Water Treatment Process
Washington County has a regional system built to serve the areas outside
the town limits of Plymouth, Roper and Creswell with major funding
coming from revenue bonds. The system is owned and operated by
Washington County.
Construction for a new system supplying .750 million gallons per day
(MGD) began in August of 1999. Historic hurricanes Dennis and Floyd
played minor roles in the history of the system causing a few delays but
the plant became operational April 9, 2001.
Wells
The plant is supplied by three deep wells rated at 350 gallons per
minute (GPM). The raw source for these wells is the Castle Hayne
Aquifer. Average well depth is 280 feet with each screened at three
withdrawal zones: 210, 230 and 265 feet.
Well #1 is on site and has auxiliary power backup from the water plant's
diesel generator in case of a power outage. Well #2 is located .5 miles
from the plant on West Old Mill Rd. Well #3 is located on Slough Rd, 1
mile from the plant. These wells have auxiliary backup power from
portable diesel generators in case of a power outage. The main
transmissions pipe from the wells to the plant is 10-inch PVC pipe.
Treatment
Our treatment plant utilizes hydrogen peroxide, chlorine, chloramine and
polyorthophosphate to treat our water prior to delivery to the customer.
Hydrogen peroxide is injected at the well to help
control Hydrogen Sulfide bacteria. It eliminates approximately 98% of this
bacteria prior to treatment of the water with chlorine.
We then use chlorine and chloramine to kill any
remianing bacteria or viruses that may be present in the water coming out of
our wells and to keep bacteria from redeveloping in the pipes going from our
plant to your tap.
Chlorine was first successfully used as a
disinfectant for water in 1908. Chlorine disinfection has just about wiped
out water-borne diseases such as cholera and typhoid in the Unided States.
The science of water treatment has progressed so far that detection and
control of contaminants in water have reduced health hazards to nearly zero.
Chloramine, a combination of chlorine and ammonia,
is used effectively to prevent waterborne diseases. In order to reduced the
growth of microorganisms or harmful bacteria, the county has been adding
chroramine to the water supply since 2005. Chloramine, when compared to
chlorine, forms a significantly lower amount of "disinfection byproducts"
such as trihalomethanes (THMs) and haloacetic acids (HAAs). Chloraminated
water is safe for drinking, bathing, cooking and all other daily uses.
Chloramine doesn't change the taste, smell or appearance of water.
Certain water users with sensitivities to chemicals
may need to continue to take precautionary measures.
Dialysis patients: Chloramine,
like any other chemical, must be removed from water prior to dialysis
treatment. Medical centers that perform dialysis are responsible for
purifying water that enters machines. People with home dialysis machines
should consult their physician. Often, home dialysis service companies can
make modifications if necessary.
Aquariums: Chloramine is toxic to both fresh- and
salt-water fish, so it must be removed from water used in aquariums and fish
ponds. That can easily be done by purchasing a dechlorinating chemical found
at at most pet supply stores.
After treating the water with chlorine and
chloramine and just prior to sending the water out of the treatment plant,
we add a chemical called
polyorthophosphate which is a blended phophate solution used
for corrosion control. It also diminishes calcium scale deposits typically
seen in hot water lines and heaters.
Storage
After treatment, the water is stored in a 500,000–gallon ground storage
tank at the plant. From there, the water is pumped to three 100,000
gallon elevated storage tanks and two 200,000 tanks, which are located
throughout the county.
Water Testing and Sampling
The County routinely tests for more than 150 different contaminates in
your water. We also test seven random sites monthly for bacteria
throughout the County. Washington County and the State are very active
in monitoring your public water, as is the EPA. Any contaminate that is
above the maximum level automatically triggers a response by the County
Water Department and the State of North Carolina Department of
Environment and Natural Resources, Division of Environmental Health
Public Water Supply Section. Each year we produce a Consumer Confidence
Report of our water, which gives you an in-depth view of your water. The
report is posted on this web site. You may also pick up a copy at our
Billing Office at 120 Adams St. in Plymouth, NC.
The Distribution Section of the Water Department maintains over 135
miles of pipeline, 145 fire hydrants, 3 active pumping stations, 5
elevated storage tanks (3 each at 100,000 gallons and 2 each at 200,000
gallons), and a 500,000-gallon storage tank at the plant. Distribution
Personnel read the water meters monthly and try to start as close to the
25th of each month as possible. The Distribution Section locates water
lines for other utilities such as Telephone, Electric, Gas and Cable TV.
This Department also puts in new services, maintains and repairs both
mainline and service connections. The main lines are flushed at least
once a year (normally, in June) and the dead-end lines are flushed
at least quarterly.