The Company tests each of its reporting units for goodwill impairment annually on October 1, or upon a triggering event, in accordance with ASC Topic 350, “Intangibles –Goodwill and Other.” Effective in the first quarter of 2026, the Company reorganized its business into two reportable segments as discussed in Note 19 – Segment Information. This changed the composition of the Company's reporting units which resulted in the combination of historical goodwill from the Assessment, Permitting and Response and Remediation and Reuse segments to its newly created Consulting and Treatment segment. Additionally, the change in composition of the Company's reporting units was considered a triggering event requiring an interim goodwill impairment test as of March 31, 2026. The Company determined that no impairment existed as the estimated fair values of its reporting units were in excess of their respective carrying values, both before and after the reorganization. Amounts related to goodwill are as follows:


	Consulting and Treatment			Measurement and Analysis			Total
Balance as of December 31, 2025	$	347,706		$	119,080		$	466,786
Foreign currency translation adjustments		(508	)		(500	)		(1,008	)
Balance as of June 30, 2026	$	347,198		$	118,580		$	465,778

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


June 30, 2026	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Customer relationships	$	264,071	$	170,165	$	93,906
Covenants not to compete		41,370		37,334		4,036
Trade names		25,938		25,839		99
Proprietary software		32,594		27,086		5,508
Patent		17,479		7,421		10,058
Total other intangible assets, net	$	381,452	$	267,845	$	113,607

December 31, 2025	Gross Balance		Accumulated Amortization		Total Intangible Assets—Net
Customer relationships	$	264,564	$	160,459	$	104,105
Covenants not to compete		41,418		36,293		5,125
Trade names		25,917		25,441		476
Proprietary software		31,982		25,912		6,070
Patent		17,479		6,872		10,607
Total other intangible assets, net	$	381,360	$	254,977	$	126,383

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 $6.7 million and $13.3 million for the three and six months ended June 30, 2026, respectively, and $7.3 million and $15.7 million for the three and six months ended June 30, 2025, respectively.

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


December 31,
2026 (remaining)	$	12,539
2027		24,687
2028		18,993
2029		12,582
2030		9,006
Thereafter		35,800
Total	$	113,607