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n Approximately 60 to 70 gallons of water was discharged from the sample port (next to the well) 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 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 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, 1,2- dichloropropane (1,2-DCP) was detected at an estimated trace concentration in the groundwater sample collected on lune 21, 2017. In response to the detection, a confirmation sample was collected from the well on June 30, 2017. As shown in the table below, 1,2-DCP was also detected at an estimated trace concentration in the confirmation sample. However, the state and federal Maximum Contaminant Level (MCL) for drinking water was not exceeded in either of the samples. Analyte Units Results 6/21/17 Results MCL 6/30/17 1,2-Dichloropropane pg/L 0.21j 0.16j 5 Notes: j = Indicates an estimated value. NE = No MCL established for this constituent. M:\5017.1030\6555 Santa Ana.docx 2