The joint venture includes Los Angeles-based AECOM, which was awarded a contract earlier this week by Denver's Regional Transit District, and HNTB Corp., of Kansas City, Mo.
The $1.3 billion extension also would include a revamped Lechmere Station in East Cambridge, Mass., the current northern terminus for Green Line light rail service. At least five new stations also are planned on the 6.1-mile main extension, with a sixth at Union Square on the Somerville spur.
Transportation Secretary Richard Davey acknowledges that the state does not yet know how it would fund the entire project, though state officials earlier have indicated the hope that federal New Starts funding would provide at least 40% of the projected cost. "There continues to be a long-term financing challenge for both the DOT and the MBTA," Davey said.
Delayed several times over many years, the Green Line extension is a court-mandated requirement as part of a settlement of a lawsuit brought by the Conservation Law Foundation. CLF filed the suit challenging the construction of Boston's Central Artery/Tunnel Project, known informally as the "Big Dig," a $14.6 billion highway project completed in late 2007.