I've reworked the list and the map of the public big rig accessible dump points around Australia. Click on the thumbnail for a bigger version.
We headed for Sydney and reached Lake Liddell Recreation Area in time for afternoon tea.
This quite a pretty place if you park where you can't see the power station. The main railway line runs close by so we eventually heard some distant rumbling and the occasional horn blast but it wasn't loud enough to disturb our sleep.