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Page 4 <br /> December 20,2023 <br /> Brusca File No. 260-004 Groundwater Monitoring Wells Workplan <br /> A two-inch diameter locking well plug will be installed at the upper end of each casing, and the <br /> top of each monitoring well will be protected with a traffic-rated, flush-mounted vault. The top <br /> of each well casing will be surveyed for location and elevation by a licensed land surveyor. <br /> Well Development <br /> Well development will be performed no sooner than 72 hours following well construction; this <br /> will allow adequate time for the grout in the well to set completely. A bailer or surge block will <br /> be used to gently tap the bottom of the well to suspend and remove settled particles. <br /> Development will be accomplished by pumping; pumping of the well will begin from a depth of <br /> about five feet from the bottom of the well and continue until approximately ten well volumes <br /> have been removed and pH, temperature, and conductivity have stabilized. The pump will be <br /> raised periodically during development to remove fines from most of the water column. <br /> Initial Groundwater Sampling <br /> Initial groundwater sampling will be performed at least 24 hours after well development so that <br /> aquifer conditions can equilibrate prior to sampling. Prior to sampling, the static water level <br /> within each well will be measured with a water level meter to the nearest 0.01 foot. <br /> Additionally, the wells will be gauged with an interface probe to determine whether free product <br /> (NAPL) is present, and if so, to measure the NAPL thickness. <br /> Groundwater purging and sampling of the groundwater monitoring wells will be performed via <br /> low flow (minimal drawdown) micro-purging techniques using a bladder pump and controller. <br /> Advantages of this purging/sampling methodology include significant reduction in the sampling- <br /> induced turbidity and minimizing the amount of generated purge water. At each well, the flow <br /> and pump controller will be monitored and adjusted to establish optimum flow, and the <br /> groundwater depth within the well will be continuously monitored to minimize drawdown. The <br /> temperature, pH, conductivity, dissolved oxygen, oxygen reduction potential, and turbidity of the <br /> well water will be measured using a flow-through cell and parameters meter during purging of <br /> each well. Following stabilization of the water quality parameters, groundwater samples will be <br /> collected via the tubing used for purging; the groundwater samples will be pumped directly into <br /> laboratory-provided sample containers (VOAs). Each groundwater sample will be labeled, <br /> placed on ice, and logged onto a chain-of-custody form prior to transport to the analytical <br /> laboratory. <br /> Equipment Decontamination and Investigation Derived Wastes <br /> Decontamination will include thoroughly cleansing and rinsing drilling, purging, measuring, and <br /> sampling equipment. Additionally, soil cuttings and wastewater generated during well <br /> installation, development and sampling will be containerized in 55-gallon drums and stored on <br /> the subject property pending disposal. <br /> LABORATORY TESTING <br /> The groundwater samples collected from the completed monitoring wells will be transported to a <br /> State-certified laboratory for analysis. The groundwater samples will be analyzed for gasoline, <br />