REVENUES - Treatment and Disposal Revenue (Details) - Treatment and disposal - T	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Event Business
Disaggregation of revenue
Threshold Tons of Non-recurring projects			1,000
Revenue (in percent)	23.00%	19.00%	19.00%	18.00%
Base Business
Disaggregation of revenue
Revenue (in percent)	77.00%	81.00%	81.00%	82.00%