COMMITMENTS AND CONTINGENCIES - Narrative (Details)		12 Months Ended
	Aug. 21, 2019 USD ($)	Jun. 30, 2019 USD ($) Facility	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Lessee, Lease, Description [Line Items]
Number of fully-permitted facilities | Facility		2
Number of processing and treatment facilities | Facility		1
Rent expense		$ 2,200,000	$ 2,000,000	$ 1,500,000
Performance bonds outstanding covering financial assurance		$ 1,000,000
Minimum
Lessee, Lease, Description [Line Items]
Option to renew lease, term		1 year
Maximum
Lessee, Lease, Description [Line Items]
Option to renew lease, term		5 years
Subsequent Event
Lessee, Lease, Description [Line Items]
Base rent per square foot	$ 14.00
Base rent per square foot, annual increase	3.00%