SITE INFORMATION AND CORRESPONDENCE FILE 2

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7-Eleven Store#14117 Results of Oxygen Injection Feasibility Pilot Study May 9, 2006 Page 2 The purpose of the test is to evaluate the potential impacts to groundwater quality resulting from reactions of injected oxygen with groundwater and soil lithologies underlying the site. OXYGEN INJECTION FIELD TEST DETAILS Prior to initiation of oxygen injection, groundwater samples were collected from injection well 1-1 and the adjacent observation well, MW-1 located 5 feet from 1-1. Analysis of the groundwater samples for general inorganic constituents and dissolved metals provide baseline groundwater chemistry data for the site. Specific protocols and methods were used in conducting the groundwater sampling as described in the following paragraphs. The depth to water was measured to within 0.01 feet in 1-1 and MW-1 from top of casing (TOC) using a water level indicator. Dissolved oxygen was also measured in each well. Both 1-1 and MWA were purged prior to collecting groundwater samples in order to assure that water standing in the well and well casing was removed and that a representative groundwater sample was collected. Well purging and sampling equipment was thoroughly cleaned prior to purging and sampling the wells. Each well was purged of approximately three casing volumes of water (or to dryness) using a submersible pump. During purging, temperature, pH, and electrical conductivity were monitored. Following purging, the groundwater level in each was allowed to recover to at least 80% of the original level prior to collection of the water samples. Ferrous iron (Fe 12) concentrations were measured in each well using a Hach field test kit immediately following well purging. In addition, dissolved oxygen concentrations were measured in each well after the groundwater level recovered and prior to sample collection. All groundwater samples were filtered in the field using a disposable 0.45 micron filter prior to being placed into appropriate containers, preserved where applicable, labeled, logged onto a chain-of-custody document, and transported on ice to Kiff Analytical, a California state-certified laboratory. Copies of field notes are in Attachment B. The groundwater samples were analyzed for the following constituents and parameters: Biochemical oxygen demand BOD Hardness Chemical oxygen demand COD H Fluoride Ion Balance Nitrogen —ammonia Chromium hexavalent Nitrogen —nitrate CAM 17 Metals Nitrogen —total Kjeldahl Silver Phosphorus Arsenic Sulfide Barium Sulfate Beryllium Alkalinity Cadmium Calcium Cobalt Magnesium Chromium total At", . 14117 02 Pilot Study Report 04-18-06.doc SECOR International Incorporated r '