NEW DELHI: The government is working on a master plan envisaging construction of about 23 lakh artificial recharge and rainwater harvesting structure in rural areas and 88 lakh in urban areas, Lok Sabha was informed today.Minister for Drinking Water and Sanitation Narendra Singh Tomar said the Central Ground Water Board has prepared a conceptual document entitled 'Master Plan for Artificial Recharge to Ground Water in India' involving ground water scientists and experts."The master plan envisages construction of about 23 lakh artificial recharge and rain water harvesting structure in rural areas and 88 lakh rain water harvesting structures in urban areas," he said during Question Hour.Tomar said various structures proposed in rural areas include percolation tanks, check dams, nala bunds, gully plugs, gabion structure and sub-surface techniques of recharge shaft and well recharge, have been recommended.He said the Ministry of Drinking Water and Sanitation has got conducted 35 research and development projects for improvement of drinking water quality in the rural areas of the country.The improvement of drinking water quality include reduction or removal of fluoride, arsenic, nitrate, iron and chromium, he said.