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Stephen Donell - 2 - 31 January 2014 Soil and Groundwater Data Field investigations obtained soil and groundwater data from the septic system area (GW-1), interior concrete patches (SB-112 and SV-25), the interior trench drain area (GW-3), and from the construction of eight permanent groundwater monitoring wells across the Site. Soil and groundwater sampling was limited to assessing impacts to shallow soils and groundwater (approximately 0 to 26 feet below ground surface (ft bgs)). Static groundwater was approximately 25 ft bgs with an overall gradient of approximately 0.002 foot/foot to the southeast. Soil and groundwater contamination is summarized below. 1. DCP and DBCP Monitoring well MW-7, on the western property boundary, contained 17 ug/L of 1,2-DCP, 0.6 ug/L of the fumigant 1,2-Dibromo-3-chloropropane (DBCP), and less than 2.01 ug/L of chloroform. Temporary monitoring well TW-3, 100 feet southeast (down-gradient) of permanent well MW-7, also contained 13.4 ug/L of 1,2-DCP, and 0.335 ug/L DBCP. These results exceed the California Maximum Contaminant Limits (MCLs) for 1,2-DCP and DBCP of 5 ug/L and 0.2 ug/L, respectively. 2. Nitrate Investigation results show all groundwater monitoring wells except monitoring well MW-8 contain elevated levels of nitrate. Monitoring wells MW-2, MW-7, MW-6, and TW-1 contain 1,186 milligrams per liter (mg/L), 934 mg/L, 819 mg/L, and 797 mg/L nitrate as (as NO3), respectively. These results all exceed the MCL for nitrate (as NO3)of 45 mg/L. Although monitoring wells MW-3 and MW-4, located along the septic system area, contained relatively lower concentrations of nitrate as (NO3)of 209.83 mg/L and 94.29 mg/L, respectively, they also exceeded the MCL. The Report shows MW-8 is upgradient, therefore the Nitrate contamination appears to be from Site activities. 3. Chloride, Sulfate, and Total Dissolved Solids (TDS) Groundwater results show chloride, sulfate, and total dissolved solids (TDS) above secondary MCLs. Seven samples contained chloride above the secondary MCL. The highest chloride concentration of 654 mg/L occurred at both temporary wells TW-1 and TW-4 located inside the warehouse. Four samples contained sulfate in exceedance of its secondary MCL with the largest sulfate exceedance of 772 mg/L occurring at monitoring well MW-2, located north of the septic system. Exceedances of the secondary MCL for TDS occurred at nine of twelve sampling locations, with the highest result of 2,410 mg/L occurring at MW-2. Similar to nitrate, all wells contained greater concentrations of these contaminants from the upgradient well MW-8, therefore the pollution appears to originate from Site activities. 4. Arsenic Sitewide arsenic concentrations in soil exceeded its California Human Health Screening Level (CHHSL) of 0.24 mg/kg. Half of the samples tested for arsenic (6 of 12 samples) exceeded the EPA Region IX Regional Screening Level (RSL) of 2.4 mg/kg for industrial soil carcinogenic target risk. However, all arsenic concentrations in sampled groundwater were below the MCL for arsenic in drinking water of 10 ug/L. 5. TPH Diesel range TPH were found in soil samples from TW-4 at 25 ft and TW-2 at 5 ft at concentrations of 16,700 mg/kg and 2,980 mg/kg, respectively. However, all groundwater samples were non-detect for TPH.