(T) REHABILITATION COSTS (U) RECOVERABLE AMOUNT OF ASSETS 66  NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS FOR THE YEAR ENDED 30 JUNE 2011 An assessment is also made at each reporting date as to whether there is any indication that a previously  recognised impairment loss may no longer exist or may have decreased. If such indication exists, the recoverable  amount is estimated. A previously recognised impairment loss is reversed only if there has been a change in the  estimates used to determine the asset’s recoverable amount since the last impairment loss was recognised. If  that is the case the carrying amount of the asset is increased to its recoverable amount. That increased amount  cannot exceed the carrying amount that would have been determined, net of depreciation, had no impairment  loss been recognised for the asset in prior years. Such reversal is recognised in profit or loss unless the asset is  carried at revalued amount, in which case the reversal is treated as a revaluation increase. After such a reversal  the depreciation charge is adjusted in future periods to allocate the asset’s revised carrying amount, less any  residual value, on a systematic basis over its remaining useful life. For an asset that does not generate largely independent cash inflows, recoverable amount is determined for the  cash-generating unit to which the assets belongs, unless the asset’s value in use can be estimated to be close to  its fair value. The recoverable amount of plant and equipment, mine properties and development and exploration and  evaluation expenditure is the higher of fair value less costs to sell and value in use. In assessing value in use,  the estimated future cash flows are discounted to their present value using a pre-tax discount rate that reflects  current market assessments of the time value of money and the risks specific to the asset. At each reporting date, the Consolidated Entity assesses whether there is any indication that an asset may  be impaired. Where an indicator of impairment exists, the Consolidated Entity makes a formal estimate of  recoverable amount. Where the carrying amount of an asset exceeds its recoverable amount the asset is  considered impaired and is written down to its recoverable amount. The estimated costs of rehabilitation are reviewed annually and adjusted as appropriate for changes in legislation,  technology or other circumstances. Cost estimates are not reduced by potential proceeds from the sale of assets  or from plant clean up at closure. The expected cost of any approved decommissioning or rehabilitation programme, discounted to its net present  value, is provided when the related environmental disturbance occurs. The cost is capitalised when it gives rise  to future benefits, whether the rehabilitation activity is expected to occur over the life of the operation or at the  time of closure. The capitalised cost is amortised over the life of the operation and the increase in the net present  value of the provision for the expected cost is included in financing expenses. Expected decommissioning and  rehabilitation costs are based on the discounted value of the estimated future cost of detailed plans prepared  for each site. Where there is a change in the expected decommissioning and restoration costs, the value of the  provision and any related asset are adjusted and the effect is recognised in profit or loss on a prospective basis  over the remaining life of the operation. The Group is required to decommission and rehabilitate mines and processing sites at the end of their producing  lives to a condition acceptable to the relevant authorities.