Evening star., 1898-10-26

storm water will be the Washington chan
mel Of the Potomac at NJ street.
The East Side Sewer.
The east side intercepting sewer. Includ-
Ing the extension Of Boundary sewer. will
convey the sewage Of the eastern section
of the city mot including that portion trib-
utary to the Tiber creek system). and II
VIII discharge into the B street and New
Jersey avenue trunk sewer at NJ street
The Water and NJ streets interceptinS
sewer will intercept the sewage OF South
Washington. now discharged into the
washington channel of the Potomac and
the sewage of the James creek valley south
Of h street. 1t will intercept also In its
lower portion. all of the storm water from
the low area between H and n streeta Il
Will empty into the B street and New Jer-
sey avenue trunk sewer at n street
The B street and New Jersey avenue
trunk sewer will receive all the storm wa
disposed OF otherwise than by pumping; Il
Will receive. at its upper end, the sewage
conveyed by the Rock creek and B street
intercepting sewer and near it's lower end
the sewage conveyed by the east side the
n street and the Tfber crek and New Jer-
sey avenue high level interceptins sewer;
| In addition. It will receive the sewage OF
the territory in which II Is located and
will. therefore. deliver to the pumping sta
tion all the sewage of the city and the
storm water OF the low district.
The pumping station Is TO be located at
the .sontherly end Of New Jersey avenue
and 1t Will be provided with sand and
screen hoists, high-duty pumps for lifting
sewage. and low-duty pumps for lifting
storm water.
At the pumping station the sewage will
be discharged into the siphon chamber
from which ii is proposed to construct an
inverted siphon consisting OF three lines OF
cast-iron pipes across the Anacostia river
to Poplar Point.
The outfall sewer will skirt the rtyer
shore between Poplar Point and Magazine
Point. 1t will be of horse shoe section y
1eet inches wide and feet inches high
Automatic regulators will be provided at
points or sewage interception, and tidal
gates VIII be placed at the outlet ends of
the old sewers and of the Intervening
trunk sewers.
To Be Completed in 1925.
This work was commenced in the year
1893, the amount expended to date and
available is $772 900, and the amount re-
| quired to complete the project is S3.257.-
tS5. At the rate Of progress heretofore
| made the completion OF the work may be
expected about 1926
The general rules followed in the work OF
| sewer construction In Washington may be
Of interest
Inc earlier sewers were built with stone
with planking; other types were of d sec
tlon with plank. stone brick bottoms
| with stone side walls and brick arches and
others were brick sewers of circular rec
uon, commonly called barrel sewers"
f1pe sewers were introduced about tn.
year 1871. and within the next succeeding
TOUR years more than sixty miles of sewers
CT this type were laid After the change in
me form of government of the District In
1914 the engineer Of the board of Commits
sioners Lieut. (now MaJoD r. L. Ho1ie.
was made aware of and corrected many de-
iects or design and construction in the
sewers more recently constructed in prog
ress and In contemplation. The sizes were
generally too small to take care of heavy
"a as'nlalis, the bottoms OF main sewers were
OF common brick masonry and were badly
worn IN cases where gradients were at q II
considerable, the forms given to the tnyerts
were such that the sewage flow was moi
concentrated. tho bedding, alignment and
)olnting Of pipe sewers were defective and
much inconvenience was caused by the in
trusion of tree roots, which developed with
the sewage flow
Inc sizes OF proposed sewers were in
creased; intercepting sewers were con-
structed: the inverts of main sewers were
designed OF materials selected to resist
abrasion, and were shaped to concentrate
the sewage flow; pipe sewers were de-
signed with concrete cradles and concrete
enveloping joints and care was taken to Sc
cure good alignment; these general rules
are at the foundation of the practice OF
today.
The sewers of Washington .dneluding the
whole Of the District Of Columbia) are de-
signed to carry storm water and sewage,
with the exception of a few small subur-
ban areas, where they are designed to
convey sewage only. An empirical formula,
which seems to fit local conditions is used
to determine the amount Of drainage to be
provided for.
The kutter Formula.
The formula gives large unit rates for
small areas. the rate decreasing as the area
increases. The sizes are determined by
the use Of the Kutter formula. in which
.O13 is used as the coeficient Of friction.
Sewers between srd "a inches In diane
ter are mads Of stone ware pipes laid upon
a cradle Of concrete masonry, the Joints be-
ing covered with a concrete-enveloptng
band. Above "a inches diameter they are
made egg shape until the feet by feet
size is reached. which is the largest regular
section: sewers above that size are con-
sidered exceptional and are designed with
reference to the location and conditions
In main sewer work that portion of the
sewer which is below the springing Nne is
constructed Of concrete masonry. lined
with wearing surface of vitrihed brick
masonry from the bottom to a line mid
lay between the bottom and the springing
lire. Above the vitrified brick masonry
the lining is Of ordinary brickwork. the
same thickness as the vitrified brick ma
sonry. In sewers feet by 9 feet and
smaller stone ware inverted blocks are
land in addition to the lining of vitrihed
and ordinary brick masonry. described
above. In a few cases of sewers having
light gradients. constructed in dry ground
and designed to convey sewage only. un-
lined concrete sewer inverts have been
constructed with satisfactory results. The
erches Of main sewers are constructed
either of ordinary brick or concrete ma
sonry, the selection being controlled by To-
cal conditions.
Concrete masonry used In pipe sewer
work and elsewhere In walls less than
inches thick is composed OF beach pebbles,