According to the Simulcast sites, Site 4 is currently broadcasting on 413.6625Mhz.
According to the database, this would be Uxbridge.
The Simulcast Zone (Site 1) is currently on 410.0625Mhz0.
Waterdown (Site 2) should be on 413.5625Mhz.
Hillsburgh (Site 3) is on 411.0375Mhz.
Niagara (Site 5) is on 410.5375Mhz.
No other sites are currently being shown as neighbours.