Evening star. [volume] (Washington, D.C.) 1854-1972, 1903-09-21
|NSURES PURE WATER
Claim Made for Washington's
Filtration Plant.
THE PROGRESS MADE
COST OF THE SYsTEM LIMITED TO
$3,46s, 4O5.
Good Prospect That the Work Will Be
Completed by January
1, 1905.
THE PROGRESS MADE

The contract for the proposed water filtra-
ton plant was let nearly six months ago,
but there was a long delay in starting
actual work and very little progress was
made for time after work was finally be-
gun. The ponderous steam shovels, how
ever, which have been busily engaged dur
Ing the last month have excavated an i'm
mense amount of material, and with the
present rate Of progress it is believed the
plant will be completed by January /, 1906
the time originally set by Congress. Then
all OF the water used in this city will be
drawn from these filter beds, which are
located near the Soldiers Home grounds.
The walt has been a long one, but now
there Is real cause for congratulation. The
proposed system is regarded as unquestion-
ably the best and most carefully designed
ever installed in this country. The delay
for the most part may be said to have been
due to the conscientious efforts of those in
charge to leave no stone unturned toward
making the filtration plant Of the national
capital a model one in every respect.
Primarily the credit for securing the plant,
1T is conceded. belongs to the Senate COM
mtttee on District affairs, through whose
generosity the appropriations were finally
made and who SO ably conducted the long
series of Investigations for determining the
most desirable method of filtration; but be-
fore the decision could be reached an i'm
mense amount of data concerning the Poto-
mac water had to be collected and large
number of experiments had to be made
with the various filters to obtain a knowl-
edge of their efficiency under the actual
working conditions. This latter work was
conducted by Col. Alex. M. Miller, and it is
probable that to him more than to any
other one man is due the successful cu1mi-
nation of the filtration scheme. He took
charge of the Washington aqueduct in 1894
and from then until now his effort has been
for the best possible solution of this per-
picking problem.
Originally the American or mechanic
system of alteration was favored. not alone
on account of the first cost. which was
stated to be very much less than for any
other, but because of the clear, sparkling
character of the water invariably resulting,
and the uniformly high efficieneies obtained
in removing from the polluted water the
disea Sc producing bacteria Strong pro-
tests from the Medical Society and the
against the use of coagulent usually
alum which is indispensable in this sys-
tenn. being used to precipitate the suspend
ed matter and thus hasten the process of
publication, and the evident willingness Of
the Senate committee after securing all
of the expert evidence obtatnable, to recon-
mend the increased amount necessary to
secure the slow sand system, led finally
to the passage of the act by Congress speci-
flying that the construction should be of
the English or slow sand type.
The Amount Appropriated.
The total amount appropriated up to the
present time has been $1,90s:OOO and the
limit in cost fixed by Congress Is So, 46S, 4O5,
When it is considered that the probable
expense of fltering will be SO per million
gallons, which. on the estimated daily con-
sumption of 750o0, 900 gallons, will entail
an additional expense annually of $164 go
it is seen that the taxpayers of the Dis
accruing from pure water.
The site, bounded by North Capitol street,
the Soldiers Home grounds and the new
Washington city reservoir, was selected
principally on account of the elevation, for
nearly the whole city can be supplied by
gravity from here. Thirty-one and one
half acres were purchased at a cost of
$500, 900, and when the work is finally COM
pleted there will be another beautiful add
ton to Washngtons unrivaIed parking
system, for the filter beds will be entirely
rooted over with concrete arches, upon
which earth will be placed and carefully
and the whole transformed into beauti-
full park. This was one of the reasons
that led to roofing over the filter beds,
but the principal one the fact that
the severe weather during the winter in
terferes very materially with the process
of filtration.
This process Is a very interesting one,
and so simple when one considers it that
it is regarded truly remarkable that a
filthy and disease producing liquid can by
this means be made a clear, healthful
water.
The Washington city reservoir will be
used as a preliminary sedimentation basin,
SO as to allow some of the suspended mat
ter to be precipitated, and pumps will lift
the water from here to the twenty nine
filter beds Of one acre each, on which the
supply of 75,OOO,0OO gallons was calculated
1t will then pass through three feet of
sand and, at the bottom. one foot of gravel
and, after being collected by the carefully
planned system of under drainage piping,
it will be delivered to the inciosed storage
reservoir absolutely pure water. This
is explained by the statement that as soon
as the water begins to percolate through
the sand some of the suspended particles
become entangled on the various grains, /
and gradually caught on the top to
form a coating of gelatinous nature
When this layer becomes from one-half to
one inch thick the bed 1t is stated, is in
perfect working condition, for then all of
the bacteria contained are screened out"
as 1t were. as the water passes through.
1t is not exactly a screening process
however, for it has been found that mil
lions of harmless germs develop in this
layer and 1t is very probable that these
prey upon the disease-producing bacteria
and destroy them. The process, of course,
goes on throughout the whole depth of
sand. but it is most marked in the top;
and 81 10 macmillan fart that no sI,hst moo