The city engineer may waive the requirement that a property be connected to city water or the sanitary sewer upon a finding that requiring the connection would result in substantial hardship to the owner or occupant; that the public health, safety and welfare would not be harmed if the property were not connected; and that the property has another water supply or another means of sewage disposal which complies with all applicable local, state and federal requirements. (1982 Code § 3.153)