Goodwill and Intangible Assets

3 Months Ended

Mar. 31, 2023

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, 2022	$	185,116		$	86,205		$	52,547	$	323,868
Goodwill acquired during the period		—			844			1,965		2,809
Acquisitions measurement period adjustments		(169	)		(10	)		—		(179	)
Balance as of March 31, 2023	$	184,947		$	87,039		$	54,512	$	326,498

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


March 31, 2023	Estimated Useful Life	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Finite lived intangible assets
Customer relationships	2-15 years	$	209,426	$	100,404	$	109,022
Covenants not to compete	4-5 years		33,805		29,020		4,785
Trade names	1-5 years		22,167		18,708		3,459
Proprietary software	3-5 years		23,324		16,942		6,382
Patent	16 years		17,479		3,856		13,623
Total other intangible assets —net		$	306,201	$	168,930	$	137,271


December 31, 2022	Estimated Useful Life	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Finite lived intangible assets
Customer relationships	2-15 years	$	208,024	$	95,768	$	112,256
Covenants not to compete	4-5 years		33,542		28,280		5,262
Trade names	1-5 years		22,061		18,256		3,805
Proprietary software	3-5 years		22,698		15,810		6,888
Patent	16 years		17,479		3,583		13,896
Total other intangible assets —net		$	303,804	$	161,697	$	142,107

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 $7.2 million and $9.4 million for the three months ended March 31, 2023 and March 31, 2022, respectively.

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


December 31,
2023 (remaining)		20,920
2024		24,607
2025		17,727
2026		13,952
2027		13,429
Thereafter		46,636
Total	$	137,271