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Water Quality Monitoring Report Forward Landfill records related to the sampling program are included in Appendix F. Field and laboratory analyses are summarized in Tables 2-2 through 2-7 and cumulative tabulated data for all monitoring points and constituents for groundwater, unsaturated zone, leachate, and surface water are presented in Appendix F. 2.1.2 gAj(& Results The quality assurance/quality control (QA/QC) program completed for the fourth quarter 2015 water quality monitoring event included analyses of two field blanks, laboratory method blanks, and one duplicate sample (MW -14). The field blanks were analyzed for VOCs by EPA Method 8260 and method blanks were analyzed for, all of the analytes included in the monitoring program. The results of the QA/QC program indicate that no VOCs were detected in the field or method blanks. Inorganic constituents including calcium, magnesium, and sodium were measured at trace concentrations in method blanks analyzed with groundwater samples. However, these constituents were measured at very low concentrations that do not affect the interpretation of primary sample results. The results of the duplicate sample collected from well MW -14 yielded good correlation with a relative percent difference (RPD) of 10 percent or less. Review of the sampling dates and laboratory analytical certificates indicates that all laboratory analyses were completed within required holding times. Based on the results jof the laboratory QA/QC analyses, it is concluded that the laboratory data generated for the fourth quarter 2015 monitoring period are acceptable and the water quality samples collected from the Forward Unit appear to be representative of water quality at the site. 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 F). 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. The groundwater elevation data obtained on November 16, 2015, were used to generate the groundwater elevation contour map shown on Figure 2-1 for the fourth quarter 2015 monitoring period, which indicates that groundwater beneath the southern and central portions of the Forward Unit flows to the south to southeast at a hydraulic gradient of 0.001 ft/ft, while groundwater beneath the northeastern portion of the Forward Unit flows to the northeast at a hydraulic gradient of 0.002 ft/ft. To calculate the approximate linear groundwater flow velocity for the Forward Unit, conservative assumptions were used, including a hydraulic conductivity of 875 gallons per day per square foot (0.04 cm/sec) and an estimated effective porosity of 35 percent • M:\ 2015.0014\FA-4Q15.docx 6 1/29/2016, Rev. 0