Asset Retirement Obligations:

12 Months Ended

Dec. 31, 2022

Asset Retirement Obligation Disclosure [Abstract]

(7)

ASSET RETIREMENT OBLIGATIONS

We have identified legal obligations related to reclamation of mining sites; removal of fuel tanks, transformers containing polychlorinated biphenyls, an evaporation pond; and reclamation of wind turbine sites at our Electric Utilities segment. In addition, we have identified legal obligations related to retirement of gas pipelines, wells and compressor stations at our Gas Utilities and removal of asbestos at our Utilities. We periodically review and update estimated costs related to these AROs. The actual cost may vary from estimates due to regulatory requirements, changes in technology and increased labor, materials and equipment costs.

The following tables present the details of AROs which are included on the accompanying Consolidated Balance Sheets in Other deferred credits and other liabilities (in thousands):


	December 31, 2021		Liabilities Incurred		Liabilities Settled			Accretion		Revisions to Prior Estimates			December 31, 2022
Electric Utilities	$	30,089	$	—	$	(3,003	)	$	1,353	$	(856	)	$	27,583
Gas Utilities (a)		45,455		—		(158	)		2,016		14,032			61,345
Total	$	75,544	$	—	$	(3,161	)	$	3,369	$	13,176		$	88,928


	December 31, 2020		Liabilities Incurred		Liabilities Settled			Accretion		Revisions to Prior Estimates		December 31, 2021
Electric Utilities	$	29,157	$	—	$	(978	)	$	1,315	$	595	$	30,089
Gas Utilities (a)		42,274		—		(66	)		1,733		1,514		45,455
Total	$	71,431	$	—	$	(1,044	)	$	3,048	$	2,109	$	75,544

(a)

The Revisions to Prior Estimates were primarily driven by changes in estimates associated with natural gas wells and compressor stations.

We also have legally required AROs related to certain assets within our electric transmission and distribution systems. These retirement obligations are pursuant to an easement or franchise agreement and are only required if we discontinue our utility service under such easement or franchise agreement. Accordingly, it is not possible to estimate a time period when these obligations could be settled, and therefore, a liability for the cost of these obligations cannot be measured at this time.