Zz Yzx wrote:

What material is the service lateral?
Galv iron?
Lead?
Copper?
Plastic?


It's PVC where it leaves the meter box, but it's copper where it
daylights and goes into the house. I'm betting its PVC from the meter
to the joint near the shut-off valve.

Prime suspect would be the coupling/adapter between
the PVC and copper. Could have a split in it.

Can you shut the water off at the meter long enough
to excavate around that likely area?