NiSource Midstream Services LLC‘s Big Pine Gathering System in the heart of the Marcellus Shale has begun serving XTO Energy Inc. under a long-term agreement. The 57-mile, 20- and 24-inch diameter system stretches into Pennsylvania’s Allegheny, Butler, Armstrong, Indiana and Westmoreland counties and interconnects to the Columbia Gas Transmission system, as well as Texas Eastern Transmission and Dominion Transmission. The system is anchored by XTO; a separate gathering agreement was recently signed with PennEnergy.