Goodwill and Intangible Assets

9 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

8. GOODWILL AND INTANGIBLE ASSETS

Amounts related to goodwill are as follows:


	Assessment, Permitting and Response		Measurement and Analysis		Remediation and Reuse			Total
Balance as of December 31, 2024	$	205,231	$	118,860	$	143,698		$	467,789
Acquisitions measurement period adjustments, net of foreign currency translation		1,096		220		(80	)		1,236
Balance as of September 30, 2025	$	206,327	$	119,080	$	143,618		$	469,025

Amounts related to finite-lived intangible assets are as follows:


September 30, 2025	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Customer relationships	$	264,958	$	155,589	$	109,369
Covenants not to compete		41,529		35,787		5,742
Trade names		25,939		25,056		883
Proprietary software		31,201		25,227		5,974
Patent		17,479		6,598		10,881
Total other intangible assets, net	$	381,106	$	248,257	$	132,849

December 31, 2024	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Customer relationships	$	264,477	$	138,787	$	125,690
Covenants not to compete		41,758		33,898		7,860
Trade names		25,939		23,375		2,564
Proprietary software		28,428		23,489		4,939
Patent		17,479		5,776		11,703
Total other intangible assets, net	$	378,081	$	225,325	$	152,756

Intangible assets with finite lives are stated at cost, less accumulated amortization and impairment losses, if any. These intangible assets are amortized using the straight-line method over the estimated useful lives of the assets.

Amortization expense was $7.3 million and $23.0 million for the three and nine months ended September 30, 2025, respectively, and $9.0 million and $24.6 million for the three and nine months ended September 30, 2024, respectively.

Future amortization expense is estimated to be as follows for each of the five following years and thereafter:


December 31,
2025 (remaining)	$	6,845
2026		25,635
2027		24,381
2028		18,967
2029		12,380
Thereafter		44,641
Total	$	132,849