Condo units should not be assessed separately for the natural gas line. Assessing condo units individually is appropriate for value-based assessments and real estate taxes, but it is not appropriate for per-lot assessments.
Condos are assigned a suffix on their shared parcel number as a practical way to apportion the value of the underlying property to each unit owner for value-based taxation. This is not necessary for apartment complexes or other improved property because the buildings and land are owned by the same entity.
The gas line per-lot assessment requires each benefitted lot to pay its share, regardless of its value or the value of any improvements. Each condo association should be assessed for its lot as listed in the borough tax roll.
The individual condo owners should not receive any assessment, just as apartment renters do not receive separate assessments for the lot they live on.
(Homer resident, but not a condo owner)