Segment Information - Components of Segment Revenues and Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023		Jun. 30, 2022		Jun. 30, 2023		Jun. 30, 2022
Segment Reporting Information [Line Items]
Segment Revenues	$ 159,101		$ 139,910		$ 290,529		$ 274,590
Segment Adjusted EBITDA	21,191		16,513	[1]	37,794		32,964	[1]
Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	159,101		139,910		290,529		274,590
Segment Adjusted EBITDA	30,665		24,912	[1]	56,596		48,850	[1]
Assessment, Permitting and Response | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	61,411		50,037		113,625		95,637
Segment Adjusted EBITDA	13,833		10,809	[1]	28,099		20,432	[1]
Measurement and Analysis | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	50,055	[2]	42,224	[2]	92,582	[3]	81,985	[3]
Segment Adjusted EBITDA	10,789		7,047	[1],[4]	17,176		13,369	[1],[4]
Remediation and Reuse | Operating Segments
Segment Reporting Information [Line Items]
Segment Revenues	47,635		47,649		84,322		96,968
Segment Adjusted EBITDA	6,043		7,056	[1]	11,321		15,049	[1]
Corporate and Other
Segment Reporting Information [Line Items]
Segment Adjusted EBITDA	$ (9,474)		$ (8,399)	[1]	$ (18,802)		$ (15,886)	[1]

[1] Includes the add back of start-up losses and investment in new services of $0.9 million and $1.7 million for the three and six months ended June 30, 2022, respectively .

[2] Includes revenue of $2.4 million and $3.4 million from the Discontinuing Specialty Lab, for the three months ended June 30, 2023 and June 30, 2022, respectively.

[3] Includes revenue of $3.9 million and $9.0 million from the Discontinuing Specialty Lab, for the six months ended June 30, 2023 and June 30, 2022, respectively.

[4] Includes Adjusted EBITDA loss of $(0.9) million and Adjusted EBITDA of $0.4 million from the Discontinuing Specialty Lab for the three and six months ended June 30, 2022, respectively.