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Accrued Capping, Closure and Post Closure | 6 Months Ended
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Oct. 31, 2013
Asset Retirement Obligation Disclosure [Abstract] |
Accrued Capping, Closure and Post Closure |
4. | ACCRUED CAPPING, CLOSURE AND POST CLOSURE
Accrued capping, closure and post-closure costs include the current and non-current portion of costs associated with obligations for closure and post-closure of our landfills. We estimate our future capping, closure and post-closure costs in order to determine the capping, closure and post-closure expense per ton of waste placed into each landfill. The anticipated timeframe for paying these costs varies based on the remaining useful life of each landfill, as well as the duration of the post-closure monitoring period. The changes to accrued capping, closure and post-closure liabilities for the six months ended October 31, 2013 and 2012 are as follows:
|  | Six Months Ended October 31, |
|  | 2013 |  |  | 2012 |
Beginning balance |  | $ | 43,170 |  |  | $ | 39,629 |
Obligations incurred |  |  | 1,918 |  |  |  | 1,960 |
Accretion expense |  |  | 1,999 |  |  |  | 1,789 |
Payments |  |  | (1,106 | ) |  |  | (2,089 | )
Ending balance |  | $ | 45,981 |  |  | $ | 41,289 |

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- Definition The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7569-110849 + Details
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