A separate and independent building sewer shall be provided for every
building, except that, where one building stands at the rear of another
on an interior lot and no private sewer is available or can be constructed
to the rear building through an adjoining alley, court, yard or driveway,
the front building sewer may be extended to the rear building and
the whole considered as one building sewer, with each building being
connected. The Sewer District does not and will not assume any obligation
or responsibility for damage caused by or resulting from any such
single connection aforementioned.