REGULATORY ASSETS, LIABILITIES, AND BALANCING ACCOUNTS

Regulatory Assets and Liabilities

Long-Term Regulatory Assets

Long-term regulatory assets are comprised of the following:



	Asset Balance at
(in millions)	June 30, 2018		December 31, 2017
Pension benefits	$	1,877	$	1,954
Environmental compliance costs	784		837
Utility retained generation	297		319
Price risk management	63		65
Unamortized loss, net of gain, on reacquired debt	84		79
Catastrophic event memorandum account ⁽¹⁾	654		274
Wildfire expense memorandum account ⁽²⁾	69		—
Other	293		265
Total long-term regulatory assets	$	4,121	$	3,793

⁽¹⁾ Represents costs related to certain catastrophic events that the Utility believes are probable of recovery. For more information, see Note 9 below.

⁽²⁾Represents costs related to insurance premiums that the Utility believes are probable of recovery. For more information, see Note 9 below.

Long-Term Regulatory Liabilities

Long-term regulatory liabilities are comprised of the following:



	Liability Balance at
(in millions)	June 30, 2018		December 31, 2017
Cost of removal obligations	$	5,775	$	5,547
Deferred income taxes	611		1,021
Recoveries in excess of AROs	467		624
Public purpose programs	636		590
Other	1,009		897
Total long-term regulatory liabilities	$	8,498	$	8,679

For more information, see Note 3 of the Notes to the Consolidated Financial Statements in Item 8 of the 2017 Form 10-K.

Regulatory Balancing Accounts

Current regulatory balancing accounts receivable and payable are comprised of the following:



	Receivable Balance at
(in millions)	June 30, 2018		December 31, 2017
Electric distribution	$	323	$	—
Electric transmission	110		139
Utility generation	120		—
Gas distribution and transmission	397		486
Energy procurement	95		71
Public purpose programs	32		103
Other	486		423
Total regulatory balancing accounts receivable	$	1,563	$	1,222



	Payable Balance at
(in millions)	June 30, 2018		December 31, 2017
Electric distribution	$	—	$	72
Electric transmission	120		120
Utility generation	—		14
Energy procurement	151		149
Public purpose programs	513		452
Other	519		313
Total regulatory balancing accounts payable	$	1,303	$	1,120

For more information, see Note 3 of the Notes to the Consolidated Financial Statements in Item 8 of the 2017 Form 10-K.