Evening star. [volume] (Washington, D.C.) 1854-1972, 1901-01-05

the slow sand filtration system. He replied
that he preferred to secure the publication
of water by filtering it through sand alone
instead OF through sand with the addition
of chemical. He had first investigated
this question many years ago. when there
was a prevalence of a certain form of stom-
ach trouble which peculiar to the
guests in a hotel in Cincinnati. With others
he investigated this subject and discovered
that there was alum in the filtered water
of the hotel. which was supplied with me-
chanical filter in which alum was used as
q coagulant.
Alum and stomach Troubles.
The method of caring for the filter was
improved and the amount of aum used was
reduced, when the stomach trouble COM
planned Of disappeared. Since that time his
experience had influenced him in favor OF
a sand filter without the use OF any chem
ical as a coaguant. He thought this was
preferable even If there were times When
the water would not be perfectly clear py
means Of the slow sand filter.
Where the mechanical system mad been
operated with great care Mr.. Hill thought
there not much difference between the
two classes of filters. He thought the STOW
sand filter gave rather better results and II
didn't require the same degree OF care TO
secure these results. If the two kinds OF
filters were given exactly the same care
there would be difference IN FAVOR OF the
plain sand filter.
Mr.. Mason was recalled and asked Wheth-
or he thought the filter beds should be COW
cred in Washington. He thought not. Inc
cost of covering filter beds would be nearly
80 per cent of the cost of the plant Col.
Miller stated that the cost of covering the
slow sand filter beds would be about S1o,-
600 an
Mr. Rudolph Herring, editor of the Engi-
neering Record, then testified He has
had very prominent connection with work
of establishing filtration plants. He was
member of the commission to consider the
matter of establishing a filtering plant for
the city of Philadelphia and had recon-
mended the mechanical system for Atlanta,
Ga about ten years ago, the expense or
the slow sand filter system being reason
why it not adopted there. There was
also no great need there for securing bac,
THEOLOGICAL results. He had recommended
in addition to the general slow sand plant
at Philadelphia. that a mechanical filter to
supply 50,0OO.000 gallons be supplied. One
as to the efficiency of the kind of filter
His report had favored filtering 200O00000
gallons of water a day for Philadelphia,
one Quarter of which would be secured by
the mechanical system.
Both Systems Recommended.
The water Of the Delaware would be fill
tered by the mechanical, while that of the
Schuylkill river water was to be filtered by
the slow sand system, according to his
recommendation. The board looked upon
the mechanical system as likely to produce
good results. Between the two methods he
thought there was little difference in the
cost ultimately, the slow sand being more
expensive to install. while the mechanical
is more expensive to maintain. He is now
investigating the subject Of filtration for
New Orleans but that investigation had not
gone far enough to allow him to determine
what system he thought best for that city.
He was satisfied that improvements are be-
ing made in the mechanical system which
make it effective if properly operated He
thought, in determining what system of fill
tration city should have. that the water
and other conditions of each place should
determine what was best for it. He was
satisfied that whatever system should be
adopted for Washington there would be but
tanned. If intelligence is not applied to the
conduct of either method Of filtration the
results would not be satisfactory, but the
slow sand filter would not be so greatly eff
fected in efficiency if not properly managed
Mr. Herring said that extensive experiments
are now being made In Moscow, Russia,
with the same water. but the results of
that investigation will not be announced for
year. Mr.. Herring was one of the engi-
neers who made the present plan for the
sewerage system Of Washington, and he
said he was glad to learn that that system
Is being carried out as recommended by
him. His knowledge Of the water supply Of
the city gained In his Investigation of Its
sewerage system was not sufficient TO allow
him to form an opinion which system of Ill
tration should be adopted there. Where the
water Is extremely turbid and carries clay
IN suspension ne believed the mechanical
system would be the more effective He
knew of no city In Europe in which the
mechanical system is being used.
Typhoid Fever Cases Reduced.
Mr.. John M. Diven, superintendent Of the
water works at Elmira. N. Y, gave some
interesting statistics concerning the typhoid
fever cases in that city. where the me-
chanical system is in use. The cases per
year were greatly reduced since the intro
duction of the filter.
Mr.. Geo. A. Johnson Of ST. Louis, Mo-,
who was the bacteriologist in connection
with the recent experiments made in Wash
ington by the War Department, also testi-
fed He said he had made 30, 900 or 1900
analyses of water during his life and had
examined fifteen different waters. He did
not think enough examinations were made
Of the water from the mechanical and slow
sand systems at Washington during the
experiment there to determine which sys-
TEN was the most effective. So far as he
had carried on his investigation the two
systems were shown to be about equal as
means of eliminating disease germs
$50 far as 1 know" he said. that water
in Washington is pretty badly polluted"
The clear Potomac water was apt to be
more polluted than that which is very tur-
bid for the reason that the great turbidity
occurs at times of freshets, when the large
volume of water causes reduction Of