaminants, which can be naturally-occurring or be the result of oil and gas production and mining activities.
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 EPAs Safe Drinking Water Hotline at (800) 426-4791.

In order to ensure that tap water is safe to drink, EPA prescribes regulations which limit the amount of certain contaminants in water provided by public
water systems. FDA regulations establish limits for contaminants in bottled water which must provide the same protection for public health.
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 (800-426-4791).
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. We 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.
Source Water Information
Source Water Name Type of Water Report Status Location
(NORTHBROOK) WELL 6 QA943510 GW Y NEAR 1 N OF CENTREVILLE APPROX. 100 FT W OF
WEXFORD DRIVE
CENTREVILLE WELL 5 QA941390 GW Y T OF CENTREVILLE APPROX. .3 MI E OF RT 213
Coliform Bacteria
Fecal Total No.
Total Coliform or E. of Positive
Coliform Coli E. Coli or
Maximum Maximum Fecal Likely Source
Maximum Contaminant Level Contaminant Highest No. Contaminant Coliform of
Goal Level of Positive Level Samples Violation Contamination
0 1 0 N
1 positive Naturally
monthly present in the
sample. environment.
Lead and Copper
Definitions: Action Level Goal (ALG): The level of a contaminant i n drinking water below which there is no known or expected risk to health. ALGs
allow for a margin of safety. Action Level: The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which
a water system must follow.
Collection Action Level 90th # Sites Unit Violation
Lead and Copper
Date MCLG (AL) Percentile Over AL Measurement Y/N Likely Source of Contamination
Erosion of natural deposits; Leaching from wood
Copper 9/3/2015 1.3 1.3 0.104 0 ppm N
preservatives; Corrosion of household plumbing systems.

NOTE: Lead is tested for triennial (every 3 years) in accordance with Federal and State Regulations in Centreville’s distribution system, and was not detected
in our most recently collected samples 2015.
Water Quality Test Results
Definitions: The following tables contain scientific terms and measures, some of which may require explanation.
Avg: Regulatory compliance with some MCLs are based on running annual average of monthly samples.
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.
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 E. coli MCL violation has occurred and/or why total coliform bacteria
have been found in our water system on multiple occasions.
Maximum Contaminant Level or 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 or 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 or 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 or 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.
mrem: millirems per year (a measure of radiation absorbed by the body)
na: not applicable.
ppb: micrograms per liter or parts per billion - or one ounce in 7,350,000 gallons of water.
ppm: milligrams per liter or parts per million - or one ounce in 7,350 gallons of water.
Treatment Technique or TT: A required process intended to reduce the level of a contaminant in drinking water.

Regulated Contaminants
Highest Range of Unit
Collection Detected levels Measurement Violation
Contamainant Date Level Detected MCLG MCL Y/N Likely Source of Contamination
Disinfection and Disinfection By-Products
Chlorine 0.7 0.5-0.7 MRDLG=4 MRDLG=4 ppm N Water additive used to control microbes.
No goal for
Haloacetic Acids (HAA5) 1 0-1 the total 60 ppb N By-product of drinking water disinfection
Not all sample results may have b een used for calculating the Highest Level Detected because some results may be part of an evaluation to determine where compliance sampling should occur in the
future
No goal for
Haloacetic Acids (HAA5) 0-1 the total 60 ppb N By-product of drinking water disinfection
Not all sample results may have b een used for calculating the Highest Level Detected because some results may be part of an evaluation to determine where compliance sampling should occur in the
future
No goal for
Haloacetic Acids (HAA5)* 1 0-1 the total 60 ppb N By-product of drinking water disinfection
Not all sample results may have b een used for calculating the Highest Level Detected because some results may be part of an evaluation to determine where compliance sampling should occur in the
future
Total Trihalomethanes 0.6-2 No goal for
(TTHM) 1 the total 80 ppb N By-product of drinking water disinfection
Not all sample results may have b een used for calculating the Highest Level Detected because some results may be part of an evaluation to determine where compliance sampling should occur in the
future
Total Trihalomethanes 0.6-2 No goal for
(TTHM) 1 the total 80 ppb N By-product of drinking water disinfection
Not all sample results may have b een used for calculating the Highest Level Detected because some results may be part of an evaluation to determine where compliance sampling should occur in the
future

Highest Range of Unit
Collection Detected levels Measurement Violation
Contaminant Date Level Detected MCLG MCL Y/N Likely Source of Contamination
Inorganic Contaminants
Arsenic - While your drinking 8 0-9 o 10 ppb N Erosion of natural deposits; Runoff from orchards; Runoff
water meets EPA standards from glass and electronics production wastes.
for arsenic, it does contain
low levels of arsenic. EPAs
standard balances the current
understanding of arsenics
possible health effects against
the costs of removing arsenic
from drinking water. EPA
continues to research the
health effects oflow 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.
Discharge of drilling wastes; Discharge from metal
Barium 2/10/2014 0.1 0.1-0.1 2 2 ppm N
refineries; Erosion of natural deposits.
0.46- Erosion of natural deposits; Water additive which
Fluoride 2/10/2014 0.46 2 4 ppm N promotes strong teeth; Discharge from fertilizer and
0.46
aluminum factories.
Highest Range of
Collection Detected levels Unit Violation
Contaminant Date Level Detected MCLG MCL Measurement Y/N Likely Source of Contamination
Radioactive Contaminants
Beta/photon emitters 3/7/2017 8.6 8.6-8.6 0 50 pCi/L N
Decay of natural and man-made deposits.
Thank you for allowing us to continue providing clean, quality water this year. In order to maintain a safe and dependable water supply we
sometimes need to make improvements that will benefit all of our customers.
Please call Kip Matthews Director of Public Works at 410-758-1180 if you have questions about this report.