NEW DELHI: Thermal power plants and collieries that continue to burn high-ash content coal, better watch out for the Environment Ministry, which has warned of legal action against them.The stringent advisory comes against the backdrop of instances of serious violations of the January 2014 notification that mandated supply and use of coal with an ash content not exceeding 34 per cent."The subject matter of non-compliance of this notification is also being heard by the National Green Tribunal. The ministry has earlier also advised all concerned for strict compliance to the said notification... it is once again advised to all collieries to strictly comply with the said notification," the Environment Ministry's circular read."In the case of any non-compliance by collieries, legal action shall be initiated immediately," it said.The ministry also directed coal companies to submit quarterly data before state pollution control boards and the regional environment ministry office on ash content of coal supplied to thermal power plants.The advisory has been issued to the Coal Ministry, state-owned Coal India, Maharashtra State Power Generation Co, Coal Controller and pollution control boards in coal mining states such as Maharashtra, Odisha, Telangana, Chhattisgarh, Jharkhand and Madhya Pradesh.In a recent study, an NGO, Centre for Science and Environment (CSE), had said many of India's coal-based power plants are way below global standards in terms of efficiency and several violate air pollution norms and are struggling to dispose of fly ash generated by them.The country generated 1,048 billion units of power last fiscal, of which 90 per cent was from coal-based thermal plant and the rest from hydel plant.