The subdivider shall be in default of the performance surety when one of the following conditions exist:
(a) The installation of all required public improvements as called for in these Regulations has not been completed within the 2-year time period and the subdivider has failed to establish reasonable cause for such delay to the satisfaction of the Municipal Manager and thereby to receive a time extension.
(b) The subdivider has not constructed the required public improvements in accordance with the minimum standards specified in these Regulations, and the subdivider is unwilling to modify and to upgrade said public improvements within a 6-month time period after receiving notice from the Municipal Manager so as to be in compliance with the provisions of these Regulations.