COMPLIANCE INFO_1985-1987 PRECISION TESTS

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GARY PETERS ENTERPRISES 11 COLCOLOMA RD. _7 RANCHO , CA. 9567 9116-639-7198 TEST DATE: 4-13-88 TO: Dave Castro U.C.L.L .N.L. P.O.Box 868 L-193 Livermore , Ca. TEST LOCATION: Site 300 Tank #874-11D (5000 gal . Diesel fuel tank no longer in service) . TEST PROCEDURE: Mixture of Helium and compressed air injected into empty 5006 gal . tank . Tank tested previously, shown to leak in piping. Trenching operation (prior to tank test) known to have damaged piping. Trench location obvious as patch in asphalt is very visible . The trench runs East and West and runs between the listed tank and building #874. When pipes were damaged in trench , they were supposedly capped off . The vent pipe was identified and plugged. The Helium/air mixture was injected to a maximum pressure of 5PS1 . A very slow decay in pressure was noted, indicating a slow leak . A survey of the area with the Helium detector found no traces of the gas. Holes were drilled in the asphalt around the tank and along the suspected piping run . Initial survey of approx . 20 test holes found no Helium. Testing continued for another hour , until Helium detected in one check valve oPenin stern check valve of the two valves) . After another half hour of testing, Helium was detected in one test hole . Helium .was found in several test hole= in the same area later . One test hole consistently showed higher concentrations of Helium, compared to all other holes with any reading. This hole is approx . 4 ft . west of the western check valve and approx . 3 ft north of the tank center• l i ne . It is noted that this hole is on the edge of the patch for the trench work previously mentioned. CONCLUSION: The concentrations found were smal 1 , indicating a all leak . The location is consistent with previous reports. The leak appears to be in the piping at the edge of the trench , probably a bad cap on the pipe or broken pipe .