The Austin weekly statesman. (Austin, Tex.) 1883-1898, 1895-10-24

sumption of water in Austin in 1890 was
given as 173 gallons per day. From the
best data obtainable / am sure that half
this amount would be entirely sufficient
for all purposes. The European and
many American cities use not over so
gallons per day per inhabitant. Then if
one square foot of filter area will dis
charge $50 to 200 gallons per "a hours
you see that it is fair to assume that
each square foot of our prospective
filter will vent 173 gallons per day. or in
other words, there will have to he ono
square foot of filter area for eyery two
persons in Austin. But if we assume
the safer and slower rate at II feet per
day there will have to be as many square
feet OF filter area as there are inhabi-
tants. sFfeel sure that this is a safe and
conservative estimate and from this We
can readily determine the filtering area
necessary, whether we adopt the filters
and settling basins, the driven wells.
or the filter gallery. The construction
OF hitter will depend upon the kind we
adopt. If we decide on natural fltra-
ton then the driven we'll or the gallery
system should be adopted. However, if
we decided to use settling basins and
filter beds, then we must construct fl
depends upon the fineness of the sand
and gravel used. Poughkeepsie, N. Y,
was the first American city to adopt the
the litter bed system of Qualification of
the public water supply. Three works
were constructed in 1871 to clarity the
water taken from the Hudson. The
whole plant consisted of a settling basin
and two filter beds, each 73X20O feet.
Each filter bed is composed of "a inches
nF Hrnn md ralo
gravel, d inches of one-half inch gravel,
6 inches of one inch stone and "a inches
Of 4 to S-inch spalls. The city of
Poughkeepsie has been using filtered
water for nearly "a years, and the city
engineer recently wrote citizen of Aus
tin that the citizens were pleased and
that in mass meeting assembled they
passed a resolution to the effect that
they would not be satisfied with any
other system.
In colder climates it becomes necessary
to cover up the beds by a roof of arches
The neglect of this has caused some Sc
rlous epldemics; Mr.. Hazen says; 1T
was found at Berlin that, owing to the
difficulty of proper cleaning the open
filters in winter, it was impossible to
keep the usual proportion of the area in
effective service, and as result, portions
of the filters were greatly overtaxed
during the prolonged periods of cold
weather This resulted in a greatly de
creased bacterial efficiency, the bacteria
in March, 1889, reaching 5000 to 1000
per cent with 100000 in raw water), al
though ordinarily the effluent contained
less than 100. An epidemic of typhoid
fever followed and was confined to that
part of the city supplied from the StralOu
works, the wards supplied from the COW
cred Tegel filters remaining free from
fever. Open filters have since been abol-
ished in Berlin"
COST OF FILTERING WATER.
Perhaps many in the audience would
like to hear something about the cost of
mum estimate of 200 gallons per square
foot per day one acre will filter 9,712,O00
gallons, and at the rate of $50 gallons
per day, 1854 900 gallons, and at 80
gallons, 1920, 400. But the present
daily supply of Austin can not be over
100000 gallons, and it is probably not
more than half this amount. One half
acre of filter area would be abundant if
worked continuously. but we know that
allow for the cleaning or the removal of
the surface, and so this area should be
doubled.
Covered filters are estimated to cost in
the United States about $6S,000 per acre,
and it is probable that uncovered filters
can be constructed for three-fourths of
this amount, or say, $4,000. The cost
of the filtration of water at the Zurich
filters is about 1925 per million gallons,
while that at Poughkeepsie, N. Y, is
from $3.50 to $4,000. These two results
are nearly equal and can be taken as
fairly representative. If we assume
$3.50 per million gallons and allow 100
gallons per day to the individual it will
cost each individual about IL cents an
nually to filter the water, and if you
count the original cost of the plant, that
is, the interest on the COST and the sink
ing fund, it will not amount to more than
40 cents, provided no extravaganza is al
lowed.