AROs represent obligations that result from laws, statutes, contracts and regulations related to the eventual retirement of certain of the Companies’ long-lived assets. Dominion Energy and Virginia Power’s AROs are primarily associated with the decommissioning of their nuclear generation facilities and ash pond and landfill closures. Dominion Energy Gas’ AROs primarily include plugging and abandonment of gas and oil wells and the interim retirement of natural gas gathering, transmission, distribution and storage pipeline components.

The Companies have also identified, but not recognized, AROs related to the retirement of Dominion Energy’s LNG facility, Dominion Energy and Dominion Energy Gas’ storage wells in their underground natural gas storage network, certain Virginia Power electric transmission and distribution assets located on property with easements, rights of way, franchises and lease agreements, Virginia Power’s hydroelectric generation facilities and the abatement of certain asbestos not expected to be disturbed in Dominion Energy and Virginia Power’s generation facilities. The Companies currently do not have sufficient information to estimate a reasonable range of expected retirement dates for any of these assets since the economic lives of these assets can be extended indefinitely through regular repair and maintenance and they currently have no plans to retire or dispose of any of these assets. As a result, a settlement date is not determinable for these assets and AROs for these assets will not be reflected in the Consolidated Financial Statements until sufficient information becomes available to determine a reasonable estimate of the fair value of the activities to be performed. The Companies continue to monitor operational and strategic developments to identify if sufficient information exists to reasonably estimate a retirement date for these assets. The changes to AROs during 2019 were as follows:

	Amount
(millions)
Dominion Energy
AROs at December 31, 2018⁽¹⁾	$		2,532
Obligations incurred during the period⁽²⁾			2,395
Obligations settled during the period			(56	)
AROs acquired in the SCANA Combination		577
Revisions in estimated cash flows⁽²⁾			(228	)
Accretion		83
AROs at June 30, 2019⁽¹⁾	$		5,303
Virginia Power
AROs at December 31, 2018⁽³⁾	$		1,445
Obligations incurred during the period⁽²⁾			2,394
Obligations settled during the period			(41	)
Revisions in estimated cash flows⁽²⁾			(202	)
Accretion		55
AROs at June 30, 2019⁽³⁾	$		3,651
Dominion Energy Gas
AROs at December 31, 2018⁽⁴⁾	$	167
Obligations settled during the period			(4	)
Revisions in estimated cash flows			(26	)
Accretion		5
AROs at June 30, 2019⁽⁴⁾	$	142

(4) Includes $153 million and $132 million reported in other deferred credits and other liabilities, with the remainder recorded in other current liabilities, at December 31, 2018 and June 30, 2019, respectively.

Dominion Energy and Virginia Power have established trusts dedicated to funding the future decommissioning of their nuclear plants. At June 30, 2019 and December 31, 2018, the aggregate fair value of Dominion Energy’s trusts, consisting primarily of equity and debt securities, totaled $5.8 billion and $4.9 billion, respectively. At June 30, 2019 and December 31, 2018, the aggregate fair value of Virginia Power’s trusts, consisting primarily of debt and equity securities, totaled $2.7 billion and $2.4 billion, respectively.