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Countryside Market 2 - 18 June 2015 10848 Copperopolis Road Stockton, San Joaquin Co. Groundwater results before and after pilot testing for OBS-1, AS-1 and AS-2 are given in micrograms per Liter (ug/L) in Table 2. Well TPHg Benzene Toluene Ethybenzene Xylenes EDB 1,2-DCA Pretest 1/13/2015 OBS-1 2,700 27 380 62 380 <2.5 7.9 AS-1 870 2.7 33 18 140 <0.5 1.0 AS-2 4,000 38 660 120 640 3.0 7.2 Post Test 1/29/2015 OBS-1 530 17 150 15 64 0.71 40 AS-1 92 0.69 0.81 <0.5 14 <0.5 <0.5 AS-2 230 4.2 21 3.4 42 <0.5 1.9 Fuel Oxygenates, including MTBE were not detected in soil or groundwater. Naphthalene was not analyzed for groundwater samples. Soil vapor results before and after pilot testing for OBS-1 and VW-1 are given in ug/L in Table 3. Well TPHg Benzene Toluene Ethybenzene Xylenes EDB 1,2-DCA Pretest 1/19/2015 OBS-1 42,000 58 2,500 370 1,140 380 <2.5 VW-1 66,000 120 750 190 210 140 <0.5 Post Test 1/28/2015 OBS-1 24,000 21 1,800 300 15 64 0.71 VW-1 850 23 120 2.3 <0.5 14 <0.5 Fuel Oxygenates, including MTBE were not detected in soil, soil gas, or groundwater. TSGI calculated petroleum hydrocarbons mass in soil as 12,312 pounds (1,865 gallons). Based on reductions in soil gas and groundwater concentrations, helium tracer testing which confirmed air was reaching AS-1 and AS-2 from OBS-1, and increasing TPH concentrations by Photo Ionization Detector in SVE-1 (31.5 to 998.9 parts per million, or ppm) and OBS-1 (13.4 to 292 ppm), TSGI concludes that AS and SVE are viable remedial actions. TSGI calculated a 15' (AS) to 20' (SVE) radius of influence for the AS/SVE remediation wells. TSGI proposes installing a total of ten (10) AS wells (eight additional AS wells) and four SVE wells (three additional SVE wells) in a grid pattern for the Work Plan. The new wells wills are proposed to be installed as 2" diameter air sparging wells AS-3 through AS-10, and 2" diameter soil vapor extraction well and VW-2 through VW-4. AS-3 through AS-10 are proposed to be screened 110' to 115' below ground surface (bgs). VW-2 through VW-4 are proposed to be screened 30' to 60' bgs. Proposed remediation equipment will consist of an air compressor, injection equipment, vacuum pump, carbon treatment vessels, control panel, flow control devices and a sound deadened metal fenced enclosure proposed to be installed on the western boundary of the Site. Proposed monitoring will include dissolved oxygen and oxygen reduction potential in all existing monitoring wells, and SVE influent and effluent. Volatile Organic Compounds will be analyzed to calculate SVE mass removal. Continuous operation of the AS/SVE system is proposed; however, optimization may require temporary isolation of one or more wells at startup. Prior to operations, permits