Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-07-03

as the WORK progressed, and In the appendix
asexecuted, together with the cost of each por-
ton Oft. Between 16 aud II miles of sewers
all hin the n and the ZOE
tntercepting sewer on @ and 18th streets In the
northw west, the sewer on street, between 4th
cepting sewer on Boundary street. in the north
east On the former sewer rock was unexpect-
edly encountered, which has caused great delay
expected that this sewer will be completed by
september 10th. On the Boundary sewer the
western section, which finds temporary out
let at the head OF Tiber sewer, is progressing
favorably and will be finished in August; She
middle section has not yet been commenced,
time dec. 31st), if it is commenced during the
present month and prosecuted vigorously;on the
eastern section (where the size is largesD the
spring, and at the rate it is progressing it can
not BY any possibility be finished within the
contract time dec 31st) The forfeit is 500
has been repeatedly notified both verbally and
In writing that this provision would be rigidly
ensorced c., Every facility has been given by the
trict Is in no way responsible for the delay. No
fault can be found with the construction SO far
as 1t has gone, but the work is unnecessarily
slow on account Of insufficient plant
Prior to the commencement of this work q
careful re-computation was made of all the
data entering into the question of the size Of
this sewer; it was tested by the latest empirical
formulate in regard to the proportion of rainfall
reaching rg the sewer under the existing and
data of the Washington station of the signal
service since its establishment was carefully
analyzed In order to form q correct Judgment
as to the heaviest rainfalls to be provided for.
AS a result Of these calculations the size of the
sewer was reduced from 20 feet circular to
16l2 feet circular. In the shape finally adopted
the invert is a semi-circle with diameter of
10 feet, and the arch a 3-center curve with span
of l 5 feet and rise of 10 feet. The saving thus
effected, without impairing the efficiency of
the sewer for the purpose for which it was de-
signed, is S20.S5 per foot.
The middle section was similarly reduced
from 10laX15S4 feet to 10 feet circular, at q
saving OF S4.53 per foot: The aggregate reduc-
ton of expense was $53.591.25. These COM
putations and all the data connected with them
have been placed in full upon the records of the
office.
With the completion of the contracts made
under the 100000 appropriation the main
sewerage of all that portion OF the city west Of
11th street east is provided for. Many miles Of
small pipe laterals will yet be needed before
every house and lot has Sc er facilities. These
can be built at comparatively small expense
year by year as needed. and the permit system
is always open to those who desire immediate
connections. But the plans for the "compe-
ton" of the sewerage took no account of the
outlets, and these Will have to be provided for
at early day. The main outlets are: First,
The James creek canal: second, The inner
harbOr along Water street; third, The sewer
canal across the flats, and fourth, Rock Creek.
which is damned at its mouth by the works OF
the Chesapeake and Ohio canal The average
distance IF the mouths of the sewers from deep
running water is from 900 to 5000 feet Pre-
limnary studies have been made Tor obtaining
deep water outlets for the sewage proper. leav-
ing the storm water to take the same course as
at present, with the following results: In the
Rock Creek ba~in which is the most important
In view OF the proximity of dwellings, an iron
pipe can be laid on the bank OF the creek. inter-
cepting the dry weather How of the sewers on
both sides and carrying it by gravity under
pressure to the main channel of the river tor
about $4,000. 1t Will be necessary to condemn
of tt.i-
for which legislation will be required.
Second. The outlet o! the i street area at l 9TH
and b streets is below low tide. In order to
Carry tue sewage across the flats to the main
channel pumping works will be necessary in
the vicinity OF 18th and u streets, and tidal
gate, at the mouth OF the sewer. After the
sewage has been raised by pumping it can he
carried by gravity in one or more pipes laid on
the piles which We're driven across the flats
while they were being filled. The cost will be
in the vicinity OF $4,000. Both OF these esti-
mates are merely approximate, as the details
have not yet been fully worked out Whether
the plans should be completed In time to submit
proper estimates to Congress at the next ses-
sion, SO that the work can be done during
the year 1ss6-'s7, Is matter for your
Consideration in view of the other pressing de-
m4nds on the District revenues Third The
james creek outlet doe. not require immediate
"a, te street area by pumping the sewage and
discharging it by gravity into the sewer on I'd
street east and extending the outlet OF this lat
ter to deep water. Fourth. For the inner har-
Dor an inlercepiing sewer will be necessary in
w alter street, and it will probably be cheaper to
build this OF an area large enough, in spite of its
into the channel at Arsenal Point. No eSti-
mates have been made Of the cost of this, as it
does not appear to be Immediately NECESSARY.
In The LAST annual report it was stated tuat
the sewers OF this city are calculated To carry 2
inches of rainfall per hour; or, what is the same
thing, they are large enough for a 3-inch rain
tall, provided only two-thirds of it reaches the
sewer. EXACTLY what portion does reach the
sewer ha. not yet been exactly determined.
ton is one-i alf; the Buckli-Llegler formula for
the conditions existing here gives seven-tenths.
1t il certain that In the wei-ouiitup districts of
this c.ty, with asphalt pavements, grades
between one and three in one hun
dred, and tin roofs connected directly
with the sewers, the loss of rainfall by
evaporation before reaching the sewer is inap-
preclable, the loss by absorption occurs only on
that portion OF the street area occupied by park
ins aud on the unpaved portions OF yards, and
1t Is probably much les, than has been hereto
tore supposed. In order to obtain accurate data
in regard to this important question seii-re-
cordins guage has peeu devised aud placed in
the White Lot sewef eight ieet in d,atneter),
which drains an area oI about 200 acres, com
pletely paved with asphalt and well built up.
BY, comparing the hourly record Of rain
iail with the hourly record OF sewer
dlseehargee it win be possible after a
observed. to tell very accurately what proper
ton OF the rainfall does reach the sewers and
how quickly it gets there. Since the sewer
gauge mas been paced III position only two
storms have occurred of any magnitude. One
OF them was One-halt inch of ram in fifteen
minutes or at the rate OF Two inches an hour.
The sewer rose almost Immediately after the
rain began, and ieli to its normal level within q
few minutes after the rain ceased; its maxi
mum height was 7-lO feet, or about three
Iourths OF the capacity Oi the sewer. The
second storm occurred on June 2Sth two days
sincel. The record OF the sewer gauge tallies
exactly with the record OF the rain gauge OF a
few minute, earlier. At its maximum period
the rain lel lOr 81 minutes at the rate OF $40
inch per hour. The sewer gauge rose to a height
of Z; ITO eet, about 47-1UO of its capacity.
Both of these storms show that sshpaIt
sewers with great rapidity, and with very little
loss. The records Oh the signal Office from 1871
to 1881, show that during that period there
have been storms between and inches per
storms OF duration less than an hour but at a
rate exceeding } inches per hour. Hardly Il
year passes without at least one storm Of 2
inches or more per hour. 1t is evident, there
fore, that the assume tion OF a 2 inch rainfall as
u basis in com i,utinS the size of the sewers is
none too large: although it is proper to add that
the sewers have not been built OF this capacity
in any other city.
The sewers laid under the permit system and
the repairs and cleaning of sewers, have been
last January, and will be reported upon by
him.
DISTRICT BUILDING.
The lack Of q suitable building for the offices
Of the District government is a matter which
requires serious attention. The present hired
quarters are in every way unsuitable They
are very combustible, and are liable to be
destroyed by fire. with all the records contained
in them, at any moment. They are wholly in-
ployed; the arrangement OF rooms is extremely
announcement, bOtn tor the public and for the