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<br />North County Recycling Center & Sanitary Landfill Public Works/Solid Waste <br />First Semiannual 2024 Groundwater Monitoring 5 ©2024 COUNTY of San Joaquin. All Rights Reserved. <br /> <br />A DMP Evaluation Report was submitted to the Regional Board on November 15, 2021 and <br />provided evaluation of the monitoring network for data gaps and effectiveness, evaluation of <br />historical changes in groundwater flow direction beneath the landfill, and three (3) proposed <br />monitoring well locations to fill gaps in the monitoring network and provide a point of compliance <br />well for Module 5. Regional Board’s review and conditional approval was provided on <br />December 13, 2021. The three monitoring wells (G-12, G-13, and G-14) were installed per the <br />approved work plan in June 2022. Due to pump procurement and supply chain delays, pumps <br />were not received and installed until June 2023. Five-Year COC sampling was completed in late <br />June 2023 and a Well Installation Report with the details of the drilling, installation, development, <br />and groundwater sampling was submitted on August 23, 2023. <br />MONITORING PROGRAM <br />Groundwater <br />Detection monitoring wells on northern side of the landfill consist of G-7 and G-8. Detection <br />monitoring wells on western side of the landfill consist of G-5B, G-9, and G-13. Detection <br />monitoring well G-11 is on southern side of the landfill. Detection monitoring wells G-10 and <br />G-14 are on eastern side of the landfill. Monitoring well G-12 is the background well for statistical <br />evaluation. <br />The groundwater well network is shown on Figure 3 and Figure 4. During November and <br />December 2016, groundwater monitoring wells G-7 and G-8 were installed. Monitoring well G-9 <br />was installed in October 2017. Monitoring wells G-5B, G-10, and G-11 were installed in February <br />and March 2018. Monitoring wells G-12, G-13, and G-14 were installed in June 2022. <br />Groundwater samples are collected consistent with the Sampling and Analysis Procedures <br />(Appendix A) and monitored semiannually for the following field parameters: <br /> Elevation (Quarterly) pH <br /> Temperature Turbidity <br /> Dissolved Oxygen (DO) Redox Potential (ORP) <br /> Electrical Conductivity (EC) <br /> <br />Groundwater samples are analyzed semiannually for the following monitoring parameters: <br /> VOCs Total Alkalinity <br /> Chloride Total Hardness <br /> Total Dissolved Solids (TDS) Chemical Oxygen Demand (COD) <br /> <br />Groundwater samples are analyzed annually for the following monitoring parameters: <br /> Bicarbonate Nitrate-Nitrogen <br /> Sulfate Calcium <br /> Magnesium Potassium <br /> Sodium <br />