The Hawaiian gazette., 1898-01-11

The tributary or connecting lines to
the main lines are called in the re-
port 1--Sr2ls. These are so directed
from different parts of the city that
full advantage Is taken Of natural
grades. everything reaching the well
in Eakaako by gravity.
The drainage system Is shown in
the drawings with blue ink, red lines
being used for the sewerage mains and
laterals.
These are the drainage routes:
Discharging into the harbor at the
Pacific Mail wharf line No. runs up
Richards, over to Halekauwila, to Ala
kea and up Alakea.
No discharges at the boat landing
and runs back TO Queen, to Fort and
up Fort It is proposed also to have
lines for Nuuanu and Maunakea
streets. Open ditch relief includes the
present old trench from Kakaako
swamps through Kawaiahao block TO
Punchbowl and up Punchbowl with a
branch up Alapai.
This system is called surface drain
age and disposes readily Of rain water
through pipes laid shallow 1t IS
known now that this is cheaper and
better than using the sewer pipes or
clinging TO the old pan of open bitches.
The estimates by Mr.. Herring are in
sections and are very complete. For
the TWO systems of sewerage and drain
age the Legislature will be asked for
about $500 Engineer Dodge is
now preparing plans for the work that
il is proposed TO undertake during the
coming summer.
Following are some interesting notes
from the report of Mr.. Herring:
The population for which the present
design has been computed IS $4,000
people An increase would require ad-
ditional sewers on other streets and
extensions at the pumping station, but
not q remodeling Of any of the sewers
now proposed.
The question Of utilizing sewage was
formerly thought TO be of considerable
Importance for economical, reasons. At
the present time the utilization in most
cases is known TO be a matter Of con-
siderable expense, the greatest value
of the sewage being its water value
when used for irrigation.
A common method of disposal in
England is TO precipitate the suspend
ed organic matter by the addition of
certain chemicals. This expedient al
lows the clarified sewage 10 be dis
charged into q running stream, or
| large body of water. without causing
| The objection that would result from
the discharge OF raw sewage. Precipi-
tation, however, when adapted to the
| needs of your city. requires so large
an expense that it cannot be recon-
NEEDED. Moreover. unless the works
are conducted with great care. the
method meets with objection from the
| offensive odOrs that may then arise.
The only proper method and The
! least expensive one fer the disposing
of the sewage of Honolulu is by q
discharge into the ocean al such a
point and under such conditions that
la thorough dilution may be obtained
This method has been practiced in
many large cities, and where the con-
| ditions are proper and the works are
suitably designed, complete satisfaction
/ has been given in every case. The
! City Of New York discharges its sew
! age into the adjoining water courses.
and no evidence remains of it. The
/ City Of Boston discharges its sewage
! into the harbor, with the outgoing
tide, and il disappears completely from
! sight after running out 10 sea a short
distance.
After locating the point of disposal
! il becomes necessary 10 deliver the
sewage 10 it in the most economical
manner. The topography Of the city
! largely influences the arrangement and
! alignment Of the system. Inasmuch
as II viii be necessary 10 pump al of
the sewage. in order 10 deliver il 10 the
+ recommended outfa,l. the best site for
q pumping station had to be determin-
ed Your City Engineer. Mr.. F. S.
Dodge. assisted me in selecting the
plan. Il proves TO be the most econo-
mical location. besides being out of
the way Of the improved sections of
the city.
The minimum depth of the sewers
below the street surface has been as
sumed at 81 feet. This was done TO
permit of the construction of flush
tanks. as well as of the proper joining
Of the house pipes with the sewers
It is otherwise often not practicable to
give the house pipes a sufficient slope.
These should have a fall of at least
one-fourth of an inch TO the foot
In the business districts. and par
ticular,y where cellars are customary
and must be drained, the sewers should
be placed from TO 10 feet deep. In
suburban districts where cellar drain
age is not generally demanded, such a
depth is, of course. not necessary.
The amount of sewage per capita
is usually assumed as being equal to
that of the water supply. I have es-
timated it at so gallons per head per
day. Half of this quantity is supposed
TO reach the sewers in six hours. and
an amount. equal to 10 per cent of this
quantity, is added for ground-water
With these quantities the sewers are
assumed to run half full
The full benefit of a sewerage sys-
TEN can be experienced only when
also that portion of it which extends
into the houses and up TO the various
sewage receptacles is properly designed
and constructed. In fact. so far as the
propagation of disease is concerned. |
the latter is even more important than |
the public portion of the system. be- !
cause IL brings any possible danger /
much nearer TO the individual
As the design and construction of |
house sewerage is in the hands of the /
property owners. municipal control of |