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, 2015 and 2014 are:



(Thousands of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2015				Dec. 31, 2014
Regulatory Assets			Current		Noncurrent		Current		Noncurrent
Environmental remediation costs	1, 11	Various	$	6,702	$	160,699	$	4,376	$	147,793
Pension and retiree medical obligations ^(a)	7	Various	6,415		86,778		6,837		91,601
Recoverable deferred taxes on AFUDC recorded in plant	1	Plant lives	—		20,586		—		16,711
State commission adjustments	1	Plant lives	724		12,945		488		11,650
Losses on reacquired debt	4	Term of related debt	803		4,134		801		4,936
Deferred income tax adjustment	1, 6	Typically plant lives	—		2,250		—		1,514
Recoverable purchased natural gas and electric energy costs		Less than one year	1,032		—		6,946		—
Monticello EPU		N/A	—		—		—		5,237
Other		Various	470		1,804		588		1,251
Total regulatory assets			$	16,146	$	289,196	$	20,036	$	280,693


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

The components of regulatory liabilities shown on the consolidated balance sheets of NSP-Wisconsin at Dec. 31, 2015 and 2014 are:



(Thousands of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2015				Dec. 31, 2014
Regulatory Liabilities			Current		Noncurrent		Current		Noncurrent
Plant removal costs	11	Plant lives	$	—	$	132,311	$	—	$	123,105
Investment tax credit deferrals	1, 6	Various	—		8,869		—		9,397
Deferred electric production and natural gas costs	1	Less than one year	9,386		—		—		—
DOE settlement	11	One to two years	1,996		—		4,931		—
Conservation programs	1	Less than one year	339		—		1,010		—
Excess depreciation reserve		Less than one year	60		—		10,999		—
Other		Various	—		109		—		172
Total regulatory liabilities			$	11,781	$	141,289	$	16,940	$	132,674

At Dec. 31, 2015 and 2014, approximately $1.0 million and $12.1 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.