The Hawaiian gazette., 1916-10-24
" Statement To The Advertiser
Engineer Estimates Cost
lS AtsI5o,ooo
BASES HIS FIGURES UPON
REPORTS IN DEPARTMENT
Discusses Comparative Value Of
Two Systems, Fast and Slow
Y. \. Filtration

The amount of bonds, $4,000,
which the city supervisors would Goat
for Installation Of filtration plant at
the big Nuuanu reservoir, is based on
fairly reliable estimates declares Fred
G.kirehhoff, engineer of the city water
works department Careful plans and
estimates for such plant were made
ss long ago as 1897, and the reports
submitted by trustworthy engineers at
that time are still in the records of the
water department.
Easing his figures on two different
reports, made in 1897 and 1899, and
figuring increased cost due to the rise
in wages and material values, Kirch-
hon estimates that the plant would cost
about 100000 "|
In communication to The Adver-
fiser, the waterworks engineer discuss
&c the different reports and the com.
parative value Of two kinds Of filtra.
tion, one known MS rapid filtration and
the other as slow sand filtration. He
favors thtHlntter, as do both predeces-
sors in the study of the subject. He
writes. -
KirchhoH's Statement ao.
The water works department of the
city of Honolulu has on file report
on the filtration Of the Nuuanu water
supply Of Honolulu, HI L by Rudolph
Herring, hydraulic and sanitary eRgin-
6ef, New York. This report and the
accompanying plans we're made in 1897.
~. The report which goes into details
OF costs Of construction and operation
Of slow filters and rapid filters, comes
to the conclusion, that slow filters
should be installed.
The site chosen for the filter was
the Queen Emma Place at Nuuanu
Avenue and P1iwa Lane.
However, further study of the 81.
tuation' latsr, in 1899, by f. b. Ed.
wards, then resident engineer on, con
structionr OF sewers led him 10 q, con
sideration Of site closer to No. /
reservoir and be drew up plan, show.
ing the general details, for slow sand
filters to be placed directly below the
reservoir @ So
" Unfortunately, owing to the lapse
~ time, Mr.. Edwards report cannot
found, but he, as his plan shows,
Avored slow nlters. The reasons for ad.
g0eating slow filters are given in Mr..
Hering's report, and hold good today,
notwithstanding the wonderful i'm.
provements in rapid filter construction.
It 10 comparatively q simple prob.
lem 10 estimate the cost of slow filters
owing to the standard construction and
the use of local materials and ordinary
skilled labor. 80 ..,. ~ ! =
There are several makes Of rapid
hlters In the market, all of course pat
eHted, and II is impossible to get re-.
liable figures Of cost without calling
for bids and giving the maDufacturers
detailed data as to site, analysis of
water, etc.
~ Mr.. Herings' estimates of costs
were made seventy years ago, so that
they can serve as guide only, today.
Estimates Filter COST
81 have made an estimate of the
cost of slow filter installation, to pass
maximum Of 100000 gallons per
twenty -four hours
This would consist of FIVE filters
with necessary valves, regulators, a
filtered water reservoir and a chlorina-
tor all to occupy space on the lot di-
Jectly below No. Reservoir, the site
proposed by Mr.. Edwards.
9 - have no detailed figures as to the
cost of rapid filters here, except those
In Mr.. Herings' report.
Owing to the increased cost of ma.
chinery, freight charges, and all classes
Of labor today, his costs for rapid fit.
ers should probably be increased fifty
per cent.
1.-THE cost Of operating rapid filters
would also show an increase owing TO
the rise in the price of chemicals, not
70 mention the increased cost Of super.
intendence and skilled labor necessary.
Rapid fitration requires chemicals
while slow does not Except in cases
Of very turbid waters), so this would
be 70 the advantage of slow filters
especially here, where we are SO far
from the chemical market.
Generally the matter of a site with
SUFFICIENT area is @ consideration, but
we are fortunate in this respect, having
b large lot available.
The slow filter appeals to me for
dhe reason that, as Mr.. Herring says
there 10 no expensive machinery to gel
out Of order and require repairs and
renewals. p.
100 Ny estimate, which follows, il
based ON Mr. Edwards plan and must
be understood TO be preliminary only
One million gallon reservoir, $4,000
ave slow filters, $l25,0OO; engineering
$4,000, making a total of $l5O,OOO.
81 am therefore in favor of slow
filters and recommend their installation
for the NutIanu water supply.
(6igned) aF. g. KIRCHEOFF,
- N ri. Nu