Connection charges, as established in § 52.72 above, shall be due and payable in cash upon application for connection to the system. In addition, the cost of labor, connecting pipe, fittings and appurtenances and installation, plus 30% of these costs, shall also be paid by the prospective user. Applications for service connections shall be made to the Authority prior to making the connection, upon forms furnished by the Authority at which time the applicant shall pay the connection charge, as established in § 52.73, plus the estimated cost of the actual connection thereof subject to refund or additional charge after the actual cost has been determined.