The open pit has been closed since 1978 but access to the pit is maintained in order to service the ventilation shaft at the eastern end of the base of the pit. The pit dimensions are 1200 m (east to west) by 650 m (north to south) and at its lowest point is approximately 150 m below ground level. The bottom of the pit is used as an access to the underground mine operations.
http://www.necz.org.zm/news/comments/eis-reports/NFC%20Mining/NFCA%20EMP.pdf