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C7 SAMPLING AND ANALYSIS On June 30, 2017, a representative of Geo -Logic Associates (GLA) visited the property at the address identified above and received permission from the resident to participate in the domestic well sampling program. The well also services the adjacent tenant residence 7253 Newcastle Road. After receiving permission, a groundwater sample was collected from sample port next to the well. A second sample was collected from this location on July 13, 2017 (the purpose of the second sample was to confirm the laboratory results from the June sample). The well access sheet, well inspection sheet, well sampling data sheets, and laboratory reports for both sets of samples are attached. Approximately 70 gallons of water was discharged from the sample point prior to collecting each groundwater sample. Before collecting the sample, the temperature, pH, and the conductivity of the groundwater were measured and recorded on the well sampling data sheet that precedes the laboratory results. After these parameters were measured, a sample was collected for laboratory analysis to identify whether volatile organic compounds (VOCs) may be present in the groundwater. The groundwater sample was collected in laboratory -supplied sample containers, filled completely, immediately capped, labeled, and placed in an ice -filled cooler. A completed chain -of -custody form identifying the sample identification, date and time collected, and the analyses to be performed accompanied the sample to BC Laboratories, a state of California certified laboratory located in Bakersfield, California. The analyses performed by BC Laboratories included VOCs by EPA Method 8260B. The July 13, 2017 sample was also analyzed for nitrate/nitrite (as nitrogen) by EPA Method 353.2. The laboratory reports attached to this letter show three values for each chemical compound that was analyzed: the method detection limit (MDL), the practical quantitation limit (PQL), and the result of the analysis. The MDL is the lowest concentration the laboratory can measure and the PQL is the lowest concentration that can be accurately quantified. A laboratory result of ND means the VOC was not detected at a concentration equal or greater than the MDL. A laboratory result followed by the letter "1" is a "trace" concentration that falls between the MDL and PQL. This value is an estimate. A reported result greater than the PQL is not qualified with a "1" and is an accurate value. The laboratory reports also include the results of internal laboratory quality control tests that are performed to verify the laboratory instruments are operating within the tolerances required by the analytical method and that the sample(s) being tested are not affected by laboratory contamination. Review of the quality control test results for the samples collected from your well in June and July 2017 shows that the laboratory equipment was operating within its specified tolerances and that the samples were not affected by laboratory contamination. RESULTS As shown on the attached laboratory reports and summarized in the following table, four VOCs were detected in the groundwater sample collected on June 30, 2017. Tetrachloroethene (PCE) and trichloroethene (TCE) were measured at quantifiable concentrations of 0.97 and 3.3 micrograms per liter (µg/L), respectively, and estimated trace concentrations of chloroform and trichlorofluoromethane (TCFM) were also detected in the primary sample. In response to the detection of these VOCs, a 40 confirmation sample was collected from the well on July 13, 2017. The trace concentrations chloroform and TCFM were not detected in the confirmation sample; however, PCE and TCE were confirmed. A M:\SO17.1030\7255 Newcastle.dou 2