PROPERTY, PLANT, AND EQUIPMENT

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

PROPERTY, PLANT, AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT

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

	December 31, 2016		December 31, 2015
Land	$	120,575	$	100,582
Asset retirement costs (non-landfill)	14,567		12,434
Landfill assets	139,708		136,624
Buildings and improvements	373,160		344,209
Camp equipment	152,740		149,361
Vehicles	541,022		500,619
Equipment	1,483,736		1,328,915
Furniture and fixtures	5,492		5,337
Construction in progress	146,904		113,657
	2,977,904		2,691,738
Less - accumulated depreciation and amortization	1,366,077		1,159,271
Total property, plant and equipment, net	$	1,611,827	$	1,532,467

Interest in the amount of $5.5 million, $2.0 million and $0.5 million was capitalized to fixed assets during the years ended December 31, 2016, 2015 and 2014, respectively. Depreciation expense, inclusive of landfill amortization was$247.0 million, $234.0 million and $239.4 million for the years ended December 31, 2016, 2015 and 2014, respectively.