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Robert Williams <br />September 28, 2023 – Orange Grove Rd W&R Center – Supplemental Tasks #2 <br />Page 3 of 6 <br /> <br />Following well construction, we will collect depth-to-water measurements after the groundwater has <br />had sufficient time to stabilize, develop and sample the wells using new disposable polyethylene <br />tubing inserted into each temporary well location and connected to a peristaltic pump. During the <br />well development activities, a handheld YSI multiparameter instrument will be used to measure <br />temperature, turbidity, dissolved oxygen, conductivity, specific conductance, and pH of the extracted <br />groundwater to verify that representative samples are collected. Development activities will cease <br />when the measured parameters have stabilized or until the sample location fails to generate <br />groundwater due to slow recovery. Following well development and confirmation of stable <br />parameters, groundwater samples will be pumped from each well directly into laboratory-provided <br />glassware. The groundwater samples will be transported in an ice-filled cooler under chain-of- <br />custody protocols and shipped overnight to a North Carolina certified laboratory for analyses of the <br />following: <br />Arsenic Aluminum Barium <br />Chemical Oxygen Demand Fecal Coliform Total Coliform <br />Calcium Copper Cadmium <br />Total Chromium Chloride Iron <br />Magnesium Manganese Mercury <br />Total Ammonia TKN (as N) Nitrate <br />Nitrite Nickel Lead <br />Oil and Grease Phenol Phosphorous <br />Orthophosphate Potassium Total Dissolved Solids <br />Total Organic Carbon pH Specific Conductance <br />Zinc Sulfate <br />Following sample collection, we will abandon the wells in accordance with 15A NCAC 02C.0113. We <br />will prepare a letter report for Orange County Solid Water that summarizes our sample collection <br />activities, provides the laboratory analytical results with comparison to results obtained from <br />monitoring well(s) installed on Field 11-8 to determine if there is a measurable contribution of <br />pollutant loading from the spray irrigation system that will impact the allowable pollutant loading <br />from the septic system planned for the solid waste site. <br />Assumptions: <br />A. Site will be accessible with our Geoprobe DPT truck-mounted rig. <br />B. Standard turnaround time (10 business days) for lab <br />C. No duplicate samples, trip blanks or equipment blanks <br /> <br /> <br />DocuSign Envelope ID: BB84C0E6-F492-4E59-8BE1-7BCC7B770892