SEGMENT REPORTING - Summarized Financial Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
OPERATING SEGMENTS
Number of reportable segments | segment	3
Revenue	$ 988,001	$ 933,854	$ 685,509
Depreciation, amortization and accretion	110,776	107,905	61,302
Capital expenditures	68,666	57,399	58,100
Total assets	1,805,398	1,831,283	2,231,244
Operating Segment
OPERATING SEGMENTS
Revenue	988,001	933,854	685,509
Corporate
OPERATING SEGMENTS
Depreciation, amortization and accretion	3,142	3,086	1,760
Capital expenditures	2,748	4,034	4,521
Total assets	59,375	63,506	75,400
Environmental Services | Operating Segment
OPERATING SEGMENTS
Revenue	451,249	425,413	440,547
Depreciation, amortization and accretion	43,746	41,540	41,133
Capital expenditures	45,602	31,027	46,202
Total assets	796,645	773,448	755,566
Field & Industrial Services | Operating Segment
OPERATING SEGMENTS
Revenue	500,187	473,754	232,402
Depreciation, amortization and accretion	44,368	43,465	15,007
Capital expenditures	15,393	16,149	5,986
Total assets	733,086	762,854	865,540
Energy Waste | Operating Segment
OPERATING SEGMENTS
Revenue	36,565	34,687	12,560
Depreciation, amortization and accretion	19,520	19,814	3,402
Capital expenditures	4,923	6,189	1,391
Total assets	$ 216,292	$ 231,475	$ 534,738