Evening journal., 1905-12-04
TWO WAYS OF
PURIFICATION
Mechanical Filter in Success
fuI Operation For Two
YearSPrOveS Economical
WILL BE GIVEN TRIAL HERE

The discussion as TO methods Of il-
tcring the city drinking water has nar-
rowed 10 the two systems, slow sand
filtration and mechanical, or sedimenta-
tion process.
The success and efficiency Of the me-
chonical process finds It's greatest IL
ustration Ia the city OF ST. Louis
The water supply Of ST. Louis Is
drawn from the Mississippi river, the
water OF which contains from 1000 to
5000 parts ia "a million Of solid matter.
This solid matter is the substance
which affords sustenance for the bac-
teria in the water ana exists I'm Mis-
sissippi river water 90 a far greater eX-
tent than in the Brahdywine water
st. Louis Plant.
The ST. Louis plant consists OF sys-
tenn OF settling basins and six weirs.
At the intake a chemical coagulant
ferrous sulphate and lime). Is passed
into the water supply. This water is
then passed through the series of basins
and through "A layer of sand into reser-
vors for distribution TO the city mains.
The use Of these chemicals does not
I in any way Interfere with the taste or
chemical constitution of the water. The
mineral analyses of the ST. Louis water
made by Professor Edward Kaiser. OF
Washington University. on the 23d OF
March, 1906. show that I'm the Missis-
sippi river water in its natural state
there are 6S parts OF lime to the mill
lion while after the addition of the CO.
agulant owing 60 the chemical COM
.bination of the lime and sulphate there
is but 81.6 parts Of lime per million
This proportion Of lime in the drinking
water IS about one-fortieth Of the
strength of that Of the average lime
water given 10 infants.
The temporary hardness OF the water
lis also decreased by the chemical action
Of the calcium bicarbonate.
Report Of Baeteriolosist.
As to the effectiveness Of the filter
1.-THE report Of the city Bacterlologist is
Jas good evidence as can be presented
A quantitive analysis recently made
lshowed the presence Of 100000 colonie,
lper million parts at the intake and but
931 per million at the LABORATORY tap
a removal Of 1916 per cent OF the bac-
lteria between the two points. Also thai
the suspended solid matter I'm the raw
lwater at the intake was 1868 part,
lper million while at the laboratory tai
There was no suspended solid matte
i'm the water. AS germs cannot livl
in water from which the suspended
solid matter has been removed this tes
proves the 81. Louis treated water q
be germ proof
The st. Louis system OF puriiica
ton" says the annual report of IN
Health Department for 1905. indicate
that almost 80 per cent. Of all organi
and Inorganic substances detrimenta
TO health are removed letween the cit
Intake and the tap Of the householder.
The matter Of cost of this plant
not very great. The reservoirs no,
being built on the Weldin farm can D
, used for the mechanical filter and tn
cost of running the filter is $3.50 pc
million gallons. made ~ as follows
Labor So cents. power cents. switch
ing, 4 cents. lime. S1.S4; iron S1.O7; in
s terest and depreciation. 1 cent; clean
. ing basins, IA cents: pumping, S2.76
= making a total of $3.50.
r Cost Of Slow Filtration.
Inc report OF the water COMMISSION
ers of Wilmington to City Counc
places the cost of slow sand hltratio
Z at 1919 per million gallons.
L The cost. of erecting mechanics
plant in connection with the reservoir
now being built. which would filter a
least 12.OO0.0O0 gallons of water per da
would be about $4,000
II is claimed for this filter that il
!. efficiency is constant, It's cost very lit
. tie, its maintenance cheap and its cl
lhciency better than any other.