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2018 ANNUAL GROUNDWATER MONITORING REPORT FORMER KEARNEY—KPF FACILITY-STOCKTON,CALIFORNIA <br /> pumping of municipal supply well CWS-77, located just west of the site, has a marked impact on water levels and the <br /> direction of groundwater movement beneath the site. <br /> The treatment system extraction wells were operating during measurement of water levels on October 30, 2018.Water <br /> supply well CWS-77 was not pumping while water levels were being measured on October 30, 2018. On October 30, <br /> 2018, groundwater in the shallow and intermediate zones was moving generally toward the center of the site, and <br /> groundwater in the deep zone was generally moving toward the east-northeast. <br /> The following discussion addresses groundwater movement as determined from data collected during the annual <br /> groundwater monitoring event the week of October 30, 2018, and compares it to observations made during the <br /> previous monitoring event in May 2018 (Appendix C, Q2 2018 Water Level Elevation Contour Maps). Groundwater <br /> flow and direction for each of these monitoring events and for monitoring events from previous years are <br /> summarized in Table 7, Groundwater Flow Direction and Gradient. <br /> The estimated linear velocity of groundwater movement for each zone was calculated using the following equation: <br /> Average linear velocity= (hydraulic conductivity x gradient)/effective porosity <br /> 3.2.1 Shallow Zone <br /> The hydraulic gradient in the shallow zone was calculated based on water levels measured on October 30, 2018, <br /> in wells SMW-5, KS-6,and KS-8.The hydraulic gradient was 0.00906 feet per foot(ft/ft)(Table 7),with groundwater <br /> flowing generally toward the center of the site (Figure 3). In May 2018, the direction of groundwater flow in the <br /> shallow zone was toward the center of the site.The gradient in May 2018 was 0.00868 ft/ft. <br /> Aquifer testing conducted at the site previously yielded estimates of hydraulic conductivity in the shallow zone <br /> ranging from 0.87 feet per day to 6.02 feet per day(Dudek&Associates 1997).The effective porosity of the shallow <br /> zone was estimated at 0.0785, based on laboratory determinations of specific retention and total porosity. Based <br /> on the observed gradient in October 2018, a high-end estimated hydraulic conductivity of 6.02 feet per day, and <br /> an effective porosity of 0.0785, the estimated average linear velocity of groundwater in the shallow zone was <br /> 0.6948 feet per day(Table 7). <br /> 3.2.2 Upper Intermediate Zone <br /> The hydraulic gradient in the upper intermediate zone is based on the water levels measured on October 30, 2018, <br /> in monitor wells KI-6, KI-8,and KPU-5.The hydraulic gradient was 0.01361 ft/ft(Table 7),with groundwater flowing <br /> generally toward the center of the site (Figure 4). In May 2018, the direction of groundwater flow in the upper <br /> intermediate zone was toward the center of the site and the hydraulic gradient was 0.01341 ft/ft. <br /> Aquifertesting previously conducted atthe site yielded estimates of hydraulic conductivity in the upper intermediate <br /> zone ranging from 4.32 feet per day to 111.31 feet per day. The arithmetic mean of these hydraulic conductivity <br /> estimates is 37.72 feet per day (Dudek&Associates 1997).The effective porosity of the upper intermediate zone <br /> was estimated to be 0.225, based on laboratory determinations of specific retention and total porosity (Dudek & <br /> Associates 1997). Based on the observed gradient in October 2018, an estimated hydraulic conductivity of 37.72 <br /> feet per day, and effective porosity of 0.225, the estimated average linear velocity of groundwater in the upper <br /> intermediate zone was 2.2816 feet per day(Table 7). <br /> D U D E K 10886-1 <br /> 8 March 2019 <br />