Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Environmental Obligations Recognized by Company

The following table sets forth a summary of changes in the Company’s liability for Environmental Obligations for the years ended December 31, 2017 and 2016.

Environmental Obligations

	(millions)
	Fitchburg				Northern Utilities				Total
	2017		2016		2017		2016		2017		2016
Total Balance at Beginning of Period	$	0.1	$	1.2	$	1.8	$	1.6	$	1.9	$	2.8
Additions		—		—		0.4		1.8		0.4		1.8
Less: Payments / Reductions		—		1.1		0.2		1.6		0.2		2.7
Total Balance at End of Period	$	0.1	$	0.1	$	2.0	$	1.8	$	2.1	$	1.9
Less: Current Portion		—		0.1		0.5		0.3		0.5		0.4
Noncurrent Balance at December 31,	$	0.1	$	—	$	1.5	$	1.5	$	1.6	$	1.5