Laserfiche WebLink
In July and December 2003, ATC conducted additional subsurface investigation activities at the <br /> site that included cone penetration testing, advancing a soil boring (S138), and installation of <br /> monitoring wells MW4 through MW7. Petroleum hydrocarbons were detected in soil samples <br /> collected from the boreholes of MW5 and MW6, and in the groundwater samples collected from <br /> MW4 through MW-7. Groundwater monitoring data and chemical analyses for MWl through <br /> MW7 are shown on Tables 1 and 2, respectively. <br /> SCOPE OF WORK <br /> Planning and Permits <br /> Upon approval of this workplan and boring locations by EHD, ATC will prepare an application <br /> to advance the borings in the City of Stockton right-of-way property. After this is complete, <br /> ATC will submit proof of access along with the permit applications and associated fees for the <br /> soil borings to EHD for approval. ATC will also schedule field personnel and equipment, notify <br /> Underground Services Alert to locate underground utilities as required, and perform any other <br /> necessary field preparation and job start-up activities. <br /> Advancement of Soil Borings <br /> To further assess the extent of impacted soil and groundwater at the site, a total of three soil <br /> borings will be advanced at the site. Groundwater flow and direction are shown on Figure 3. The <br /> proposed boring locations are shown on Figure 4. <br /> These soil borings will be advanced utilizing a truck mounted Geoprobe® drilling rig employing <br /> direct push technology, and at least two soil samples and one groundwater sample will be <br /> collected from each boring. If the boring shows obvious signs of impact by petroleum <br /> hydrocarbons, no groundwater sample will be collected; a permit will be attained and a <br /> monitoring well will be drilled via hollow stem auger. These borings will be advanced to <br /> evaluate the lateral extent of petroleum hydrocarbon impacted groundwater. It is anticipated that <br /> several of the borings will be advanced at off-site locations. Proposed boring locations are <br /> shown on Figure 4. <br /> These soil borings will be advanced to first encountered groundwater, anticipated to be <br /> approximately 55 feet bgs. Drilling will be conducted by a C-57 State licensed drilling company. <br /> A field geologist will be present to log soil samples. Descriptions of soil types encountered and <br /> sample collection intervals will be recorded on boring logs. Soil samples will be collected at <br /> five-foot intervals. Each soil sample will be field screened with a Photoionization Detection <br /> (PID) meter or similar instrument and at least two soil samples from each of the three borings, <br /> based on field observations (i.e. odor, discoloration, PID readings), will be placed in a cooler <br /> with ice and submitted for laboratory analysis. <br /> s:\22493\rcpons\Wkpin_add_inv2005.doc 3 <br />