PROPERTY, PLANT, AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

The Company depreciates and amortizes the capitalized cost of these assets, using the straight-line method as follows:

Asset Classification	Estimated Useful Life
Buildings and building improvements
Buildings	20-42 years
Leasehold and building improvements	2-45 years
Camp and lodging equipment	8-15 years
Vehicles	2-15 years
Equipment
Capitalized software and computer equipment	3-5 years
Containers and railcars	8-16 years
All other equipment	4-30 years
Furniture and fixtures	5-8 years

Property, plant and equipment consisted of the following (in thousands):

	December 31, 2019		December 31, 2018
Land	$	131,023	$	123,734
Asset retirement costs (non-landfill)	15,924		15,148
Landfill assets	182,276		154,918
Buildings and improvements (1)	499,159		440,188
Camp and lodging equipment	158,277		152,998
Vehicles (1)	785,056		721,735
Equipment	1,779,366		1,697,490
Furniture and fixtures	6,054		5,453
Construction in progress	36,679		20,931
	3,593,814		3,332,595
Less - accumulated depreciation and amortization	2,005,663		1,770,617
Total property, plant and equipment, net	$	1,588,151	$	1,561,978

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(1)

December 31, 2019 balances inclusive of ROU assets classified as finance leases.