The country's domestic coal production target could not be achieved in 2010-11 mainly on account of Environment Ministry not allowing the expansion of projects falling in areas categorised as critically polluted under Comprehensive Environment Pollution Index (CEPI).Coal Minister Sriprakash Jaiswal in a written reply to the Rajya Sabha said the other reasons for lower coal production have been the law and order problems in Jharkhand and Orissa, excessive rains and non-finalisation of a few contracts related to production because of court litigation.The Minister said, a number of steps are being taken by Coal India, which accounts for more than 80 per cent of the domestic coal production, to augment output.In 2009, the Ministry of Environment and Forests (MoEF) had introduced the CEPI to categorise the environmental quality at given locations and conducted a nation-wide assessment of industrial clusters. Coal India missed its output target and produced 431.33 million tonnes (MT) of coal in 2010-11 against the revised target of 440.20 MT.