Laserfiche WebLink
Limited Subsurface Investigation� tion Report- Chevron Service Station #/9-1848 <br /> October 28, 1997 <br /> RESULTS OF THE SUBSURFACE INVESTIGATION <br /> Soil encountered during this investigation consisted predominately of fine-grained sand with fines <br /> to an approximate depth of 15 feet bgs A silty clay stratum approximately 3 to 5 feet thick was <br /> encountered in all borings at approximate depths between 15 and 20 feet bgs Silty sand and <br /> sand with fines were encountered to the total depth explored in borings B1 through B3 Detailed <br /> descriptions of the subsurface materials encountered during drilling are presented on the boring <br /> logs (Appendix B) <br /> CHEMICAL ANALYTICAL RESULTS <br /> A total of eight soil samples and four grab groundwater samples were submitted for chemical <br /> analysis Analyses were performed by Sequoia Analytical of Redwood City (FLAP #1210) <br /> Copies of the laboratory reports and chain-of-custody forms are included in Appendix C Soil <br /> chemical analytical data are summarized in Table 1 and groundwater chemical analytical data <br /> are summarized in Table 2 <br /> . Chemical Analytical Procedures <br /> Soil and grab groundwater samples submitted to the laboratory were analyzed for TPI-Ig and <br /> methanol by Environmental Protection Agency (EPA) Method 8015 Modified, and for volatile <br /> organics and oxygenates by EPA Method 8020 and 8260. <br /> Soil Chemical Analytical Results <br /> Petroleum hydrocarbons, oxygenates, or methanol were not detected in any of the soil samples <br /> collected from bonngs BI through B4 Soil chemical analytical data are summarized in Table 1 <br /> Groundwater Chemical Anal tical Results <br /> Grab groundwater samples collected from borings BI through 134 did not contain detectable <br /> concentrations of petroleum hydrocarbons or oxygenates Groundwater chemical analytical data <br /> are summarized in Table 2 <br /> CONCLUSIONS <br /> Petroleum hydrocarbons, oxygenates, or methanol were not detected in soil or grab groundwater <br /> samples collected north, northeast, and west of the former USTs The MTBE detected in <br /> samples from well C-2 appears to have been delineated <br /> 639201-3 3 <br />