A sure­ty bond by an insur­ance com­pa­ny autho­rized to do busi­ness in the State of Illi­nois or Irrev­o­ca­ble Let­ter of Cred­it shall be post­ed by the appli­cant with the Coun­ty Clerk as approved by the Coun­ty Board before con­struc­tion of the improve­ments or facil­i­ties is start­ed. Such sure­ty bond shall be one and one‑half (1 1/2) times the amount deter­mined by the Coun­ty Engi­neer as equal to the esti­mat­ed con­struc­tion cost of all improve­ments intend­ed to de ded­i­cat­ed to the Coun­ty, oth­er pub­lic body or approved pri­vate legal enti­ty. Per­for­mance of work nec­es­sary to com­plete con­struc­tion and instal­la­tion of the required improve­ments to be ded­i­cat­ed to the Coun­ty, oth­er pub­lic body, or approved pri­vate legal enti­ty shall be com­plet­ed with­in two (2) years of the date of approval of the final plat, unless such time is extend­ed by writ­ten agree­ment between the appli­cant and the Coun­ty Board. If such improve­ments are not sat­is­fac­to­ri­ly installed with­in the time peri­od spec­i­fied or required, then such sure­ty bond or pro­por­tion there­of shall be for­feit­ed by the appli­cant, and the pro­ceeds of the sure­ty bond shall be used to pay for the com­ple­tion of installing such improve­ments in accor­dance with the require­ments spec­i­fied here­in.