Landfill and Environmental Costs (Tables)

9 Months Ended

Sep. 30, 2016

Environmental Remediation Obligations [Abstract]

Summary of accrued landfill and environmental liabilities

A summary of accrued landfill and environmental liabilities as of September 30, 2016 and December 31, 2015 follows:



	2016			2015
Landfill final capping, closure and post-closure liabilities	$	1,211.9		$	1,181.6
Environmental remediation liabilities	615.1			646.1
Total accrued landfill and environmental costs	1,827.0			1,827.7
Less: current portion	(177.0		)	(149.8		)
Long-term portion	$	1,650.0		$	1,677.9

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 ended September 30, 2016 and 2015:



	2016			2015
Asset retirement obligation liabilities, beginning of year	$	1,181.6		$	1,144.3
Non-cash additions	30.4			29.9
Acquisitions and other adjustments	0.5			11.4
Asset retirement obligation adjustments	(3.2		)	(5.9		)
Payments	(56.7		)	(50.4		)
Accretion expense	59.3			59.2
Asset retirement obligation liabilities, end of period	1,211.9			1,188.5
Less: current portion	(94.3		)	(103.1		)
Long-term portion	$	1,117.6		$	1,085.4

Summary of activity in environmental remediation liabilities

The following table summarizes the activity in our environmental remediation liabilities for the nine months ended September 30, 2016 and 2015:



	2016			2015
Environmental remediation liabilities, beginning of year	$	646.1		$	697.5
Net additions charged to expense	0.3			(1.3		)
Payments	(50.7		)	(50.1		)
Accretion expense (non-cash interest expense)	17.6			18.7
Acquisitions and other adjustments	1.8			2.8
Environmental remediation liabilities, end of period	615.1			667.6
Less: current portion	(82.7		)	(76.1		)
Long-term portion	$	532.4		$	591.5