MARKWEST GAS SERVICES, L.L.C. — Integrity Assurance Notification

PROGRAMThe sale of the Markwest Javelina Processing Facility and associated pipelines as publicly released operates under the following OPID’s (39924, 09171, 39926) and results in a change that meets the requirements of 195.64 (c)(2)(i),(ii),(iii) and (v) for the associated liquid pipelines subject to notification to PHMSA and which resulted in a substantial change under 192.909 for the associated natural gas and hydrogen pipelines by the divesture of these pipelines reducing the HCA mileage of the MPLX G&P (Markwest) gas transmission pipeline system by 43%, a reduction greater than 25% is considered a significant change to our Integrity Management Plan and requires notification to PHMSA per 192.909.”#