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PAGE #5 — EH 23 046 FORM <br />ATTACHMENTS: <br />9a. Describe, in detail, how the soil and/or water sample(s) beneath the tank and <br />piping will be obtained: <br />THE VAULT HAD NO KNOWN PIPING. SAMPLES WERE TAKEN IN 199 <br />BY <br />CORING THROUGH THE BOTTOM OF THE VAULT AT BOTH ENDS AN <br />TA,KING A SOIL SAMPLE IN THE NATIVE SOILS. BTEX WAS NONE <br />DETECTED. TPH (d) WAS 4100 AND 7100 mg/kg ON THE NORTH AND SOUTH <br />RESPECTIVELY. TPRH WAS 520 TO 1800 mg/kg ON THE NORTH THE <br />ORTH <br />AND SOUTH RESPECTIVELY. NO FURTHER TESTING UNDER THE VA <br />JLT IS <br />PROPOSED. FURTHER TESTING TO DETERMINE THE LATERAL EXTENT <br />OF <br />THE RELEASE IN THE DOWNGRADIENT DIRECTION IS PROPOSED, <br />CONSISTING OF A HAND LUGER BORING 30 FEET FROM THE VAULT <br />WHICH <br />IS SAMPLED AT DEPTHS OF 5', 10' AND 15'. THE SOIL SAMPLES WO <br />JLD BE <br />TESTED FOR TPH AS BUNKER C. THERE WILL BE AN ADDITIONAL <br />TESTING OF EXISTING DOWNGRADIENT WELL B TO DETERMINE TH <br />CONCENTRATION OF TPH AS BUNKER C IN THE GROUNDWATER. <br />ASSUMING THAT THE SOIL AND GROUNDWATER SAMPLES ARE NON <br />DETECTED, NO FURTHER TESTING WOULD BE PROPOSED. <br />10. Describe how the excavation will be backfilled with suitable material upon <br />removal: <br />THE EXCAVATION IS COMPLETE AT THIS TIME AND IS LESS THAN 4 FEET <br />DEEP. THE EXCAVATION WILL BE BACKFILLED WITH PEA GRAVEL <br />(CALTRANS CLASS IA, 113 OR 2 PERMEABLE MATERIAL, 68-1.025). SUCH <br />MATERIAL DOES NOT REQUIRE ANY FURTHER COMPACTIVE EFFOR TO <br />SATISFACTORILY SUPPORT A 2" THICK AC COVER. A 2" THICK AC COVER <br />WHICH IS CROWNED AT NOT LESS THAN 3 % FROM THE CENTER TO THE <br />EDGES WILL BE THE FINAL LAYER. <br />