In such cases where sewer service lines have been extended from one (1) property to another, the continued use of such extensions shall not be permitted after the time sewer mains or trunks are laid in the street or alley abutting the latter property. At that time, connections shall be promptly made to the abutting sewer main or trunk at the expense of the owner of the property, and the use of the cross-property service line shall be discontinued. (Prior code 13.04.180)