▁clean up ▁costs ▁at ▁the ▁site , ▁begin ▁construction ▁by ▁the ▁spring ▁of ▁ 2 0 1 4 ▁and ▁open ▁the ▁station ▁no ▁later ▁than ▁early ▁ 2 0 1 7 . ▁In ▁October ▁ 2 0 1 2 , ▁the ▁Som er ville ▁Board ▁of ▁Ald erm en ▁approved ▁the ▁Union ▁Square ▁R ede velop ment ▁Plan ▁and ▁author ized ▁an ▁$ 8 ▁million ▁bond , ▁including ▁$ 6 ▁million ▁to ▁purchase ▁the ▁land ▁and ▁$ 2 ▁million ▁for ▁clean up ▁and ▁station ▁planning . ▁ ▁In ▁December ▁ 2 0 1 4 , ▁the ▁F TA ▁said ▁it ▁intended ▁to ▁pay ▁$ 9 9 6 ▁million ▁of ▁the ▁extension ' s ▁$ 2 . 2 ▁billion ▁costs . ▁The ▁remainder ▁of ▁exp enses ▁will ▁be ▁paid ▁by ▁the ▁state , ▁from ▁either ▁its ▁operating ▁funds ▁or ▁b onds . ▁On ▁April ▁ 1 8 , ▁ 2 0 1 4 , ▁Governor ▁Patrick ▁signed ▁a ▁$ 1 2 . 7 ▁billion ▁bond ing ▁bill ▁which ▁included ▁$ 1 . 3 ▁billion ▁for ▁the ▁Green ▁Line ▁Ext ension , ▁as ▁well ▁as ▁$ 2 . 3 ▁billion ▁for ▁South ▁Coast ▁Rail ▁and ▁$ 3 2 5 ▁million ▁for ▁South ▁Station ▁expansion . ▁ ▁In ▁August ▁ 2 0 1 5 , ▁the ▁MB TA ▁dis closed ▁that ▁the ▁project ▁would ▁cost ▁approximately ▁$ 3 ▁billion , ▁a ▁$ 1 . 0 8 ▁billion ▁increase ▁from ▁previous ▁estimates . ▁The ▁re vised ▁cost ▁called ▁into ▁question ▁whether ▁the ▁project ▁could ▁be ▁completed ;