ASSET RETIREMENT OBLIGATIONS

12 Months Ended

Dec. 31, 2013

Asset Retirement Obligation Disclosure [Abstract]

ASSET RETIREMENT OBLIGATIONS

Asset Retirement Obligations

The utility segments have asset retirement obligations primarily related to removal of natural gas distribution mains and service pipes (including asbestos and PCBs); asbestos abatement at certain generation facilities, office buildings, and service centers; dismantling wind generation projects; disposal of PCB-contaminated transformers; closure of fly-ash landfills at certain generation facilities; and removal of above ground storage tanks. The utilities establish regulatory assets and liabilities to record the differences between ongoing expense recognition under the asset retirement obligation accounting rules, and the ratemaking practices for retirement costs authorized by the applicable regulators. Integrys Energy Services has asset retirement obligations related to the removal of solar equipment components.

The following table shows changes to our asset retirement obligations through December 31, 2013:

(Millions)	Utilities				Integrys Energy Services		Total
Asset retirement obligations at December 31, 2010	$	320.9			$	—	$	320.9
Accretion	17.1				—		17.1
Additions and revisions to estimated cash flows	64.4			*	0.5		64.9
Settlements	(5.7		)		—		(5.7		)
Asset retirement obligations at December 31, 2011	396.7				0.5		397.2
Accretion	20.3				0.1		20.4
Additions and revisions to estimated cash flows	(2.4		)		1.6		(0.8		)
Settlements	(5.6		)		—		(5.6		)
Asset retirement obligations at December 31, 2012	409.0				2.2		411.2
Accretion	20.8				0.1		20.9
Additions and revisions to estimated cash flows	70.1			*	0.5		70.6
Settlements	(11.2		)		—		(11.2		)
Asset retirement obligations at December 31, 2013	$	488.7			$	2.8	$	491.5

* Revisions were made to estimated cash flows related to asset retirement obligations primarily due to an increase in the weighted average cost to retire a foot of natural gas distribution pipe at PGL.