Savannah morning news. [volume] (Savannah) 1868-1887, 1885-08-31
LONDON SEWAGE.
What 1t is Estimated to be Worth, and
Plans for its Disposal Considered.
From RrndRtreets Rannrte

Via it is Estimated to be Worth, and
Plans for its Disposal Considered.
From Bradstreets ReDorts.
1t has been computed that the annual
value Of London sewage amounts to
S.. Cd. per individual, and, estimating
the population at 4,0O0,0 900 persons, the
total value would be more thar $4,000, 900
per annum. 1t would thus appear, on the
face of it, that, in some way or other, this
sum should be saved for the city.
There are two ways Of deriving profit
from sewage. One is by the application
of sewage to land, as, for instance, is done
in Pullman, Ill.,, OF from treatment by
chemical processes. Presidents for the
first plan exist in Great Britain, the more
notable ones being in Edinburgh and Dom
caster; but from neither OF these could the
commissioners derive sufficient
ment to infer that the pumping and other
expenses would not cancel all of the pos
sible profits.
The second plan is regarded as yet more
unfavorable, for the ''available material
value of the sewage is at present too small
to admit Of obtaining from it any product
which can be sold at anything like the
cost of its production
With reference to the plans for the treat
ment of the metropolitan sewage, four
possible schemes are presented and ana
lyzed. These are broad irrigation, filtra-
ton through land, processes of deposition
or precipitation, and precipitation supple
mented by application to land.
The testimony seems to be quite decis-
i've and uniform that for every 100 persons
one acre would be needed in broad irriga-
ton, and that the sewage should be strain
ed OF purified before being permitted to
finally pass upon the surface Of the land.
When it is remembered that $1,000 acres
are equal to about so square miles the
impracticability of this scheme is appa-
rent. for no such farming area can be
found in the neighborhOod of London.
The method which meets with the great
est favor from the commission is the last
one mentioned. The chief advantage is
that the sewage is thereby much more
thoroughly deprived of its noxious quail
ties. The process is found in actual use
in Birmingham, and is described as fol-
lows:
1.-The sewage is treated with lime and
allowed to deposit in a series CT large
tanks. The clarified liquid is then passed
through porous land, after which 1t runs
into the river, being found perfectly inOc-
uous. The sludge deposit, which amounts
to $50 tons a day, is allowed TO run in its
semi-fuid state upon a portion OF the land
laid out to receive it, after which it is dug
into the ground, which is covered with
soil, planted, cropped, and used for fltra-
ton. One acre per week is allotted Tor
this purpose, and the land 50 used remains
for three years before sludge is put upon
it again. Thus the quantity of land re-
quired for the disposal of the sludge would
be 156 acres"
Such a system meets the chief difficult
ties. 1t does not require the large area
demanded tor broad irrigation, and it
clarifies the filth which is now polluting
the Thames. even to the bridge.
The history of London's sewerage eX-
pertinent conclusively shows that a CITY
has not solved the problem when it has
even devised a method for drawing of its
drainage. The termini mus be consid-
cred, as well as the lines Of transpor-
tation.