water purification

In large ciities like Delhi, where water from the tap can smell and taste bad, I purchase bottled water. In towns and villages, if the locals drink the water from the tap, I boil the water with a small 350-watt electric immersion coil (purchased in any Indian electrical supply or hardware store). A 350-watt coil will work fine on a liter of water; once it comes to a boil, unplug and remove the coil, then cap the pot with a lid, and allow to sit for awhile before drinking.