The record-union., 1896-07-28
THE DRAINAGE SYSTEM.
Something Of the Plan About to be
Submitted.
City Surveyor Mullenny Gives Rea-
sons Why the Plan Should
be Adopted.

The "Record-Union" having asked
City Surveyor Mullenny to explain some
features of the proposed drainage sys-
tenn, on the adoption of which the peo-
pie of this city will vote on the 18th of
august, that gentleman has submitted
the following:
1T is acknowledged that the only
feasible plan for disposing of city drain
age is to eject it into the river; for this
purpose a pumping plant should be con-
structed at a convenient distance from
the river, to which all drainage should
he conducted in a conduit of proper ca
pacity.
The present plan, recently adopted
by the Board of Trustees, provides that
the pumping station is to be placed at
Front and streets, with discharge
pipes leading over the levee and down
into the river below low water mark;
pumps to draw from a sump or reservoir
and arranged so that the actual lift will
he only the difference in hight between
surfaces-not less than two pumps to
be placed in position in order to econo
mize for dry weather drainage; then to
construct a brick main intercepting
sewer or conduit from the pumping sta
it will receive drainage from the Sew
enteenth-street sewer-to be placed at
Il low grade and given proper fall to per-
nit of an extension to the eastern limits
of the city, as future developments re-
quire; to be six feet iii diameter and di
minish to four feet in diameter at
Seventeenth street. It's capacity is to be
three times that of the present sewers,
nd
tire area of the city amounting to one
snch in twenty-four hours, which would
be equal to about 3,0OO000 gallons per
hour.
The conduit is to be placed at an ele-
Walton that will drain the lowest portion
of sewage lake. which we now use as a
reservoir. 1t will be of brick, laid in
cement mortar, circular in form, with
smooth vitrified split pipe invert In the
bottom-twenty to twenty-four inches in
dlameter-for dry weather flow to con-
fine the volume to a narrow channel
thus affording the least friction and
Rccelerating the velocity-the bottom of
the brick main on each side of the split
pipe invert to be filled with concrete and
remented over.
This main conduit to be placed at an
.,
so that when filled completely water
would not back up in these sewers.
We must not lose sight of the fact
that flushing is required during the dry
season especially, in order to keep lat
eral or alley sewers clean; it being un-
derstod, of course, that the cesspools
and vaults are to be abolished and the
house drainage to be discharged directly
int I,;-
can draw from our present water sup
ply to the extent of q quarter of mil
hon gallons daily, which will be ample
and can easily be supplied from the
water works, handling from 1000 900 to
100000 gallons daily. 1t Is not the
amount of water that is used, but the
manner in which it is used for this pur-
pose that produces desirable results.
1T is therefore deemed the most ex-
redient to put automatic flush tanks in
operation in the near future-one at the
head of each alley sewer-discharging
from $50 to 300 gallons each, twice a
day. Such a volume shot suddenly into
a sewer of eight inches in diameter Is
the most effective method of cleansing
and the cheapest; main sewers do not
require direct flushing, as 1t is a fact
ever, their velocity of flow would be ac-
CELEBRATED by this method.
In this brief outline I have pointed
out the practical features of this plan,
which should appeal to the technical
man as we'll as the man of common
sense.
1T may be of interest to those who
fear that this plan does not offer COM
plex arrangements enough to warrant
its acceptance to explain that it is de-
signed according to scientific princi-
pies and the modern ideas of sanitary
specialists.
In the pumping arrangement there
IS to be the most economical method of
pperation-only so much pumping power
10 be applied as will fit the conditions
the siphon principle to be employed so
that the actual lift will be the difference
IN hight between surface of Sump and
surface of river
The material for the main sewer is
such as is being used In all our large
cities for storm-water drainage; brick
laid i'm cement results in a solid stone,
SO far as all practical uses are con-