Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2018

Summary of Significant Accounting Policies

Schedule of investment in property and equipment

Our investment in property and equipment as of the dates presented was as follows (in thousands):

	Estimated	December 31,		September 30,
	useful lives	2017		2018
Land	n/a	$	15,382		18,649
Gathering systems and facilities	20 years		1,781,386		2,075,542
Fresh water permanent buried pipelines and equipment	20 years		472,810		510,374
Wastewater treatment facility	30 years		—		299,567
Fresh water surface pipelines and equipment	5 years		46,139		61,865
Landfill	n/a(1)		—		58,318
Heavy trucks and equipment	5 years		—		4,831
Above ground storage tanks	10 years		4,301		4,824
Construction-in-progress(2)	n/a		654,904		316,545
Total property and equipment			2,974,922		3,350,515
Less accumulated depreciation			(369,320)		(476,641)
Property and equipment, net		$	2,605,602		2,873,874

(1)   Amortization of landfill costs is recorded over the life of the landfill on a units-of-consumption basis.

(2)   As of December 31, 2017, construction-in-progress included $355 million for the construction of the wastewater treatment facility and landfill, which was placed in service in May 2018.