I am wondering what would be the correct location to connect the unconnected green ground wire in main panel next to meter. The detached garage has it's own ground rod. It is being fed by the double pole 50 amp breaker in main panel next to meter. I attached photos. The bare aluminum cable in main connects to ground bus bar in breaker box located inside house. The ground rod under meter connects to inside meter box only. The hanging #6 green wire and 3 other black #6 wires run 60ft underground in conduit to detached garage sub panel. Two black #6 are on each pole of double 50 amp breaker and other black #6 is on neutral bar of main box next to meter.