State-level environmental review (MEPA) was completed in July 2010. Federal-level environmental review (NEPA) documents were submitted to FTA in September 2011, and a public hearing was held on October 20, 2011 (to accompany a 45-day public comment period).
A Finding of No Significant Impact (FONSI) was issued by FTA on July 9, 2012. The July 2012 issuance of the FONSI completed the federal-level environmental review process. Federal environmental clearance is the culmination of several years of technical work done by MassDOT and the MBTA with close cooperation from the Cities of Cambridge, Somerville, and Medford, as well as the participation of hundreds of individuals and local organizations.