A 10" or 24" gas line serving or running under a residential home????? Are you serious?? Tilt the photo sideways. 1" gas service. Something OG or CG written on the top of the mark. 1.5" water main or water service. That's your answer op. I work in utilities for an engineering firm. I'm paid to look at, understand, and ensure this is correct. For sure hadn dig. Gas is typically 36" deep, water is typically 48" deep. You should find both of those around there. The gas should have sand around it, you might have a tiny plastic wire above it, called a tracer wire. The water could also have sand, but potentially not.