REVENUES - Treatment and Disposal Revenue (Details) - T	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Technical Services | Minimum
Disaggregation of revenue
Revenue Contract Term	1 year
Remediation | Minimum
Disaggregation of revenue
Revenue Contract Term	1 year
Event Business | Treatment and disposal
Disaggregation of revenue
Threshold Tons of Non-recurring projects	1,000
Revenue (in percent)	17.00%	16.00%
Base Business | Treatment and disposal
Disaggregation of revenue
Revenue (in percent)	83.00%	84.00%