Employee Benefit Plans

The components of net periodic benefit costs for Registrant’s pension plan, postretirement plan and SERP for the three months ended March 31, 2018 and 2017 are as follows:



	For The Three Months Ended March 31,
	Pension Benefits						Other Postretirement Benefits						SERP
(dollars in thousands)	2018			2017			2018			2017			2018		2017
Components of Net Periodic Benefits Cost:
Service cost	$	1,401		$	1,251		$	57		$	59		$	274	$	232
Interest cost	1,921			1,967			72			85			222		223
Expected return on plan assets	(2,791		)	(2,610		)	(123		)	(122		)	—		—
Amortization of prior service cost (benefit)	—			—			—			—			—		3
Amortization of actuarial (gain) loss	345			209			(182		)	(170		)	262		194
Net periodic pension cost under accounting standards	876			817			(176		)	(148		)	758		652
Regulatory adjustment — deferred	—			433			—			—			—		—
Total expense recognized, before surcharges and allocation to overhead pool	$	876		$	1,250		$	(176	)	$	(148	)	$	758	$	652

In accordance with new accounting guidance (Note 1), effective January 1, 2018, Registrant changed the financial statement presentation for the costs of its defined benefit pension plans and other retirement benefits. The components of net periodic benefits cost, other than the service cost component, have been included in the line item “Other, net” in Registrant's income statements. Prior period amounts have been reclassified on the income statements to conform to the current period presentation.

Registrant expects to contribute approximately $6.1 million to its pension plan during 2018.

Regulatory Adjustment:

As authorized by the CPUC in the most recent water and electric general rate case decisions, GSWC utilizes two-way balancing accounts for its water and electric regions and the general office to track differences between the forecasted annual pension expenses in rates or expected to be in rates and the actual annual expense recorded by GSWC in accordance with the accounting guidance for pension costs. As of March 31, 2018, GSWC had a total of $2.1 million over-collection in the two-way pension balancing accounts included as part of the pension regulatory asset (Note 3).