Asset Retirement Obligations

12 Months Ended

Dec. 31, 2020

Asset Retirement Obligation [Abstract]

Asset Retirement ObligationsWe have recognized asset retirement obligations associated with various legal obligations including costs to remove and dispose of certain construction materials located within many of our facilities, certain costs to retire pipeline, removal costs for certain underground storage tanks, removal of certain pipelines known to contain PCB contamination, closure costs for certain sites including ash ponds, solid waste management units and a landfill, as well as some other nominal asset retirement obligations. We also have an obligation associated with the decommissioning of our two hydro facilities located in Indiana. These hydro facilities have an indeterminate life, and as such, no asset retirement obligation has been recorded.

Changes in our liability for asset retirement obligations for the years 2020 and 2019 are presented in the table below:


(in millions)	2020			2019
Beginning Balance	$	416.9		$	352.0
Accretion recorded as a regulatory asset/liability	17.3			15.7
Additions	5.5			—
Settlements	(13.9)			(5.4)
Change in estimated cash flows	86.0		(1)	54.6		(2)
Other	(16.2)		(3)	—
Ending Balance	$	495.6		$	416.9

(1)The change in estimated cash flows for 2020 is primarily attributed to revisions to the estimated costs associated with refining the CCR compliance plan, changes in estimated costs for electric generating stations and the changes in estimated costs for retirement of gas mains. See Note 20-D. "Environmental Matters" for additional information on CCRs.

(2)The change in estimated cash flows for 2019 is primarily attributed to changes in estimated costs and settlement timing for electric generating stations and the changes in estimated costs for retirement of gas mains.

(3)Represents the Columbia of Massachusetts Asset Retirement Obligations that were included in the sale of the Massachusetts Business that occurred on October 9, 2020.

Certain non-legal costs of removal that have been, and continue to be, included in depreciation rates and collected in the customer rates of the rate-regulated subsidiaries are classified as "Regulatory liabilities" on the Consolidated Balance Sheets.