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SWMU B-34 RCRA Facility Investigation Report Addendum
Section 2 - Field Investigation
During March 2003, fourteen surface soil samples were collected at SWMU B-34 to define the horizontal extent of contamination, as recommended in the RFI Report. Sample locations, shown in Figure B34-8, were selected based on results of the Phase I (March 2000) RFI sampling, and extended outward from known areas of above-background contamination. APPL Laboratory in Fresno, California analyzed each surface soil sample for barium, chromium, copper, nickel, and zinc using EPA method SW-6010B, cadmium by EPA method SW-7131A, and lead by EPA method SW-7421. These metals are the metals that were detected at above-background concentrations during the Phase I sampling effort. Although VOCs and SVOCs were not detected during the Phase I sampling, Phase II samples collected near the piping outfall were also analyzed for these compounds (using EPA methods SW-8260B and SW-8270C) to determine if contaminants had been released from the pipe in the past. No indication of surface or buried waste management activities was evident during the field effort.
All decontamination, sample preparation, and sample handling followed protocols established in the Field Sampling and Analysis Plan (Volume 1-4, Field Sampling Plan and Quality Assurance Project Plan). All sampling points were predetermined before the fieldwork was performed. Parsons field crew located the predetermined sampling points in the field using a Trimble Asset-grade geographic positioning system (GPS). All sample locations and analytical data have been incorporated into the CSSA geographic information system (GIS).
Results of the Phase II (March 2003) surface soil sampling effort are summarized in Table B34-2 and a full tabulation of all analytical results is provided in Appendix A. The extent of metals contamination in surface soil was only defined along a portion of the eastern side of the site (near sample locations B34-SS10, B34-SS11, and B34-SS12). All of the other samples collected in March 2003 contained above-RRS1 concentrations of one or more metals, most commonly lead, but also chromium, copper, and zinc. Metals were detected above RRS1 (background) criteria in eleven of the surface soil samples. Barium, nickel, and cadmium did not exceed their RRS1 criteria in any of the March 2003 surface soil samples. In addition, eight VOCs and numerous SVOCs were detected in the samples collected near the piping outfall area. Most of the results were non-detects that were M-flagged due to a matrix effect.
Chromium exceeded its RRS1 criteria in four samples. The lowest result is 41.2 mg/kg from B34-SS02, while the highest result is 53.4 mg/kg from B34-SS05. The background concentration for chromium in CSSA soils is 40.2 mg/kg; therefore, these exceedances are considered slight.
Copper exceeded its RRS1 criteria in seven samples. The lowest copper result is 28.54 mg/kg from the B34-SS02 field duplicate sample, while the highest result is 146.75 mg/kg from B34-SS13. Zinc exceeded its RRS1 criteria in eight samples. The lowest zinc result is 86.32 mg/kg from B34-SS01, while the highest result is 207.51 mg/kg from B34-SS13. The copper and zinc results that exceeded RRS1 were an average of 54.5 mg/kg and 59.72 mg/kg higher than their RRS1 criteria, respectively. The CSSA background concentrations for copper and zinc are 23.2 mg/kg and 73.2 mg/kg, respectively.
Lead exceeded its RRS1 criteria in ten samples. The lowest lead result is 89.63 mg/kg from B34‑SS14, while the highest result is 573.62 mg/kg from B34-SS13. The RRS1 criteria for lead is 84.5 mg/kg; the lead exceedance averaged 192.45 mg/kg.
Samples B34-SS2, B34-SS3, and B34-SS13 were analyzed for VOCs and SVOCs, in addition to metals. B34-SS01 was also inadvertently sampled for SVOCs. VOCs that were detected include 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, dichlorofluoromethane, hexachlorobutadiene, methylene chloride, toluene, naphthalene, and p-isopropyltoluene. Five of these VOCs (1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, dichlorofluoromethane, hexachlorobutadiene, and naphthalene) were detected in every sample, but all of the results were M-flagged. P-isopropyltoluene was only detected in B34-SS03 at a concentration of 0.0013 mg/kg (F-flagged). Methylene chloride and toluene were detected in all samples. As seen in Table B34-2, all of the methylene chloride results were J-flagged and the toluene results were B-flagged. Thirty-eight SVOCs were detected; however, all results were M-flagged due to a matrix effect. All concentrations were below respective RLs.