SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($) segment	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($) segment
SEGMENT INFORMATION
Number of reportable segments | segment	3	3	3	3
SEGMENT INFORMATION
Revenue	$ 371,349	$ 389,273	$ 1,103,028	$ 1,210,493
Impairments and abandonments		32	91	11,554
Income before taxes	24,155	16,775	48,693	54,364
Depreciation, amortization and accretion	39,567	35,162	115,910	104,622
Capital Expenditures	37,436	44,220	124,717	123,193
Income from operations	24,515	16,750	51,884	54,484
Operating segment | Water Services
SEGMENT INFORMATION
Revenue	236,499	252,488	698,630	793,484
Impairments and abandonments				60
Income before taxes	23,739	18,268	66,828	64,046
Depreciation, amortization and accretion	19,495	22,822	61,621	68,562
Capital Expenditures	17,466	10,236	40,882	43,773
Operating segment | Water Infrastructure
SEGMENT INFORMATION
Revenue	82,966	59,756	215,700	172,495
Impairments and abandonments		32	45	388
Income before taxes	21,511	10,909	45,478	28,427
Depreciation, amortization and accretion	17,558	9,192	46,088	26,825
Capital Expenditures	18,670	30,197	80,083	68,392
Operating segment | Chemical Technologies
SEGMENT INFORMATION
Revenue	55,823	79,532	197,724	251,042
Impairments and abandonments				11,106
Income before taxes	715	9,163	10,845	19,313
Depreciation, amortization and accretion	1,853	2,638	5,534	7,390
Capital Expenditures	1,235	3,523	3,604	8,672
Operating segment | Other
SEGMENT INFORMATION
Impairments and abandonments	(46)
Income before taxes	45	(3)	(6)	(3)
Eliminations
SEGMENT INFORMATION
Revenue	(3,939)	(2,503)	(9,026)	(6,528)
Corporate
SEGMENT INFORMATION
Impairments and abandonments	46		46
Income before taxes	(21,495)	(21,587)	(71,261)	(57,299)
Depreciation, amortization and accretion	661	510	2,667	1,845
Capital Expenditures	65	264	148	2,356
Material reconciling items
SEGMENT INFORMATION
Income from operations	46,010	38,337	123,145	111,783
Interest expense, net	(1,906)	(765)	(5,204)	(4,290)
Other income, net	$ 1,546	$ 790	$ 2,013	$ 4,170