Asset Retirement Obligations

12 Months Ended

Dec. 31, 2021

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

We have legal obligations associated with our facilities and right-of-way contracts we hold. Where we can reasonably estimate the ARO, we accrue a liability based on an estimate of the timing and amount of settlement. We record changes in these estimates based on changes in the expected amount and timing of payments to settle our obligations. We did not have any material assets that were legally restricted for use in settling asset retirement obligations as of December 31, 2021 and 2020.

The following table presents the changes in our net asset retirement obligations (in millions):


	December 31,
	2021		2020
Net asset retirement obligations at January 1	$	35.1	$	34.8
Liabilities acquired(1)	—		0.3
Liabilities incurred	—		0.3
Liabilities settled	(0.4)		(0.8)
Accretion expense	1.9		1.9
Other(2)	(0.4)		(1.4)
Net asset retirement obligations at December 31(3)	$	36.2	$	35.1

(1)Primarily relates to the NGL Asset Acquisition in 2020. See Note 3 for a further discussion of these acquisitions.

(2)Relates to obligations associated with the abandonment and dismantlement of our Marcellus West Union compressor assets in 2021 as further discussed in Note 2 and the obligations included in the sale of our Fayetteville assets in 2020 as further discussed in Note 3.

(3)Includes $1.4 million and $1.0 million of current ARO liabilities at December 31, 2021 and 2020.