SITE INFORMATION AND CORRESPONDENCE

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Pre-Design Technical Sumay 4- 19 December 1996 DDRW-Sharpe S. Surface sample SS0012 collected in the North Balloon contained 100 ug/I of soluble chromium. Since this sample is only approximately 10 -15 feet out of the area identified for excavation it seems appropriate to include this area into the North Balloon excavation. Additionally, the configuration of the area to be excavated would be simplified if this point were included. Specific Comments 1. Table 4-2, 44, 4-6, 4-7 and 4-10 list results of soil samples containing with metals concentrations greater than 10% of the Action Level. Please explain why the criteria of greater than 10% of the action level was selected. All results at or above the action levels should be presented. 2. Page 4-1, Section 4.2.1.2, states that the OF 2 ROD identifies eight areas in the North Balloon and six areas in the South Balloon as exceeding the action levels for lead and chromium and refer the reader to Figure 1-1. Figure 1-1 does not delineate eight areas in the North Balloon and/or six areas in the South Balloon. This discrepancy should be rectified. 3. Figure 4.8 shows area S33/29 to include only the previous samples identified as SB29-B4 and SB29-B 12, thereby leaving the area identified as S1329-139 overlooked by this round of field work. Please clarify why this area was not included in this effort. 4. Table 4-1 indicates the number of soil samples collected for metals analysis at sites S-3, 5-26, S- 36, 5-30 and 5-33/29. The number appearing in the column labeled"data" does not agree with the number of data points identified as "Radian surface scrape locations" shown on the corresponding figures 4-1 thru 4-9. Please explain the discrepancy. 5. Figure 4-21 shows a cross-section at P-IE with the cross-section location map shown in the lower right corner of this figure. Sampling locations CPO128 and CPO122 are transposed in the cross-section location map of this figure. 6. Page 4-9, Section 4.2.4.7 states that"DI WET analysis of soil samples collected previously within Sites S-30 and 5-36 were all below 40ug/l for lead and chromium." This statement is in error as the sample identified as 21E of 1F, located between 0-2 feet BGS within Site 5-36, contained 12,300 ug/1 of lead and 227 ug/1 chromium from DI WET analysis. The sample identified as 6C which could be considered part of Site 5-30 also contained soluble lead at 241 ug/I by DI WET analysis. 7. Page 4-31, Section 4.3.8.5, describes Figure 4-32 as displaying contaminant contours found at Site P-2B however Figure 4-32 is labeled Soil Gas at Site P-3A. Please correct. 8. Page 4-33, Section 4.3.9.9. The statements that"the mass calculated at P-4B indicates..." occurs within the discussion on Site P-3A. Please correct. 9. Page 4-41, Section 4.3.15.10 refers to Table 4-28. Table 4-28 is labeled as WE concentrations for Site 6A. Please correct.