Evening star. [volume] (Washington, D.C.) 1854-1972, 1903-01-29
ALUM AS A COAGULANT
USE OF IT FOR CLARIFYING
WATER MAY BE PREVENTED.
Opposition Comes From Medical So
ciety of the District - Not
Unanimous, However.

The result Of the hearing before Senator
Gallinger, acting chairman Of the commit
tee on the District Of Columbia. yesterday
afternoon. is likely to be to prevent the use
of any alum as coagulant in clarifying
the water brought into the District during
times Of great turbidity. This hearing vas
given because Of an amendment that Sena-
tor Dillingham; intended to propose to the
District bill making an appropriation for
facilities for treating the water above the
distributing reservoir TN order to clear 1t
during certain seasons Of the year. While
this amendment did not state that alum
was to be used that was the object Of It.
There was considerable opposition to the
use of any alum In this connection oy the
committee of the Medical Society OF the
District Of Columbia that appeared at The
hearing yesterday afternoon, but 1t was not
at all unanimous or to the extent OF the
opposition that was manifested when the
proposition to provide mechanical nttratiOn
was made when Congress first appropriated
for a filtration plant This is because OF
the fact that much less alum is used under
the. system now proposed which will pc m
connection with the slOW-Sand nltrallon
system being installed.
AS proposed this of alum would have
been applied at the Dalecarlia reservoir
above the city. At this receiving reservoir
works would be built by which only dur
ing times of great turbidHy of the water
a solution Of alum would be thrown into
the water at the point at which the river
water enters into the reservoir. This
would cause a more rapid precipitation of
mud than takes place by means of mere
natural processes of sedimentation. The
cost of such an auxiliary work would be
only about $4,000.
May Be Addeu at Any Time.
The consideration that will probably in
f1uence the committee finally to eliminate
this portion of the work Of filtration from
the plan is in effect that 1t may be added
at any time in the future without more
expense than would be involved while the
general filtration plant Is being constructed.
1t has nothing to do directly with the fl
tering Of the water by the slow sand pro-
cess 1t is said that by the time the water
Is carried from the Dalecarlia reservoir,
where settling takes place, to the Washing
ton city reservoir, at the head of list street
northwest, and then pumped on the Ultra
ton beds. passed through them, then into
the distributing reservoir and finally to the
city. there will be very significant amount
Of alum remaining in the water. But, at
any rate, under the system in contempla-
ton, If 1t should ever be carried out, the use
of alum could be discontinued at any time,
and, in fact, would not probably be used
on an average of much more than week
SO during certain seasons Of the year.
The opening of the bids for the erection OF
q
in charge of the Washington aqueduet. yes
terday afternoon, developed the fact that
the lowest of these bids is in excess OF the
estimated cost upon which Congress up to
the present time has based its approprfa-
lions. There were only three bidders for
the entire work, and 1t developed that many
of the items of the bid were far in excess
in price to estimates. one reason Of which is
given by the advance that has taken place
in the markets.
The result of this bidding will be placed
before the Senate committee on appropria-
tons, as that committee will wish to know
exactly the cost of the project provided for
before 1t takes final action on the District
bill, now before it. 1t is within the posi-
bilities that 1t may be decided that bids
must again be called for, but the committee
may accept the situation and be willing to
provide for the contract under the terms
Of the lowest bidder, though 1t involves an
increase.
An Element Considered.
One of the elements that figures in the
high bidding for the construction of filtra-
ton plant is the fact that an energetic con-
tractor has purchased the right to dump
earth in all of the low places IN the vicinity
Of the filtration plant, at the head of list
street, just south of the Soldiers Home. In
this section there has been heavy grading,
so that there are many deep holes which 1t
would benefit the owners of the land to
have filled up But, as stated, an energetic
contractor and SPECTATOR who was one Of
the former bidders for the work Of excavat
Ing for the filtration plant, has purchased
the right to use all Of these dumping
grounds exclusively, and that right can be
secured from him only by his consent.
This disadvantage Is somewhat offset by
reason Of the fact that in the latest plan
for the filtration plant the elevation Of the
filter beds is about seven feet higher than
under the former plan. This will involve
less excavation than would otherwise have
been necessary.
A suggestion has been made which will be
of value in connection with this work to
the effect that the grading required by the
proposed location Of the union station on
Massa chusetts avenue will make necessary
a large amount OF additional earth there.
and this is near enough to the filtration
beds to allow the dumping of earth exca-
Yated in the construction Of that plant