Property and Equipment

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

PROPERTY AND EQUIPMENT

5. PROPERTY AND EQUIPMENT.

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

	December 31,
	2021			2020
Facilities and plant equipment	$	364,039		$	357,740
Land		4,072			4,837
Other equipment, vehicles and furniture		7,656			7,858
Construction in progress		22,505			11,828
		398,272			382,263
Accumulated depreciation		(175,722	)		(152,777	)
	$	222,550		$	229,486

Depreciation expense was $23,292,000, $30,268,000 and $47,909,000 for the years ended December 31, 2021, 2020 and 2019, respectively.

The Company capitalized interest of $628,000, $224,000 and $563,000 for the years ended December 31, 2021, 2020 and 2019, respectively, related to its capital investment activities.