On 1 November 2021, spatial units CL1, CL2 and GW1 were temporarily reclassified as part of the Intermediate TB Area North (ITBAN) from the Low TB Area.
Ar 1 Tachwedd 2021 cafodd unedau gofodol CL1, CL2 a GW1 eu hailddosbarthu dros dro fel rhan o'r Ardal TB Ganolradd y Gogledd (ITBAN) o'r Ardal TB Isel.