PROPERTY, PLANT AND EQUIPMENT

6 Months Ended

Jun. 30, 2020

Property, Plant and Equipment [Abstract]

The following table sets forth the Partnership’s property, plant and equipment:


		As of
	Estimated	June 30,		December 31,
	Useful Lives	2020		2019
	(Years)	(In thousands)
Produced water disposal systems	10-30	$	678,883	$	600,797
Crude oil gathering systems⁽¹⁾	30	133,856		129,658
Natural gas gathering and compression systems⁽¹⁾	10-30	113,045		98,426
Sourced water gathering systems⁽¹⁾	30	111,480		101,887
Total property, plant and equipment		1,037,264		930,768
Less: accumulated depreciation, amortization and accretion		(81,572)		(61,132)
Land	N/A	88,309		88,509
Total property, plant and equipment, net		$	1,044,001	$	958,145

(1)Included in gathering systems are $83.5 million and $138.6 million of assets at June 30, 2020 and December 31, 2019, respectively, that are not subject to depreciation, amortization and accretion as the systems were under construction and had not yet been put into service.

Depreciation expense related to property, plant and equipment was $10.0 million and $8.2 million for the three months ended June 30, 2020 and 2019, respectively. Depreciation expense related to property, plant and equipment was $20.5 million and $16.2 million for the six months ended June 30, 2020 and 2019, respectively.

Internal costs capitalized to property, plant and equipment represent management’s estimate of costs incurred directly related to construction activities. Capitalized internal costs were immaterial for the six months ended June 30, 2020 and 2019.

Capitalized interest related to property, plant and equipment was immaterial for the six months ended June 30, 2020 and 2019.

The Partnership evaluates its long-lived assets for potential impairment whenever events or circumstances indicate it is more likely than not that the carrying amount of the asset, or set of assets, is greater than the fair value. An impairment involves comparing the estimated future undiscounted cash flows of an asset with the carrying amount. If the carrying amount of the asset exceeds the estimated future undiscounted cash flows, then an impairment charge is recorded for the difference between the estimated fair value of the asset and its carrying value. No impairment charges were recorded during the three and six months ended June 30, 2020. Given the rate of change impacting the oil and natural gas industry described above, it is possible that circumstances requiring additional impairment testing will occur in future interim periods, which could result in potentially material impairment charges being recorded.