Asset Retirement Obligations

6 Months Ended

Jun. 30, 2021

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

Asset Retirement Obligations

During the six months ended June 30, 2021, the Company revised its cost estimates for existing Asset Retirement Obligations (ARO) at Cholla related to updated estimates for the closure of ponds and facilities, which resulted in an increase to the ARO of $11.1 million. (See additional details in Notes 4 and 8.)

The following schedule shows the change in our asset retirement obligations for the six months ended June 30, 2021 (dollars in thousands): 

	2021
Asset retirement obligations at January 1, 2021	$	705,083
Changes attributable to:
Accretion expense	18,828
Settlements	(2,853)
Estimated cash flow revisions	10,932
Asset retirement obligations at June 30, 2021	$	731,990

In accordance with regulatory accounting, APS accrues removal costs for its regulated utility assets, even if there is no legal obligation for removal.  See detail of regulatory liabilities in Note 4.