We were planting a couple bushes next to a sign and my helper nicked the casing of a cable buried at only about 9"-10" below the surface. The cable is about 5/8.. maybe 3/4 diameter with a black plastic covering. There was no ID tape above it. I can see where he nicked a small aluminum (maybe) piece off just below the black covering so I am worried we damaged something here. I didn't touch it or cover it back up or anything. Just wondering what to do, what to expect? What would this be? Who should I call Monday? Thanks!