COMPLIANCE INFO_FILE 5 - Laserfiche WebLink

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Supplemental Information The 814-DlU1 tank system was installed in 1972 and is located on the west side of Building 814. It supplied diesel fuel to an emergency generator that served Building 814. The tank system consists of a 300-gallon, single-walled,carbon steel underground storage tank(UST), associated fill pipe,vent pipe, and fuel supply and return piping. Piping within and beneath concrete will be closed in place. All other accessible piping will be removed. It is not known whether a concrete anchor pad is present beneath the tank. If a concrete anchor pad is present, it will be removed as part of this closure plan. The UST is located beneath an unpaved, grassy area. The standby emergency generator, and its associated UST, 814-D1U1, were removed from service in 1972. UST 814-DlUl will not be replaced. The system was registered with the State Water Resources Control Board in 1986 as 814-41D and has subsequently been renamed 814-D1U1. Figure 1 (see Appendix B) shows the location of the 814-DlUl tank system in relation to the Lawrence Livermore National Laboratory (LLNL), Site 300. Figure 2 (see Appendix B) shows a plan view of the 814-DlUl tank system in relation to Building 814. UST 814-DlUl has not leaked according to previous tank testing reports. LLNL had contracted with the Gary Peters Enterprises to perform precision tank tests using the Tank Audit LEAK COMPUTER on this underground diesel fuel storage system. The most recent test results, which were in 1987,included as Appendix C, show the tank and piping to be product tight. After the tank leak test,the water used for tank testing was removed from the tank, and UST 814-DlU1 was decontaminated. If minor soil contamination is found when the tank is removed,LLNL will remove up to 10 cubic yards of suspected contaminated soil.The underlying soil will then be sampled to determine if any contamination is remaining in the soil. If soil contamination appears to be more than minor,or if there is an indication of contaminated groundwater,LLNL will perform further investigation and cleanup activities in agreement with San Joaquin County,Public Health Services. Any contaminated soil removed from the excavation will be stored, sampled, and disposed of properly. Water samples from the groundwater monitoring wells near 814-D lU 1 (see Figure 3)are not currently analyzed for diesel fuel. If soil contamination is found, and if there is reason to suspect that the contaminants have migrated from the area, groundwater samples from the monitoring wells could be analyzed for diesel fuel. However, groundwater contamination is not expected due to the tank integrity and the depth to groundwater of approximately 92 feet. Groundwater monitoring well,W-814-01 (see Figure 3), was installed in the center of a former "disposal lagoon." The disposal lagoon was a shallow, earthen depression, used to drain away non-hazardous building effluent. A State Water Resources Control Board Underground Storage Tank Permit Application-Form B will be completed and sent to San Joaquin County,Public Health Services-Environmental Health Department once UST 814-D1U1 has been removed. A-1