Evening star. [volume] (Washington, D.C.) 1854-1972, 1901-08-17
DISPOSAL OF SEWAGE
REPORT ON BACTERIAL METHODS
EMPLOYED IN ENGLAND.
Description of LOndOn's Main Drain
age System-Chemical Precipita-
ton and Septic Tanks.
From the Engineering Record.

From the Engineering Record.
Late last year the city council Of Toronto
authorized Mr.. c. H. Rust, the city en-
gineer. to make a personal examination of
the bacterial methods of sewage disposal in
England, in order to report on their avail
ability for Toronto. He visited the Abbey
mills works of the London main drainage
system and the plants at Sutton, Exeter,
Hampton. Croydon. Leicester. Birming-
| ham. Oswestry. Manchester Sheffield,
Leeds, Carlisle, Glasgow and Barrhead. On
his return he submitted four propositions
for the disposal Of the Toronto sewage. as
follows:
System. cost. cost
E ssss |,ne 1890
Septic tank system, ..... 2'S5o o'0 S sa'%S
Septic tank system, 3d.. 1,SSo,ooo p,ooV
The first system Is recommended on &C
count Of It's financial advantages and the
difficulty of procuring land for disposal
works at a reasonable cost. Mr.. Rust
states. however, that a bacterial system
of disposal for the city would be thorough
Iy efficient and satisfactory, and his con-
illusions on this subject, deduced from the
experience and Investigations OF the cities
and towns mentioned, are given as ioi-
lows:
The chemical precipitation Of sewage,
which has been extensively adopted IN
England, has proved to be unsatisfactory
struction 1t only prepares the sewage IOr
publication, a work now much more en-
GENTLY done by the septic tank Inc pu-
rifcation of sewage by bacterial action, az
fer wears of experiments, seems to be the
only method which. at present, gives prom
Use of successful application. AT the WORKS
I visited, in every instance the eHuent was
clear and satisfactory, and there appeaIeu
to be no danger of after-putrefactlon. Inc
operation of the bacteria beds In winter
in England, where, of course, the climate
is much milder than In this country lCan-
ada, does not appear TO De seriously a.
fected but 1 think before any extensive
system of bacteria beds is constructed mere
(Toronto) it would be advisable to con-
duct some experiments in the winter to as
certain definitely their practlcapliity our-
ing our severe winter
Contact Beds and Filters.
In addition to the treatment by the Or
binary Dibdin contact beds, experiments
have been made with continuous filters.
such as the Whitaker and Bryant. and the
stoddard filters, which are capable of deal
ing with a much greater amount of sewage
than the ordinary Dibdin contact bed. the
patentees claiming that as much as 3ooo'-
600 to 5000, 600 (imperiaD gallons of sewage
nor acre per day can be treated. The only
CITY at present, believe, where cohtlhu-
Gus filter is in operation on large scdle 10
at Accrington. [ saw small one IN use
of
of opinion that the climatic conditions In
this country are such as to prohibit their
use here. IL 1t were not for this drawback
there is no doubt that for small towns TINS
kind of filter would be advantageous
The lifetime of contact beds is not yet
definitely known. The choking Of the beds
managed unskillfully would propap!y De
rapid and 1t has not yet been proved that
this can in any case be entirely prefehteu.
IN some places the beds have been in use
Ave ar six years and their efficiency has de-
creased in some cases as much as % per
cent within a short time after they were
put in operation, but AFTER tnat no Iurt t
decrease was noticed. 1t is probable AFTER
being a few years in use that the surface
of the beds would have to be replaced Win
fresh material. If some arrangement could
be made, however, so that all the sewage
could be freed from sludge before being
put on the beds there Is no doubt that they
could dispose of a great deal more sewage
and their efficiency would be maintained
for a much longer PERIOD. Al 6raolo i!L
where the sewage is difficult to deal with
on account of the manufacturing refuse
contained therein. the contact beds have. L
understand, gradually filled up. In other
places there has also been some trouble
with the sludge accommodating on the sur
face AS have just explained. this would
be obviated If the sludge could be prevent
ed from reaching the beds, or by having
larger capacity for detritus or septic tanks.
The sludge Nuisance.
The septic tank Is no doubt the most
satisfactory method of getting rid of the
sludee nuisance, and has an advantage IN
the small area of land required. In the So
called Exeter system 1t has been the prac-
tice to make the tank practically air-dght,
but engineers generally are of the opinion
that this is not now necessary. the septic
action being found to be just as satisfac-
tory without cover. but it would probably
be found advisable in this country. owing
to climatic conditions, to have a roof of
some description over the tanks. The
question Of the capacity. of the tanks Is
another important subject upon which
there has been some difference of opinion.
The Exeter syndicate, understand, in pre-
pairing plans, provided for capacity equal
to one and one-fourth days supply of sew
age. Other engineers in designing plans
have had this capacity considerably re-
duced. considering 1t only necessary to
provide for twenty-four hours flow, and In
some cases / found the capacity even less
than this In dealing with the sewage Of
large cities this Is matter to be carefully
considered, as the first cost OF construct
Ing these tanks is very high. As Toronto
sewage Is much less polluted than English
sewage, the tanks could probably be re-
duced here to a minimum; that is. worked