(1) Approval given by the local authority in terms of this Part shall become null and void after the expiration of twelve months from date of such approval unless the construction of the building of installation of sewerage works concerned is commenced within that period.

(2) Whenever the construction of a building or an installation of sewerage works has been discontinued for a period in excess of six months, the local authority may, by written notice, require the owner to complete the work within such reasonable period as may be specified in such notice.

(3) If the owner fails to comply with the notice served in terms of subsection (2), the local authority may revoke the approval given under this Part, and may, by written notice, require the owner concerned-

a) to restore the site to its original condition within such further period as may be specified in the notice; or

b) to take such other action as the local authority may specify in order that the work and site may be rendered safe, tidy and as little offensive as possible.