(a) A permit for a private sewage disposal system shall not become effective until the installation is completed to the satisfaction of the director of public works.
(b) The applicant for the permit shall notify the director of public works when the installation work is ready for final inspection and before any underground portions are covered. The inspection shall be made within 24 hours of the receipt of written notice by the director of public works.
(c) The director of public works shall be allowed to inspect the installation work at any stage of construction in addition to the final inspection.