At the time of securing a permit for street excavation, the applicant shall deposit one hundred dollars ($100.00) or such larger amount as, in the opinion of the Director of Service, is adequate for the purpose of replacing the pavement. Contractors and public utilities engaged in an extensive program requiring considerable excavation may make a single deposit, in an amount fixed by the Director of Service, to cover their whole program. If the Director of Service shall determine that the applicant is financially responsible and competent to replace the pavement, the applicant may file a bond to cover satisfactory performance and shall be permitted to refill the excavation and replace the pavement, subject to inspection and approval by the Director of Service. The bond shall be returned if performance is satisfactory.