PROPERTY, PLANT AND EQUIPMENT

3 Months Ended

Mar. 31, 2019

Property, Plant and Equipment [Abstract]

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



	March 31, 2019		December 31, 2018
Land	$	129,684	$	123,734
Asset retirement costs (non-landfill)	15,258		15,148
Landfill assets	160,093		154,918
Buildings and improvements ⁽¹⁾	465,707		440,188
Camp equipment	156,031		152,998
Vehicles	753,490		721,735
Equipment	1,711,470		1,697,490
Furniture and fixtures	5,476		5,453
Construction in progress	27,028		20,931
	3,424,237		3,332,595
Less - accumulated depreciation and amortization	1,835,624		1,770,617
Total property, plant and equipment, net	$	1,588,613	$	1,561,978

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(1) Inclusive of finance lease.

Interest in the amount of $0.1 million and $0.3 million was capitalized to property, plant and equipment during the three months ended March 31, 2019 and March 31, 2018, respectively. Depreciation expense, inclusive of landfill and finance lease amortization, was $65.9 million and $65.6 million for the three months ended March 31, 2019 and March 31, 2018, respectively.