Following the removal of a fuel UST, the primary fuel piping failed a pneumatic pressure test and a subsequent Helium leak-detection test. Enpro examined available data from several sources including tank and pipe integrity tests (before the UST removal); pressure and helium tests (after the UST removal); soil sampling and analysis; emergency generator burn-tests; and day-tank inventory records. Enpro demonstrated that the pipe failure could not have existed prior to UST removal and a fuel release could not have occurred by analyzing day-tank inventory data, pipe failure data and by performing a hydraulic analysis. Based upon the analysis and data presented by Enpro, the lead agency granted site closure without additional investigation. This saved the client an estimated $75,000 in avoided excavation and investigation costs.