Whenever the issue of how to end pollution is raised, it hits a block: technology. Take the case of air pollution: among other things, the issue boiled down to catalytic convertors, an imported technology. Now that the spectre of contaminated water stares us in the face, a question emerges: who's making moolah out of the muck? The familiar answer: companies that use imported technology to treat water. India faces today a double challenge. It is poor and it is polluted. So could there be indigenous innovation that cuts costs and removes modern toxins poisoning our environment? NIDHI JAMWAL searches for answers