v3.10.0.1
Landfill and Environmental Costs (Tables)
 6 Months Ended
Jun. 30, 2018
Environmental Remediation Obligations [Abstract]  
Summary of accrued landfill and environmental liabilities
A summary of accrued landfill and environmental liabilities as of June 30, 2018 and December 31, 2017 follows:
 
2018
 
2017
Landfill final capping, closure and post-closure liabilities
$
1,282.3

 
$
1,257.7

Environmental remediation liabilities
555.4

 
564.0

Total accrued landfill and environmental costs
1,837.7

 
1,821.7

Less: current portion
(150.5
)
 
(135.2
)
Long-term portion
$
1,687.2

 
$
1,686.5
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 six months ended June 30, 2018 and 2017:
 
2018
 
2017
Asset retirement obligation liabilities, beginning of year
$
1,257.7

 
$
1,224.6

Non-cash additions
21.8

 
22.3

Acquisitions, net of divestitures and other adjustments
1.9

 
(25.1
)
Asset retirement obligation adjustments
(17.6
)
 
0.1

Payments
(22.1
)
 
(28.3
)
Accretion expense
40.6

 
39.9

Asset retirement obligation liabilities, end of period
1,282.3

 
1,233.5

Less: current portion
(81.0
)
 
(71.7
)
Long-term portion
$
1,201.3

 
$
1,161.8
Summary of activity in environmental remediation liabilities
The following table summarizes the activity in our environmental remediation liabilities for the six months ended June 30, 2018 and 2017:
 
 
2018
 
2017
Environmental remediation liabilities, beginning of year
$
564.0

 
$
602.9

Net additions charged to expense
2.5

 
—

Payments
(21.2
)
 
(23.8
)
Accretion expense (non-cash interest expense)
10.1

 
10.6

Acquisitions, net of divestitures and other adjustments
—

 
(6.1
)
Environmental remediation liabilities, end of period
555.4

 
583.6

Less: current portion
(69.5
)
 
(74.3
)
Long-term portion
$
485.9

 
$
509.3