Asset Retirement Obligations (Notes)

12 Months Ended

Dec. 31, 2018

Asset Retirement Obligations Disclosure [Line Items]

Asset Retirement Obligations [Text Block]

Asset Retirement Obligations

The Company estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work.

The Company does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $2.4 billion and $2.3 billion as of December 31, 2018 and 2017, respectively.

The following table presents the Company's ARO liabilities by asset type as of December 31 (in millions):



	2018		2017

Fossil fuel facilities	$	371	$	380
Quad Cities Station	345		342
Wind generating facilities	174		138
Offshore pipeline facilities	33		32
Solar generating facilities	20		19
Other	42		43
Total asset retirement obligations	$	985	$	954

Quad Cities Station nuclear decommissioning trust funds	$	504	$	515

The following table reconciles the beginning and ending balances of the Company's ARO liabilities for the years ended December 31 (in millions):



	2018			2017

Beginning balance	$	954		$	954
Change in estimated costs	10			(18		)
Additions	28			21
Retirements	(45		)	(45		)
Accretion	38			42
Ending balance	$	985		$	954

Reflected as:
Other current liabilities	$	43		$	60
Other long-term liabilities	942			894
Total ARO liability	$	985		$	954

The Nuclear Regulatory Commission regulates the decommissioning of nuclear power plants, which includes the planning and funding for the decommissioning. In accordance with these regulations, MidAmerican Energy submits a biennial report to the Nuclear Regulatory Commission providing reasonable assurance that funds will be available to pay for its share of the Quad Cities Station decommissioning.

Certain of the Company's decommissioning and reclamation obligations relate to jointly owned facilities and mine sites, and as such, each subsidiary is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, the respective subsidiary may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. The Company's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities.

The changes in estimated costs relate primarily to the Quad Cities Station due to a change in the inflation rate and, for 2017, a new decommissioning study conducted by the operator of Quad Cities Station that changed the estimated amount and timing of cash flows.

In January 2018, MidAmerican Energy completed groundwater testing at its coal combustion residuals ("CCR") surface impoundments. Based on this information, MidAmerican Energy discontinued sending CCR to surface impoundments effective April 2018 and will remove all CCR material located below the water table in such facilities, the latter of which is a more extensive closure activity than previously assumed. The incremental cost and timing of such actions is not currently reasonably determinable, but an evaluation of such estimates is expected to be completed in the first quarter of 2019, with any necessary adjustments to the related asset retirement obligations recognized at that time.

PacifiCorp [Member]

Asset Retirement Obligations Disclosure [Line Items]

Asset Retirement Obligations [Text Block]

PacifiCorp estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work.

PacifiCorp does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. Cost of removal regulatory liabilities totaled $994 million and $955 million as of December 31, 2018 and 2017, respectively.

The following table reconciles the beginning and ending balances of PacifiCorp's ARO liabilities for the years ended December 31 (in millions):



	2018			2017

Beginning balance	$	215		$	215
Change in estimated costs	9			(8		)
Additions	—			6
Retirements	(5		)	(6		)
Accretion	8			8
Ending balance	$	227		$	215

Reflected as:
Other current liabilities	$	21		$	25
Other long-term liabilities	206			190
	$	227		$	215

Certain of PacifiCorp's decommissioning and reclamation obligations relate to jointly owned facilities and mine sites. PacifiCorp is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, PacifiCorp may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. PacifiCorp's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities.

MidAmerican Energy Company [Member]

Asset Retirement Obligations Disclosure [Line Items]

Asset Retirement Obligations [Text Block]

Asset Retirement Obligations

MidAmerican Energy estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work.

MidAmerican Energy does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $708 million and $688 million as of December 31, 2018 and 2017, respectively.

The following table presents MidAmerican Energy's ARO liabilities by asset type as of December 31 (in millions):



	2018		2017

Quad Cities Station	$	345	$	342
Fossil-fueled generating facilities	93		113
Wind-powered generating facilities	123		103
Other	1		1
Total asset retirement obligations	$	562	$	559

Quad Cities Station nuclear decommissioning trust funds⁽¹⁾	$	504	$	515


(1)	Refer to Note 6 for a discussion of the Quad Cities Station nuclear decommissioning trust funds.

The following table reconciles the beginning and ending balances of MidAmerican Energy's ARO liabilities for the years ended December 31 (in millions):



	2018			2017

Beginning balance	$	559		$	567
Change in estimated costs	(10		)	(14		)
Additions	17			8
Retirements	(28		)	(26		)
Accretion	24			24
Ending balance	$	562		$	559

Reflected as:
Other current liabilities	$	10		$	31
Asset retirement obligations	552			528
	$	562		$	559

MidAmerican Funding, LLC and Subsidiaries [Domain]

Asset Retirement Obligations Disclosure [Line Items]

Asset Retirement Obligations [Text Block]

Asset Retirement Obligations

Refer to Note 11 of MidAmerican Energy's Notes to Financial Statements.

Nevada Power Company [Member]

Asset Retirement Obligations Disclosure [Line Items]

Asset Retirement Obligations [Text Block]

Asset Retirement Obligations

Nevada Power estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work.

Nevada Power does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $320 million and $307 million as of December 31, 2018 and 2017, respectively.

The following table presents Nevada Power's ARO liabilities by asset type as of December 31 (in millions):



	2018		2017

Waste water remediation	$	37	$	39
Evaporative ponds and dry ash landfills	12		11
Asbestos	5		3
Solar	2		3
Other	27		24
Total asset retirement obligations	$	83	$	80

The following table reconciles the beginning and ending balances of Nevada Power's ARO liabilities for the years ended December 31 (in millions):



	2018			2017

Beginning balance	$	80		$	83
Change in estimated costs	11			6
Retirements	(11		)	(13		)
Accretion	3			4
Ending balance	$	83		$	80

Reflected as:
Other current liabilities	$	13		$	4
Other long-term liabilities	70			76
	$	83		$	80

In 2008, Nevada Power signed an administrative order of consent as owner and operator of Reid Gardner Generating Station Unit Nos. 1, 2 and 3 and as co-owner and operating agent of Unit No. 4. Based on the administrative order of consent, Nevada Power recorded estimated AROs and capital remediation costs. However, actual costs of work under the administrative order of consent may vary significantly once the scope of work is defined and additional site characterization has been completed. In connection with the termination of the co-ownership arrangement, effective October 22, 2013, between Nevada Power and California Department of Water Resources ("CDWR") for the Reid Gardner Generating Station Unit No. 4, Nevada Power and CDWR entered into a cost-sharing agreement that sets forth how the parties will jointly share in costs associated with all investigation, characterization and, if necessary, remedial activities as required under the administrative order of consent.

Certain of Nevada Power's decommissioning and reclamation obligations relate to jointly-owned facilities, and as such, Nevada Power is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, the respective subsidiary may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. Management has identified legal obligations to retire generation plant assets specified in land leases for Nevada Power's jointly-owned Navajo Generating Station and the Higgins Generating Station. Provisions of the lease require the lessees to remove the facilities upon request of the lessors at the expiration of the leases. Nevada Power's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities in other long-term liabilities on the Consolidated Balance Sheets.

Sierra Pacific Power Company [Member]

Asset Retirement Obligations Disclosure [Line Items]

Asset Retirement Obligations [Text Block]

Asset Retirement Obligations

Sierra Pacific estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work.

Sierra Pacific does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $210 million and $211 million as of December 31, 2018 and 2017, respectively.

The following table presents Sierra Pacific's ARO liabilities by asset type as of December 31 (in millions):



	2018		2017

Asbestos	$	5	$	5
Evaporative ponds and dry ash landfills	2		2
Other	3		3
Total asset retirement obligations	$	10	$	10

The following table reconciles the beginning and ending balances of Sierra Pacific's ARO liabilities for the years ended December 31 (in millions):



	2018		2017

Beginning balance	$	10	$	10
Retirements	—		—
Ending balance	$	10	$	10

Reflected as:
Other current liabilities	$	—	$	—
Other long-term liabilities	10		10
	$	10	$	10

Certain of Sierra Pacific's decommissioning and reclamation obligations relate to jointly-owned facilities, and as such, Sierra Pacific is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, the respective subsidiary may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. Sierra Pacific's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities in other long-term liabilities on the Balance Sheets.