The cost of any project shall include (1) the cost of locating, establishing and constructing the project; (2) the administrative staff, office and other expenses of the board and commission; (3) the cost of construction of all works and appurtenances necessary to efficient operation and maintenance of the project; (4) the cost of acquiring any lands and/or rights of way; (5) all engineering, legal and other professional fees; (6) the cost of the service and publication of all notices; (7) interest on bonds for the first year, if bonds are to be issued; and (8) an amount not exceeding 10% of those costs which are to be assessed against public corporations, to cover contingent expenses.