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<br />North County Recycling Center & Sanitary Landfill Department of Public Works/Solid Waste <br />First Semiannual 2025 Groundwater Monitoring Report ©2025 COUNTY of San Joaquin. All Rights Reserved <br /> 14 <br />6 GROUNDWATER DIRECTION AND FLOW RATE <br />Groundwater elevations at the site vary seasonally, but overall trends at the site have been <br />decreasing since 2001. Groundwater elevations at G-14 were anomalously high compared to <br />the rest of the monitoring network during this First Quarter 2025 (approximately 16 feet higher <br />than the average elevation of the rest of the monitoring network). As a result, G-14 was not used <br />in contouring. During First Quarter 2025, wells G-1A, G-2A, G-3D, G-4, and G-5 were dry and <br />well G-6 had a water level that was below the bottom of screen and did not represent the level <br />of the water table. During Second Quarter 2025, wells G-1A, G-2A, G-3D, G-4, G-5A, and G-6 <br />were dry. As a result, these wells were not utilized during contouring. Groundwater gradients <br />and flow directions were based on the elevations in the remaining wells (Figures 3 and 4). <br />Local groundwater flow beneath the site is variable and appears to vary depending on <br />agricultural pumping, infiltration due to storm events, and regional changes in the aquifer. <br />Groundwater flow was calculated towards the southwest and west-southwest during the first half of <br />2025. The aver age calculated groundwater velocity to the southwest during First Quarter 2025 <br />was 101 ft/yr with a hydraulic gradient of 0.003 ft/ft. The average calculated flow velocity to the <br />west-southwest during Second Quarter 2025 was approximately 67 ft/yr with a hydraulic <br />gradients of 0.002 ft/ft (Appendix F).