(1) The cost of the scheme shall be met wholly or in part by a contribution to be levied by the Planning Authority on each final plot included in the final scheme calculated in proportion to the increment which is estimated to accrue in respect of such plot by the Arbitrator :
Provided that-
(i) no such contribution shall exceed half the increment estimated by the Arbitrator to accrue in respect of such final plot, subject to the condition that where the total cost of a scheme exceeded half the total amount of increments, the proportion of such contribution shall not be less than half the increment ;
(ii) no such contribution shall be levied on a plot used, allotted or reserved, for a public purpose or purpose of the Planning Authority, such plot being solely for the benefit of the owners or residents within the area of the scheme ;
(iii) the contribution levied on a plot used, allotted or reserved for a public purpose or purposes of the Planning Authority which is beneficial partly to the owners or residents within the area of the scheme and partly to the general public shall be calculated in the proportion to the benefit estimated to accrue to the general public from such use, allotment or reservation.
(2) The owner of each final plot included in a final scheme shall be primarily liable for the payment of the contribution leviable in respect of such plot.