Evening journal., 1905-12-07
ARGUMENT FOR
MECHANICAL
FILTRATION
Expert Tells Of the Action
Of Chemical on Drink
ing Water
RESULT OF SOME TESTS

The arguments advanced by the ad.
yocates of slow sand filtration as a
method of purifying the Brandywino
water are chiefly that the character of
the water is such that there IS no need
for chemicals It merely needs a
and slow sand filtration is the
best method for obtaining that. 1--WE
do not need to put chemicals in the
water and thus make it worse!" says
one prominent city official.
"T cannot conceive why people want
to make the Brandywine water worse
by adding sulphate of iron and other
chemicals to it, says another.
VIII Be No Taste.
And still another with the same be-
nighted ignorance says "Why. the wa
ter will taste after mechanical filtra-
ton just as artificial ice does after be-
ing frozea- with ammonia. We will
taste the chemicals the lime and iron
in It and people will not like that"
This argument is being used exten-
sively by many uniformed with the
simplest chemical action and an analy-
sis OF the statements of these slow
sand filtration advocates is worth
while
In the first place artificial ice in no
way comes in contact with ammonia
gas used in the process OF freezing It.
Some uniformed individual heard that
ammonia was used in the process OF
manufacturing it and imagined he tast-
ed ammonia I'm the ice
The same characteristic applies to
the man who imagines that because
chemicals are put in the water they
can be tasted or will be injurious Wa
ter supplies for all cities have minerals
I'M solution TO some extent IN them.
Some have iron, some lime. some sui
phur. some soda, etc, and other chem
icals mixed I'm certain quantities added
to such water viii procipitate those
minerals in solution and form an insol-
luble compound which Is separated by
la mechanical filter from the water be-
fore distribution to the city.
Another matter is that clear water is
not necessarily pure water and the
mere removal of mud from the water
supply does not mean that the water
is free from germs or dangerous mat
ter.
Il will be interesting to those who
have been frightened by the bug-a-boo
Of adding chemicals TO the water to
note the reports Of the action of chem
.icals on water where mechanical filters
are in use.
Work Of Mechanical Filter.
Bacteriologlst Card Of York, Pa
where there is a mechanical filter OF
1000, 600 gallons daily capacity, says
Herewith I send you the results OF
the seven days test Of the filter plant
This was very remarkable test moi
only because of the high bacterial re
moval but because of the uniformity o
! the results.
1 have no recommendation as to the
operation of the plant as / consider
a that perfection.
Samples we're taken every day be
fore filter water was put in the mechan
:, ical filter and showed the followeinl
y average:
= Turbidity parts per million ...a 81
Color parts per million.... ...s 35l
. Alkalinity parts .....a ........ 24'
I Bacillus colonies presen
:, Bacillurs colonies. .presen
Samples Of the filtered water wer'
taken from a faucet the city ever.
day to ascertain the condition in tn
houses.
The results obtained showed an avel
age condition of the water as follows
S Turbidity parts per million .. -... 0.
Color parts per millon.. ........ 0.
Alkalnity parts. .. - g.. .......l5.
Bacteria per cubic centimeter ....0.4
Bacillus colonies .... not presen
10 The results of this test show ths
go the citizens OF York are receiving
water of greater purity and | do nc
!. know of water supply which is be
~ ter or I'm fact as good"
In a statement made to the Ever
"a ing Journal by L. c. Levy, Sanitar
L Expert, regarding the working Of tn
If Danville. Va. mechanical filter, VIII
IS saws, "hve samples taken at diferer
times unbeknown TO the Water d.
partment showed that out of 29.75
bacteria present in the water befor
G IL entered the filters the tests Shove
y lt2 aftor filtered and that there coul
have been added q grain Of aiuminul
sulphate per gallon without any Of
d passing through the. filter. Ahese test
e. show that the filter is capable Of fu
II lnishing a perfectly clear water and on
n