ASSET RETIREMENT OBLIGATIONS

FirstEnergy has recognized applicable legal obligations for AROs and their associated cost primarily for nuclear power plant decommissioning, reclamation of sludge disposal ponds, closure of coal ash disposal sites, underground and above-ground storage tanks, wastewater treatment lagoons and transformers containing PCBs. In addition, FirstEnergy has recognized conditional retirement obligations, primarily for asbestos remediation.

The ARO liabilities for FES primarily relate to the decommissioning of the Beaver Valley, Davis-Besse and Perry nuclear generating facilities and totaled $1,758 million and $713 million as of December 31, 2017 and 2016, respectively. FES uses an expected cash flow approach to measure the fair value of their nuclear decommissioning AROs.

FirstEnergy and FES maintain NDTs that are legally restricted for purposes of settling the nuclear decommissioning ARO. The fair values of the decommissioning trust assets as of December 31, 2017 and 2016 were as follows:



	2017		2016
	(In millions)
FirstEnergy	$	2,678	$	2,514
FES	$	1,856	$	1,552

The following table summarizes the changes to the ARO balances during 2017 and 2016:



ARO Reconciliation	FirstEnergy			FES
	(In millions)
Balance, January 1, 2016	$	1,410		$	831
Liabilities settled	(27		)	(18		)
Accretion	95			56
Liabilities Incurred	4			32
Balance, December 31, 2016	$	1,482		$	901
Changes in timing of estimated cash flows ⁽¹⁾	944			944
Liabilities settled	(12		)	(11		)
Accretion	101			62
Liabilities Incurred	—			49
Balance, December 31, 2017	$	2,515		$	1,945

⁽¹⁾ See Note 2, "Asset Sales and Impairments" for further discussion.

During the second quarter of 2017, in connection with NG purchasing the lessor equity interests of the remaining non-affiliated leasehold interests from an owner participant in the Beaver Valley Unit 2 sale leaseback and the expiration of the leases, OE and TE transferred the ARO (included within the FES liabilities incurred above) and NDT assets associated with their leasehold interests to NG, with the difference of $73 million credited to the common stock of FES.

During 2016, in connection with NG purchasing the lessor equity interests of the remaining non-affiliated leasehold interests from an owner participant in Perry Unit 1, OE transferred the ARO (included within the FES liabilities incurred above) and related NDT assets associated with the leasehold interest to NG with the difference of $28 million credited to the common stock of FES. As of June 30, 2016, NG owns 100% of Perry Unit 1.

In April 2015, the EPA finalized regulations for the disposal of CCRs (non-hazardous), establishing national standards for landfill design, structural integrity design and assessment criteria for surface impoundments, groundwater monitoring and protection procedures and other operational and reporting procedures to assure the safe disposal of CCRs from electric generating plants. On September 13, 2017, the EPA announced that it would reconsider certain provisions of the final regulations. Based on an assessment of the finalized regulations, the future cost of compliance and expected timing had no significant impact on FirstEnergy's or FES' existing AROs associated with CCRs. Although not currently expected, changes in timing and closure plan requirements in the future, including changes resulting from the strategic review at CES, could materially and adversely impact FirstEnergy's and FES' AROs.