New Delhi, Dec. 29 -- Amid concerns that the Centre's definition of the Aravalli hills will open the range up for mining, the Union environment ministry earlier this month ordered states and Union territories to conduct just one survey of forests to be mined, saying "repetitive" surveys caused delays and "unnecessary expenditure".

In the letter, dated December 11, the ministry said separate surveys by multiple agencies as well as the bidder delayed the execution of mining leases.

Experts, however, criticised the move and pointed out that each survey had separate objectives and unique parameters. A joint check, they argued, will not meet these standards, impinge on each department's autonomy and will water down a crucial process baked in...