Asset retirement obligations (“ARO”)

9 Months Ended

Sep. 30, 2013

Asset Retirement Obligation Disclosure [Abstract]

Asset retirement obligations (“ARO”)

Asset retirement obligations (“ARO”)

Our asset retirement obligations consist primarily of costs associated with the disposal of spent pot liner used in the reduction cells of our domestic facilities.

The reconciliation of the changes in the asset retirement obligations is presented below:

	Nine months ended September 30, 2013			Year ended December 31, 2012
Beginning balance, ARO liability	$	16,124		$	15,171
Additional ARO liability incurred	1,648			1,166
ARO liabilities settled	(1,493		)	(1,380		)
Accretion expense	1,334			1,167
Additional ARO liability from Sebree acquisition	10,106			—
Ending balance, ARO liability	$	27,719		$	16,124

Certain conditional AROs related to the disposal costs of fixed assets at our primary aluminum facilities have not been recorded because they have an indeterminate settlement date. These conditional AROs will be initially recognized in the period in which sufficient information exists to estimate their fair value.