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<br /> Work Plan Addendum -2- 21 September 1992
<br /> DDRW, Sharpe
<br /> Of particular concern, is that no other investigation is proposed for the two
<br /> waste solvent tanks (Nos. 29 and 52) . These waste solvent tanks were discussed
<br /> at the 7 May 1992 Project Manager's Meeting. This is our third letter regarding
<br /> our concern that these non-fuel USTs have been inadequately investigated (our
<br /> previous letters were 7 November 1991 and 17 April 1992) . Furthermore, UST No.
<br /> 29 is not in the existing or proposed ground water extractions systems. If
<br /> ground water contamination is found in the area of UST No. 29, remediation must
<br /> be included in the 1994 site-wide ROD. My concerns regarding WMUs in the South
<br /> Balloon Area have not even been addressed in this Work Plan. The Work Plan
<br /> should be revised to reflect Sharpe's commitment to investigate these potential
<br /> ground water contamination sources.
<br /> The September 1991 Work Plan for USTs and the February 1992 PAR for USTs
<br /> provided a summary table (Table 2-2 and 1-2, respectively) for all fuel and non-
<br /> fuel USTs. Based on this table, there were 14 non-fuel USTs (Nos. 10, 11, 20,
<br /> 27, 35, 36, 37, 48, 49, 50, 51, 53, 55 and 71) which contained either waste oil
<br /> or contaminated fuel . Table 2-1 of the Work Plan Addendum lists only eight of
<br /> these tanks (Nos. 27, 35, 36, 37, 48, 49, 55 and 71) . Discrepancies between the
<br /> tables need to be clarified. Table 2-1 also lists an oil/water (O/W) separator
<br /> (No. 60) . However, there are six O/W separators listed in the older tables (60,
<br /> 66, 67, 68, 69 and 70) . It is unclear why only one 0/W separator would require
<br /> investigation over the other five O/W separators.
<br /> The February 1992 PAR for USTs provided the results for the first phase of
<br /> investigation of USTs. Eight USTs were investigated (Nos. 2, 5, 6, 15, 18, 27,
<br /> 34 and 49) . Only three of these USTs contained non-fuels, No. 6 (pesticides) ,
<br /> No. 27 (diesel/waste oil ) and No. 49 (waste oil) . Because two of the 14 waste
<br /> oil/contaminated fuel USTs have already been investigated and five non-fuel USTs
<br /> are proposed for investigation (Nos. 35, 36, 37, 48 and 71) , there appear to be
<br /> seven non-fuel USTs that are not proposed for investigation (Nos. 10, 11, 20,
<br /> 50, 51, 53 and 55) . Sharpe should investigate these additional non-fuel USTs to
<br /> determine if these are potential sources of ground water contamination.
<br /> Additional monitor wells may be needed in the areas of these USTs.
<br /> The Work Plan Addendum proposes to investigate the non-fuel USTs by using test
<br /> pits for only six of the USTs containing waste oil or contaminated fuel . Sharpe
<br /> should provide additional justification or data as to why the additional eight
<br /> waste oil/contaminated fuel USTs are not to be investigated. USTs which are not
<br /> investigated in this phase must be investigated in a subsequent phase. Once all
<br /> of the non-fuel USTs have been investigated, a summary table listing the
<br /> findings of contaminant concentrations should be prepared.
<br /> A summary table of the WMU investigations has not been presented in the Soils FS
<br /> Report. It is not possible to assess whether specific WMUs have caused
<br /> significant soil contamination which poses a potential threat to water quality
<br /> and the need for additional monitor wells immediately down gradient of these
<br /> WMUs cannot be adequately assessed. A spread sheet, similar to what was
<br /> provided for the USTs, is needed to assure that adequate investigation of each
<br /> WMU has been conducted.
<br /> 2. Sharpe proposes to collect additional soil samples in the North Balloon Area for
<br /> the pesticide mix area (near Building T-47) and WMU No. 26. In the pesticide
<br />
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