Segment and Geographic Location Information - Components of Segment Revenues and Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2023		Sep. 30, 2022		Sep. 30, 2023		Sep. 30, 2022
Segment Reporting Information [Line Items]
Segment Revenues	$ 167,937		$ 130,312		$ 458,466		$ 404,902
Segment Adjusted EBITDA	23,303		18,373	[1]	61,097		51,337	[1]
Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	167,937		130,312		458,466		404,902
Segment Adjusted EBITDA	32,676		25,313	[1]	89,272		74,163	[1]
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Segment Adjusted EBITDA	(9,373)		(6,940)	[1]	(28,175)		(22,826)	[1]
Assessment, Permitting and Response | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	57,009		46,414		170,634		142,051
Segment Adjusted EBITDA	14,878		9,820	[1]	42,977		30,252	[1]
Measurement and Analysis | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	50,468	[2]	43,754	[2]	143,050	[3]	125,739	[3]
Segment Adjusted EBITDA	10,352		8,483	[1],[4]	27,528		21,852	[1],[4]
Remediation and Reuse | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	60,460		40,144		144,782		137,112
Segment Adjusted EBITDA	$ 7,446		$ 7,010	[1]	$ 18,767		$ 22,059	[1]

[1] Includes the add back of start-up losses and investment in new services of $1.3 million and $2.9 million for the three and nine months ended September 30, 2022, respectively.

[2] Includes revenue of $2.0 million and $3.9 million from the Discontinuing Specialty Lab, for the three months ended September 30, 2023 and September 30, 2022, respectively.

[3] Includes revenue of $5.9 million and $12.9 million from the Discontinuing Specialty Lab, for the nine months ended September 30, 2023 and September 30, 2022, respectively.

[4] Includes Adjusted EBITDA loss of $(0.5) million and $(0.1) million from the Discontinuing Specialty Lab for the three and nine months ended September 30, 2022, respectively.