15. Asset Retirement Obligations

(PPL, LG&E and KU)

PPL's, LG&E's and KU's ARO liabilities are primarily related to CCR closure costs. See Note 10 for information on the CCR rule. LG&E and RIE also have AROs related to natural gas mains and wells. LG&E's and KU's transmission and distribution lines largely operate under perpetual property easement agreements, which do not generally require restoration upon removal of the property. Therefore, no material AROs are recorded for transmission and distribution assets. For LG&E, KU and RIE, all ARO accretion and depreciation expenses are reclassified as a regulatory asset or regulatory liability. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, deferred accretion and depreciation expense is recovered through cost of removal.

The changes in the carrying amounts of AROs were as follows.


	PPL		LG&E		KU
Balance at December 31, 2023	$	158	$	85	$	66
Accretion	2		1		1


Obligations settled	(5)		(2)		(3)
Other	1		—		—
Balance at March 31, 2024	$	156	$	84	$	64

Asset Retirement Obligations [Line Items]

Asset Retirement Obligations

15. Asset Retirement Obligations

(PPL, LG&E and KU)

PPL's, LG&E's and KU's ARO liabilities are primarily related to CCR closure costs. See Note 10 for information on the CCR rule. LG&E and RIE also have AROs related to natural gas mains and wells. LG&E's and KU's transmission and distribution lines largely operate under perpetual property easement agreements, which do not generally require restoration upon removal of the property. Therefore, no material AROs are recorded for transmission and distribution assets. For LG&E, KU and RIE, all ARO accretion and depreciation expenses are reclassified as a regulatory asset or regulatory liability. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, deferred accretion and depreciation expense is recovered through cost of removal.

The changes in the carrying amounts of AROs were as follows.


	PPL		LG&E		KU
Balance at December 31, 2023	$	158	$	85	$	66
Accretion	2		1		1


Obligations settled	(5)		(2)		(3)
Other	1		—		—
Balance at March 31, 2024	$	156	$	84	$	64