Delaware gazette and state journal., 1896-04-09
wILMINaroN,S FILTER.
A Harrisburg Reporter Visits the Local
Plant and Describes II.

4
! Every one is still Interested and de-
manding that something be done TO
| improve tho condition of the Harris
burg drinking water. At present 1t is
not worry bad, but the spring rains will
| bring down the coal culm and mud in
large quantities again AT certain sea.
sons Of the year filter would be needed
while at other times tho river water is
pure and wholesome. The Star. lnde-
pendent has already given the public
opinions of the leading experts on filtra-
tion, as we'll as the views of DIR. Benja-
min Lee, secretary OF the State Board
of Health, on the needs of Harrisburg.
Descriptions were also given of the fl
tering plants which are being so sue
cessfully operated at Wilkesbarre and
Danville, a representative Of the paper
having visited both places.
This week Star independent repre-
sentative inspected the filtering plant
at Wilmington, Del. That city has
the plant which has been placed in use
tering and purifying company of Phila-
delphi6. The system differs from all
others by reason of it being buried be.
| htdlu tht buIidCb Vi lut cdTlu dui tlhO
because of the use of iron salts gener-
ated by galvanic action, and the plant
| has a capacity of tiltering 10, 000 600
gallons every "a hours 1t has been in
| operation about two years and is very
much liked by the city authorities of
| Wilmington. 1t cost 500, 600 to con-
struct it and about GO cents per l,000,
| goo gallons to filter the water. III the
IT, a n \
it is proposed to use the ground or plot
over it for sort of a lawn or small park.
Being located on the banks of the
Brandywine from which the water is
taken, the site was we'll located Aftor
the water has been filtered it is pumped
| into the reservoir from which 1t is dis
tributed to the consumers. A great
deal of mechanism, iron tanks, pipes,
braces, flume tanks, NC, give ono the
first impression that the system is
rather complicated, but to certain
extent this disappears when once it's
workings are explained. The city
pumping station aClioins the filterng
plant and is a well arranged water
house. Chief Engineer J. A. Bond
has given the city of Wilmington an
excellent service, as can be seen by the
well kept machinery and the showing
the water department has made.
This and another plant are the only
ones the United States liltering COM
pany has in operation, and in order to
supply the consumption, duplicate
plant will be built below the present
station. 1t is estimated that it will
cost from $50, 000 to so, 600 to build
the duplicate plant Of 1900, 600 gallons.
There are advantages in having this
underground arrangement no extra
buildings or heat being required to
meet the climatic changes. Much
masonry is used all the sides and over
head work being arrhed and built of
brick. The aeritication is accomplished
| by pumping through the water as it
flows along the tanks, by means of an
air pump. In this way air is constantly
ascending through the water. The
residents who were interviewed say the
water is always very satisfactory and
changes in the condition Of the Brandy.
wine water are not noticed since the
tiltering plant has boen installed. This
system is known az an upward sand FL
| teration with iron and air treatment.
When the inspection was made this
week, the Brandywine water was not
in bad condition.
The United States filter company
management believes that its system
| of filtration could be placed where the
| pipe yard above tho water house is now
located. After the filter has been com
| pleted the ton Of the plant could be
used as at present, it being covered
over, only openings being left for ven
| tilation and light. These can be closed
! al ffrhA Ias
| essential that they be opened during an
| entire winter. The Wilmington plant
| does not present an attractive appear
| anco, but il is claimed to do the work.
| Engineer Bond said the people arc
pleased With the work it is doing. The
washing Of the beds could not be shown
at this time, it being necessary to keep
all the beds at work. There are five
OF them, one under each arch These
arches are over loo feet in length.
DESCRIPTION or FiLrERTNG AND PURIFY
1NG PiANT.
The plant ut Wilmington, Del. is
! placed under ground that it may not be
affected by climatic changes. The
/ purifier occupies the space above tho
| skew back OF the arch, while the cham
/ Der hcncath contains the settling tanks
and upward filter.
Ehe water 70 he treated is delivered
by gravity and the power generated
| thereby is used to entrain air into the
water.
Aerfication of the water 10 be treated
- an important factor in this process.
| Water is first drawn from the reservoir
| into cast iron rectangular duets sus-
| pended from tho afchway. In the first
\ 30 feet Of these duets, cast iron omen
cages 8 inches square, containing
wrought iron, or bundles of round iron,
| are suspended from an overlaying shaft
in the loops Of link belt chain, gearing
| into sprocket wheels on the shafts
Rotary motion is given these from
! power derived from water at entrance
end passing through turbine wheel.
or at exit end by water passing over an
overshot wheel. A continuous motion
is necessary TO prevent the iron from
rusting together and to stimulate, hy
abrasion, the delivery of the iron
salt into the passing water. Tho iron is
here subjected to galvanic current
which creates a chemical solution of
the iron salts soluble in ali the varie-
ties OF water 10 be handled. After tho
iron treatment free air il introduced
from an air chamber laying between
first and second water ducts, and sup
piled from the air reservoir, which
i hastens the coagulation Of the carbuns
contained in the water; time for which
is allowed by The ducts being nlaced one
above the other with very slight fall
and running tho whole length Of the
bed, through which the water passes
very slowly.
THE FtLTERGNG MATERIAL.
The water is delivered from the