MarkWest Energy Partners, L.P. (NYSE: MWE) (MarkWest) today provided information regarding an August 2013 landslide which impacted a MarkWest natural gas liquids (NGLs) pipeline in a remote area of northern Wetzel County, West Virginia, causing a line break. The landslide originated from significant erosion and run-off from heavy rainfall. MarkWest shut down the pipeline and immediately commenced repairs and remediation of the impacted portions of the pipeline. Repairs and remediation to the pipeline and rights of way in the landslide impacted areas are currently underway, and MarkWest is diligently working to complete the remedial work and return the pipeline to service. The pipeline and the Mobley processing facilities will remain shut down until the pipeline remedial work is completed, which is expected to be approximately mid-October. The Sherwood processing facility continues to operate at curtailed levels and NGLs from that facility are being transported by truck for fractionation and sale. No other MarkWest facility has been impacted. MarkWest does not expect the shutdown of these facilities to have a material impact on its financial results. MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of natural gas liquids; and the gathering and transportation of crude oil. MarkWest has a leading presence in many unconventional gas plays including the Marcellus Shale, Utica Shale, Huron/Berea Shale, Haynesville Shale, Woodford Shale and Granite Wash formation. This press release includes “forward-looking statements.” All statements other than statements of historical facts included or incorporated herein may constitute forward-looking statements. Actual results could vary significantly from those expressed or implied in such statements and are subject to a number of risks and uncertainties. Although MarkWest believes that the expectations reflected in the forward-looking statements are reasonable, MarkWest can give no assurance that such expectations will prove to be correct. The forward-looking statements involve risks and uncertainties that affect operations, financial performance, and other factors as discussed in filings with the Securities and Exchange Commission (SEC). Among the factors that could cause results to differ materially are those risks discussed in the periodic reports filed with the SEC, including MarkWest’s Annual Report on Form 10-K for the year ended December 31, 2012 and our Quarterly Report on Form 10-Q for the quarter ended June 30, 2013. You are urged to carefully review and consider the cautionary statements and other disclosures made in those filings, specifically those under the heading “Risk Factors.” MarkWest does not undertake any duty to update any forward-looking statement except as required by law.