By Manish Chadda, BCE, MIE,FIV,CE(I),D. Auto, PPC

Now a days disposal of waste is become a nuisance and of great concern for community and for individual too. And again if by disposing a waste we contaminate the ground water, which is depreciating at alarming level.

We dispose the solid waste by carrying and dumping into a low laying area. Most of the time in small city and even in big cities it is not a fully engineered operation and not even designed and operated according to the acceptable standard. The method to be adopted is filling refuse in layers of 1.5 meter or so, and each such layer is to be covered by good earth of at-least 20cm thickness, so that the refuce is not exposed. This filling is done by dividing the entire site into small portions. This filled up layer of refuse and good earth shall be left for at-least seven days and compacted continuously by any mechanical means generally by trucks which are used for getting refuse before filling the second layer. And also insecticides are sprayed on fill to prevent breeding of mosquitoes and flies. Finally at the top a 1 meter layer of good earth is filled and compacted to prevent rodents from borrowing into the refuse.

Do you think or sure about that the above process is used for sanitary fill. No, not at all, not even in big cities. No one can take care about filling in layers and not even it is possible to cover each and every layer by good earth. It is firstly due to scarcity of low laying area, it is not possible to divide the entire area into pocket. Secondly, there is insufficient staff to take care of this thing. Third reason, as there is less area and more garbage, they are not getting sufficient time gap between two consecutive sanitary fillings. And finally controlled tipping becomes a costly affair as no good earth may be available nearby.

Because of all this there is continuous evolution of foul gases near the site. Sometime these gases may often be explosive in nature. These sites become a good breeding ground for mosquitoes and flies. What more concern is, Leachate.

Leachate is a coloured liquid that come out of the dumping site. It happens because the dumped garbage contain harmful and sometime carcinogenic non-bio-degradable substance, such as plastics, unused medicines, paints, sanitary napkins, house hold chemicals & acids etc. come out with a seepage during rain. The serious problem occurs when highly poisonous and polluted Leachate seep down to the underground water table and contaminates the ground water. This can lead to disease like cholera, typhoid, etc.

The remedy is a segregation of waste at source, that is at the point of collection and combustible matter are burnt (incineration) and incombustible and recyclable matter such as glass, metals, paper etc. are separated out for recycling and reuse. And hazardous waste is to be properly treated before being disposed. The best method among all is aerobic composting as the final end product of this is compost, which is used as fertilizer for farms.