About 8.8 million households are located in 33,510 urban slums across the country of which nearly 44 per cent of the habitats are on private land, a government study conducted in 2012 showed.
"Maharashtra, with an estimated 7,723 slums, accounted for about 23 per cent of all slums in urban India, followed by Andhra Pradesh (13.5 per cent) and West Bengal (12 per cent)," National Sample Survey Office (NSSO) said in its 69th round of survey during July-December 2012.
It said 33,510 slums were estimated to be in the urban areas of the country of which 41 per cent were notified.
According to the study, in about 60 per cent of all slums, the majority of houses had pucca structures.
The proportion of such slums was 85 per cent among notified slums but only 42 per cent of non-notified slums.
"At the all-India level 71 per cent of all slums had tap as major source of drinking water, the figure being 82 per cent for notified slums but only 64 per cent for non-notified slums," NSSO study said, adding that 27 per cent of such habitats had no garbage disposal arrangement.
"The phenomenon of absence of electricity in slums appeared to be largely confined to non-notified slums.
“At all-India level only 6.5 per cent of all slums had no electricity – the corresponding figures being 11 per cent for non-notified slums but only 0.1 per cent for notified slums," it said.
The survey said that at the all-India level 24 per cent of slums benefited from welfare schemes such as Jawaharlal Nehru National Urban Renewal Mission, Rajiv Awas Yojana or any other scheme run by the Central government or state government or any local body.
The NSSO study 'Key Indicators of Urban Slums' presents estimates in respect of notified and non-notified slums in the country.
The key indicators are based on the central sample, surveyed by officials of NSSO, consisting of 3832 urban blocks spread over all states and Union Territories.
At the all-India level, 881 slums were surveyed in urban blocks.