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, 2014 and 2013 are:



(Thousands of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2014				Dec. 31, 2013
Regulatory Assets			Current		Noncurrent		Current		Noncurrent
Environmental remediation costs	1, 11	Various	$	4,376	$	147,793	$	4,376	$	117,684
Pension and retiree medical obligations ^(a)	7	Various	6,837		91,601		8,202		85,220
Recoverable deferred taxes on AFUDC recorded in plant	1	Plant lives	—		16,711		—		12,679
Losses on reacquired debt	4	Term of related debt	801		4,936		801		5,737
State commission adjustments	1	Plant lives	488		11,650		410		9,355
Conservation programs	1	Less than one year	—		—		404		—
Deferred income tax adjustment	1, 6	Typically plant lives	—		1,514		—		1,763
Recoverable purchased natural gas and electric energy costs		Less than one year	6,946		—		673		—
Monticello EPU		Pending rate cases	—		5,237		—		—
Other		Various	588		1,251		—		755
Total regulatory assets			$	20,036	$	280,693	$	14,866	$	233,193


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

The components of regulatory liabilities shown on the consolidated balance sheets of NSP-Wisconsin at Dec. 31, 2014 and 2013 are:



(Thousands of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2014				Dec. 31, 2013
Regulatory Liabilities			Current		Noncurrent		Current		Noncurrent
Plant removal costs	11	Plant lives	$	—	$	123,105	$	—	$	116,293
DOE settlement	11	Less than one year	4,931		—		6,814		—
Investment tax credit deferrals	1, 6	Various	—		9,397		—		9,976
Conservation programs	1	Less than one year	1,010		—		1,187		—
Deferred electric production and natural gas costs	1	Less than one year	—		—		1,542		—
Excess depreciation reserve		Various	10,999		—		—		—
Other		Various	—		172		174		155
Total regulatory liabilities			$	16,940	$	132,674	$	9,717	$	126,424

At Dec. 31, 2014 and 2013, approximately $12.1 million and $0.1 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.