Laserfiche WebLink
Mr . Muniappa Naidu <br /> Page 3 <br /> Current Investigation <br /> On December 2 , 2019 Ground Zero submitted a workplan and boring permit application to <br /> San Joaquin County EHD to conduct a follow up soil and groundwater investigation . <br /> Protocols , Pre-field Work and Permitting Activities <br /> Fieldwork was conducted in accordance with the workplan and Ground Zero ' s Quality <br /> Assurance/Quality Control Plan and the Site-Specific Health & Safety Plan on file with EHD . <br /> A drilling permit was obtained from EHD (Attachment A) . Underground utilities were <br /> checked by clearly marking the proposed boring locations in white paint and calling the <br /> location in for a clearance ticket by Underground Services Alert (USA) . <br /> Fieldwork <br /> Three borings were drilled and sampled on January 16 , 2020 at the locations shown on <br /> Figure 2 . One shallow boring was installed within the former tankpit and two deeper <br /> borings were drilled 10 feet and 40 feet northeast of the tankpit in the hydraulically <br /> downgradient direction . Note that based on years of monitoring data from the JM <br /> Equipment site , located east adjacent to the subject site , shallow groundwater occurs at an <br /> average depth of approximately 13 feet and flows in a northeasterly direction . <br /> Soil samples were collected in all three borings and groundwater samples were collected <br /> from the two deeper borings . One soil sample was collected at a depth of five feet in the <br /> shallow boring . The sample was collected in a drive- sampling device containing a clean <br /> stainless - steel sampling sleeve . The deeper borings were continuously cored with samples <br /> contained in acetate sleeves . The sample from the shallow boring and the samples <br /> collected from the capillary fringe ( 12 feet bgs) in the deeper borings were sealed with <br /> Teflon film, capped , uniquely identified and placed in a chilled ice chest pending shipment <br /> to the laboratory for analysis . <br /> Upon completion of the soil sampling in the deeper borings , the rods were pulled and a <br /> Hydropunch sampling tool was advanced to a depth of approximately 18 feet. <br /> Groundwater samples were collected into 40-m1 HCl-preserved VOA vials using a <br /> peristaltic pump . The groundwater samples were checked for headspace , uniquely <br /> identified , and stored in a chilled ice chest pending delivery to the laboratory . Soil and <br /> groundwater sampling was witnessed by Mr. Paul Nso of San Joaquin Co . EHD . <br /> The borings were then sealed with neat cement grout emplaced via tremie pipe and the <br /> surface pavement restored . The grout sealing was witnessed by Mr . Jeff Wong of San <br /> Joaquin Co . EHD . Field Notes are included in Attachment B . <br /> Laboratory Analysis <br /> The samples were delivered under chain of custody protocol to State-certified BC <br /> Laboratories for analysis . The soil samples were analyzed for TPHg by LUFT-GC/MS ; for <br /> VOCs by EPA Method 8260 ; and for total lead by EPA Method 6010B . The groundwater <br /> samples were analyzed for TPHg and VOCs by LUFT-GC/MS and 8260B . <br /> Additional UST Soil and GW Sampling Report <br />