Landfill and Environmental Costs (Tables)

9 Months Ended

Sep. 30, 2015

Environmental Remediation Obligations [Abstract]

Summary of accrued landfill and environmental liabilities

A summary of accrued landfill and environmental liabilities as of September 30, 2015 and December 31, 2014 follows:

	2015			2014
Landfill final capping, closure and post-closure liabilities	$	1,188.5		$	1,144.3
Environmental remediation liabilities	667.6			697.5
Total accrued landfill and environmental costs	1,856.1			1,841.8
Less: current portion	(179.2		)	(164.3		)
Long-term portion	$	1,676.9		$	1,677.5

Summary of activity in asset retirement obligation liabilities, which include liabilities for landfill final capping, closure and post-closure

The following table summarizes the activity in our asset retirement obligation liabilities, which include liabilities for landfill final capping, closure and post-closure, for the nine months endedSeptember 30, 2015 and 2014:

	2015			2014
Asset retirement obligation liabilities, beginning of year	$	1,144.3		$	1,091.3
Non-cash additions	29.9			29.1
Acquisitions and other adjustments	11.4			3.7
Asset retirement obligation adjustments	(5.9		)	(17.7		)
Payments	(50.4		)	(36.5		)
Accretion expense	59.2			58.4
Asset retirement obligation liabilities, end of period	1,188.5			1,128.3
Less: current portion	(103.1		)	(90.1		)
Long-term portion	$	1,085.4		$	1,038.2

Summary of activity in environmental remediation liabilities

The following table summarizes the activity in our environmental remediation liabilities for the nine months endedSeptember 30, 2015 and 2014:

	2015			2014
Environmental remediation liabilities, beginning of year	$	697.5		$	551.7
Net additions (credited) charged to expense	(1.3		)	36.2
Payments	(50.1		)	(75.0		)
Accretion expense (non-cash interest expense)	18.7			19.0
Acquisitions	2.8			—
Environmental remediation liabilities, end of period	667.6			531.9
Less: current portion	(76.1		)	(74.8		)
Long-term portion	$	591.5		$	457.1