The Federal Energy Regulatory Commission on Thursday denied a rehearing request submitted by Gunpowder Riverkeeper and the Woodstock Residents, who had objected to the Commission's Nov. 21, 2013 order granting Columbia Gas Transmission authority to construct and operate pipeline facilities in Baltimore and Harford counties in Maryland (see Daily GPI, Nov. 25, 2013). The groups "make no showing that they will be irreparably harmed" by the project, Commissioners said in their order. The Line MB Expansion is part of a system-wide, approximately $2 billion, five-year modernization program designed to improve Columbia's aging infrastructure. The expansion calls for the phased construction of approximately 21.1 miles of 26-inch diameter pipeline from the current terminus of Columbia's existing Line MB in Baltimore County to the existing Rutledge Compressor Station in Hartford County and associated facilities. The project, which the company estimates will cost about $132 million, is expected to be placed into service by the end of this year.