Property, Plant and Equipment

12 Months Ended

Dec. 31, 2015

Property Plant And Equipment [Abstract]

Property, Plant and Equipment

Note 4: Property, Plant and Equipment

The following table summarizes the major classes of property, plant and equipment by category as of December 31:

					Range of Remaining	Weighted Average
	2015		2014		Useful Lives	Useful Life
Utility plant:
Land and other non-depreciable assets	$	141	$	137
Sources of supply		705		681	12 to 127 Years	51 Years
Treatment and pumping facilities		3,070		2,969	3 to 101 Years	39 Years
Transmission and distribution facilities		8,516		7,963	9 to 156 Years	83 Years
Services, meters and fire hydrants		3,250		3,062	8 to 93 Years	35 Years
General structures and equipment		1,227		1,096	1 to 154 Years	39 Years
Waste treatment, pumping and disposal		313		281	2 to 115 Years	46 Years
Waste collection		473		399	5 to 109 Years	56 Years
Construction work in progress		404		303
Total utility plant		18,099		16,891
Nonutility property		405		378	3 to 50 years	6 Years
Total property, plant and equipment	$	18,504	$	17,269

Property, plant and equipment depreciation expense amounted to $405, $392, and $374 for the years ended December 31, 2015, 2014 and 2013, respectively and was included in depreciation and amortization expense in the accompanying Consolidated Statements of Operations. The provision for depreciation expressed as a percentage of the aggregate average depreciable asset balances was 3.13% for the year ended December 31, 2015 and 3.20% for years December 31, 2014 and 2013.