"Cross-connection" means any physical connection between a potable water supply and any unapproved source or system through which backflow can occur. Furthermore, it is any potable water supply outlet which is submerged or can be submerged in wastewater and/or any other source of contamination. See also the definitions given for "Backflow" in Section 13.72.080 and for "Back-siphonage" in Section 13.72.100. (Ord. 1987-9 § 2.10, 1987)