4.LANDFILL ACCOUNTING

At September 30, 2015, the Company owned or operated 42 municipal solid waste (“MSW”) landfills, nine exploration and production (“E&P”) waste landfills, which only accept E&P waste, and nine non-MSW landfills, which only accept construction and demolition, industrial and other non-putrescible waste. At September 30, 2015, the Company’s landfills consisted of 50 owned landfills, five landfills operated under life-of-site operating agreements and five landfills operated under limited-term operating agreements. The Company’s landfills had site costs with a net book value of $1,665,295 at September 30, 2015. For the Company’s landfills operated under limited-term operating agreements and life-of-site operating agreements, the owner of the property (generally a municipality) usually owns the permit and the Company operates the landfill for a contracted term. Where the contracted term is not the life of the landfill, the property owner is generally responsible for final capping, closure and post-closure obligations. The Company is responsible for all final capping, closure and post-closure liabilities at the landfills it operates under life-of-site operating agreements.

The Company’s internal and third-party engineers perform surveys at least annually to estimate the remaining disposal capacity at its landfills. Many of the Company’s existing landfills have the potential for expanded disposal capacity beyond the amount currently permitted. The Company’s landfill depletion rates are based on the remaining disposal capacity, considering both permitted and probable expansion airspace, at the landfills it owns and landfills it operates, but does not own, under life-of-site agreements. The Company’s landfill depletion rate is based on the term of the operating agreement at its operated landfill that has capitalized expenditures. Expansion airspace consists of additional disposal capacity being pursued through means of an expansion that has not yet been permitted. Expansion airspace that meets certain criteria is included in the estimate of total landfill airspace.

Based on remaining permitted capacity as of September 30, 2015, and projected annual disposal volumes, the average remaining landfill life for the Company’s owned landfills and landfills operated under life-of-site operating agreements is estimated to be approximately 33 years. As of September 30, 2015, the Company is seeking to expand permitted capacity at six of its owned landfills and two landfills that it operates under life-of-site operating agreements, and considers the achievement of these expansions to be probable. Although the Company cannot be certain that all future expansions will be permitted as designed, the average remaining life, when considering remaining permitted capacity, probable expansion capacity and projected annual disposal volume, of the Company’s owned landfills and landfills operated under life-of-site operating agreements is approximately 38 years, with lives ranging from approximately 2 to 184 years.

During the nine months ended September 30, 2015 and 2014, the Company expensed $61,226 and $62,334, respectively, or an average of $3.87 and $4.09 per ton consumed, respectively, related to landfill depletion at owned landfills and landfills operated under life-of-site agreements.

The Company reserves for final capping, closure and post-closure maintenance obligations at the landfills it owns and landfills it operates under life-of-site operating agreements. The Company calculates the net present value of its final capping, closure and post-closure liabilities by estimating the total obligation in current dollars, inflating the obligation based upon the expected date of the expenditure and discounting the inflated total to its present value using a credit-adjusted risk-free rate. Any changes in expectations that result in an upward revision to the estimated undiscounted cash flows are treated as a new liability and are inflated and discounted at rates reflecting current market conditions. Any changes in expectations that result in a downward revision (or no revision) to the estimated undiscounted cash flows result in a liability that is inflated and discounted at rates reflecting the market conditions at the time the cash flows were originally estimated. This policy results in the Company’s final capping, closure and post-closure liabilities being recorded in “layers.” The Company’s discount rate assumption for purposes of computing 2015 and 2014 “layers” for final capping, closure and post-closure obligations was 4.75% and 5.75%, respectively, which reflects the Company’s long-term credit adjusted risk free rate as of the end of 2014 and 2013. The Company’s inflation rate assumption is 2.5% for the years ending December 31, 2015 and 2014. The resulting final capping, closure and post-closure obligations are recorded on the condensed consolidated balance sheet along with an offsetting addition to site costs which is amortized to depletion expense as the remaining landfill airspace is consumed. Interest is accreted on the recorded liability using the corresponding discount rate. During the nine months ended September 30, 2015 and 2014, the Company expensed $2,756 and $2,445, respectively, or an average of $0.17 and $0.16 per ton consumed, respectively, related to final capping, closure and post-closure accretion expense.

The following is a reconciliation of the Company’s final capping, closure and post-closure liability balance from December 31, 2014 to September 30, 2015:


Final capping, closure and post-closure liability at December 31, 2014	$	61,500
Adjustments to final capping, closure and post-closure liabilities		(37)
Liabilities incurred		3,325
Accretion expense associated with landfill obligations		2,756
Closure payments		(66)
Assumption of closure liabilities from acquisitions		1,061
Final capping, closure and post-closure liability at September 30, 2015	$	68,539

The Company performs its annual review of its cost and capacity estimates in the first quarter of each year.

At September 30, 2015, $39,511 of the Company’s restricted assets balance was for purposes of securing its performance of future final capping, closure and post-closure obligations.