As a result of issues generated in the ordinary course of business, DESC is involved in various regulatory matters. Certain regulatory matters may ultimately result in a loss; however, as such matters are in an initial procedural phase, involve uncertainty as to the outcome of pending reviews or orders, and/or involve significant factual issues that need to be resolved, it is not possible for DESC to estimate a range of possible loss. For regulatory matters that DESC cannot estimate, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the regulatory process such that DESC is able to estimate a range of possible loss. For regulatory matters that DESC is able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any estimated range is based on currently available information, involves elements of judgment and significant uncertainties and may not represent DESC’s maximum possible loss exposure. The circumstances of such regulatory matters will change from time to time and actual results may vary significantly from the current estimate. For current matters not specifically reported below, management does not anticipate that the outcome from such matters would have a material effect on DESC’s financial position, liquidity or results of operations.

In June 2019, DESC submitted the 2015 Task Order as a stand-alone rate schedule, which governs DESC’s provision of retail service to the DOE at the Savannah River Site. The 2015 Task Order also includes provisions that govern the operations and maintenance of certain transmission facilities, which DESC has determined to be services that are likely subject to FERC’s jurisdiction. DESC requested that the FERC accept the 2015 Task Order for filing to become effective in August 2019 and accept the refund analysis included in the filing. At June 30, 2019, DESC’s Consolidated Balance Sheets include reserves of $10 million included within revenue subject to refund for the potential refund of amounts collected under the 2015 Task Order as well as under two prior task orders commencing in 1995 and each covering ten-year periods. During the second quarter of 2019, DESC recorded a $6 million ($4 million after-tax) charge primarily within interest charges in DESC’s Consolidated Statements of Comprehensive Income (Loss). This matter is pending.

In July 2018, the South Carolina Commission issued orders implementing a legislatively-mandated temporary reduction in revenues that could be collected by DESC from customers under the BLRA. These orders reduced the portion of DESC’s retail electric rates associated with the NND Project from approximately 18% of the average residential electric customer's bill to approximately 3%, which equates to a reduction in revenues of approximately $31 million per month, retroactive to April 1, 2018. As a result, in the

second quarter of 2018 DESC recorded a charge of $109 million ($82 million after-tax) to operating revenues in DESC’s Consolidated Statements of Comprehensive Income (Loss). The temporary rate reduction remained in effect until February 2019 when rates pursuant to the SCANA Merger Approval Order became effective.

Other than the following matter, there have been no significant developments regarding the pending regulatory matters disclosed in Note 2 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2018 or Note 2 to the Consolidated Financial Statements in DESC’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2019.

In June 2019, DESC filed with the South Carolina Commission its monitoring report for the 12-month period ended March 31, 2019 with a total revenue requirement of $437 million. This represents a $7 million overall increase to its natural gas rates under the terms of the Natural Gas Rate Stabilization Act effective for the rate year beginning November 2019. This matter is pending.

Rate-regulated utilities recognize in their financial statements certain revenues and expenses in different periods than do other enterprises. As a result, DESC has recorded regulatory assets and regulatory liabilities which are summarized in the following tables. Except for NND Project costs and certain other unrecovered plant costs, substantially all regulatory assets are either explicitly excluded from rate base or are effectively excluded from rate base due to their being offset by related liabilities.

	June 30,		December 31,
(millions)	2019		2018
Regulatory assets:
NND Project costs	$	138	$	127
Deferred employee benefit plan costs		16		16
Other unrecovered plant		14		14
DSM programs		16		14
Other		75		52
Regulatory assets - current		259		223
NND Project costs		2,572		2,641
AROs		324		380
Deferred employee benefit plan costs		230		256
Deferred losses on interest rate derivatives		308		442
Other unrecovered plant		73		79
DSM programs		53		51
Environmental remediation costs		21		24
Deferred storm damage costs		34		35
Deferred transmission operating costs		27		15
Other		117		123
Regulatory assets - noncurrent		3,759		4,046
Total regulatory assets	$	4,018	$	4,269
Regulatory liabilities:
Monetization of guaranty settlement	$	67	$	61
Income taxes refundable through future rates		48		52
Reserve for refunds to electric utility customers		136		—
Other		18		13
Regulatory liabilities - current		269		126
Monetization of guaranty settlement		1,003		1,037
Income taxes refundable through future rates		826		607
Asset removal costs		552		541
Deferred gains on interest rate derivatives		77		75
Reserve for refunds to electric utility customers		813		—
Other		6		4
Regulatory liabilities - noncurrent		3,277		2,264
Total regulatory liabilities	$	3,546	$	2,390

Regulatory assets have been recorded based on the probability of their recovery. All regulatory assets represent incurred costs that may be deferred under GAAP for regulated operations. The South Carolina Commission or the FERC has reviewed and approved through specific orders certain of the items shown as regulatory assets. In addition, regulatory assets include, but are not limited to, certain costs which have not been specifically approved for recovery by one of these regulatory agencies, including deferred transmission operating costs that are the subject of regulatory proceedings discussed in Note 11. While such costs are not currently being recovered, management believes they would be allowable under existing rate-making concepts embodied in rate orders or applicable state law and expects to recover these costs through rates in future periods. In the future, as a result of deregulation, changes in state law, other changes in the regulatory environment or changes in accounting requirements or other adverse legislative or regulatory developments, DESC could be required to write off all or a portion of its regulatory assets and liabilities. Such an event could have a material effect on DESC's financial statements in the period the write-off would be recorded.

NND Project costs reflects expenditures associated with the NND Project, which pursuant to the SCANA Merger Approval Order, will be recovered from electric service customers over a 20-year period ending in 2039. See Note 11 for more information.

AROs represent deferred depreciation and accretion expense related to legal obligations associated with the future retirement of generation, transmission and distribution properties. The AROs primarily relate to DESC’s electric generating facilities, including Summer, and are expected to be recovered over the related property lives and periods of decommissioning which may range up to approximately 106 years.

Employee benefit plan costs have historically been recovered as they have been recorded under GAAP. Deferred employee benefit plan costs represent amounts of pension and other postretirement benefit costs which were accrued as liabilities and treated as regulatory assets pursuant to FERC guidance, and costs deferred pursuant to specific South Carolina Commission regulatory orders. DESC expects to recover deferred pension costs through utility rates over periods through 2044. DESC expects to recover other deferred benefit costs through utility rates, primarily over average service periods of participating employees up to 11 years.

Deferred losses or gains on interest rate derivatives represent (i) the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges and (ii) the changes in fair value and payments made or received upon settlement of certain other interest rate derivatives not so designated. The amounts recorded with respect to (i) are expected to be amortized to interest expense over the lives of the underlying debt through 2043. The amounts recorded with respect to (ii) are expected to be similarly amortized to interest expense through 2065.

Other unrecovered plant represents the carrying value of coal-fired generating units, including related materials and supplies inventory, retired from service prior to being fully depreciated. DESC is amortizing these amounts through cost of service rates over the units' previous estimated remaining useful lives through 2025. Unamortized amounts are included in rate base and are earning a current return.

DSM programs represent deferred costs associated with electric demand reduction programs, and such deferred costs are currently being recovered over five years through an approved rate rider.

Environmental remediation costs are associated with the assessment and clean-up of sites currently or formerly owned by DESC. Such remediation costs are expected to be recovered over periods of up to 16 years. See also Note 11.

Deferred storm damage costs represent storm restoration costs for which DESC expects to receive future recovery through customer rates.

Deferred transmission operating costs includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects recovery from customers through future rates. See also Note 11.

Various other regulatory assets are expected to be recovered through rates over varying periods through 2047.

Monetization of guaranty settlement represents proceeds related to the monetization of the Toshiba Settlement. In accordance with the SCANA Merger Approval Order, this balance, net of amounts that may be required to satisfy certain liens, will be refunded to electric customers over a 20-year period ending in 2039. See Note 11.

Income taxes refundable through future rates includes (i) excess deferred income taxes arising from the remeasurement of deferred income taxes in connection with the enactment of the 2017 Tax Reform Act (certain of which are protected under normalization rules and will be amortized over the remaining lives of related property, and certain of which will be amortized to the benefit of customers over prescribed periods as instructed by regulators) and (ii) deferred income taxes arising from investment tax credits, offset by (iii) deferred income taxes that arise from utility operations that have not been included in customer rates (a portion of which relate to depreciation and are expected to be recovered over the remaining lives of the related property which may range up to 85 years). See also Note 6.

Reserve for refunds to electric utility customers reflects amounts previously collected from retail electric customers of DESC for the NND Project to be credited to customers over an estimated 11-year period in connection with the SCANA Merger Approval Order. See Note 11.

Asset removal costs represent estimated net collections through depreciation rates of amounts to be expended for the removal of assets in the future.