PROPERTY, PLANT AND EQUIPMENT

9 Months Ended

Sep. 30, 2017

Property, Plant and Equipment [Abstract]

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



	September 30, 2017		December 31, 2016
Land	$	121,806	$	120,575
Asset retirement costs (non-landfill)	14,905		14,567
Landfill assets	143,503		139,708
Buildings and improvements	411,006		373,160
Camp equipment	171,163		152,740
Vehicles	613,767		541,022
Equipment	1,628,256		1,483,736
Furniture and fixtures	5,586		5,492
Construction in progress	52,523		146,904
	3,162,515		2,977,904
Less - accumulated depreciation and amortization	1,550,544		1,366,077
Total property, plant and equipment, net	$	1,611,971	$	1,611,827

Interest in the amount of $0.2 million and $0.4 million was capitalized to fixed assets during the three and nine months ended September 30, 2017, respectively. Interest in the amount of $1.5 million and $4.0 million was capitalized to fixed assets during the three and nine months ended September 30, 2016, respectively. Depreciation expense, inclusive of landfill amortization, was $64.0 million and $189.2 million for the three and nine months ended September 30, 2017, respectively. Depreciation expense, inclusive of landfill amortization, was $62.6 million and $185.4 million for the three and nine months ended September 30, 2016, respectively.