Regulated Operations (Tables)

12 Months Ended

Dec. 31, 2015

Our regulatory assets and liabilities reflected within our Consolidated Balance Sheets as of December 31 are summarized in the following table.



In millions	2015		2014
Regulatory assets
Recoverable ERC	$	31	$	49
Recoverable pension and retiree welfare benefit costs	12		12
Recoverable seasonal rates	10		10
Deferred natural gas costs	6		3
Other	9		9
Regulatory assets - current	68		83
Recoverable ERC	370		329
Recoverable pension and retiree welfare benefit costs	113		110
Recoverable regulatory infrastructure program costs	83		69
Long-term debt fair value adjustment	66		74
Other	38		49
Regulatory assets - long-term	670		631
Total regulatory assets	$	738	$	714
Regulatory liabilities
Accumulated removal costs	$	53	$	25
Bad debt over collection	42		33
Accrued natural gas costs	24		27
Other	15		27
Regulatory liabilities - current	134		112
Accumulated removal costs	1,538		1,520
Regulatory income tax liability	27		34
Bad debt over collection	21		12
Unamortized investment tax credit	20		22
Other	5		13
Regulatory liabilities - long-term	1,611		1,601
Total regulatory liabilities	$	1,745	$	1,713

Environmental Exit Costs by Cost

The following table provides additional information on the estimated costs to remediate our current and former operating sites as of December 31, 2015.



In millions	# of sites	Probabilistic model cost estimates ⁽¹⁾	Engineering-based estimates ⁽¹⁾		Amount recorded		Expected costs over next 12 months		Cost recovery period
Illinois ⁽²⁾	26	$200 - $457	$	50	$	250	$	32	As incurred
New Jersey	6	115 - 195	7		122		18		7 years
Georgia and Florida	13	29 - 52	23		52		12		5 years
North Carolina ⁽³⁾	1	n/a	7		7		5		No recovery
Total	46	$344 - $704	$	87	$	431	$	67


(1)	The year-end ERC cost estimates were completed as of November 30, 2015. The liability recorded reflects a reduction of these cost estimates for expenses incurred during December.


(2)	Nicor Gas is responsible in whole or in part for 26 MGP sites, two of which have been remediated and their use is no longer restricted by the environmental condition of the property. Nicor Gas and Commonwealth Edison Company are parties to an agreement to cooperate in cleaning up residue at 23 of the sites. Nicor Gas’ allocated share of cleanup costs for these sites is 52%.


(3)	We have no regulatory recovery mechanism for the site in North Carolina and there is no amount included within our regulatory assets. Changes in estimated costs are recognized in income during the period of change.

Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets

The actual bad debt experience and resulting refunds are shown in the following table.



			Actual		Total		Amount refunded in				Amount to be refunded in
In millions	Benchmark		bad debt		refund		2014		2015		2016		2017
2015	$	63	$	12	$	51	$	—	$	—	$	30	$	21
2014	63		35		28		—		16		12		—
2013	63		21		42		25		17		—		—

Regulatory Asset Off Balance Sheet [Member]

Regulated Operations [Line Items]

Schedule of Regulatory Assets

The following table illustrates our authorized ratemaking amounts that are not recognized on our Consolidated Balance Sheets. These amounts are primarily composed of an allowed equity rate of return on assets associated with certain of our regulatory infrastructure programs. These amounts will be recognized as revenues in our financial statements in the periods they are billable to our customers.



In millions	Atlanta Gas Light			Virginia Natural Gas		Elizabethtown Gas		Nicor Gas		Total
December 31, 2015	$	103	⁽¹⁾	$	12	$	4	$	3	$	122
December 31, 2014	113			12		2		—		127

(1)

In October 2015, Atlanta Gas Light received an order from the Georgia Commission, which included a final determination of the true-up recovery related to the PRP. The order allows Atlanta Gas Light to recover $144 million of the $178 million of incurred and allowed costs that were deferred for future recovery. These deferred costs were originally requested in a February 2015 filing for a true-up of unrecovered revenue. See Note 12 for additional information on Atlanta Gas Light's global resolution of this and other matters that were previously raised before the Georgia Commission.