Laserfiche WebLink
Appendix B:Previous Environmental Activities <br /> ' petroleum-hydrocarbon plume sourced from one or both of the two petroleum pipelines located <br /> approximately 34 feet northeast of the Hunter Container building, and owned by Southern <br /> Pacific Pipeline Company and Chevron. Geological Technics recommended that"San Joaquin <br /> County and RWQCB work with the two pipeline companies to address the petroleum <br /> hydrocarbon issue." <br /> RADIAN INTERNATIONAL, LLC (RADIAN) 1997 GROUNDWATER <br /> INVESTIGATION <br /> On February 27, 1997, Radian was contracted by CPL to conduct a limited groundwater <br /> investigation at the Hunter Container property to determine if TCE had affected the groundwater. <br /> Radian advanced three cone penetration test(CPT)borings (CPT-1, CPT-2, and CPT-3), and <br /> groundwater samples were collected at two distinct intervals, 35 and 50 feet bgs, and tested by an <br /> analytical laboratory. TCE was not detected in any sample. Cis-1,2-dichloroethene, a <br /> degradation product of TCE, was detected in one of the groundwater samples at a concentration <br /> ' below the United States Environmental Protection Agency(EPA) Maximum Contaminant Level <br /> (MCL) for drinking water. Radian concluded that"TCE and other chlorinated organic <br /> hydrocarbons have not impacted groundwater." <br /> RADIAN 1998 SITE INVESTIGATION' <br /> In July 1998, six soil borings (B-1 through B-6)were advanced at Hunter Container and three <br /> ' monitoring wells (MW-2, MW-3, and MW-4) were installed. TPHg, TPHd, and TPHmo were <br /> detected in borings B-1, B-4, B-5, B-6, and monitoring well MW-2. Elevated concentrations of <br /> TPHg(1,400 mg/kg) were detected in B-5 at 10 feet bgs, and TPHd(21,000 mg/kg) and TPHmo <br /> (15,000 mg/kg)were also detected in B-5 at 20 feet bgs. Laboratory analytical results indicated <br /> TPHd concentrations of 2,300 and 300 µg/L in wells MW-2 and MW-3, respectively; and a <br /> TPHmo concentration of 700 gg/L In MW-2. No other constituents of potential concern <br /> ' (COPCs)were detected in groundwater samples. <br /> GEOMATRIX CONSULTANTS, INC. (GEOMATRIX) 2000 SOIL AND <br /> GROUNDWATER INVESTIGATION <br /> ' On November 9 through 11, 1999, at the request of Chevron Environmental Management <br /> Company(CEMC), Geomatrix advanced seven soil borings (GMX-1 through GMX-7)to assess <br /> the vertical and lateral extent of affected soil and groundwater. Borings GMX-6 and GMX-7 <br /> were advanced off site, on the east side of Highway 33. Additionally, groundwater samples were <br /> collected from monitoring well WFSMW-1 on the Western Farm Service (now Crop Production <br /> Services [CPS])property and tested for the COPCs. The investigation also evaluated the <br /> presence of TCE in site soil at the request of the Central Valley Regional Water Quality Control <br /> Board(RWQCB). <br /> TPH quantified as crude oil (TPHc)was detected in soil at a concentration of 10,000 mg/kg at <br /> 37 feet bgs from GMX-3, and polynuclear aromatic hydrocarbons (PAHs)were detected at <br /> concentrations ranging from 0.007 to 0.55 mg/kg. <br /> 6. Radian, 1997. 27 February 1997 Groundwater Sampling at 35275 Welty Road, Vernalis, California. March. <br /> 7. Radian, 1998. Site Investigation at 35275 Welty Road, Vernalis, California. <br /> 8. Geomatrix,2000. Soil and Groundwater Investigation Report,35275 Welty Road,APN 255-180-09, Vernalis, California. <br /> February. <br /> B-3 SAIE <br />