ARCHIVED REPORTS_REPORT SUMMARIZING INSTALL OF MONITORING WELLS MW4,MW5,MW7,MW8 & SOIL BORING RDM1 & 4TH QTR 2013 GROUNDWATER SAMPLING

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is Ms. Angela Lee Huntbrook Holdings,LLC February 12, 2014 Page 10 in all of the samples collected from RDM-1 between 18 and 48.5 fogs. Benzene was reported in each of the samples collected between 30 and 48.5 fbgs at concentrations ranging from 0.61 to 3.3 mg/kg, with the highest concentration reported at 38 fbgs. TPHg was reported in each of the samples collected between 18 and 48.5 fbgs at concentrations ranging from 1,700 to 21,000 mg/kg with highest concentration reported at 18 togs. TPHd, following silica gel cleanup, was reported in each of the samples collected between 18 and 48.5 fbgs at concentrations ranging from 300 to 2,400 mg/kg with highest concentration reported at 30 fogs, but the laboratory reported it as being a higher boiling point than typical diesel. Naphthalene was reported in each of the samples collected between 18 and 48.5 fbgs at concentrations ranging from 6.7 to 150 mg/kg with highest concentration reported at 18 fogs. • Cone Penetrometer Test Borin¢CPT-1 On October 10, 2013, RDM supervised California Push Technologies Incorporated of Menlo Park, California, advance a cone penetrometer test (CPT) boring at location CPT-1 (Figure 2) using a • Geoprobe Model 6625CPT rig with an approximately 20-ton push capacity. The purpose of the CPT boring was to collect two to three depth discrete groundwater samples between the depths of 65 and approximately 100 fbgs to further assess the vertical extent of petroleum hydrocarbons in groundwater beneath the site. Unfortunately,the CPT rig encountered refusal(per ASTM D-5778 refusal criteria)at a depth of 70 fbgs and no groundwater samples could be collected as planned. A copy of California Push Technologies,Incorporated's report and boring log is included in Enclosure L. • On November 5, 2013, RDM supervised Middle Earth GeoTesting Inc. (Middle Earth) of Orange, California attempt to advance the CPT boring using a larger (25-ton) CPT rig, but refusal (per ASTM D-5778 refusal criteria) was encountered at approximately 64 fbgs with the larger CPT rig. A copy of Middle Earth's report and boring log is included in Enclosure L. • The CVRWQCB was notified of the CPT boring results and RDM discussed evaluating an alternative drilling method for completing this scope of work since it may require additional budget approval from the USTCF. Manaeement of Investieation-Derived Waste • Approximately 5 cubic yards of drill cuttings (soil)were generated during the field work and stockpiled on, and covered with, visqueen on the subject site. One, 4-point composite sample (SP-la,b,c,d) was collected from the stockpile and submitted to Kiff laboratory for analysis of: • BTEX, TPHg, fuel oxygenates (MTBE, TAME, DIPE, TBA, and ETBE), lead scavengers (1,2 DCA and EDB), naphthalene, and chlorinated VOCs (full list) by EPA Method 826013; and, • TPHd by EPA Method 8015 Modified with and without silica gel cleanup (if TPHd was reported in initial sample); silica gel cleanup was performed using EPA Method 3630C Modified; • Total Lead by EPA Method 6010 • The soil stockpile sample analytical results are summarized in Table 3 and a copy of the laboratory analytical report with chain-of-custody documentation is included in Enclosure M. The soil was hauled offsite on February 4, 2014, by Woodward Drilling of Rio Vista, California, for disposal under non- hazardous waste manifest to Potrero Hills Landfill in Suisun City, California. A copy of the disposal . manifest and landfill scale tag is included in Enclosure N.