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 and substation facilities, the removal and dismantlement of biomass generation facilities, the dismantling of wind generation projects, and the closure of coal combustion residual landfills at our 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	$	54.5
Accretion	1.2
Revisions to estimated cash flows	16.7		(1)
Liabilities settled	(1.1)
Balance as of September 30, 2021	$	71.3

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