The installation, operation, and maintenance of sewage lift stations in connection with sewer systems being installed in new residential developments will be permitted in those instances where it is demonstrated that a gravity outlet for sewage is not reasonably available because of lack of accessibility or because of exorbitant costs. The pump used in these lift stations shall be a factory-assembled duplex pump or duplex ejector supplied by a reputable manufacturer. No lift station shall be installed or constructed until the plans and site location for the installation and construction have been approved by the safety-service director.
('73 Code, § 51.06)