The Republican. [volume] (Oakland, Md.) 1877-current, 1885-09-05
LONDON SEWAGE.
What 1t Is Estimated to BE Worth, and
Plans for Its Disposal Considered.

What 1t Is Estimated to BE Worth. and
Plans for Its Disposal Considered.
1t has been computed that the annual
value of London sewage amounts to S..
Cd. per individual. and, estimating the
population at 100000 persons, the
total value would be more than IS, 000,-
600 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 s by the APP
plication of sewage to land, as, for in
stance, is done at Pullman, ILL.,, or from
treatment by chemical processes. Pre-
cedents for the first plan exist in
Great Britain, the more notable ones
being in Edinburgh and Doncaster; but
from neither of these could the commits
sioners derive sufficient encouragement
to infer that the pumping and other ex-
penseS would not cancel all of the pos
sible profits. The second plan is re-
garded as yet more unfavorably, for tho
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
treatment of the metropolitan sewage,
four possible schemes are presented and
analysed. These are broad irrigat on,
filtration through land, processes of de-
position or precipitation, and precipita-
hxy n,o,,lionN.,>,, -
land. The testimony seems to be quite
decisive and uniform that for every 100
persons one acre would be needed in
broad irrigation, and that the sewage
should be strained or purified before
permitted to finally pass upon the sur
face of the land When tits remembered
that 10000 acres are equal to about
sixty-two square miles, the impracticabil-
ity of this scheme is apparent, for no
such farming area can be found in the
neighborhood of London.
The method which meets with the
greatest favor from the commission is
the last one mentioned. The chief adj
vantage is that the sewage is thereby
much more thoroughly deprived Of its
noxious qualities. The process is
IOIuu III dCGudl use Ill b4lIlllII : nam, anu
is described as follows: The sewage
is treated with lime and al
lowed to deposit in series of
large tanks; the clarified liquid is
then passed through porous land, after
which it runs into the river, being found
perfectly innocuous. The sludge de-
post, which amounts to $50 tons day,
is allowed to run in its semi-flu;d staUe
upon 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 for
this purpose, and the land so used re-
mains for three years before sludge is
put upon it again. Thus the quantity Of
land required for the disposal Of the
sludge would be 1856 acres" Such
system meets the chief difficulties. 1t
does not require the large area de-
manded for broad irrigation, and it
clarifies the filth which is now poluting
the Thames, even up to the bridge The
history Of LondOn's sewerage expert
ment conclusively shows that city has
not solved the problem when it has
even devised a method for drawing OIL
its drainage. The termni must be con-
sidered. rs well as the lines Of trans
portation.-BradstreeGS reports.