WORK PLANS - Laserfiche WebLink

Home Browse Search

Mr. Alan M. Buehler May 19, 2017 notified at least 72 hours prior to intrusive field activities. In addition, each location will be hand cleared using an air knife and/or hand auger to a minimum depth of 6.5 feet bgs to further evaluate the presence of potential underground utilities near the proposed soil boring locations. Soil Borings, Sampling,and Screening Previously proposed borings B-49 and B-50 are near wells EW-2/EW-3 and VW-1, respectively. Previously proposed boring B-51 is offsite near well MW-15. Proposed borings B-52 and B-53 are near well VW-15MN-16 and boring BS-9, respectively. Borings B-49, B-50, B-51, B-52, and B-53 are proposed to approximately 70 feet bgs, and soil samples will be collected near previously impacted areas. Boring B-54 is proposed near 1-2-1-2.5 to update benzene and ethylbenzene concentrations at historical soil boring location L1-1-2.5 that exceeds the Direct Contact thresholds presented in Table 1 of the Low Threat Closure (LTC) Policy. Borings B-55 and B-56 are proposed near the former waste oil tank grab samples AT-1A and AT-2A, and boring B-57 is proposed in the northeast corner of the property outside the known petroleum hydrocarbon impacted area to establish naturally occurring background metals concentrations. Proposed soil samples will be collected at 2.5 feet bgs (B-54), 13 feet bgs (B-55), 6 feet bgs (B-56), and 6 and 13 feet bgs (B-57). Soil samples will be collected and submitted for chemical analysis based on field photo ionization detector(PID) measurements. Arcadis proposes advancing the soil borings using 8-inch hollow stem augers (HSA). During HSA advancement, soil will be collected with a split-spoon sampler at approximate 5-ft intervals and logged in accordance with the Unified Soils Classification System and screened for the presence of volatile organic compounds (VOC) using a PID. The PID results, measured in parts per million, from the field screening will be recorded on the field boring logs. The soil screening procedures will involve measuring approximately 30 grams of soil from a relatively undisturbed soil sample and placing this sample in a sealed container(zip-lock bag). The bag will be warmed in the sun for approximately 20 minutes, and the head space within the bag will be tested for VOCs. Select soil samples will be placed on ice, cooled to approximately 4 degrees Celsius(°C) and transported under chain-of-custody documentation to a State of California certified laboratory to be analyzed as summarized below. Soil samples collected from borings B-49, B-50, B-51, B-52, B-53, and B-54 (2.5 feet bgs)will be analyzed for the following constituents: • GRO [C6-C12] by USEPA Method 8015B modified • BTEX, and 1,2-DCA by USEPA Method 8260B • MTBE by USEPA Method 8260B Soil samples collected from borings B-55 (6 feet bgs) and B-56 (13 feet bgs)will be analyzed for the following constituents: • GRO [C6-C12], DRO, and TOG by USEPA Method 80158 modified • VOCs, SVOCs, PCBs, and Title 22 metals by USEPA Method 8260B arcadis.com Page: CA 06100 170519 BP Revised Work Plan.docx 3/6