ASSET RETIREMENT OBLIGATIONS

9 Months Ended

Sep. 30, 2021

Asset Retirement Obligation Disclosure [Abstract]

ASSET RETIREMENT OBLIGATIONS

ASSET RETIREMENT OBLIGATIONS

We have recorded AROs primarily for asbestos abatement at certain generation facilities, office buildings, and service centers; the dismantling of wind generation projects; the dismantling of solar generation projects; the disposal of polychlorinated biphenyls-contaminated transformers; and the closure of coal combustion residual landfills at certain generation facilities.

On our balance sheets, AROs are recorded within other long-term liabilities. The following table shows changes to our AROs during the nine months ended September 30, 2021:

(in millions)	Nine Months Ended September 30, 2021
Balance as of January 1, 2021	$	45.5
Accretion	1.3
Revisions to estimated cash flows	(8.9)		(1)
Balance as of September 30, 2021	$	37.9

(1)    This decrease was primarily due to revisions made to estimated cash flows for the legal requirement to dismantle, at retirement, our wind generation projects.