Note 4: Utility Plant

The components of utility plant by category at December 31 are as follows:


	Range of Remaining Useful Lives		2012		2011
Water plant
Land and other non-depreciable assets			$	129,953	$	128,286
Sources of supply		16 to 147 Years		623,015		565,301
Treatment and pumping facilities		3 to 101 Years		2,944,178		2,665,525
Transmission and distribution facilities		5 to 120 Years		7,033,958		6,632,828
Services, meters and fire hydrants		9 to 93 Years		2,729,679		2,539,696
General structures and equipment		3 to 112 Years		865,992		693,880
Wastewater plant		2 to 115 Years		565,894		546,002
Construction work in progress				349,496		460,529

				15,242,165		14,232,047
Less accumulated depreciation				3,657,221		3,360,005

			$	11,584,944	$	10,872,042

Utility plant depreciation expense of continuing operations amounted to $314,639 in 2012, $268,987 in 2011 and $250,107 in 2010. The Company’s regulated utility subsidiaries record depreciation in conformity with amounts approved by state regulators after regulatory review of information the Company submits to support its estimates of the assets’ remaining useful lives.

The provision for depreciation expressed as a percentage of the aggregate average depreciable asset balances was 2.94% in 2012, 2.68% in 2011, and 2.62% in 2010, respectively.