Evening journal., 1909-12-23

The water passes from the sedimenta-
ton reservoir by gravity to the regu at
ing chamber, then into the nlter In the
regulating chamber the level OF tho water
on the alter beds is controlled. The filter
medium consists OF two feet OF sand
which is dredged from the Delaware
river. and an underdrainage system OF
five courses OF gravel varying In size from
one-tenth of an inch to two and three in
ches.
Innovations In Process.
After the water has run through the
altering medium Il Is collected In a main
collecting pipo supported below tho bot
tom OF the filters and is then conveyed 20
the pipe gallery where the rate OF flow
from each filter bed is controlled. After
passing through the Ventura meters and
controlling valves the water is delivered
through a S6-inch cast-lron main collector
to the filtered reservoir. and then to tho
city's distribution system.
There are numerous Innovations IN the
design and construction OF this plant in
comparison with those already In exist
ence in other places Among these fea-
lures. and perhaps the greatest, is the
manner OF operating and cleansing the
filter. 1t will be noted in the preceding
description OF the plant that tho hlter
beds are long and narrow. This form OF
construction has permitted the installa-
tion Of a mechanical device for washing
the sand while il is in place on the beds.
It consists of crane having a SS-foot
span with its superlmposed cross-travel
carriage. the latter being 20 feet long. on
this cross travel carriage is mounted the
washing machine. The machine can be
run along the filter beds on rails provided
for the purpose, then transferred to the
cross-carriage to be carried from ono bed
TO another. It is operated by electricity.
Hollow Tooth Cleans Sand.
The sand is stirred up by means OF hoi-
low teeth projecting into Il and through
which jets Of water are forced. The stirrer
wheels are encased in steel chambers, As
the dirt which has collected on tho sand
IN the process OF filtration Is brought into
suspension by the action OF the stlrrer
wheels and jets Of water, 1t can be with
drawn by applying suction and dlscharg-
ed 20 the sewer provided for this pur-
pose.
Another interesting feature applied in
the building of the plant for this city is
that Of constructing the filters above the
filtered water reservoir. BY this plan a
considerable saving was made in the
first cost Of construction in that the
amount Of grounr required is less and
also that the roof Of the filtered water
reservoir serves as the floor Of the filters
It resulted also in a saving OF excavation
and Of concrete II the reservoir and Ill
ters had been built separately, a sepa-
rate roof would have been Required FOR
each.
In the grouping OF the buildings in this
way there is a loss OF head which would
not occur If the buildings were CONSTRUCTED
separately, but the works are on higf
ground and the loss of head between the
} filters and the reservoir is not matter
OF any great consequence.
To End Typhoid Terror.
At present the water supply comes d.
rect from the sedimentation basin tC
which reservoir it is pumped by two en-
gines each with a capacity OF 12.000O0
gallons every 24-hours. II flows by gravity
from the preliminary filter TO these en-
gines. With the completion Of the fina
, filters, however, the water will pasi
through them after leaving the sedimenta
tion reservoir and then to the hltere,
water reservoir then 70 the city.
, The Inauguration of the new system 1
/ anxiously awaited by the residents Of thi
city. The water supply, especially durin
Z the past summer, was worse than It wa
\ ever known to be in previous years. Dur
ing the dry spell the water not only hai
an obnoxious taste, but had foul odo
l that was so sickening that very little o
, the city supply was used. Residents relie
2 on well water, springs or the water sup
e Piled by private companies.
e The numerous cases Of typhoid feve
= that have occurred here in recent year,
especially in the warm weather, are a
said 10 have been due to the impurltie
, I'm the drinking water. For this reason
Wilmington residents are anxious 70 Sc
{ the final filters completed, and for thl
& reason the inauguration OF the new sys
j tenn and the running OF the water throug
f the filters will indeed be a most welcom
and acceptable Christmas present 10
them.