Laserfiche WebLink
Work Plan for UGT Investigations -5- 7 November 1991 <br /> DDRW, Sharpe Site <br /> Tank Site Rationale for Well Installation <br /> D-42 Soil sample data had high concentrations of gasoline and <br /> BTX and elevated concentrations of diesel (110, 15.99 and <br /> 1000 mg/kg, respectively) . <br /> D-44 Soil sample data had high concentrations of diesel , <br /> gasoline and BTX (2700, 230 and 20.1 mg/kg, respectively) . <br /> Page 3-1. The Plan states that the soil borings are to extend to a depth of 15 <br /> feet. A depth of 15 feet below ground surface may not provide <br /> representative samples from beneath the UGT. The soils borings should be <br /> installed in the excavated tank site and samples should be collected <br /> starting at the base of the excavated tank and should extend to the <br /> ground water table, which may or may not be 15 feet. <br /> Page 3-1. The Plan states that all 20 soils borings will be analyzed for lead. <br /> However, based on the analytical results for heavy metals in the soils <br /> samples from the tank sites (as listed in Table 2-2) , very few of the <br /> tank sites appear to have elevated concentrations of lead. Therefore, <br /> analysis for lead may be excessive. The Plan should have more clearly <br /> justified why analysis for lead is needed at each of the soil borings <br /> sites. <br /> Pages 3-2 Figures 3-1 to 3-4 depict the locations of the soils borings and <br /> to 3-5. monitoring well locations. These Figures depict 16 soils borings and <br /> seven monitor well locations. These numbers of borings and wells do not <br /> correspond to the number of borings and wells as discussed in the text <br /> and tables. Therefore, the Figures need to be revised to correspond to <br /> the text. <br /> Figures 3-1 to 3-4 depict the locations of the soils borings outside of <br /> the area of the tank excavations. The soils borings should be installed <br /> inside of the area of the former tanks. Soils samples taken vertically <br /> through the former tank site, rather than outside of the tank site, are <br /> more likely to have been impacted from a leak in the tank. <br /> Page 3-9. Tables-1 lists the analytical parameters for the proposed soils borings. <br /> Tank area 0 (tank D-6) is to be analyzed for organochlorine pesticides <br /> (Method 8080) and volatile organics (Method 8240) . Rather than analyzing <br /> for volatile organics in samples from a tank that was known to contain <br /> pesticides, the samples should be analyzed for some of the other types of <br /> pesticides such as organophosphorus pesticides (Method 8140) , carbamate <br /> pesticides (modified Method 632) and chlorinated herbicides (Method <br /> 8150) . <br /> Page 3-10. Figure 3-5 depicts the proposed soils samples locations to be analyzed <br /> for lead using a portable X-ray fluorescence (XFR) unit in the area of <br /> Building S-119. Soils samples S3-SED1, as listed on page 6-247 in the RI <br /> Report, did not reveal high concentrations of lead in the sludge samples <br /> from the sump. Therefore, it is unclear why so many samples need to be <br /> analyzed for lead using the XFR unit. The Plan should have more clearly <br />