The Union government's decision to make it mandatory for all thermal power plants to use only "washed " coal from June 2001 has drawn flak from Delhi-based Tata Energy Research Insititute (TERI). This decision is economically and environmentally unwise for existing power plants, says Mahanadi Coalfields former chairman-cum-managing director C R Das and TERI fellow S K Chand in their study on the issue. Improving the quality of coal for use in thermal stations will push up the fuel cost of power plants, increase the quantity of pollutants and not necessarily improve the performance of the power plant.