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Based on the presence of impacted soil, additional investigations were completed in 1993, which included the drilling of fourteen borings and the installation of three groundwater monitoring wells. The results of the soil investigation indicted that impacted soil at the subject property was primarily confined at a depth of 40 to 50 feet below ground surface (bgs) with ' maximum concentration of Total Petroleum Hydrocarbons as Gasoline (TPH-G) at 425 milligrams per kilogram (mg/kg) with only trace concentrations (less than 0.005 mg/kg) of benzene, toluene, ethylbenzene, and total xylenes (BTEX) detected. Maximum groundwater concentrations detected were 53 micrograms per liter (ug/L) of TPH-G, 0.39 ug/L of TPH as diesel (TPH-D), and trace concentrations (less than 3 ug/L) of BTEX. In a November, 1995 Workplan, three additional borings were proposed to be advanced at the subject property and were to be constructed into vapor extraction wells. PSI was unable to obtain a copy of the report detailing this investigation, but summary documentation prepared for ' site closure indicated that vapor-extraction wells were only installed in two of the borings. The summary documentation as presented by SJEHD stated 'low levels of TPH-G and TPH-Diesel, very low levels of TEX, and no detectable levels of benzene" were identified as part of the soil investigation. There is no evidence of any vapor-extraction test or implementation. Groundwater monitoring at the subject property was conducted between fourth quarter 1993 through the third quarter of 1996. The results of the final groundwater monitoring event ' indicated that TPH-G was detected in samples collected at a maximum concentration of 130 ug/L; TPH-D was detected at a maximum concentration of 98 ug/L; and benzene was detected at a maximum concentration of 0.8 ug/L. Based on the low concentrations of petroleum ' hydrocarbons at the subject property, site closure was requested. These concentrations are below current Regional Water Quality Control Board (RWQCB) environmental screening levels (ESLs). Based on review of site documentation, monitoring wells were not located immediately ' down gradient of the former tank pit; therefore monitoring wells at the subject property were not optimally placed. PSI concluded that to provide data immediately down gradient of the former tank excavation further investigation would be required. ' The subject property was granted closure on August 19, 1996 by the SJEHD based on historic low levels of contamination in groundwater and the lack of appreciable hydrocarbon mass in the vadose zone. The site monitoring wells were destroyed under the approval of the SJEHD in ' 1996. As of 1996, residual soil contamination was present primarily at a depth of 40 to 60 feet bgs. Additionally, residual groundwater contamination was also present at a depth of approximately 68 feet bgs, as referenced above. These concentrations were deemed to be de ' minimus. Site Reconnaissance Two hydraulic auto lifts are located at Sanchez Smog on the Subject Property. According to Mr. Sanchez, owner, no leaks have been noted associated with the hydraulic lifts. The age of ' the hydraulic lifts is not known but they appear to be original with the building which were installed in association with a former service station at the property and are no longer used as part of automobile repair. Soil borings and monitoring wells installed as part of the previous ' investigation of the property did not investigate the current hoists. Based on the lack of investigation of the hoists, PSI considers them to represent a potential environmental concern. ' 2