Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-04-24

freshet of 1889; the damage done by this
flood was very great; and If like one were
to occur now, the damage would be still
greater. as there are many more cellars to
be flooded and more business to be inter-
rupted than there was then. Throughout
much Of this area, the level of the surface
is SO little above the level of the ground
water that II is impossible to construct the
deep Easements and cellars which important
business property requires.
In the adopted plan, to meet this diff
Guilty, as well as the sewage disposal prob
lem. 1t is intended to construct dixie on
virginia avenue from high ground on e
street to high ground near the monument,
and another along the banks of James
creek canal and across N street southwest
SO as to prevent the waters of the river
from overfiowing the low area Of the city;
to keep them from backing up through the
sewers, tide gates will be placed at the OUT
let's. trunk sewer fifteen feet In d.
ameter will be built along B street from
"a street northwest to the pumping sta
ton at the foot of New Jersey avenue on
the Eastern branch. Into this trunk sewer
Will empty all of the sewers of the low
area, an intercepting sewer built along the
pank OF Rock creek to cut off all the sew
age now flowing into that stream from
Georgetown. as well as Washington; an
other marginal interceptor built along
Water street to keep the sewage out of
the Washington channel, and finally the
Easby's Point and F street high level in
terceptor, which we are now building. This
sewer, together with two other high level
If terceptorS one on 1-2 and NJ street
southwest, and the other following the mar
gin of the low area from Indiana avenue
down to New Jersey avenue, perform the
function of intercepting the storm water
from the higher ground surrounding the
low area and carrying 1t off to the river so
as to diminish as much as possible the
work demanded of the pumps. These sew
ers are located as near the margin Of the
area subject to overflow as is possible con-
n diScharge
into the river. During dry weather, when
these sewers carry sewage only, the outlets
into the river will not be used; the first Will
discharge its sewage into the 3 street trunk
sewer at its head, the second into the
Water street intercepting sewer, and the
third will carry its sewage direct to the
pumping station. During heavy rains when
these large high-level interceptors are run
ming nearly fully with storm water, the
sewage which they carry will be so diluted
that its discharge into the river will be I'M
Objectionable. The sewage Of the eastern
part of the city, together with the dry
weather flow of the Boundary sewer, Will
be carried by marginal interceptor along
the bank Of the Eastern branch direct to
the pumping station.
You see now that this plan provides
means by which all of the dry weather
sewage Of the city shall be brought to the
pumping station, at the foot of New Jersey
avenue together with all storm-water of
the area which lies too low to drain into
the river during freshets.
The Pumping Station.
AT this pumping station We will have a
proper number Of large centrifugal sewage
! pumps, which will deliver into a low stand
| pipe, connected with iron pipes. running
| under the Eastern Branch to a trunk sewer
| on the other side of the branch, which will
discharge at the selected outlet near the
| naval magazine. There will also be large
| storm-water pipes, which will discharge
! directly into the Eastern Branch.
In operating this system We have three
| cases which may arise. We may have or
| binary weather. either dry or with moderate
rains; we may have heavy rains. and we
may have heavy rains accompanied by q
freShet in the river.
I'm the first case, in ordinary weather al
the sewage will be delivered to the pump.
at the pumping station, which will b,
operated at such a rate as to keep the leve
OF the water In the trunk sewer low, so a.
| to keep down the level of the ground watel
in the low area.
When heavy rains come on, all Of tn,
high level intercepting sewers will, for
while. continue to deliver both sewage ans
storm water into the trunk sewer, unit
they have been well flushed out AS tn,
storm continues, to avoid overlooking tn
trunk sewer the connections with the higi
level interceptors will be partially or en-
tirely closed, and these latter will dis
| charge directly into the river. In the mean
Wnlit, tne water ana sewage brought doWf
by the trunk sewer has begun to exceet
the capacity of the dry weather sewag,
pumps and the level of the sewage begins
to rise in the trunk sewer. Additional
sewage pumps are started but If the storm
continues, even these will not keep dowr
the level of the sewage In the trunk sewer
In the course of time this level rises s,
much that it becomes higher than tn,
| water In the Eastern Branch, the pump,
will then be stopped, and the sewer will
| overflow into the Eastern Branch through
open tide gates. BY this time, however
the large amount of storm water iowin,
into the trunk sewer will have so IA
diluted the sewage that there will be n,
risk of polluting the Eastern Branch b,
allowing the sewer to discharge into II
AS the storm abates. the level in the trunl
sewer will fall, until it becomes the sam,
as that In the branch. The tide gates will
then be closed, and the pumps startet
up again, and the contents of the sewe
pumped down to its normal level as rapidly
as possible SO as to create a rapid curren
in the sewer, and scour out any deposits
that may have taken place while tn,
velocity in the sewer was checked.
Finally, when a heavy storm occurs ant
we happen to have a freshet in the rive
at the same time, II is evident that we can
not let the trunk sewer discharge through