As an alternative to the completion of the required improvements,
the subdivider may file a certified check or irrevocable letter of
credit to cover the full cost of the required improvements deemed
necessary by the Planning Board with the Village Clerk. Any such letter
of credit shall comply with the requirements of § 7-730
of Village Law and shall be satisfactory to the Planning Board, Village
Board, Village Engineer and Village Attorney as to form, sufficiency,
manner of execution and surety. The Planning Board shall determine
an appropriate period of time [not to exceed three years] set forth
within the letter of credit within which the required improvements
shall be completed. The term of the security agreement may, however,
be extended by mutual agreement of the Planning Board and the subdivider.