The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1897-01-10
The strangest sewage-Disposal Plant
in the World-Purifcatio by Mi
crObes

In attempting the solution of its sew
age problem, the City of Exeter in
England, has recently made a remark
able experiment. The latter is an in
| land city, without the advantage of a
large river whose volume is sufficient
so that the direct discharge of the
sewage Will not pollute the stream. 1t
has had, therefore, the option of the
only two methods of disposal hereto
fore successful, viz; the sewage farm
or chemical publication, both of which
are expensive and often unsa tisfactory.
Instead of choosing either of these, its
city surveyor Donald Cameron, has
invented what he terms the septic
tank system, which he has patented
and which, after having first had
preliminary trial on a small scale has
now been installed on a scale sufii-
cient to fully meet the wants of the
city.
The Exeter plant is a wonderfully
ingenious affair, designed to give the
microbes the freest possible play, so
that they will complete their work with
the utmost rapidity. The sewage is
first discharged into a tank, from
which light and air are excluded. This
tank, in the case of the Exeter plant,
which has a capacity Of $4,000 gallons
per day, is 81 feet long and IS feet
wide, and about 10 feet deep. Before
roughly screened to prevent the entry
of large substances OF debris, such as
brick bats and the like. Within this
receptacle the anaerCbis microbes
those which flourish without access to
the air, multiply with extraordinary
speed, and quickly break down the
solid substances of the discharge, so
that the sewage energies completely
nquified. 1t has also in this receptacle
been freed from grit, and flows through
al outlet at about half the height of
the tank. The design of this is to
maintain the exclusion of the air and
at the same time not draw off the
undecomposed solids which naturally
sink to the bottom of the basin.
Having thus undergone ali the puri-
fication which can be effected by the
microbes whose ways are in the dark,
the sewage is now turned over TO an
entirely different family of microbe-
organisms, those which thrive only
with an abundance of light and air.
As the water is drawn off from the
tank, it Is conducted over a small weir,
which thoroughly aerates it and re-
lieves it from the slight odor which
yet clingS to it 1t is then drawn into
large open filters.
OF the latter, in the Exeter plant,
there are five, occupying a space of
about 400 square yards. Two of these
lAttIS d46 QSEQ DIT IL TIME,
filling an automatically shut off when
filed by a simple hydraulic contriv-
ance. Within these filters the aerobic
or air loving bacteria complete the
process begun by their predecessors
and the result is that the contents
drawn off from them forms clear
crystalline stream absolutely free from
any odor, from any sort Of germs, and
much purer than an ordinary English
river. The filters. by the way, are or
binary affairs comprised of coke, breeze
and furnace clinkers. It has been
clearly demonstrated that pathogenic
or disease producing germs are neither
by nor can they survive
this process, and thus purified, the
sewage cannot by any possibility pol
lutte the stream into which it finally
flows.
The beauty OF this apparatus lies in
the fact that it is almost completely
automatic and requires practically lit
tie or no care whatever. Indeed, it
may be left for an entire week without
attention There is no expensive or
machinery required, no
outlay for chemicals and it presents
none of the features of an ordinary
sewage purifying plant.
Although in the Exeter system the
process is carried out, Mr.
Cameron believes that the sewage
would be extremely valuable for irri-
cation purposes if it were not put
through the filters but were taken di-
rectly as it flows over the weir after
its release from the large septic tank
and were spread over the fields before
its decompoSed organic substances, the !
nitrateS and so forth were removed !
by the filters. So successful has the
new system proven itself to be, that it
is now being introduced into several
other cities of England, and will I'M
doubleday come into wide use with in
land towns, where the conditions are |
similar to those which obtain at Exc
ter.