Laserfiche WebLink
Work Plan for Shallow Soil Assessment and Proposed Well Sampling Schedule Modification <br />Stockton Charter Way Commingled Plume #CP0057 <br />February 17, 2023 <br />Per the CRWQCB-CVR directive dated December 20, 2022, the following sections present a Work <br />Plan to describe and detail the proposed scope of work. For reference, Figure 1 presents a Site <br />Location Map and Figure 2 presents a Site Plan with Proposed Soil Boring and Well Locations. <br />Historical soil analytical data are summarized in Table 1 and historical groundwater monitoring <br />and analytical data are summarized in Table 2. Soil boring and well construction details are <br />provided as Table 3. Regulatory correspondence is provided in Appendix A. <br />2.0 SHALLOW SOIL ASSESSMENT <br />Per the CRWQCB-CVR letter dated December 20, 2022 (Appendix A), additional shallow soil <br />assessment is proposed to confirm that post -remediation soil conditions at the former ARCO <br />property meet LTCP criteria. <br />2.1 PRE -FIELD ACTIVITIES <br />2.1.1 Health and Safety <br />Stantec will generate a site-specific Health and Safety Plan (HASP) or equivalent RMS -1 for the <br />proposed scope of work as required by the Occupational Health and Safety Administration <br />(OSHA) Standard "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR <br />1910.120). The document will be reviewed and signed by all onsite consulting personnel and <br />subcontractors prior to performing work at the site. <br />2.1.2 Permitting and Utility Clearance <br />Prior to conducting subsurface work, a subsurface drilling permit will be obtained from San <br />Joaquin County Environmental Health Department (SJCEHD). Underground Service Alert (USA) <br />will be contacted to delineate subsurface utilities near the proposed boring locations with <br />surface markings, and a private utility locator service will be contracted to clear the area. <br />Manual hand auger equipment will be used in place of an air knife so that shallow soil samples <br />can be collected for laboratory analysis. <br />2.2 SOIL BORING ADVANCEMENT <br />Hand auger soil borings (HA -1 and HA -2) will be advanced to ten feet below ground surface <br />(bgs) at the locations adjacent to P-1 and P-2 shown on Figure 2. Proposed soil boring <br />construction details are summarized in Table 3. <br />Soil borings will be manually advanced using hand auger equipment. Hand auger soil borings <br />will be advanced to collect soil samples at 5 and 10 feet for analysis of benzene, ethylbenzene, <br />and naphthalene to demonstrate compliance with the Direct Contact and Outdoor Air <br />Exposure criteria of the State Water Resources Control Board (SWRCB) LTCP. Soil samples will be <br />collected using an AMS hand auger core sampler or similar sampling device. AMS hand auger <br />core sampler and similar technologies involve the use of an outer stainless steel core to prevent <br />borehole collapse and an inner sleeve to collect relatively undisturbed soil samples. Sampling <br />® Stantec 5 <br />