Execution Of Deep Cleaning, Regular Cleaning Of Each Floor Including Back Up House Areas Of Concourse &Amp Platform Level, Entry Areas, Subways (Jessore Road Side &Amp Airport Side) , Track Area, Undercroft Areas Of Nscbi Airport Metro Station, Yard, Cut &Amp Cover Tunnel And Adjoining Area Over Ground Including Disposal Of Debris/Rubbish From Ch. 5030m To 7026m, In Connection With Extension Of Metro Railway From Noapara To Barasat Via Bimanbandar