Section 442(2) in The Bombay Provincial Municipal Corporations Act, 1949
(2)Improvement expenses shall be recoverable in instalments of such amount not being less for any premises than twelve rupees per annum, and at such intervals as will suffice to discharge such expenses, together with interest thereon at such rate not exceeding six per cent per annum as the Standing Committee may fix from time to time, within such period not exceeding thirty years as the Commissioner with the approval of the Corporation may in each case determine.