WORK PLANS - Laserfiche WebLink

Home Browse Search

Mr. Ross Atkinson Page 2 of 4 published information (San Joaquin County Flood Control & Water Conservation District) groundwater is expected to flow toward the east or northeast. Analytical Results of Broken Tile Material On August 23, 2001, Advanced GeoEnvironmental collected twenty samples of the tile material. Laboratory analysis detected concentrations of total TPHd ranging from 200 to 2,500 parts per million (ppm) and averaging 1,010 ppm. Leachable concentrations of TPHd (DI -WET extraction) ranged from 11 ppm to 38 ppm and averaged 22 ppm. Leachable Cr6 ranged from 10 parts per billion (ppb) to 40 ppb and averaged 26.5 ppb. PROPOSED SCOPE OF INVESTIGATION To investigate whether the contaminants have impacted groundwater, Ground Zero proposes to drill and sample three soil borings at the approximate locations shown on Figure 2. Based upon the data obtained, groundwater monitoring wells may or may not be proposed. Drilling and Discrete Soil and Groundwater Sampling Drilling will be conducted under the supervision of an experienced geologist. A C-57 licensed drilling contractor will advance the soil borings using a Geoprobe rig. Soil will be classified in accordance with ASTM Designation D2488-90, which is equivalent to the Unified Soil Classification System. A photoionization detector (PID) will be used to screen all soil samples for evidence of hydrocarbon contamination. Soil and groundwater samples will be collected from the borings for laboratory analysis. Direct Push Drilling and Sample Collection A total of three soil borings will be advanced at the approximate locations shown on Figure 2 using a truck mounted Geoprobe rig. One boring will be placed in the indicated downgradient direction of the tile stockpile. One boring will be located immediately upgradient of the stockpile and the third boring will be located near the extreme southwestern comer of the property. This boring is intended to serve as a background sampling point. The borings will be drilled to fust groundwater, which is expected to occur at a depth of 30 feet or less. Upon completion, the soil borings will be backfilled with neat cement grout to ground surface. Soil samples will be collected from the borings at five-foot intervals to total depth for lithologic identification and field screening for contamination. Selected soil samples will be submitted to a State -certified laboratory for analysis. Soil sample selection will be based on field evidence of petroleum hydrocarbon contamination such as discoloration, odors, PID readings, as well as lithologic changes. If no evidence of contamination is noted in the field, two soil samples from each boring will be selected for analysis based on lithology. Samples selected for analysis will be immediately capped, segregated and preserved by placing in an ice chest at a temperature of approximately 4°C, and wil be transported to the laboratory under chain of custody protocol. G:\GROUNDZE\Alcgm\REPOItTS\hydpuWKPLAN.doc