The national Republican. [volume] (Washington City [D.C.]) 1866-1870, 1869-03-24

Hill and Navy Yard, which from lie natural
inclination may be drained into the Eastern
branch area about l,086 acres.
Section vI-Includes that part Of the Is
land which borders on and slopes TO the Po-
tomac, and has sufficient elevation to drain
Into Ii area $50 acres.
Section vII-Embraces 90 much Of the
Island as slopes towards James creek and
may be drained Into grand main sever to
be constructed along said creek area 748
acres sewage 1,195,sl3,4es gallons an-
nually.
In order TO convey the sewage Of sections
I, III, ~, and VII, to the basin or recep-
tacle, recommend the construction Of q
grand main sewer, commencing ut the basin
and running thence along James creek to
the intersection Of south q and south Capitol
street, and thence along the line Of the canal
to Twenty-frst street west, This sewer TO
be Of sufficient capacity to receive and con-
yey the sewage Of the above sections,
amounting to l39, 9e3,3 T2 gallons annually,
1851 ,44 gallons daily, or 1854 gallons
per minute.
To insure efficient drainage without any
danger OF flooding the diameter Of this sewer
will require to be at least l2 feet from the
basin to the point at Third street west, where
the main sewer, which drains section I, en-
tiers; from that point 10 Twenty-flrst street
west, feet In diameter; depth at Twenty
first street west, Is feet, with an inclination
Of IS feet on the whole length, or nearly 9
inches In every 100 feet. This fall will be
sufficient without adding unnecessarily to
the depth Of the receptacle. Length OF this
sewer, 81, 800 feet area drained into II,
2,ST6 acres.
Having estimated the amount OF sewage
which will be conveyed through the grand
main sewer, II becomes necessary to deter
mine the capacity Of the receiving basin or
tank. That receptacle will require to be
sufficiently large to contain the sewage which
may pass into it during "a hours at least.
Now the number OF gallons Of sewage due on
the whole area to be drained into this basin
is 10, SOL ,434 gallons In "a hours. Then 49,.
SOL ,434 divided by ~ is equal to 2,60S,'
| i9l cubic feet, the capacity which said basin
should be made. 1t will require to be sunk
to such a depth that It's whole capacity will
be below the level the outfall Of the sewer
which enters.
A proper covering should be placed over
this basin, and an engine placed thereon In
q convenient place TO pump out the liquid
aud raise the manure into barges.
The value Of sewage as a manure has been
demonstrated by numerous experiments,
made principally In connection with some Of
the large cities Of Europe.
The practical average result OF such eN-
periments Is, that land on which sewage Is
being used which let formerly at $40 per
acre around London, now lets at $50 per
acre, or In other words, the producing power
has been increased threefold.
In one instance eight tons of sewage was
applied to an acre, and fifteen tons OF ordi-
nary manure applied to an adjoining acre,
aud the produce Of the former was twice the
amount Of the latter, giving the result Of
nearly four to one 10 favor of sewage as q
manure.
Now ordinary stable manure sells for from
40 to 60 cents per load In this cltyi from the
foregoing 1t may be seen that sewage Is
worth three times as much, so that II the
expense Of raising Is deducted, the sewage
will be worth at least Ell per load, price
sufficiently large to make the proposed sys
TEN an important source Of revenue to the
corporation.
The total manurlng matter, solid aud
liquid, produced In a city, including that
from manufactures, has been estimated at
one ton annually for each member OF the
population.
Taking 10000 as the population of this
city, we have 1900 tons Of sewage manure
duo annually from 5000 or 1903, $50 tons from
1876 acres, the area proposed TO be drained
Into this receptacle. This sewage will be
worth say, In round numbers, sl0O, 900; as
the population increases the income of course
will also Increase, and should the great bulk
Of the sewage be eventually intercepted by
establishing receptacles at Rock creek and
the navy-yard, large amount would thus be
added TO the above annual revenue.
This system Of drainage is not entirely
new, but 1t is the application OF systems sue
cessfully carried out by the celebrated en-
gineer, Robert Stephenson, and Others, under
similar circumstances.
These main drains or sewers, although
running along the line Of natural water
courses, are independent of themi for water
| courses run In many places through private
property, and on that account could not be
used successfully for general drainage pur-
poses. They should therefore be arched
over and made to answer the purpose Of sur
face drainage, while the sewers are intended
! for underground drainage.
| The Tlber should be archcd over from the
| botanical gardens to the Potomac, and the
grand main sewer take the place of the
canal.
IL Is not necessary to construct these main
drains to their whole length at once, but
they should be commenced at their outlets
and continued in systematic manner ac-
cording to the requirements Of the popula-
ton.
have not dwelt here on the construction
OF the parallel or minor drains, for they will
fall naturally into the main sewers, nor do
deem 1t necessary In this paper to enter
into minor matters Of detail and construc-
| ton.
In my opinion, the expense of all general
improvements Of this kind should be borne
equally by the general government, the
city government and the property benefited
in this case, the whole superficial area
drained. The main drain should be Is feet
below the grade and the minor drains IL.
P. II. DoSEGAS,
sup't and Insp'r of Sewers, &c.
| WAsHIHGTOs, ID. e., March IS, 1860.