With no let-up in pollution by ash let loose after burning rice husk by industrial boilers the State Pollution Control Board has served notices on 15 units in the Baddi-Barotiwala-Nalagarh industrial area to switch over to alternative fuels like furnace oil, diesel or petrol for all boiler operations within a month. These units which comprise textile and paper mills have been directed to submit an action plan about switchover to an alternative fuel. The board has also directed these units to keep rice husk and the ash so generated under sheds. The board had received complaints that ash was being thrown either in water bodies or in the fields. This led to widespread pollution and created problems for the villagers. Though after such complaints the Baddi-Barotiwala-Nalagarh Development Authority (BBNDA) had earmarked a site in the Katha industrial area along the banks of the Balad river to dump ash but it served little purpose. Board officials said this ash found its way into the houses of villagers whenever strong winds blew over the area. The units served with these notices included Winsome Textiles, Bhandari Deepak Industries, Nirmal Spinning Mill, Auro Dying and Auro Textiles, Birla Textiles, Shri Ganesh fats, Haripur Paper Mills, C.M.Fibres, Raj Industries, Siddhartha Group of Spinning Mills, Rupana Paper Mill, Sebbacuss distillery and Sara Textiles. Officials said rice husk was preferred as a fuel as it was a cheaper option though on the environmental front it proved hazardous. With as much as 15 to 17 per cent ash being generated directly from rice husk it was considered highly pernicious to the environment. Its use also increased the amount of suspended particulate matter in the air, deteriorating air quality.