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In point 10 water level trends have been discussed. The premonsoon water level depths have been indicated as varying between 30ft to 120ft in the aquifers immediately underneath the top clay layer. The bore holes in Dhamaka toilets are reaching in the same aquifer to the depth of 30ft to 40ft. Naturally the vertical separation may be non existent in many cases. There, the attenuation of microbial and chemical contamination will depend only on lateral separation, increasing travel time marginally. Once nitrate levels exceed 50 mg/Lt that source has to be abandoned for drinking water purposes. Hence, continuous monitoring of these sources for microbial and chemical contamination would become very essential. Microbial contaminations can be taken care of by purification processes like chlorination. However, if nitrate levels increase the only way is to abandon the source. This monitoring will have to be done for private tube wells also, in a planned manner. 14. Observations and comments a. In the area specific situation Dhamaka latrine is a suitable design with some modifications and reservations. Bore hole latrine is generally considered as a less desirable option. However, in hydrogeological situation existing in these districts, there is no suitable alternative to borehole latrine. b. As they exist today, Dhamaka latrine can’t be considered as sanitary latrine. The existing design needs to be modified. Following modifications are suggested. c. Modifications to toilet seat as indicated in point 12 are suggested. d. There are indications that in some tube wells and dug wells microbial contamination have taken place. Therefore periodical rigorous monitoring, where ground water from wells (government established or private) is used for drinking, is necessary. Public health laboratories in each district can do this. e. Similarly continuous monitoring for chemical contamination is necessary. Public health laboratories in each district can do this. f. Data about private tube wells is not available. Each Gram Panchayat and each District PHED may maintain this data.

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Dhamaka latrines in Rajasthan, India.  
Dhamaka latrines in Rajasthan, India.  

Study about appropriateness of design, possibility of conversion to sanitary latrine and extent of groundwater pollution caused Dhamaka lat...

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