This document discusses various sanitation methods for rural areas. It describes the functioning of septic tanks, which use anaerobic bacteria to break down waste into simpler compounds. For rural latrines, it recommends simple options like arborloos that compost waste and urine diversion dry toilets that require no water. It also details pit latrines, borehole latrines and water seal latrines. The Sulabh Shauchalaya public toilet is highlighted as a low-cost pour-flush system that converts waste to manure using bacterial decomposition. In villages, sanitation requires affordable, maintainable options that purify waste without water or electricity.

1. ENVIRONMENT & HEALTH:
SANITATION
GROUP B

2. CONTENTS
 Mode of functioning, working of
septic tank & Purification of sewage
 Sanitary latrine for a small family in a
village setback (common and
inexpensive)
 Sulabh Shauchalaya.

3. Septic Tank Latrine
It is an ideal sanitary water-seal latrine which can meet
the requirements of families in towns and cities having
piped water supply but no sewerage system.
The tank is an underground, rectangular, cement
concrete tank, having an inlet, outlet, cover and a vent
pipe, into which the household sewage, which is a
mixture of night soil, urine and wash water, is drained.
MODE OF FUNCTIONING OF SEPTIC TANK FOR PURIFICATION OF SEWAGE

4. The solids settle down in the tank, to form sludge
,while the lighter solid including grease and fat rise to
the surface to form "scum".
The solids are attacked by the anaerobic bacteria and
are broken down into simpler chemical compounds.
This is the first stage of purification, called anaerobic
digestion. The sludge is much reduced in volume as a
result of anaerobic digestion, and is rendered stable
and inoffensive.
A portion of the solid is transferred into liquid and
gases(principally methane) which rise to the surface in
the form of bubbles.
WORKING OF A SEPTIC TANK FOR PURIFICATION

5. The liquid which passes out of the outlet pipe from time to time is called the " effluent". It
contains numerous bacteria, cysts,helminthic ova and organic matter in the solution or fine
suspension.
The effluent is allowed to percolate into the sub-soil.It is dispersed by means of perforated or
open-jointed pipes laid in trenches 90 cm (3 ft.) deep and the trenches are then covered with soil
.There are millions of anaerobic bacteria in the upper layer of the soil,which attack the organic
matter present in the effluent.
As a result ,the organic matter is oxidized into stable end-products, i.e.nitrates, carbon dioxide
and water.This stage of purification is called aerobic oxidation. To sum up,two stages are involved
in the purification of sewage .The first , anaerobic digestion takes place in the septic tank
proper,and the second stage aerobic oxidation takes place outside the septic tank,in the sub-soil.
Together these two stages complete the purification of sewage.

6. Since septic tank is recommended for individual families cleaning is required once in 5 years.
However, in large installations, cleaning is done every alternate years.
The following are the requirements of a septic tank installation:
• There must be abundant supply of water, so as to flush out the excreta to the tank.
• No disinfectant or detergent to be used in the tank, because of the destruction of the putrefactive
bacteria.
• There must be sufficient space, between the fluid level and the cover to accommodate the ‘Scum’ and
the gas.
• There should be a ventilator pipe to let off the foul gas.
• The sludge to be removed periodically (i.e. desludging).

7. As the sewage enters, the septic tank through
the inlet pipe, the nonputrescible black
semisolid particles settle down to the bottom
of the tank to form ‘sludge’ and the grease,
fat and light solid matter floats on the surface
to form ‘scum’, which is an air tight layer and
cuts off air to the fecal matter.
Under the scum the anaerobic bacteriae are
actively at work breaking down the solid
masses into simpler substances of fine
suspension.
PURIFICATION OF SEWAGE

8. The complex protein molecules are broken down into amines, amino acids, evoluting gasses like methane,
carbon dioxide, carbon-monoxide, hydrogen sulphide, etc.
The colloids in suspension become crystalloids in solution and are ready to take up oxygen. This is the first
stage of purification.
In the next stage, the effluent (the liquid coming out of the outlet pipe periodically) which contains
numerous bacteria, ova, cysts and organic matter, is turbid but translucent with a sickly but otherwise
offensive smell. Since the effluent still contains nitrogen as ammonia, should be oxidized by aerobic bacteria
present in the soil to nitrites and nitrates. Therefore, it is subjected to further purification by the action of
aerobic bacteria by subsoil irrigation into the surrounding earth through perforated pipes. This is the second
stage of aerobic oxidation.
The sludge is much reduced in volume as a result of anaerobic digestion. It becomes stable and inoffensive.
When the sludge grows to a certain height it interferes with the action of septic tank. It is time for removal.
Meanwhile the scum is also removed. The sludge and the scum are disposed off by trench method. Cleaning
is done through the manhole.

10. Most common and inexpensive sanitary latrine for rural families are as
follows:-
1)ARBORLOO
◦ An arborloo is an simple and ecological type of toilet.
◦ It's concept is to compost directly the feces in a pit ,and to grow subsequently
in a fruiting tree on this very fertile soil.
2)URINE DIVERSION DRY TOILET (UDDT) ECO-SAN TOILET
◦ More hygiene toilet for rural.
◦ No bad smell
◦ Improved health and nutrition.
◦ Relatively simple explanation
◦ Can be built and repaired with locally available materials.
◦ No water required for flushing.-Multiple designs possible(sitting/squatting)
◦ wet/dry cleaning
RURAL SANITARY LATRINES

11. 3)BORE HOLE LATRINE
◦ The latrine consist of a circular hole 30 to 40cm(12-16 in.) in
diameter ,dug vertically into the ground to a depth of 4 to 8
m(13-26ft).
◦ A special equipment known as auger is required to dig a bore
hole.
◦ A concrete squatting plate with a central opening and foot rests
is placed over the hole.
◦ In loose and sandy soils,the hole is lined with bamboo matting or
earthen-ware rings to prevent craving in of the soil.
◦ when the contents of the hole reach within 50 cm (20 in.) of the
ground level,the squatting plate is removed and hole is closed
with earth and new hole is dug.
◦ Bore hole can serves a small family with 5 or 6 people for over a
year(small capacity).

12. 4)DUG WELL / PIT LATRINE
◦ It is an improvement over bore hole latrine.
◦ It is a circular pit about 75 cm(30 in.)in diameter and 3 to
3.5 m (10-12 ft.) deep is dug into the ground for the
reception of nightsoil.
◦ Pit is lined with pottery rings to prevent craving in of the
soil.
◦ Concrete squatting plate is placed on the top of the pit
and the latrine is enclosed with a superstructure.
◦ Easy to construct and no special equipment is required.
◦ Last for about 5 years for a family of 4 to 5 persons.
◦ first introduced in Singur, West Bengal during 1949

13. 5)WATER SEAL LATRINE
◦ It is an hand flushed"water seal" type of latrine.
◦ Squatting plate is fitted with a water seal.
◦ It prevent access by flies.
◦ It prevents escape od odours and goul gases and thereby
eliminates the nuisance from smell.
◦ Once the latrine is flushed, nightsoil is no longer visible.
◦ More acceptable to rural people than the bore hole or pit
privy without water seal.

14. If the pit is directly underneath the squatting plate it is called ‘Direct type’ (Dug well and bore-
well latrines)
And if away from squatting plate it is called ‘Indirect type’ of latrine. (water seal latrine)
Twin Pit Latrines:
The two pits are often used simultaneously which goes against the very principle of the twin pit
which means that once one of the pits is full, the hole is blocked for some time to allow the
pathogens present in excreta to be removed naturally before the full pit is emptied.

15. •It is a low cost pour-flush, water-seal type of latrine,
installed in public places in many parts of the India.
•Basically, it is an improved version of the standard
handflush latrine (e.g., RCA type).
•It consists of a specially designed pan and a water-
seal trap connected to a pit of 1metre square and a
1metre deep.
•Excreta undergoes bacterial decomposition and is
converted to manure(compost).
SULABH SHAUCHALAYA

16. •This method requires very little water.
•It is well-lighted and ventilated, maintaining the privacy
and cleanliness.
•These latrines are eco-friendly.
•The Sulabh Shauchalaya can be constructed in the
minimum possible space- in a narrow lane, courtyard of a
house or in the bedroom.
The Sulab toilet can be constructed in areas where the
waste water is high and even in upper floors of buildings.

17. Sulabh International, the investors, not only build but
also, maintain the system of Sulabh Community latrines.
It was first invented by Patna biased firm.
Their usual structure is a lavatory block of several dozen
seats, with a bathing block adjoining.
The system is to charge Rs5 per user. Delhi has opted for
this system in all its slum.
This system has drawn praise from ecologist and
planners.

18. PSM - A H Suryakantha
K Park’s PSM
www.bing.com/images
REFERENCES

19. Roll no. 11 – Pranshu Dwivedi
Roll no. 12 – Siddharth Gurung
Roll no. 13 – Mohsin Ahmed Ansari
Roll no. 14 – Gemin Langkam
Roll no. 15 – Radhe Nampi
Roll no. 16 – Yanu Kodak
Roll no. 17 – Nani Kuru
Roll no. 18 – Marjum Haji
Roll no. 19 – Tiling Rema
Roll no. 20 – Tadar Matma
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