Goodwill and Intangible Assets

3 Months Ended

Mar. 31, 2022

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, 2021	$	176,541		$	83,770	$	51,633	$	311,944
Goodwill acquired during the period		3,874			—		150		4,024
Acquisitions measurement period adjustments		(91	)		296		—		205
Balance as of March 31, 2022	$	180,324		$	84,066	$	51,783	$	316,173

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


March 31, 2022	Estimated Useful Life	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Finite lived intangible assets
Customer relationships	2-15 years	$	202,212	$	79,690	$	122,522
Covenants not to compete	4-5 years		32,941		25,950		6,991
Trade names	1-5 years		21,422		15,826		5,596
Proprietary software	3-5 years		22,081		12,481		9,600
Patent	16 years		17,479		2,763		14,716
Total other intangible assets —net		$	296,135	$	136,710	$	159,425


December 31, 2021	Estimated Useful Life	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Finite lived intangible assets
Customer relationships	2-15 years	$	196,323	$	74,010	$	122,313
Covenants not to compete	4-5 years		32,622		25,113		7,509
Trade names	1-5 years		20,403		15,139		5,264
Proprietary software	3-5 years		22,077		11,155		10,922
Patent	16 years		17,479		2,490		14,989
Total other intangible assets —net		$	288,904	$	127,907	$	160,997

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 $9.4 million and $8.6 million for the three months ended March 31, 2022 and March 31, 2021, respectively.

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


December 31,
2022 (remaining)		24,727
2023		27,504
2024		22,978
2025		16,405
2026 and thereafter		67,811
Total	$	159,425