PROPERTY, PLANT AND EQUIPMENT

6 Months Ended

Jun. 30, 2019

Property, Plant and Equipment [Abstract]

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



	June 30, 2019		December 31, 2018
Land	$	134,306	$	123,734
Asset retirement costs (non-landfill)	15,358		15,148
Landfill assets	164,816		154,918
Buildings and improvements ⁽¹⁾	472,383		440,188
Camp equipment	158,992		152,998
Vehicles	777,968		721,735
Equipment	1,732,020		1,697,490
Furniture and fixtures	5,511		5,453
Construction in progress	34,949		20,931
	3,496,303		3,332,595
Less - accumulated depreciation and amortization	1,899,386		1,770,617
Total property, plant and equipment, net	$	1,596,917	$	1,561,978

______________________

(1) Inclusive of finance lease.

Interest in the amount of $0.1 million and $0.2 million was capitalized to property, plant and equipment during the three and six months ended June 30, 2019, respectively. Interest in the amount of $0.1 million and $0.4 million was capitalized to property, plant and equipment during the three and six months ended June 30, 2018, respectively. Depreciation expense, inclusive of landfill and finance lease amortization, was $65.5 million and $131.4 million for the three and six months ended June 30, 2019, respectively. Depreciation expense, inclusive of landfill amortization, was $64.2 million and $129.8 million for the three and six months ended June 30, 2018, respectively.