SR2500864 - Laserfiche WebLink

Home Browse Search

Geospte& consultants including those regarding petroleum vapor intrusion to indoor air(including characterizing the bioattenuation zone through collection of oxygen data), as well as direct contact and outdoor air exposure. Soil vapor data will be used to develop the CSM. Grab-groundwater samples will be collected from first encountered groundwater to delineate the lateral extents of petroleum impacts to groundwater to the east(boring 817B-11), south(boring 817B-19), and west(borings 817B-15 and 817B-16) of the former UST excavation area. An additional grab groundwater sample will be collected from boring 817B-13, adjacent to the soil vapor location where the highest detection of benzene was noted(SVP-3). Groundwater samples will be collected from the existing monitoring well network to be able to capture current concentrations that are reflective of conditions at the time of grab groundwater sampling. Groundwater sample data will be used to evaluate groundwater-specific criteria listed in the LTCP, as well as develop the CSM. The analytical results produced from this investigation will be compared against the criteria presented in the LTCP. Target locations, sampling depths, and target analytes are summarized in Table 1 and Figure 8. The remainder of this Work Plan describes the scope of work for implementing the above activities. 4. INVESTIGATION WORK PLAN 4.1 Pre-field Activities Prior to the initiation of field work, Geosyntec will conduct the following activities: • Coordinate with the Port of Stockton to notify tenants of field investigation activities, as needed. • Develop a task-specific Task Hazard Analysis (THA)based on field activities and conditions anticipated in the field. • Obtain a soil boring permit from San Joaquin County Environmental Health Department(SJCEHD). • Mark boring and sample locations in white paint or whisker and nail markers with a handheld global positioning system (GPS)unit. • Submit an Underground Service Alert (USA) ticket to notify utility line owners prior to investigation regarding planned investigation activities. • Contract a private utility locator to clear the boring locations for subsurface utilities. At the beginning of each day prior to field activities, a safety tailgate meeting will be conducted to discuss field activities to be performed, potential hazards and related safe work practices, use of personal protection equipment(PPE), decontamination procedures, and emergency response protocols. 4.2 Field Activities The following sections outline protocols for collecting soil, soil vapor, grab groundwater, and monitoring well groundwater samples. Figure 8 illustrates proposed soil, soil vapor, grab Investigation Work Plan—UST 817B 6 December 2024