If any person, corporation, firm, or business entity located outside the city limits desires city water service and pays all expenses incurred in extending the water mains and secures all necessary easements, so that the city incurs no expense in such connection, and the city elects to provide such water service to such patron, and provided all mains and lines installed shall meet the requirements and approval of the Director of Public Works, then such patron shall be furnished water at a rate of one hundred fifteen percent (115%) of the "in- city" rate.