Nigeria, Oct. 25 -- What is that stench? Oh, it is the waste collection and disposal truck leaving a trail of small debris and foul smell in its wake. Incidentally, each part of Lagos seems to have its own distinctive smell, but the common denominator is that none exactly smells of roses.

Like many rapidly growing cities, Lagos faces the arduous task of keeping its environment clean while accommodating an expanding population, increasing consumption and rising volumes of waste. With an estimated 13,000 to 15,000 metric tonnes of waste generated daily, the demands on its collection and disposal systems are enormous. From waste accumulating at collection points through an aging and insufficient fleet of compactor trucks to landfill capacit...