Diagnose for leaking call, found no issue/leak between existing backflow, then also from existing back flow to building. Water seems to be in used from inside the building. Verified no leak on external plumbing system with on site contact Keith. Verified meter was not moving while plumbing inside was isolated. Additionally verified that no water was being used inside the building at this time (no movement on meter). Changed leaking backflow test fitting at Keith’s request. Verified no leak on backflow device at this time at replacement of test fitting.