Inventory

Inventory consists of natural gas held in storage for transmission and processing, and also includes materials and supplies. The NGLs previously included in inventory were disposed of as part of the Empress sale on August 4, 2016. See Note 2 for further discussion related to the sale of Empress. Natural gas inventories primarily relate to the Distribution segment in Canada and are valued at costs approved by the OEB. The difference between the approved price and the actual cost of gas purchased is recorded as either a receivable or a current liability, as appropriate, for future disposition with customers, subject to approval by the OEB. The remaining inventory is recorded at the lower of cost or market, primarily using average cost. The components of inventory are as follows:



	September 30, 2016		December 31, 2015
	(in millions)
Natural gas	$	214	$	217
NGLs	—		23
Materials and supplies	73		67
Total inventory	$	287	$	307