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)	September 30, 2018		December 31, 2017
Pension benefits	$	1,837	$	1,954
Environmental compliance costs	851		837
Utility retained generation	285		319
Price risk management	67		65
Unamortized loss, net of gain, on reacquired debt	80		79
Catastrophic event memorandum account ⁽¹⁾	760		274
Wildfire expense memorandum account ⁽²⁾	77		—
Fire hazard prevention memorandum account ⁽³⁾	65		1
Other	407		264
Total long-term regulatory assets	$	4,429	$	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.

⁽³⁾Represents costs related to wildfire prevention vegetation management work that the Utility believes are probable of recovery.

Long-Term Regulatory Liabilities

Long-term regulatory liabilities are comprised of the following:



	Liability Balance at
(in millions)	September 30, 2018		December 31, 2017
Cost of removal obligations	$	5,888	$	5,547
Deferred income taxes	437		1,021
Recoveries in excess of AROs	489		624
Public purpose programs	660		590
Other	1,133		897
Total long-term regulatory liabilities	$	8,607	$	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)	September 30, 2018		December 31, 2017
Electric distribution	$	31	$	—
Electric transmission	109		139
Gas distribution and transmission	624		486
Energy procurement	131		71
Public purpose programs	120		103
Other	311		423
Total regulatory balancing accounts receivable	$	1,326	$	1,222



	Payable Balance at
(in millions)	September 30, 2018		December 31, 2017
Electric distribution	$	—	$	72
Electric transmission	132		120
Utility generation	70		14
Gas distribution and transmission	9		—
Energy procurement	69		149
Public purpose programs	588		452
Other	362		313
Total regulatory balancing accounts payable	$	1,230	$	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.