Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-08-03
ARDUOUS ROUTINE
4BR|NGS D. c. WATER
Conduits From Great Falls
Dam First Step in Task
of Publication.

When the householder turns a spigot
In his home and commands a flow OF
clear, sparkling water, 1t is difficult for
him to realize the arduous and in
tricate work that must be performed
on the muddy liquid that is brought to
town by the two great conduits which
supply the citys water mains before
water. free from disease-eearing dit
and germs. is ready for his use
The Districts water supply all comes
from dam built at Great Falls. This
is taken in two large conduits f1rst
TO Dalecarlia Reservoir on the Conduit
road near the District line. About
200 100000 gallons of water travel
through the conduits each "a hours.
Half of this is used for the Districts
various domestic, business and indus
trial needs. The other half Is diverted
into a hydroelectric plant which pro-
.duces power for the pumps which
propel the water from Dalecarlia to the
storage reservoirs in the city. The
Dalecarlia pumping plant forces the
water through city mains to all the
services except for a small section near
the present Reno Reservoir. This sec
ton is so high that water is pumped
up into water towers by pumps at the
Reno Reservoir
muuuy Oh
When the water arrives at Dalecarlia
It is extremely muddy. So much so, IN
fact that there is a small hydraulic
dredge floating in the reservoir which
is put into service now and then TO
dredge out the mud from the spot where
the conduit empties into the reservoir.
Next it is led into a series of settling
tanks, where much of the remaining
mud is eliminated. The mud that Is
left is so fine that special treatment
is necessary to get it out Of the water.
This is accomplished by dumping into
the water certain quantities of alumni
mum sulphate, which is used as Co
agulant." It draws the mud particles
together into large units, such as are
easily taken out in the filtering process.
The aluminium sulphate is made right
at the plant from bauXite, an aluminium
ore. and sulphuric acid. The bauxItc
is sucked up to the top of high tower
by device like large vacuum cleaner.
Then it is dumped little by little into
large, lead-lined tanks of sulphuric
acid, with which it combines to form
the aluminium sulphate.
After the water has heen treated with
the sulphate, it is led through sand
filters. These are large square beds Of
gravel on which sand is placed The
sand removes even microscopic traces OF
nlu0, WIFI It's accompanying OdCtClid
and allows pure water only to go
through AS a double precaution, how
ever. compressed chlorine gas is placed
in the water, in the proportion of one
pound of chlorine to 900 900 gallons of
water This proportion is high enough
to kill bacteria. but too low TO affect
the taste of the water.
Daily Tests Are Made
In order to make sure of the purity
Of the water daily chemical and BAG
THEOLOGICAL tests are conducted in the
Dalecarlia laboratory. Samples are
taken of the water at Great Falls, OF
the water as it comes out of each filter,
and at faucets throughout the city Sc
lected haphazardly. Thus dangerous
water can always be detected. Should
bacteria show up in the sample taken
from a filter, the filter is at once put
out of commission and cleaned. The
filters are given regular cleaning once
q day in addition to this. This is done
by forcing ND filtered water from the
bottom of the filter through the top,
which carries away with it back to the
river all the mud and other foreign
matter taken out of the filtered water
n the filtering process.
The power at the hydroelectric plant
Is produced by allowing water to fall
80 feet through large pipe at very
sharp incline. This head of water
strikes the blades of the turbines in
two generators, and whirls them around
ct great speed. turning the energy de-
veloped from the fall of the water into
electrical energy The station is in a
small house on the banks of the c. q o.
Canal. 1t is absolutely automatic in
all respects. There are never any at
tendants there except when trouble de-
velops, which is seldom. The building
Il kept locked The power developed
there Is not enough to run the pumps
during their periods of maximum usage,
as in the dry hot days of last month.
When the load becomes too heavy. part
Of 1t is automatically thrown onto the
power lines supplied with power from
the Potomac Electric Power Co. AS
soon as the power station can take care
Of the load the lines from the power
company are automatically discon-
nected. Should anything go wrong with
either generator it automatically places
itself out of commission and the power
compsny's line is automatically con-
rected UP. When there is a break
down a system of signals worked out
with colored lights flashes at the con-
troll room of the pumping station and
mechanics are sent down to do repairs.
On days when there is heavy con-
sumption of water, the water going
through the power plant Is curtailed
and routed through the distributing
system to the city. Eventually, in about
80 years. it Is expected that the popu-
lstion growth will bring about a situa-
ton where all of the water is needed
for consumption Then the station will
be strapped. But meantime it pays for
Itself entirely in about three years. The
cost of power generated there is about
2iz mills. The cost of power bought
from the company is l cent per kilowatt
hour Power bought from the power
company last year cost $4,000. The
cost during the present fiscal year is
estimated at $5o, 900, depending on
population growth and other factors.
The entire cost of handling the water
supply including all the details men,