Property, Plant and Equipment

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

7.  PROPERTY, PLANT AND EQUIPMENT

A summary of the historical cost of property, plant and equipment is as follows:

		December 31,
thousands	Estimated Useful Life	2016		2015
Land	n/a	$	4,012	$	3,744
Gathering systems and processing complexes	3 to 47 years	6,462,053		6,061,004
Pipelines and equipment	15 to 45 years	139,646		136,290
Assets under construction	n/a	226,626		329,887
Other	3 to 40 years	29,605		25,853
Total property, plant and equipment		6,861,942		6,556,778
Accumulated depreciation		1,812,010		1,697,999
Net property, plant and equipment		$	5,049,932	$	4,858,779

The cost of property classified as “Assets under construction” is excluded from capitalized costs being depreciated. These amounts represent property that is not yet suitable to be placed into productive service as of the respective balance sheet date.

Impairments. As of December 31, 2016, net property, plant and equipment includes impairments of $15.5 million. WES recognized an impairment of $6.1 million at WES’s Newcastle system, which was impaired to its estimated fair value of $3.1 million, using the income approach and Level 3 fair value inputs, due to a reduction in estimated future cash flows caused by the low commodity price environment. Also during 2016, WES recognized impairments of $9.4 million, primarily related to the cancellation of projects at the DJ Basin complex and Springfield and DBJV systems, and the abandonment of compressors at the MIGC system.

During 2015, WES recognized impairments of $515.5 million, primarily due to impairments of $280.2 million at the Red Desert complex and $220.9 million at the Hilight system. Using the income approach and Level 3 fair value inputs, the Red Desert complex was impaired to its estimated salvage value of $6.3 million and the Hilight system was impaired to its estimated fair value of $28.8 million. These impairments were triggered by a reduction in estimated future cash flows caused by the low commodity price environment and resulting reduced producer drilling activity and related throughput. Also during 2015, WES recognized impairments of $14.4 million, primarily due to (i) the abandonment of compressors at the MIGC system and (ii) the cancellation of projects at the Non-Operated Marcellus Interest systems and the Brasada, Red Desert and DJ Basin complexes.

During 2014, WES recognized impairments of $5.1 million, primarily related to (i) a non-operational plant in the Powder River Basin that was impaired to its estimated salvage value of $2.4 million, using the income approach and Level 3 fair value inputs, (ii) the cancellation of various capital projects by the third-party operator of the Non-Operated Marcellus Interest systems and (iii) a compressor no longer in service at the Hilight system.