Segment Information - Components of Segment Revenues and Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Segment Revenues	$ 139,910	$ 136,224	$ 274,590	$ 270,041
Segment Adjusted EBITDA	16,513	20,963	32,964	37,762
Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	139,910	136,224	274,590	270,041
Segment Adjusted EBITDA	24,912	28,656	48,850	51,801
Assessment, Permitting and Response | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	50,037	70,705	95,637	145,967
Segment Adjusted EBITDA	10,809	14,856	20,432	30,660
Measurement and Analysis | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	42,224	39,117	81,985	72,557
Segment Adjusted EBITDA	7,047	9,491	13,369	14,351
Remediation and Reuse | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	47,649	26,402	96,968	51,517
Segment Adjusted EBITDA	7,056	4,309	15,049	6,790
Corporate and Other
Segment Reporting Information [Line Items]
Segment Adjusted EBITDA	$ (8,399)	$ (7,693)	$ (15,886)	$ (14,039)