▁Som er ville ▁to ▁offset ▁the ▁additional ▁bur dens ▁in ▁traffic ▁and ▁poll ution ▁within ▁the ▁city ▁due ▁to ▁completion ▁of ▁the ▁Big ▁Dig ▁project . ▁The ▁current ▁phase ▁of ▁planning ▁began ▁in ▁ 2 0 0 5 ▁with ▁the ▁completion ▁of ▁the ▁MB TA ' s ▁" B ey ond ▁Le ch m ere ▁North west ▁Cor rid or ▁Study ▁Major ▁In vest ment ▁Study / Al tern atives ▁Analysis ". ▁ ▁Despite ▁this ▁legal ▁commit ment , ▁however , ▁the ▁Green ▁Line ▁Ext ension ▁project ▁lag ged ▁far ▁behind ▁schedule , ▁prompt ing ▁the ▁City ▁of ▁Som er ville ▁and ▁the ▁Conserv ation ▁Law ▁Foundation ▁to ▁file ▁a ▁law suit ▁to ▁keep ▁the ▁project ▁moving . ▁In ▁ 2 0 0 6 , ▁this ▁lit ig ation , ▁with ▁the ▁help ▁of ▁community ▁support ▁and ▁advoc acy ▁groups ▁such ▁as ▁Som er ville ▁Transport ation ▁Equ ity ▁Part ners hip ▁( ST EP ) ▁and ▁the ▁Union ▁Square ▁Task ▁Force , ▁finally ▁brought ▁about ▁a ▁mult im ill ion - d ollar ▁state ▁invest ment ▁in ▁planning ▁for ▁the ▁Green ▁Line ▁Ext ension ▁with ▁mand ated ▁completion ▁date ▁of ▁December ▁ 2 0 1 4 . ▁Pot ential ▁station ▁stops ▁were ▁announced ▁for ▁the ▁first ▁time ▁in ▁May ▁ 2 0 0 8 . ▁In ▁May ▁ 2 0 1 0 , ▁Mass D OT ▁and ▁the ▁City ▁of ▁Som er ville ▁reached ▁an ▁agreement ▁to ▁re loc ate ▁the ▁planned ▁maintenance ▁facility ▁further ▁into ▁the ▁industrial ▁Inner ▁B elt ▁District