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u TPH as gasoline was reported at a concentration of 13,000 mg/kg in sample NCS -4, collected from the east end of the UST excavation immediately after tank removal. Other organic compounds reported above laboratory detection limits in sample NCS -4 were 110 mg/kg benzene, 440 mg/kg toluene, 900 mg/kg total xylenes, and 240 mg/kg ethylbenzene. TPH as gasoline was reported at a concentration of 35 mg/kg in sample NCS -5, collected from under the product delivery piping. Other organic compounds reported above laboratory detection limits in sample NCS -5 were 0.13 mg/kg toluene. The three valence states for xylene were reported below detection limits. No analysis were reported for total xylenes. Each of the three soil samples was analyzed for 1,2-dibromoethane and concentrations were reported below detection limits in each sample. Total lead was reported above laboratory detection limits in each of the soil samples. Total lead concentrations ranged from 22.1 to 64.2 mg/kg. Organic lead was reported below laboratory detection limits in each of the soil samples. Reported lead concentrations are below California Code of Regulations hazardous material classification criteria total threshold limit concentration (TTLC) for inorganic lead is 1,000 mg/kg, and the TTLC for organic lead is 13 mg/kg). However, the total lead values of 64.2 mg/kg for sample NCS -5 is greater than 10 times the soluble threshold limit concentration (STLC) level and may potentially be hazardous. Tank Testing Results Both tanks 817B-1 and 817B-3 passed the tightness test as certified in a report from Testing and Technology dated May 28, 1992 (Appendix D) using the method described in Section 3.0. The leak status is reported as passed for each of the tanks with the pass criteria being that no tracer was detected in the samples and less than one-quarter inch of water was detected in the tank bottom at the time of sampling. According to EPA standard test procedures for evaluating leak detection methods, the Tracer Tight® method is capable of detecting leaks of 0.05 gallons per hour with a probability of detection (Pp) of 0.97 and probability of false alarm (PFA) of 0.029. The results have been submitted to both the Navy and the San Joaquin County Public Health Services, Environmental Division. 14