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page 2, 1207 S Aurora <br /> Fieldwork continued on April 26-27, 1999, with the installation of the fourth on-site <br /> shallow groundwater monitoring well, and the two off-site wells located across the street <br /> to the north. The pilot hole was drilled on May 3, 1999. To date, the two additional wells <br /> for vertical assessment to 70 feet bsg have not been installed. <br /> According to the report, section 3.6;page 5, soil samples from only two of the borings <br /> were submitted for laboratory analysis. This is unfortunate, and contrary to both the <br /> work plan and the information given to PHSIEHD in the field. The purpose of this work <br /> plan was to investigate the vertical and lateral extent of the contaminant plume at this <br /> site, in both soil and groundwater, which has yet to be defined. Prior work at this site <br /> consisted of nine geoprobe soil borings advanced to 40 feet bsg. Of those nine borings, <br /> only two were non-detect for all petroleum hydrocarbon constituents analyzed for in each <br /> soil sample analyzed. These two borings were B-3, located to the west of the western <br /> most source area, and B-9 which was located between and to the north of the two <br /> source areas. Of the nine soil samples collected at 40 feet bsg, six evidenced <br /> detectable levels of petroleum hydrocarbons. Analysis of the 46-foot bsg samples <br /> collected from the monitoring well installations would have provided information on the <br /> vertical extent of contamination and should have been completed. Changes to the <br /> scope of work outlined, and approved, in work plans should not be made without prior <br /> consultation with PHSfEHD. The report failed to provide the laboratory QA/QC sheets <br /> and the chain-of-custody documentation for the limited soil analysis that was done. <br /> Development and sampling of the installed groundwater monitoring wells apparently took <br /> place on April 30, 1999. This was done without prior notification to PHSIEHD, effectively <br /> denying them the opportunity to witness the sampling. Please note that PHSIEHD is to <br /> be notified at least 48 hours in advance of all fieldwork mobilizations. As with the soil <br /> sample analysis, the report failed to include any supporting documentation for the water <br /> sample analysis that was performed. There were no field logs from the water sampling <br /> event, no QA/QC sheets from the lab and no chain-of-custody. Final review of the report <br /> cannot be completed until these documents are received by PHSIEHD. In the future, all <br /> analytical data included in a report should be presented in a tabulated format. <br /> In a conversation with the Cleanup Fund it was learned that JJW submitted a cost <br /> proposal to install the two 70-foot bsg wells with conductor casings, but requested that <br /> pre-approval for them be postponed until after the pilot hole was completed. Please <br /> instruct your consultant to instigate pre-approval for the required wells, and proceed with <br /> scheduling a driller to complete the approved work plan. If you have any questions, <br /> comments or wish to schedule fieldwork call Lori Duncan at (209) 468-0337. <br /> Donna Heran, REHS, Director <br /> Environmental Health Division <br /> Lon Duncan, REHS Mar are H a orio REH <br /> Z_� <br /> g g <br /> Site Mitigation Unit IV Supervisor, Unit IV <br /> cc: Mark List, CVRWQCB <br /> Mark Jerpbak, JJW Geosciences Inc. <br /> Pieter Crosby, PC Toxic <br />