EMPLOYEE BENEFIT PLANS

6 Months Ended

Jun. 30, 2011

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS

NOTE 8—EMPLOYEE BENEFIT PLANS

The following table shows the components of net periodic benefit cost for our benefit plans:

	Pension Benefits												Other Postretirement Benefits
	Three Months						Six Months						Three Months						Six Months
	Ended June 30						Ended June 30						Ended June 30						Ended June 30
(Millions)	2011			2010			2011			2010			2011			2010			2011			2010
Service cost	$	2.4		$	3.1		$	5.6		$	5.8		$	1.7		$	1.2		$	3.5		$	2.9
Interest cost	8.9			9.1			18.1			18.3			3.7			3.3			7.6			7.0
Expected return on plan assets	(11.9		)	(10.1		)	(23.4		)	(19.8		)	(3.5		)	(3.6		)	(7.1		)	(7.1		)
Amortization of transition obligation	—			—			—			—			—			0.1			0.1			0.1
Amortization of prior service cost (credit)	1.2			1.2			2.4			2.4			(0.8		)	(0.9		)	(1.7		)	(1.8		)
Amortization of net actuarial loss	2.1			0.7			4.3			2.1			0.6			0.1			1.5			0.6
Regulatory deferral *	—			1.1			—			2.2			—			(0.3		)	—			(0.6		)
Net periodic benefit cost	$	2.7		$	5.1		$	7.0		$	11.0		$	1.7		$	(0.1	)	$	3.9		$	1.1

* The PSCW authorized us to recover net increased 2009 pension costs and to refund net decreased 2009 other postretirement benefit costs as part of the limited rate case re-opener for 2010.  Amortization and recovery/refund of these costs occurred in 2010.

We record transition obligations, prior service costs (credits), and net actuarial losses that have not yet been recognized as a component of net periodic benefit cost as net regulatory assets.

We make contributions to our plans in accordance with legal and tax requirements.  These contributions do not necessarily occur evenly throughout the year.  For the six months ended June 30, 2011, $60.9 million of contributions were made to our pension plans and contributions made to our other postretirement benefit plans were not significant.  We expect to contribute an additional $1.8 million to our pension plans and $10.8 million to our other postretirement benefit plans during the remainder of 2011.  Additional contributions are dependent on various factors, including our liquidity position and the impact of tax law changes.