text: Estimates of future expenditures for Ñnal capping, closure and post-closure are developed annually by 
  engineers. These estimates are reviewed by management at least annually and are used by the Company's 
  operating and accounting personnel to adjust the rates used to capitalize and amortize these costs. These 
  estimates involve projections of costs that will be incurred during the remaining life of the landÑll for Ñnal 
  capping activities, after the landÑll ceases operations and during the legally required post-closure monitoring 
  period. Additionally, the Company currently retains post-closure responsibility for several closed landÑlls. 
  
  Under SFAS 143, a liability for an asset retirement obligation must be recognized in the period in which 
  it is incurred and should be initially measured at fair value. Absent quoted market prices, the estimate of fair 
  value should be based on the best available information, including the results of present value techniques in 
  accordance with Statement of Financial Accounting Concepts No. 7, ""Using Cash Flow and Present Value in 
  Accounting Measurements'' (""SFAC 7''). The oÅset to the liability must be capitalized as part of the carrying 
  amount of the related long-lived asset. Changes in the liability due to the passage of time are recognized as 
  operating items in the income statement and are referred to as accretion expense. Changes in the liability due 
  to revisions to estimated future cash Öows are recognized by increasing or decreasing the liability with the 
  oÅset adjusting the carrying amount of the related long-lived asset. 