In many countries, waste disposal options revolve around open burning or landfill. Technical and economic constraints prevent further development.
Over 25 years ago, I was working in Ecuador and became aware of the problem of landfill of sanitary and medical wastes in circumstances where sub-tropical rainfall and a high water table made it inevitable that high rainwater levels would flood landfill to such an extent that water from wells and stream would be contaminated with organisms from those wastes in less than 24 hours.
Now it is reported that every time it rains, the city of Dhaka faces acute drainage problem as major parts of the city get inundated. City dwellers have been facing the problem for many years and there is no sign of improvement at all rather the situation becomes even worse when various government authorities start their maintenance work during the rainy season. The storm water becomes polluted as it mixes with solid waste, clinical waste, silt, contaminants, domestic wastes and other human activities that increase the water borne diseases.
Clearly, in many parts of the world there remains a need for economic and technical aid, with the development of improved approaches to waste management that address these particular issues with low cost and robust low tech developments. This must go hand-in-hand with approaches to the provision of secure supply of clean drinking water which is still unavailable.