Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-12-16

How He Proposed to Keep the water In Coed
Condition.

Condition.
As announced in The SrAR Col George
ii. Elliot, the engineer officer in charge Of the
Washington aqueduct. has come to the conclu-
sion tina. some system of filtration must be in
troduced as part Of the water supply system
of the District In February, 1856, the Senate
adopted a resolution requesting the Secretary
of War Ito ascertain the advissbiiity and prac.
ticability or providing the water supply o: the
capital with filters and other appliances for
cleansing and purifying the water" In re-
Spouse TO this report on the subject was made
by Capt. Thos. W. Syuons Of the corps Of en-
gineers. in which it was claimed that filtration
was both desirable and practicable.
Capt Symons discussed the various systems
OF filtration, concluding that the system of
natural filtration, in which advantage IL taken
o! natural deposits of sand and gravel, WAS
not applicable TO the case Of the District
Tho tltcr bed System he considered not ad-
vantaSeous on account of its great first cost
Its great cost OF maintenance, and for other
reasons. re concluded that the practicable
solution OF the problem lay in the direction Of
Filter with chemical and mechanical features.
MECHANICAL FILTER PROPOSED.
"By the adoption of filters Of a proper form
and sufficient In size and number to do the
work required" the report said, nearly all the
objections to the flter-bed system are over
come. The chief objection to any me-
fact that considerable loss Of head
is experienced in forcing the water
through the filters and in applying 1t to our
own case the necessity was apparent at once OF
replacing this lost head very simple and
economical method of doing this suggested
itself and has been published in the plans here
with submitted.
cit Consists generally in using some of the
surplus water brought down By tho aqueduct
for furnishing power to replace the head lost by
filtration and also all that which is required
for the aerstion of the water, for working the
hydraulic valves for the Introduction OF CO.
aSu,ant when deemed necessary and for any
other purpose incidental to the work The de-
tails Of TIE plan are given more fully hereafter.
Tho plan for accomplishing this is to convey
the requisite amount Of water from the reser-
voir, together with the waste water lost in
washing the filters. to turbine water
wheels placed at q suitable position to util-
ize the head of the water in the res
eryoir above the canal or river. These tur-
blne wheels will then be connected up in the
mos. suitable manner for running the centrifu-
gal pumps and for doing any other required
work This is, In brief, the general plan upon
which this report is based"
TIE PLAN AND cosr.
The plans approved by Capt Symous pro-
posed filter. which was a cylinder of steel
thirty feet in diameter and seventeen fee. high.
divided by steel diaphragm into two parts. In
the lower compar tment 10 the fltering mate
rial. The upper is intended for the wash
ing and cleansing Of the fltering material.
which IL AL transferred TO it in a state
Of violent agitation by hydraulic currents.
There was proposed with the plan complete
system OF pipes, valves and otaer appurte-
nances. 1t was proposed to locate the works on
the terrace just south of the distributing reser-
voir and between it and the Chesapeake and
Ohio canal
The plan was intended to furnish filtering
capacity for 4O,O0O.O00 gallons per day with ar
engagements TO increase this amount to 50,000,-
600 OF 60, 0000 600 whenever it became necessary.
The loss OF head occasioncd by forcing the
water through the filters was to be restored by
means OF centrifugal pumps driven by water
power.
The plan also provided for aerating the water
by injecting air into the conducting pipe and
also for chemical publication when necessary.
The total estimated cost of the system OF filters
proposed was SG0O, 900. and the annual cost Of
maintenance for the filtration of 40 600, 900 gal
Ions day 5000.