REVENUES (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) segment	Mar. 31, 2021 USD ($)
Disaggregation of revenue
Number of reportable segments | segment	3
Revenue	$ 240,980	$ 228,619
Treatment and disposal
Disaggregation of revenue
Revenue	114,165	101,820
Transportation and Logistics
Disaggregation of revenue
Revenue	30,143	23,812
Industrial Services
Disaggregation of revenue
Revenue	29,842	26,665
Small Quantity Generation
Disaggregation of revenue
Revenue	15,039	13,052
Total Waste Management
Disaggregation of revenue
Revenue	10,589	9,882
Remediation
Disaggregation of revenue
Revenue	5,360	11,975
Emergency Response
Disaggregation of revenue
Revenue	31,416	37,355
Other Services
Disaggregation of revenue
Revenue	4,426	4,058
Operating Segment | Environmental Services
Disaggregation of revenue
Revenue	114,766	104,142
Operating Segment | Field & Industrial Services
Disaggregation of revenue
Revenue	112,323	118,249
Operating Segment | Energy Waste
Disaggregation of revenue
Revenue	13,891	6,228
Operating Segment | Treatment and disposal | Environmental Services
Disaggregation of revenue
Revenue	96,280	88,060
Operating Segment | Treatment and disposal | Field & Industrial Services
Disaggregation of revenue
Revenue	10,781	9,977
Operating Segment | Treatment and disposal | Energy Waste
Disaggregation of revenue
Revenue	7,104	3,783
Operating Segment | Transportation and Logistics | Environmental Services
Disaggregation of revenue
Revenue	18,486	16,082
Operating Segment | Transportation and Logistics | Field & Industrial Services
Disaggregation of revenue
Revenue	7,273	6,329
Operating Segment | Transportation and Logistics | Energy Waste
Disaggregation of revenue
Revenue	4,384	1,401
Operating Segment | Industrial Services | Field & Industrial Services
Disaggregation of revenue
Revenue	28,870	26,256
Operating Segment | Industrial Services | Energy Waste
Disaggregation of revenue
Revenue	972	409
Operating Segment | Small Quantity Generation | Field & Industrial Services
Disaggregation of revenue
Revenue	15,039	13,052
Operating Segment | Total Waste Management | Field & Industrial Services
Disaggregation of revenue
Revenue	10,589	9,882
Operating Segment | Remediation | Field & Industrial Services
Disaggregation of revenue
Revenue	5,360	11,975
Operating Segment | Emergency Response | Field & Industrial Services
Disaggregation of revenue
Revenue	31,416	37,355
Operating Segment | Other Services | Field & Industrial Services
Disaggregation of revenue
Revenue	2,995	3,423
Operating Segment | Other Services | Energy Waste
Disaggregation of revenue
Revenue	$ 1,431	$ 635