Asset Retirement Obligations

12 Months Ended

Dec. 31, 2012

Asset Retirement Obligation Disclosure [Abstract]

AssetRetirementObligationDisclosureTextBlock

8. ASSET RETIREMENT OBLIGATIONS

Our accrued asset retirement obligations relate to our gas storage and transmission facilities. At the end of the useful life of our facilities, we are legally obligated to remove certain transmission facilities including underground pipelines, major river spans, compressor stations and meter station facilities. These obligations also include restoration of the property sites after removal of the facilities from above and below the ground.

During 2012 and 2011, our overall asset retirement obligation changed as follows (in thousands):

		2012		2011
Beginning balance		$	80,313	$	65,155
	Accretion		5,543		5,162
	New obligations		15		2,257
	Changes in estimates of existing obligations (1)		(18,231)		8,116
	Property Dispositions & Settlements		-		(377)
Ending balance		$	67,640	$	80,313
_____________________

• Changes in estimates of existing obligations are primarily due to the annual review process, which considers various factors including inflation rates, current estimates for removal cost, discount rates, and the estimated remaining life of assets.The increase in 2011 is primarily attributed to a decrease in the discount rate. The decrease in 2012 is primarily attributed to a decrease in removal cost estimates.