Property, Plant, and Equipment

9 Months Ended

Sep. 30, 2022

Property, Plant and Equipment [Abstract]

Property, Plant, and Equipment

8. PROPERTY, PLANT, AND EQUIPMENT

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

thousands	Estimated Useful Life	September 30, 2022		December 31, 2021
Land	N/A	$	10,983	$	10,955
Gathering systems – pipelines	30 years	5,466,010		5,386,003
Gathering systems – compressors	15 years	2,247,871		2,172,953
Processing complexes and treating facilities	25 years	3,413,159		3,375,317
Transportation pipeline and equipment	4 to 48 years	172,256		169,356
Produced-water disposal systems	20 years	912,599		882,527
Assets under construction	N/A	228,418		98,473
Other	3 to 40 years	785,203		750,494
Total property, plant, and equipment		13,236,499		12,846,078
Less accumulated depreciation		4,696,816		4,333,171
Net property, plant, and equipment		$	8,539,683	$	8,512,907

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

Long-lived asset and other impairments. During the nine months ended September 30, 2021, the Partnership recognized impairments of $29.2 million, primarily attributable to (i) $14.1 million of impairments at the DJ Basin complex due to cancellation of projects and (ii) an $11.8 million other-than-temporary impairment of the Partnership’s investment in Ranch Westex (see Note 7).