NiSource unit Columbia Gas Transmission and MarkWest Energy Partners Announce Additional Plans to Expand Natural Gas Midstream Services in West Virginia

NiSource Inc. unit Columbia Gas Transmission Corp. and MarkWest Energy Partners, LP announced their intention to jointly expand natural gas gathering and processing services to support increased production volumes in the Appalachian Basin of central West Virginia.

Columbia Gas and MarkWest are in discussions with several natural gas producers regarding plans to provide new gathering and processing services near Columbia Gas’ Cobb aggregation system in Kanawha, Jackson and Roane counties of West Virginia.

The expansion includes MarkWest’s previously announced expansion of its Cobb gas plant, which will increase the total processing capacity to approximately 70 MMcf/d by mid 2009.

The natural gas liquids recovered at the Cobb gas processing plant will continue to be fractionated at MarkWest’s Siloam fractionation, marketing and storage complex, which is in the final stages of a significant expansion. The Cobb and Siloam expansions are currently under construction and require no additional capital beyond that included in MarkWest’s previously announced growth capital forecast.

The expansion would also include Columbia adding horsepower to its existing Cobb compressor station and installing new field gathering and compression facilities to bring new gas volumes to the Cobb gas processing plant. As increases in production warrant, additional capacity could be added with incremental horsepower and additional expansion of the Cobb gas processing plant.

These plans for expansion of gathering and processing services are in addition to the Columbia Gas Transmission and MarkWest announcement in August of 2008 to expand similar services near Majorsville, W.Va., serving the northern panhandle area of West Virginia and western Pennsylvania.

Producers and natural gas shippers should direct questions to Brian Blount, NiSource Gas Transmission & Storage Business Manager of Appalachian Supply and Origination, at 304-357-2626 or bblount@nisource.com.