COLLECTION AND REMOVAL OF NIGHT-SOIL.
In mofussil towns in Bengal the night-soil is generally collected from
public and private latrines by conservancy carts drawn by bullocks, and
varying in capacity from 60 to 200 gallons. These, as a rule, begin work
early in the morning so as to avoid causing a nuisance in the
thoroughfares, travel at a very low rate of speed, not over 2 miles an
hour, and only make one trip a day, in the majority of cases, owing to
the distance the trenching grounds are away from the centre of the town.
This means that a large proportion of the human excreta remains at least
24 hours in the receptacles of the latrines in the immediate vicinity of
densely populated localities. In the temperate climate of England it is
accepted as an axiom that sewage should never be more than 24 hours in
finding its way to the outfall, as it is, when it has begun to
decompose, more dangerous than when fresh and decomposition sets in much
more quickly in the semi-tropical climate of Bengal. In many cases the
quantity of night-soil collected per head per diem is exceedingly small;
the average amount of solid matter evacuated by natives may be taken at
10 ounces, and of urine 30 ounces, whereas returns from several
municipalities show a quantity varying from ·047 to ·37 of a gallon
removed by the conservancy carts. These quantities are, however,
calculated on the entire area of the municipalities, including the
suburbs, where, owing to the custom of Indians, the gardens and adjacent
fields dispose of a large quantity. In order to obtain reliable results,
the densely crowded areas should be divided up into blocks or sections,
keeping the figures well separated in the municipal books, the density
of population per block calculated and the quantity of night-soil
removed registered daily. Many of the Indian bazaars are long narrow
ones, situated on a high ridge of ground, in which case it is desirable
to have several trenching grounds, one for each block or group of
blocks, instead of having one large one situated at a considerable
distance from the centre of the town.
[Illustration:
FIG. 15.—CRAWLEY’S PATENT NIGHT-SOIL CART.
]
[Illustration:
FIG. 16.—RECEPTACLE CARTS.
]
[Sidenote: Conservancy Carts.]
[Sidenote: Receptacle Carts.]
In order to effect the speedy removal of fæcal matter, the provision of
suitable conservancy carts is of vital importance. Fig. 15, page 32, is
an illustration of Crawley’s Patent Night-Soil Cart, and is a good one
for general purposes. It is made entirely of wrought iron, with an
air-tight door for filling and emptying; the latter is done by releasing
a clip from the front of the barrel which connects it to the shafts and
opening the lid, when the barrel turns on its centre and shoots out the
contents. A 75–gallon capacity cart costs Rs. 130; a 110–gallon, Rs.
160; and a 200–gallon one Rs. 225. Small carts are preferable to large
ones, as they take a shorter time to fill, and therefore tend to the
more speedy removal of night-soil from crowded localities. They are also
more easy to handle at the trenching grounds.
It will sometimes be found advisable to provide receptacle carts for
removing receptacles from latrines. Fig. 16, page 33, shows this
arrangement. These, however, owing to their weight, and to the
difficulties of placing and removing the receptacles when full cannot,
excepting under special conditions, be recommended for municipal
purposes. They cost, including 12–gallon receptacles, about Rs. 275.
Each latrine must be provided with a receptacle, into which the buckets
are emptied, this being placed in a convenient position at the back of
the latrine; the cart starts on its rounds with six empty receptacles,
visits the latrines where it picks up the full ones, and replaces them
by clean ones. They are supplied in 6, 12 and 24–gallon sizes to suit
requirements, and the arrangement avoids the nuisance of transferring
the contents to a second utensil.
[Illustration:
FIG. 17.—NIGHT-SOIL RECEPTACLES AND HAND TRUCKS.
]
[Sidenote: Hand Carts.]
Hand carts are necessary in order to remove night-soil from houses built
in narrow lanes and places where it is impossible to get bullock carts
into. Fig. 17, page 34, shows a convenient arrangement for this. The
receptacles vary in size from 12 to 33–gallons, and cost from Rs. 37 to
Rs. 68 each; the bodies are detached from the hand truck by simply
raising the handles and disengaging the two-forked bearings with the
trunnion; they are fitted with a hinged lid and are made of strong
galvanized iron; the hand truck is of strong and light design, the whole
being of wrought iron.
[Sidenote: Cesspools.]
Where regularly-flushed masonry-lined side drains are unavailable, the
drainage from houses must be led into masonry-lined cesspools, which
will be cleaned out daily by the municipal sweepers, and the contents
removed in conservancy carts. These cesspools should be semi-circular in
shape, and plastered on the inside with Portland cement. In many cases,
where masonry drains exist, it will be found possible to intercept this
sullage, and purify it through Biological Agency in small tanks, filled
with pieces of vitrified brick, broken so as to pass through a 2–inch
ring. The broken bricks will last for about a year, when they should be
renewed.
[Sidenote: Sullage Filter.]
A drawing of a small Sullage Filter is given in Fig. 18, page 36. The
estimated cost of which is Rs. 180.
[Sidenote: Prompt Disposal.]
It is of the very greatest importance to insist on the prompt disposal
of night-soil and refuse, and all means which aid this, good roads,
proper care and feeding of animals, good carts, and the provision of
houses for sweepers, help to a great extent.
[Sidenote: Registering Private Latrines.]
In order to systematise the removal of night-soil from private latrines,
all these should be registered and numbered according to the beats of
the attendant, or otherwise definitely indicated and located, and the
sweepers told off accordingly.
[Sidenote: Wheels and Axles.]
When purchasing carts especial attention should be paid to the quality
of the wheels and axles. The carts should not be too heavy and must be
of a convenient height to facilitate working.
[Illustration:
SULLAGE FILTER
FIG. 18.
]