The final plat shall be accompanied by the following:
(a) The developer shall present evidence acceptable to the Solicitor that all taxes against proposed roads and streets have been paid and that all encumbrances or liens of record against such proposed roads have been released.
(b) A certificate showing that all improvements have either been installed and approved by the proper officials or agencies or that a performance bond, cash bond or escrow account, insuring their installation has been accepted by Council.