The city’s skyline is set for a makeover from August 2004, with tighter environmental laws requiring the use of construction materials that have a fly ash content of at least 25 per cent.
By 2007, traditional red clay bricks will have to be phased out completely, following a September 2003 change in the rules governing the use of fly ash in all construction activity within a 100km radius of coal-based power plants.
Kolkata’s power supply comes from such plants, and their locations put almost the entire metropolitan area under the ambit of the modified notification. The principal secretary of West Bengal’s environment department, Mr Hirak Ghosh, who is also chairman of the pollution control board, said the 1997 notification by the Union ministry of environment and forests has been made more stringent by an amendment dated September 14, 2003.
“In case a brick manufacturer or construction agency fails to comply, the pollution control board would withdraw its licence, while the government will cancel mining leases,” Mr Ghosh told a seminar on high-volume fly ash concrete technology, here on Monday. The seminar was organised by the Confederation of Indian Industry.
Mr Ghosh said the thermal power plants are required to supply the ash free. The power plants will have to work out a plan to end dumping and disposal of ash on land.
Major builders in Kolkata have welcomed the new rules, but pointed out that the government must ensure that there are enough vendors. Mr Sumit Dabriwal, managing director of Calcutta Metropolitan Group Ltd, told FE that fly ash bricks are cost effective, and 15 per cent of bricks used by his company are from fly ash.
“The constraint is that since we don’t manufacture our own bricks or cement, the vendors will have to actually participate in this sort of movement,” he said. At the seminar, Mr Ghosh noted that the production of one tonne of portland cement results in the emission of one tonne of carbon dioxide, a greenhouse gas.
Mixing fly ash will increase cement volumes without requiring extra capacity. Cement majors here are already mixing a certain amount of fly ash with their product, which is sold as the PPC variety.
Mr Harshvardhan Neotia, a major player in cement as well as housing, said 95 per cent of the cement made by his company, Ambuja Cement Eastern Ltd, is of the PPC variety and only five per cent is ordinary Portland cement. Mr Neotia,