PROPERTY, PLANT, AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

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

Asset Classification	Estimated Useful Life
Buildings and building improvements
Buildings	30–40 years
Leasehold and building improvements	2–40 years
Camp equipment	12–15 years
Vehicles	3–12 years
Equipment
Capitalized software and computer equipment	3–5 years
Solar equipment	20 years
Containers and railcars	15–20 years
All other equipment	8–20 years
Furniture and fixtures	5–8 years

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

	December 31, 2014		December 31, 2013
Land	$	98,507	$	99,794
Asset retirement costs (non-landfill)	10,871		10,938
Landfill assets	110,984		100,983
Buildings and improvements	338,242		327,956
Camp equipment	180,575		187,831
Vehicles	471,615		425,296
Equipment	1,302,424		1,201,296
Furniture and fixtures	5,517		5,260
Construction in progress	45,605		58,010
	2,564,340		2,417,364
Less - accumulated depreciation and amortization	1,005,506		815,194
Total property, plant and equipment, net	$	1,558,834	$	1,602,170