ARCHIVED REPORTS_2017_8 - Laserfiche WebLink

Home Browse Search

• confirm the laboratory results from the primary sample). The well access sheet, well inspection sheet, well sampling data sheets,and laboratory reports for both sets of samples are attached. Approximately 60 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 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 "J" 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 "J"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. RESULTS As shown on the attached laboratory reports and summarized in the following table, acetone (a common laboratory contaminant) was detected at a quantifiable concentration in the groundwater sample collected on June 22, 2017. In response to the detection, a confirmation sample was collected from the well on June 30, 2017. As shown in the table below, acetone was not detected in the confirmation sample. Furthermore, no state or federal Maximum Contaminant Levels for drinking water were exceeded. Analyte Units Results Results MCL 6/22/17 6/30/17 Acetone µg/L 43 ND NE Notes: j=Indicates an estimated value. NE=No MCL established for this constituent. ND=Not detected. • M:\5017.1030\6258 Santa Ana.docx 2