Asset Retirement Obligations

3 Months Ended

Mar. 31, 2020

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

Asset Retirement Obligations

In the first quarter of 2020, APS recognized an asset retirement obligation ("ARO") for its share of corrective action and water monitoring costs at Four Corners and the Navajo Plant (see additional details in Notes 4 and 8), which resulted in a decrease to the ARO of $11 million for Four Corners and an increase to the ARO of $5 million for the Navajo Plant.

The following schedule shows the change in our asset retirement obligations for the three months ended March 31, 2020 (dollars in thousands): 

	2020
Asset retirement obligations at January 1, 2020	$	657,218
Changes attributable to:
Accretion expense	10,219
Settlements	(2,295		)
Estimated cash flow revisions	(5,821		)
Asset retirement obligations at March 31, 2020	$	659,321

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.