Cooking with compost
Sulabh International, which has designed and installed over 2,000 public lavatories in slums and resettlement colonies, has just developed a lavatory design that recycles compost to generate biogas for cooking fuel. "We plan to set up 61 such complexes throughout the country," says N D Mazumdar, director (technical research) of Sulabh. Earlier, Sulabh had generated biogas from compost to light street lamps, but this is the first time that it is being used for cooking.
The new design is being tried out in Mangolpuri, near Delhi, where a 40-unit lavatory complex meant for a community of 2,000 people has been set up. The design is an improved version of the traditional pour-flush latrine, which consists of a water-seal trap and a compost pit and incorporates a biogas digester. Unlike traditional latrines that use about 12.5 litres for flushing, Sulabh units use merely 2 litres. The biogas plant supplies cooking gas to 30 families for 3 hours every day. Besides, fertiliser compost is available as a by-product. "Initially the users expressed reservations about cooking with this gas, particularly about baking rotis over an open flame for which they preferred firewood or cowdung. But we hope that more and more people will switch over when the fuel saving becomes evident," says Mazumdar.
The Municipal Corporation of Delhi has paid Rs 19 lakh for the construction of the Mangolpuri complex, which Sulabh will maintain for 30 years. Like all other Sulabh facilities, this is also pay-and-use. However, women and children are exempt from payment. A similar complex that is being constructed in Trilokpuri, a resettlement colony in east Delhi, will be ready for use soon.