The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1896-03-05
Agents, Honolulu. II. L.

ton of the relative merits of the so
| called combined and reL0tiUe syste ms
of sewerage. Each of these two sys-
! TENS claims special advantages over
the other, and each one has its advo-
| Gates.
| The final choice between them must
| depend upon a careful study of the
particular situation, with a due regard
! for a great variety of circumstances,
which can only be done by an expert
on the spot.
Until within a few years the COM
bined system was the one most eX
tensively in use, and it is today that
by which sewage-removal is sought
to be effected in London, Paris, New
York and most of the large cities of
the old as we'll as of the new world.
| This system is an inheritance from
ancient Rome, which had her ctO0c0
ne0Iine0, huge underground conduit
of masonry, thirteen feel vile and
deep, that received the miscellaneous
filth from many lesser drains, and
finally poured the whole into the swift
flowing Tiber.
This ime-honored system is desig-
Ated the combined system, from the
fact it receives not only sewage proper,
as I have defined it, but also the wash
of the streets and the floods Of
storm, or rain-water, with all the
dirt, sand and coarse litter which are
thereby transported.
This fact involves the necessity of
adapting the capacity of the conduit
TO the maximum downpour of water
in the rainy season, plus the water
and sewage proper which represent
the average amount of domestic waste
of the community to be accom-
modated.
First The sewers of this system
are therefore of large size and very
expensive. The cost of sewer in
creases in a ratio disproportionate to
its size, and the expense of putting in
the large sewers of the mbined sys-
tenn is so great "a to forbid their ause
to many of the community that M ght
be able to afford the small pipe sewers
of the separate-system.
A failure to estimate rightly and
provide sufficiently in the size of the
sewer for this immense Outpour is
most disastrous.
Second-A still greater drawback
is from the frequent cIogging and OBJ
struction of the sewers by the dirt
and rubbish, which are carried into
them with the water from the streets
and areas.
It was supposed, and has been
claimed, that the immense flood of
rain water periodically poured into
a sewer would flush and scour it clean.
But experience has disappointed this
expectation. Instead of this, it has
been found that, while the first rush
of water in time of flood may carry
along its own solids, that which comes
later, while the flood is subsiding,
deposits it's dirt and rubbish, and
makes an initial obstruction
Once begun, the tendency is for the
obstruction to increase by additions,
until the sewer is completely blocked
up.
Putrescent matters are stranded
above the point of obstruction and
there remain to decOmpOse and give
off their foul gases. Sewers of this
sort are aptly termed sewers of deposit,
cesspOols.
Third In order to mend this diff
Guilty, engineers have devised the
one of which is placed so
as to intercept the coarse trash
wherever water from the street enters
the sewer. But even this device is
not found to be effective, more or
less dirt, sand and leaves still pass
into the sewer, and form instructions. |
Besides this the catch basins them
selves, though periodically emptied, |
soon become intolerable nuisances |
from the decaying matters they re-
ceive.
Fourth. -AnOther serious drawback |
of the large sized d, combined sewer is
the fact that, being from their large |
size necessarily made of porous mat
erial, generally bricks laid in mortar,
while in wet season they allow the .
subsoil water to drain into them, in a
time of drought, when the level of
the ground water has fallen below
the level of the sewer, they act in the
wrong direction and permit the water
within them to leak away and faint
the ground with its impurities. The
water thus lost from the sewer is
taken from the current which should
be kept within the sewer to maintain
3 cleansing volume of how If the
amount that leaks out is considerable,
the solid matters which, without such
loss, would be carried along, are
stranded in the sewer and become a
source of corruption.
Fifth.-Still another objection to
the combined sewer, arising from its
arge size, is the fact that the volume
IF air in it is so great that no ordinary
means to Ventilate it have been found
sufficient to keep it sweet.
SiXth.-Again the flow in a large
mbined sewer cannot be depended
lpon, but is irregular and intermit-
ent, now raging torrent and anon a
Till connecting a string Of
tagnant pools. The sewage, when
from them, is therefore in
lOXIous state of putrescence.
In fine the evils and drawbacks OF
he combined system of sewerage are
o great, that, if the only alternative
pen to Honolulu were choice be-