The Company's recorded asset retirement obligations are primarily related to owned natural gas storage wells and offshore lines and platforms. At the end of the useful life of these underlying assets, the Company is legally or contractually required to abandon in place or remove the asset. An ARO is required to be recorded when a legal obligation to retire an asset exists and such obligation can be reasonably estimated. Although a number of other onshore assets in the Company's system are subject to agreements or regulations that give rise to an ARO upon the Company's discontinued use of these assets, AROs were not recorded because these assets have an indeterminate removal or abandonment date given the expected continued use of the assets with proper maintenance or replacement.

Individual component assets have been and will continue to be replaced, but the pipeline system will continue in operation as long as supply and demand for natural gas exists. Based on the widespread use of natural gas in industrial and power generation activities, management expects supply and demand to exist for the foreseeable future. The Company has in place a rigorous repair and maintenance program that keeps the pipeline system in good working order. Therefore, although some of the individual assets may be replaced, the pipeline system itself will remain intact indefinitely.

The following table is a general description of ARO and associated long-lived assets at December 31, 2011.

	In Service
ARO Description	Date	Long-Lived Assets	Amount
			(In thousands)

Retire natural gas storage wells	Various	Natural gas storage wells	$	517
Retire offshore platforms and lines	Various	Offshore lines		3,180
Remove asbestos	Various	Mainlines and compressors		872

As of December 31, 2011, the Company had no legally restricted funds for the purpose of settling AROs.

The following table is a reconciliation of the carrying amount of the ARO liability for the periods presented. Changes in assumptions regarding the timing, amount, and probabilities associated with the expected cash flows, as well as the difference in actual versus estimated costs, will result in a change in the amount of the liability recognized.

		Years Ended December 31,
		2011		2010		2009

			(In thousands)

Beginning balance		$	56,751	$	58,449	$	50,941
	Incurred		1,162		28,605		8,289
	Revisions		(412)		(11,395)		(3,246)
	Settled		(16,624)		(19,721)		(1,553)
	Accretion expense		180		813		4,018
Ending balance		$	41,057	$	56,751	$	58,449

In 2010, additional AROs of $28.6 million were established primarily for the Company's offshore assets. During 2010, the Company largely completed its assessment and repairs of the property damaged by Hurricane Ike in 2008, which resulted in accelerated abandonments of such property, and determined that the estimated third party abandonment costs for all of its offshore property needed to be increased. Also in 2010, the Company recorded an $11.4 million downward revision to its prior ARO liability estimates, primarily for the costs of abandoning certain other specific offshore properties as a result of favorable weather conditions, changes in equipment used, and some changes in scope of the respective projects, which were primarily related to abandonments required as a result of permanent damage from Hurricane Ike. The ARO liability associated with Hurricane Ike was further reduced by settlements of $19.7 million. Such revisions and settlements were primarily associated with AROs of $8.3 million and $33.8 million recorded in 2009 and 2008, respectively, associated with damage caused by Hurricane Ike. During 2011, the Company recorded settlements of approximately $16.6 million, primarily associated with the abandonment of certain offshore properties damaged by Hurricane Ike. See Note 15 – Commitments and Contingencies – Other Commitments and Contingencies – 2008 Hurricane Damage for additional related information.