Such deposit shall be made concurrent with an agreement between the applicant and the Borough concerning the uses of the deposit, which shall include the following stipulations: that said funds shall be used by the Borough solely for the construction of such off-site and off-tract improvements as specified in said agreement and for the other expenses incidental thereto and the acquisition of any easements or rights-of-way in connection therewith; that such deposit may be appropriated by the Borough, with other funds of the Borough, toward the accomplishment of such purposes and may be co-mingled with other appropriated funds and expended by the Borough within a specified time agreed upon by the applicant, said funds shall be returned to the applicant; that, upon completion of the work by the Borough or its contractors, the properties specially benefitted by such improvements shall be assessed as provided by law, including the property of applicant; and that the applicant's deposit shall be credited against the assessment made upon the applicant's property, whether or not the applicant is then the owner thereof, and if such deposit was less than the amount ultimately assessed against such property, then the owner(s) of said property shall pay the difference between the deposit, the amount assessed, and the excess shall be refunded to the applicant without interest.