COMPLIANCE INFO_FILE 5 - Laserfiche WebLink

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00 Supplemental Information It is not known when the 830-D1U1 tank system was installed. Located on the south side of Building 830,it supplied diesel fuel to an emergency generator. The tank system consists of a 280-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. The area is paved with asphalt. The emergency generator, and its associated UST, 830-DlUl,were removed from service in 1987. UST 830-DlUl will not be replaced. The system was registered with the State Water Resources Control Board in 1984 as 830-11D and has subsequently been renamed 830-D1U1. Figure 1 (see Appendix B) shows the location of the 830-DlUl tank system in relation to the Lawrence Livermore National Laboratory (LLNL), Site 300. Figure 2 (see Appendix B) shows the 830-D lU 1 tank system in relation to Building 830. Figure 3 (see Appendix B) shows a plan view of the 830-DlU1 tank system Figure 4(Appendix B) shows the locations of nearby groundwater monitoring wells and groundwater data. UST 830-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 for the past 4 years. The most recent test results,from Clayton Environmental Consultants using the Homer EZY- CHEK method, are included as Appendix C and show the tank and piping to be product tight. 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 830-DIU1 (see Figure 4) 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 104 feet. There are not enough groundwater wells located in the first water-bearing zone in the area of Building 830 to infer groundwater contours for Figure 4. It is presumed that the groundwater in the area flows south. Groundwater monitoring well,W-830-09 is located the closest to UST 830-D1U1, but lies cross-gradient. The location and groundwater data for the nearest downgradient monitoring well,designated W-830-04A, is shown on Figure 4. The disposal lagoon shown in Figure 2, was a shallow,earthen depression,used to drain away Building 830 process operation effluent. The disposal lagoon is no longer used. 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 830-D1U1 has been removed. A-1