v3.24.2
Landfill and Environmental Costs (Tables)
 6 Months Ended
Jun. 30, 2024
Environmental Remediation Obligations [Abstract]  
Schedule of accrued landfill and environmental costs
A summary of accrued landfill and environmental liabilities as of June 30, 2024 and December 31, 2023 follows:
20242023
Landfill final capping, closure and post-closure liabilities$2,004.9 $1,937.2 
Environmental remediation467.8 485.4 
Total accrued landfill and environmental costs2,472.7 2,422.6 
Less: current portion(140.5)(141.6)
Long-term portion$2,332.2 $2,281.0 
Schedule of final capping, closure and post-closure costs
The following table summarizes the activity in our asset retirement obligation liabilities, which includes liabilities for final capping, closure and post-closure, for the six months ended June 30, 2024 and 2023:
20242023
Asset retirement obligation liabilities, beginning of year$1,937.2 $1,786.4 
Non-cash additions29.6 30.7 
Acquisitions, net of divestitures and other adjustments4.1 11.8 
Asset retirement obligation adjustments2.8 (9.7)
Payments(22.2)(24.5)
Accretion expense53.4 48.6 
Asset retirement obligation liabilities, end of period2,004.9 1,843.3 
Less: current portion(74.3)(76.6)
Long-term portion$1,930.6 $1,766.7 
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, 2024 and 2023:
20242023
Environmental remediation liabilities, beginning of year$485.4 $487.5 
Payments(26.7)(21.2)
Accretion expense (non-cash interest expense)8.4 9.0 
Acquisitions, net of divestitures and other adjustments0.7 32.4 
Environmental remediation liabilities, end of period467.8 507.7 
Less: current portion(66.2)(63.4)
Long-term portion$401.6 $444.3