Dig Safe is the state service in my area. I wouldn’t even bother calling if I was only going down 8 inches.
In any case they don’t mark where you can or can not dig. They only mark where things are believed to exist. They aren’t particularly good about it in my experience. It’s never caused a major issue but finding an electrical main ten feet from where it is supposed to be is frustrating. About 25% of the time they don’t mark anything (even if it exists) in which case the law is they have 7 days to mark, if they haven’t we’ve met our obligation and it’s considered safe to dig.
Looks like no line to me. I’d go forward.