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The Research Cum Action Project at Tamil Nadu, financed by the Ford Foundation and Ministry of Health, Government of India, has its genesis in 1956.  The major objective of the project was to improve Educational Methods, Conducting Systematic Research in various Public Health Programmes and to evolve a Low Cost Sanitary Latrine suitable for the rural household.


A Pour-flush Latrine consists of a squatting pan of a special design, having a steep gradient at the bottom and a particular depth and a trap having 20 mm waterseal.  This is so designed that the human excreta of one person can be flushed by pouring nearly 2 litres of water.  The excreta is discharged into the leaching pits.  The squatting pan is connected to the leaching pit through a pipe.  These pits are lined with honey comb brick work or open joined stones, so as to allow the liquid in the pits to percolate and gases to be absorbed into the soil; and at the same time preventing the pit from collapsing.  The sludge gets digested and settles down gradually.

The pits are used alternately.  When one pit is filled, it is stopped being used and the excreta is diverted to the second pit.  The filled up pit is left unused; and in about 24 months the contents become rich organic humus, innocuous, free of pathogen and smell.  When convenient, it is emptied and contents could be used as fertiliser.  It is then ready to put back into use when the second pit becomes full in its turn.

With simple care and cleaning by the household, the pour-flush latrine is a very satisfactory and hygienic sanitation system. They can be located inside the house, since water-seal prevents odour or insect nuisance.


The size of leach pits depends on factors such as :  soil characteristics, sub-soil water level, interval of cleaning, number of  users and people's food habit.  The dimensions of the leaching pits for 5 number of users for three years is 900 mm internal diameter and 1100 mm effective depth.  The pits should be located 8m away from the drinking water sources.


Maintenance of pour-flush latrines is very easy and simple.  Day-to-day maintenance consists only of washing the latrine floor and cleaning the pan.  No other maintenance cost is needed.  The cost of cleaning the pits can be covered by sale of humus obtained from the pits.


The squatting pan and trap can be ceramic, fibre glass reinforced polyester plastic (GRP) or cement.


The cost of construction of a pour-flush latrine with single pit without super structure works out at Rs.2,100/-

For more details and guidance, contact:

          1.  The Deputy Director,
               Institute of Public Health,
               Poonamallee, Chennai-600 056.
          2.  The Health Educator (Medical),
                RCAP, Thanjavur.
          3.  Public Health Engineer,
               RCAP, Dindigul.
          4.  Public Health Engineer,
               RCAP, Tirunelveli.