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NCRWA.COM |
Winter 2014
feature
had to be performed daily. Drying beds at
the side of the plant receive the backwash,
which is later disposed of by piping to the
Town’s wastewater treatment plant.
McGill Associates was the engineering
firm responsible for designing the water
system upgrade, and the Mount Olive
water system is the first in the state to use
this technology. Boiling Chair WTP was
selected as the site for pilot testing for the
new filter media to remove colloidal and
ferrous iron and manganese. A single large
pressure filter vessel with red and white
sand filter media was installed several
months ago, replacing an old greensand
filter. Testing soon began on determining
optimal filter loads and run times. After
the initial pilot test results are confirmed,
the plan is to replace one of the three
remaining greensand and anthracite filters
with a new pressure vessel filled with red
and white sand filter media each year. The
new pressure vessels are equipped with a
sight glass on the side so the operator can
view the condition of the sands.
Spencer Bush of WaterEngineering of
Cassatt, South Carolina explained the
advantages of his company’s red and white
sand filter media. “No filter media works
here for long runs because of the high iron
content in the raw water. Colloidal iron
is also a problem here and is difficult to
remove”. Colloidal iron is a very fine solid
particulate material (typically between 0.1
and 0.001 microns in diameter) which,
when suspended in water, can neither be
settled nor filtered. The new filter media
are expected to increase run times, more
effectively reduce ferrous and colloidal
iron in drinking water, and decrease the
volume of backwash.
The chemical nature of the sands is
proprietary information, but Mr. Bush
explained that the sands are naturally-
occurring minerals which appear to be
composed of rectangular equi-dimensional
grains. A jar of the sands is really heavy,
showing a high specific gravity. The white
sands also have a catalytic property that
helps remove colloidal iron.
The new filters are consistently producing
iron levels in the finished water of about
0.01 mg/L. The run times on the filters
have increased from one day to three days
and the volume of backwash water has
been reduced. The so far successful pilot
test has shown very positive results and full
implementation of the project is expected.
Mr. Charles Brown, Town Manager and
Mr. Deems Blanton, Water superintendent
said they had to provide more water for
Mt. Olive Pickles. At first they tried to
run the filters with just the red and white
sand, but had to go back and add caustic
soda to bring the hardnes down for the
pickle plant.
Mt. Olive Town Clerk, Mrs. Arlene G.
Talton, has been with the town for 50 years.
I am not going to tell her age because is it
not nice to divulge such information. Mr.
Maylon Weeks worked for the town 50 years,
and has since passed away. We are dedicating
this article to Mr. Weeks and Mrs. Talton for
their commitment to the town.
Mt. Olive is the first in the
State to use a new water
treatment technology with red
and white sand filtrations. The
Town’s water system has 69
miles of distribution lines, and
has a finished water storage
capacity of 1.5 million gallons.
