Notwithstanding the foregoing, the City may authorize installation of the extension by an independent contractor provided:
(a) The contractor has been approved by the City in writing;
(b) The total cost of the project has been agreed upon by the City and applicant in writing;
(c) The applicant has entered into a binding written contract with the approved contractor for the work at the agreed cost; and
(d) All of the installation is performed under the supervision and direction of the City Engineer.
(1965 Code §22-15)