The plumbing inspector notified me that what appeared to be an underground supply line was being buried in the same trench as the plumbing pipe he was inspecting and that it was buired too shallow. I went to the job site and found 2" black poly pipe already buried. It was verified that no FIR permit has been applied for this work. A stop work order was posted on site and Tim Frost was notified in plan review. Pictures were taken and emailed to Tim Frost as well of the installed piping.