Asset Retirement Obligations

12 Months Ended

Dec. 31, 2018

Asset Retirement Obligation Disclosure [Abstract]

MPLX’s assets subject to AROs are primarily certain gas-gathering pipelines and processing facilities, a crude oil pipeline and other related pipeline assets. MPLX also has land leases that require MPLX to return the land to its original condition upon termination of the lease. MPLX reviews current laws and regulations governing obligations for asset retirements and leases, as well as MPLX’s leases and other agreements.

The following is a reconciliation of the changes in the ARO from January 1, 2017 to December 31, 2018:



(In millions)	2018		2017
AROs at beginning of period	$	28	$	25
Liabilities incurred	1		2
Accretion expense	1		1
AROs at end of period	$	30	$	28

At December 31, 2018 and 2017, there were no assets legally restricted for purposes of settling AROs. The AROs have been recorded as part of “Deferred credits and other liabilities” on the accompanying Consolidated Balance Sheets.

In addition to recorded AROs, MPLX has other AROs related to certain gathering, processing and other assets as a result of environmental and other legal requirements. MPLX is not required to perform such work until it permanently ceases operations of the respective assets. Because MPLX considers the operational life of these assets to be indeterminable, an associated ARO cannot be estimated and is not recorded.