ASSET RETIREMENT OBLIGATIONS (Tables)

6 Months Ended

Jun. 30, 2024

Asset Retirement Obligation Disclosure [Abstract]

Schedule of changes to asset retirement obligations

The following table shows changes to our AROs:

(in millions)	2024			2023
Balance at January 1	$	374.2		$	479.3
Accretion	7.4			8.5
Additions	165.7		(1)	16.6		(2)
Liabilities settled	(3.7)			(1.5)
Balance at June 30	$	543.6		$	502.9

(1)    AROs increased primarily as a result of AROs being recorded related to the new EPA CCR Rule that was enacted in April 2024. See Note 23, Commitments and Contingencies, for more information.

(2)    AROs increased primarily as a result of AROs being recorded for the legal requirement to dismantle, at retirement, the Red Barn wind-powered generation project and the Sapphire Sky and Samson I non-utility renewable generation projects.