Property, Plant, and Equipment

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

9. PROPERTY, PLANT, AND EQUIPMENT

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


		December 31,
thousands	Estimated Useful Life	2022		2021

Land	N/A	$	10,982	$	10,955
Gathering systems – pipelines	30 years	5,519,592		5,386,003
Gathering systems – compressors	15 years	2,266,410		2,172,953
Processing complexes and treating facilities	25 years	3,419,201		3,375,317
Transportation pipeline and equipment	4 to 48 years	174,241		169,356
Produced-water disposal systems	20 years	932,627		882,527
Assets under construction	N/A	263,353		98,473
Other	3 to 40 years	779,187		750,494
Total property, plant, and equipment		13,365,593		12,846,078
Less accumulated depreciation		4,823,993		4,333,171
Net property, plant, and equipment		$	8,541,600	$	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 impairments. During the year ended December 31, 2021, the Partnership recognized a long-lived asset impairment of $14.2 million at the DJ Basin complex due to cancellation of projects.

During the year ended December 31, 2020, the Partnership recognized a long-lived asset impairment of $150.2 million for assets located in Wyoming and Utah. These assets were impaired to estimated fair values of $112.2 million. The Partnership assesses whether events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The fair value of assets with impairment triggers were measured using the income approach and Level-3 fair value inputs. The income approach was based on the Partnership’s projected future EBITDA and free cash flows, which requires significant assumptions including, among others, future throughput volumes based on current expectations of producer activity and operating costs. These impairments were primarily triggered by reductions in estimated future cash flows resulting from lower forecasted producer throughput and lower commodity prices. The remaining long-lived asset impairments of $24.3 million were primarily at the DJ Basin complex and DBM oil system due to the cancellation of projects and impairments of rights-of-way.