ARCHIVED REPORTS_2008_22 - Laserfiche WebLink

Home Browse Search

A single sample set was collected from each point containing sufficient liquid and submitted to BC Laboratories, Inc. (BC) of Bakersfield, California, a state certified laboratory under contract to Forward. Samples were analyzed for the parameters stipulated in RWQCB Order No. R5-2003-0049. Table 2-1 summarizes site monitoring parameters, analytical methods, and monitoring frequency. Water quality samples were also analyzed in the field for dissolved oxygen, turbidity,temperature, specific conductance, and pH and recorded on well data sheets. The groundwater monitoring wells, surface water monitoring points, and leachate monitoring points were sampled in accordance with the sampling and analysis procedures detailed in Appendix B. The well data sheets, laboratory data, certificates of analyses, and chain-of-custody records for the sampling program are included in Appendix C. The laboratory analyses and field results for groundwater monitoring wells, surface water stations, lysimeter and leachate sampling stations are summarized in Tables 2-2 through 2-8. 2.1.2 QA/QC Results The quality assurance/quality control (QA/QC)program completed for the first quarter 2008 water quality monitoring event included analyses of five field blanks, five trip blanks, five laboratory method blanks,and one duplicate sample. The trip, field, and laboratory method blanks were analyzed for volatile organic compounds (VOCs)by EPA Method 8260. The results of the QA/QC program indicate that chloroform and t-butyl alcohol were detected in field blank, and methylene chloride was detected in the trip blank collected during the March 18, 2008 lysimeter sampling event. Review of the primary sample results indicates that only t-butyl alcohol was detected in the primary samples collected from the Forward Unit and was flagged as a suspected laboratory contaminant. Review of first quarter 2008 sampling dates and laboratory analytical certificates indicates that with the exception of the nitrate as nitrogen concentrations measured in four, samples the laboratory analyses were completed within required holding times. The holding times for nitrate as nitrogen was missed by less than 24 hours and are believed to be representative of the water quality conditions measured at the site. During the first quarter 2008 monitoring event, a duplicate sample was collected from well MW-19 and labeled MW-DUP. As shown on Table 2-2,the duplicate sample analyses yielded good correlation(within 5%)with the primary sample results. Based on the results of the laboratory QA/QC analyses, it is concluded that the laboratory data generated for the first quarter 2008 monitoring period are generally acceptable. 2.1.3 Groundwater Elevations and Contours Prior to purging and sampling, each well was sounded for water depth using a weighted electronic sounder to an accuracy of 0.01 foot, and the static water level was recorded on a Well Data Sheet(Appendix C). The groundwater elevations were calculated for each well by subtracting the depth-to-water measurement from the top-of-casing reference elevation. The current groundwater elevation data for the Forward Unit is summarized in Table 2-3. D:\2007-0043TA-1Q08.doc 4 Geologic Associates