
12.	Regulatory Assets and Liabilities

NSP-Wisconsin’s consolidated financial statements are prepared in accordance with the applicable accounting guidance, as discussed in Note 1. Under this guidance, regulatory assets and liabilities are created for amounts that regulators may allow to be collected, or may require to be paid back to customers in future electric and natural gas rates. Any portion of the business that is not rate regulated cannot establish regulatory assets and liabilities. If changes in the utility industry or the business of NSP-Wisconsin no longer allow for the application of regulatory accounting guidance under GAAP, NSP-Wisconsin would be required to recognize the write-off of regulatory assets and liabilities in net income or OCI.

The components of regulatory assets shown on the consolidated balance sheets of NSP-Wisconsin at Dec. 31, 2016 and 2015 are:



(Thousands of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2016				Dec. 31, 2015
Regulatory Assets			Current		Noncurrent		Current		Noncurrent
Environmental remediation costs	1, 11	Various	$	10,669	$	148,880	$	6,702	$	160,699
Pension and retiree medical obligations ^(a)	7	Various	5,989		93,160		6,415		86,778
Recoverable deferred taxes on AFUDC recorded in plant	1	Plant lives	—		22,345		—		20,586
State commission adjustments	1	Plant lives	703		14,008		724		12,945
Losses on reacquired debt	4	Term of related debt	801		3,333		803		4,134
Deferred income tax adjustment	1, 6	Typically plant lives	—		2,078		—		2,250
Other		Various	—		2,384		1,502		1,804
Total regulatory assets			$	18,162	$	286,188	$	16,146	$	289,196


^(a)	Includes the non-qualified pension plan.

The components of regulatory liabilities shown on the consolidated balance sheets of NSP-Wisconsin at Dec. 31, 2016 and 2015 are:



(Thousands of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2016				Dec. 31, 2015
Regulatory Liabilities			Current		Noncurrent		Current		Noncurrent
Plant removal costs	11	Plant lives	$	—	$	139,735	$	—	$	132,311
Investment tax credit deferrals	1, 6	Various	—		8,342		—		8,869
Deferred electric production and natural gas costs	1	Less than one year	11,377		—		9,386		—
DOE settlement	11	Less than one year	4,822		—		1,996		—
Conservation programs	1	Less than one year	1,122		—		339		—
Other		Various	107		112		60		109
Total regulatory liabilities			$	17,428	$	148,189	$	11,781	$	141,289

At Dec. 31, 2016 and 2015, approximately $0 million and $1 million of NSP-Wisconsin’s regulatory assets represented past expenditures not currently earning a return, respectively. This amount primarily includes Monticello EPU costs and recoverable purchased natural gas and electric energy costs.