
	Environmental Services		Safety-Kleen Sustainability Solutions		Totals
Balance at January 1, 2025	$	1,296,204	$	180,995	$	1,477,199

Measurement period adjustments from prior period acquisitions	146		(99)		47

Foreign currency translation	1,824		735		2,559
Balance at June 30, 2025	$	1,298,174	$	181,631	$	1,479,805

The Company assesses goodwill on an annual basis as of December 31 or at an interim date when events or changes in the business environment (“triggering events”) would more likely than not reduce the fair value of a reporting unit below its carrying value. During the period ended June 30, 2025, no such triggering events were identified.

As of June 30, 2025 and December 31, 2024, the Company’s intangible assets consisted of the following (in thousands):


	June 30, 2025						December 31, 2024
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	194,062	$	128,561	$	65,501	$	191,921	$	123,939	$	67,982
Customer and supplier relationships	698,473		275,162		423,311		697,326		256,657		440,669
Other intangible assets	120,458		52,080		68,378		120,316		46,490		73,826
Total amortizable permits and other intangible assets	1,012,993		455,803		557,190		1,009,563		427,086		582,477
Trademarks and trade names	119,990		—		119,990		119,510		—		119,510
Total permits and other intangible assets	$	1,132,983	$	455,803	$	677,180	$	1,129,073	$	427,086	$	701,987

Amortization expense of permits, customer and supplier relationships and other intangible assets was $13.7 million and $27.0 million in the three and six months ended June 30, 2025, respectively. Amortization expense of permits, customer and supplier relationships and other intangible assets was $14.0 million and $26.9 million in the three and six months ended June 30, 2024, respectively.

The expected amortization of the net carrying amount of finite-lived intangible assets at June 30, 2025 was as follows (in thousands):


Years Ending December 31,	Expected Amortization
2025 (six months)	$	26,664
2026	51,494
2027	49,414
2028	48,049
2029	46,971
Thereafter	334,598
	$	557,190