Chicago eagle. [volume] (Chicago, Ill.) 1889-19??, 1901-05-04

IlOn lnat tne cause OF the previous pOl-
luton of the water was the One.third
of the sewage that, 1t is assumed. the
canal Is taking care Of-with no rca.
sonable proof advanced, however, that
such Is the case. and therefore, with
this onc.third disposed of. the remain.
ing two-thlrds will not pollute. proba.
bly, because the one.third destroys the
effects of the two.thirds-,that is, the
less absorbs the greater which, to say
the least Is a great feat Of engineer.
ing skill and new discovery of ap-
piled science worthy of grave and care.
ful consideration.
1t Is hardly probable, though 1t may
be fact. that the mere reversal of the
flow of the river. even II 1t does not
take away an ounce of sewage, would
create a belief that the water was
pure. But let us analyze the statement
carefully; first there Is the remarkable
discovery that a rainfall Of one and
onc.half inches over water course eX-
tending a distance of thirty-four miles
has not added anything to the natural
gravity flow of the stream. This
shows cOnclusively the engineering
skill with which the canal has been
planned and built; II 1t could be applied
generally to streams throughout the
be In case Of frcshets, as no possible
danger would occur--the natural grav-
ity flow not being changed by the add.
cd fall Of rain. What wonderful
thing Is engineering skill when It can
be applied and prevent the result of
natural laws. How will It be, however,
when you come to add the remaining
two.thirds of the drainage and sewage
that the canal was supposed TO be built
to take care Of?
The article says In the old days the
river carried Its one.third of the sew
age into the lake ana 'rcndered the
water polluted and unfit to he used fOl
drinking" Here we have 1t again; II
Is this one-third river sewage that did
all the evil. Now, let us apply a few
main facts to the statement. The orig
inal south branch into which the larg
est percentage of the river sewage
was discharged, had q length about five
miles and, with this short length, Ol
head of water, according to the report
the damage In case of u heavy rainfall
was done. Every one should know tina
II you add One-third more OF sewage
and an increased length or head o
waterway, with no means OF increas
ing the capacity Of the outlet, you ar'
decreasing the amount Of pollution tina
will flow into the lake, In the event o
a heavy rainfall. This Is common sens
the more you add to the source o
supply OF the river, the less you vii
discharge into and from the river. ]
with five miles and One-thlrd OF tn
territory, there were great pollution o
the lake, OF course, with about twenty
eight miles added to the stream an'
two-thirds more of territory, there WI
be less.
This Is precisely the reverse of III
other proposition, for 1t makes III
greater produce the less. Truly tn
science of engineering has made II
markable advance, when applied to III
drainage canal and its capabllty OF dis
posing of the, sewage of the city. !
has made the less absorb the effect
of the greater in one case, ana Ia
made the greater supply produce a les
result in another instance.
There is another point, inslgnliican
no doubt, in view of the fact that II
matter how much you increase the SUI
ply, the gravity flow will not be IN
creased and the canal will do It's a
legged work of taking care of the sew
age. Every mile of additional pave
streets with the now open land cOvere
by buildings, adds to the water suppl
per acre that will enter the sewer an
the river, and as a matter OF necessity
the flow should increase, but the ski
of the engineer has looked ahead 10
this possibility by planning and built
ing the canal to take care of the add
tional supply without any increase j
the gravity flow.
AS a matter of fact, Is the cana
built so that no increase Of gravit
flow is possible? If so, what dispOs
ton is made of the back water-ech
. answers none. Possibly the purpose Z