As the development community celebrates being on track to achieve the Millennium Development Goals drinking water targets, it will be too easy to overlook the fact that sanitation lags far behind.
More than a billion people worldwide still have no access to a toilet. The immediate health impact is obvious, but the 'sanitation gap' also undermines other development objectives because of its effect on employment and productivity.
Community participation will be crucial to catching up, argues Aarti Daryanani. Focusing on South Asia, which is making the slowest sanitation progress in the world, she argues that lessons must be learnt