Is having a torn acl and foot numbness related?

No: Acl tears are isolated within the knee. However, in extreme cases of swelling, the foot can become numb, though this is rare. More likely there is a separate cause of the numbness.

Possibly: Possibly, particularly if they occurred at the same time. The acl tear itself would not cause numbness, but in the same injury that you tore your acl, you could potentially injured the peroneal nerve, which runs right by the knee. The other possibility is it could be coming from the back. Don't hesitate to discuss with your doctor. A nerve conduction test could be helpful as well.