The Providence news. (Providence [R.I.]) 1891-1906, 1893-02-21


not because of its danger TO health, but
because OF its cost In all systems there
are mechanical appliances very carefully
aud accurately constructed so as TO SUP
ply the proper amount. The $4,000, 900
gallons that the city needs would ap-
prox mately be half ton OF the basic
salts OF alumina whose cost would be
about $500.
MIR. Parkhurst Speaks.
Mr.. Parkhurst said he would be glad
IL the committee could prove that any
system of filtration could be secured at
n reasonable cost. But the only exam
Piles referred to by the committee. namely
hose of Hamburg and Altoona. were ex-
amples OF natural sand filtration. The re-
suits of this kind of filter in London and
Berlin have shown that natural filtration
is the best method. In Rotterdam poor
results were obtained because the filters
were over worked and the rate of filtra-
tion was too rapid.
Mr.. Parkhurst felt that this danger
Was also possible in mechanical filter,
namely, that imperfect filtration would
result from too great pressure or too
great head. The only tabulated expe-
rience OF this country was that OF the
State Board of Health I'm Massachusetts,.
The result OF their experiments was such
natural filtration. They believed that
low rates are better and safer than high
rates OF filtration and that deep filter
Is better than a shallow one. They found
that the filtration re te of 1.000.0 900 gallons
per day per acre was about the best and
most practical. Mr.. Barney had failed TO
find any results of mechanical expert
ments that compared with those OF sand.
Prof. Sedgwick stated that by natural
filtration all typhoid germs were re-
moved. But he had made no reference TO
mechanical filtration in n recent paper.
The State Board of Health was asked
by the city of Brockton To provide some
method for filtering its water supply.
The mechanical ii filters with alum were
tried, aud chemical analysis showed
that, with pound of alum to $4,000
gallons OF water, the effect was practi-
caliy nothing. But that when six pounds
ofalum were "a lded, the bacteria were re-
duced TO one-tenth OF the original
amount; that only one-ei ghth OF the inn
purities and color remained. This water
was clear, aud appeared satisfactory, but
IL contained alum ana suiphuric acid TO
such an extent that tn State Board OF
Health could not recommend the sys-
TEN.
Mr. Parkhurst felt that this was a
great question, and needed to be at
tacued carefully. He wished to ask Mr..
Shedd. who was present what his expe-
rience and judgment were in regard to
the two methods of filtration.
The City Engineers Ideas.
Mr.. Shedd. city engineer, said 1t was
of the first Importance that a filtration
system should be erected at once In order
to procure the best water possible from
the Pawtuxet. As to methods he thought
the opinions of experts ought to
be taken, so AS to get the best
results AS the least possible cost.
He had seen the National filter in use at
Narragansett Pier aud his experience was
not satisfactory. The company claimed
that IL was overworked. That was per-
haps true. The rate OF filtration was the
one chief point to be considered Some
Wesi ern cities had used alumni so exten-
sively as to injure the health of the ln-
habitants. he believed that with
proper care the mechanical filtra-
order, but he also believed that the most
satisfactory results coull be obtained with
the natural filter bed lie had built bed
of this kind in Wellington. Kan. The
foundation OF this filter was prick laid
close as possible. This filter bed was
cleaned by reversing the water flow, aud
the film of impurities was raised as a
whole aud flowed away with the water.
1t had proved satisfactory though no
psychological analysis had been made.
But he understood that Mr.. Parkhurst's
question was what he thought of the
two systems, and being asked he would
say that he aid not think that the plan
proposed by the committee was the best.
He Thought some Intern .diate plan be-
tween mechanical and natural liberation
might be devised.
Commissioner Smith Speaks.
Commissioner Robert Il. Smith was re-
quested to speak. He corroborated Mr..
Barney's remarks, His idea differed
from Mr.. Shedd, who perhaps wanted
the filter placed on the banks of the
Pawtuxet river. in that he felt that the
filtration should he carried on at the
station. Mr.. Kendrick asked in regard
to the Wilmington aud Philadelphia
filters.
Mr.. Barney stated that Wilmington
did not use the filter. 1t used the air
lift. The lift was only about 1000. 900
gallons. At Pettaconsett the lift was
200 feet and the amount would be
Is. .0O0, 900 gallons.
Mr.. Kendrick referred to the various
reports showing that the water Of the
city was as pure AZ that Of any other city.
The typhoid fever had been much less
since tue lntfOu ucJlon OF water from lts
present sources than before the water
was secured from the Pawtuxet He did
not thiak that the City Council believed
that the water supply was any worse
than it had been for the last twenty
years. He offered resolution as sub
stitute.
Resolved That the commissioner Of public works
be and he Is hereby directed To contract for suit
able system OF mechan cal gravity filters. substan
italy as rcco mehded IN the refort Of said COM
mittee, capable OF altering htee million gallols
PER day at "a cost no, 20 exceed hundred thous-
aud dollars. provided the same ~ recommended by
the superintendent OF health commissioner o. pub
lie WORKS and city engineers and
Rcsolrod That the commissioner OF public works
he and he is hereby directed TO construct suitable
foun ations and buildings TO receive and contain
filters nj expense not 10 exceed thirty thou
sand dollars. In accOfdaI Ice VITA plans and spec-
cations 70 be furnished by the city engn eer. and
ResOlrtd, That the comm ssioner OF public works
be and he hereby T. dir cted. under the advice aud
direction OF said joint special committee ap ointed
by resolution No co.. approved September 22 1892,
TO which committee his honor the mayor. is added
aforesaid 20 contract for pneumatic alr-lifts in
accordance with the rccomme hdations OF the re-
millions pee day, and AT cost not 90 exceed fifty
thousand dollars provided such al lifts are recon-
mended by "a terintendent OF health commissioner
OF public works and city engin err aud
hesolrcd That for the purpose OF carrying the
aforesaid reso tion uto effect the sum OF one hun
drcd aud eighty thousand dollars l. hereby added
90 the appropriation for tue construction o. the
Providence Water Works ard the CT y treasurer
acting under e advice of tn joint standing com.
mlttee on fnsnoe Is hereby authorized 10 hire the
same.
Why He offered II.