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Annual Drinking Water Quality Report
Gloucester County Public Utilities

INTRODUCTION
This Annual Drinking Water
Quality Report for calendar year 2006 is designed to inform
you, the customer, about your drinking water quality. Our
goal is to provide you with a safe and dependable supply of
drinking water, and we want you to understand the efforts we
make to protect your water supply. The quality of your
drinking water must meet state and federal requirements
administered by the Virginia Department of Health (VDH).
Gloucester County Public Utilities has not had any
violations of a contaminant level or any other water quality
standard during the reporting year. Included in this report
are details about where your water comes from, what it
contains and how it compares to standards set by the EPA and
VDH. Gloucester County Public Utilities is committed to
providing you with information about your water supply,
because customers who are well informed are our best allies
in supporting improvements necessary to maintain the highest
drinking water standards. If you have any questions about
this report or any aspect of your drinking water or want to
know how to participate in decisions that may affect the
quality of your drinking water, please contact Lawrence A.
Dame, Director of Public Utilities, at (804) 693-1230 (ldame@gloucesterva.info).
GENERAL INFORMATION
Drinking water,
including bottled drinking 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 can be obtained
by calling the Environmental Protection Agency’s Safe
Drinking Water Hotline (800‑426‑4791).
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: (1) Microbial contaminants, such as
viruses and bacteria, which may come from sewage treatment
plants, septic systems, agricultural livestock operations,
and wildlife. (2) 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.
(3) Pesticides and herbicides, which may come from a
variety of sources such as agricultural, urban stormwater
runoff, and residential uses. (4) Organic chemical
contaminants, including synthetic and volatile organic
chemicals, which are byproducts of industrial processes and
petroleum production, and can also come from gas stations,
urban stormwater runoff, and septic systems. (5)
Radioactive contaminants, which can be naturally occurring
or be the results of oil and gas production and mining
activities. 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.
Food and Drug Administration 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
microbiological contaminants are available from the Safe
Drinking Water Hotline (800-426-4791).
Your drinking water
comes from two sources. The first is known as surface
water, which comes from the Beaverdam Reservoir. The water
is treated at the County’s water treatment plant. Your
water treatment plant employs state of the art technology
which includes chemical coagulation, sedimentation and
filtration. Raw water is pumped from the Beaverdam
Reservoir where potassium permanganate and carbon are
added. Potassium permanganate is used to remove iron,
organics and some manganese. Carbon is used to remove
color, organics and to control taste and odor. This water
is pumped into a mixing basin where alum and polymer are
added for coagulation. The mixed water is then drawn into
vacuum chambers where it “pulsates” into our super pulsator
units, which separates large particles from the water.
These large particles are removed from the treatment process
and disposed at the local landfill. Settled water from the
super pulsator is then filtered where chlorine is first
added for disinfection and manganese removal. The filtered
water is stored at the plant where it is pumped out into the
system. The second source of your drinking water comes from
groundwater. The County’s Reverse Osmosis (RO) plant went
into operation in April of 2003, and we began blending this
water with the treated surface water from two deep wells.
These wells are approximately 1400 feet deep. The water is
then pumped to the RO plant where we first add the only
chemical in the process, an antiscalant that prevents
fouling of the membranes used in the process. Once at the
plant, the well water passes through a series of sock
filters that remove tiny particles that may have been
brought up from the well. This also prevents the fouling of
the membranes. After the filters, high-pressure pumps are
used to pump the water through the membranes used in the
reverse osmosis process. This removes dissolved solids from
the groundwater, leaving water that is nearly the same as
bottled water. We then pump the water over to the County’s
clearwell, located at the surface water plant where chlorine
is added for disinfection and then pumped out into the
system for your use.
Under a new program
developed by VDH, a detailed source water assessment has
been conducted to find ways to better protect our water
sources. This assessment allows our staff, along with the
VDH, to implement measures to reduce or eliminate the
sources of contamination.
As a first step
toward protection of our sources of drinking water, the
Hampton Roads Planning District Commission (HRPDC) and
Virginia Department of Health (VDH), evaluated the
susceptibility of this water supply to contamination.
Contamination sources and pathways were reviewed using maps,
known and observed activities, water quality data and
information about the water source. Using criteria
developed by the State in its EPA‑approved Source Water
Assessment Program, the following was determined:
Source
Susceptibility
i. Beaverdam Reservoir
High
ii. R.O. Well #1
Low
iii. R.O. Well
#2
Low
This
does not mean that your drinking water is currently unsafe.
Your current water quality is described in the rest of this
report. A copy of the source water assessment report is
available by contacting Mr. Lawrence A. Dame, Director of
Public Utilities, at (804) 693-1230.
DEFINITIONS
Contaminants in your
drinking water are routinely monitored according to Federal
and State regulations. The tables on the next few pages
show the results of our monitoring for calendar year 2006.
In the tables and elsewhere in this report you will find
many terms and abbreviations you might not be familiar
with. The following definitions are provided to help you
better understand these terms:
Non-detects
(ND) - lab analysis indicates that the contaminant is not
present.
Parts per million (ppm)
or Milligrams per liter (mg/l) - one part per million
corresponds to one minute in two years or a single penny in
$10,000.
Parts per billion
(ppb) Micrograms per liter - one part per billion
corresponds to one minute in 2,000 years or a single penny
in $10,000,000.
Parts per trillion (ppt)
or Nanograms per liter (nanograms/l) - one part per
trillion corresponds to one minute in 2,000,000 years or a
single penny in $10,000,000,000.
Picocuries per liter
(pCi/L) - picocuries per liter is a measure of the
radioactivity in water.
Action Level
(AL) - the concentration of a contaminant which, if
exceeded, triggers treatment or other requirements which a
water system must follow.
Treatment Technique
(TT) - a required process intended to reduce the level of
a contaminant in drinking water.
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.
Secondary Maximum
Contaminant Level, or SMCL - set recommended levels for
contaminants that affect water’s taste, color, odor or
appearance.
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.
NTU (Nephelometric
Turbidity Unit) - the amount of turbidity in a water
sample as measured by the amount of light scattered by
turbidity of the sample.
Maximum Residual
Disinfectant Level (MRDL) - the level of a disinfectant
added for water treatment that may not be exceeded at the
consumer’s tap without an acceptable possibility of adverse
health effects.
Maximum Residual
Disinfectant Level Goal (MRDLG) - the level of a
disinfectant added for water treatment at which no known or
anticipated adverse effect on the health of persons would
occur.
WATER QUALITY
RESULTS
I. Microbiological
Contaminants
|
Contaminant |
MCLG |
MCL |
No. of Samples Indicating Presence of Bacteria |
Violation(Y/N) |
Month of Sampling |
Typical Source of Contamination |
|
Total Coliform Bacteria |
0 |
Presence of coliform bacteria in more than one
sample per month |
1 |
No |
October 2006 |
Naturally present in the environment |
II. Contaminants
Regulated at the Treatment Plant
|
Contaminant |
Ideal Goals EPA’s MCLG |
Highest Allowable Level EPA’s MCL |
Level Detected |
Typical Source of Contaminant |
|
Aluminum |
|
- |
0.058 ppm |
Natural geology, mining |
|
Antimony |
6 ppb |
6 ppb |
<2 ppb |
Discharge from petroleum refineries, soldering |
|
Arsenic |
N/A |
50 ppb |
<2 ppb |
Natural geology, runoff from orchards |
|
Barium |
2 ppm |
2 ppm |
<0.2 ppm |
Natural geology, mining |
|
Beryllium |
4 ppb |
4 ppb |
<2 ppb |
Discharge from metal refineries, coal burning |
|
Cadmium |
5 ppb |
5 ppb |
<2 ppb |
Natural geology, corrosion of galvanized pipes |
|
Chromium |
100 ppb |
100 ppb |
<10 ppb |
Natural geology, discharge pulp mills |
|
Cyanide†* |
200 ppb |
200 ppb |
<10 ppb |
Discharge metal, plastic, fertilizer factories |
|
Lead |
0 |
AL = 15 ppb |
<2 ppb |
Corrosion of household plumbing |
|
Mercury |
2 ppb |
2 ppb |
<0.2 ppb |
Natural geology, runoff farms |
|
Nickel |
100 ppb |
100 ppb |
<10 ppb |
Natural geology |
|
Selenium |
50 ppb |
50 ppb |
<10 ppb |
Natural geology, discharge metal refinery |
|
Thalium |
2 ppb |
2 ppb |
<2 ppb |
Natural geology |
|
Nitrate/Nitrite-Nitrogen+ |
10 ppm |
10 ppm |
<0.05 ppm |
Natural geology, fertilizer runoff, septic
leachate |
|
Gross Alphaª |
0 |
15 pCi/L |
0.2 pCi/L |
Erosion of natural deposits |
|
Gross Beta*ª |
0 |
50 pCi/L |
1.0 pCi/L |
Decay of man-made products and natural deposits |
|
Combined Radiumª |
0 |
5pCi/L |
0.4 pCi/L |
Erosion of natural deposits |
Samples were collected October 23, 2006. +Sample
was collected on April 10, 2006. *The MCL for beta
particles is 4 mrem/year. EPA considers 50 pCi/L to be the
level of concern for beta particles. †Sample was tested
December 2, 2004. ªSamples collected on March 7, 2005.
|
Contaminant |
Ideal Goals EPA’s MCLG |
Highest Allowable Level EPA’s MCL |
Highest Detected |
Lowest Monthly Percentage of Samples Meeting the
Turbidity Limit |
Typical Source of Contaminant |
|
Turbidity |
NA |
95% Below 0.3 NTU |
0.481 NTU |
100% |
Soil runoff |
|
Date |
- |
- |
09-08-2006 |
|
|
|
Contaminant |
MCLG |
Required Removal Ratio |
Removal Ratio |
Running Annual Average |
Typical Source of Contaminant |
|
Lowest Quarterly |
Monthly Range |
|
Total Organic Carbon* |
TT |
1.0 |
1.02 |
.57 – 1.71 |
1.17 |
Naturally present in the environment |
*Total organic carbon results are given as removal
ratios. Running annual average equal to or greater than one
meets water quality standards.
III.
Other Contaminants Regulated in the Distribution System
|
Contaminant |
MCLG |
Required Removal Ratio |
Removal Ratio |
Typical Source of Contamination |
|
Highest Compliance Level |
Quarterly Range |
|
Trihalomethanes (THM) |
0 |
80 ppb |
46 |
4-98 ppb |
Disinfection interaction |
|
Haloacetic Acids (HAA) |
0 |
60 ppb |
17 |
0-25 ppb |
Disinfection interaction |
IV.
Contaminants Regulated at the Customer’s Tap
|
Contaminant |
Ideal Goals EPA’s MCLG |
Highest Allowable Level EPA’s MCL (Action Level) |
90th Percentile |
No. of Sites Exceeding A.L. |
Typical Source of Contamination |
|
Lead** |
0
ppb |
15 ppb |
17.5 ppb |
7 |
Corrosion of household plumbing systems; erosion of
natural deposits |
|
Copper** |
1.3 ppm |
1.3 ppm |
0.119 ppm |
0 |
Corrosion of household plumbing systems; erosion of
natural deposits |
**Samples were collected
last in December of 2006.
Infants and children
who drink water containing lead in excess of the action
level could experience delays in their physical or mental
development. Children could show slight deficits in
attention span and learning abilities. Adults who drink
this water over many years could develop kidney problems or
high blood pressure.
V.
Disinfectants
|
Disinfectant |
Units of Measurement |
MRDLG |
MRDL |
Level Detected (Annual Average) |
Violation (Y/N) |
Range of Detection at Sampling Points |
Typical Source |
|
Chlorine |
ppm |
4 |
4 |
1.56 mg/L |
N |
.78 – 2.66 mg/L |
Water additive used to control microbes |
VI.
Other Contaminants That Affect Taste, Odor and Appearance
But Do Not Normally Affect the
Health of Humans
|
Contaminant |
SMCL |
Level Detected |
Source of Contaminant |
|
Ammonia |
NL |
<0.04 ppm |
Natural geology |
| |