This report was revised in September 2008 to remove acid-extractable sodium data from Tables 4. 8, 4.28,4.43, and 4.59. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in April 2004.The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area (WMA) T-TX-TY. This report is the first of two reports written to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from boreholes C3830, C3831, and C3832 in the TX Tank Farm, and from borehole 299-W-10-27 installed northeast of the TY Tank Farm.

Executive SummaryThis report was revised in September 2008 to remove acid-extractable sodium data from Tables 4.8, 4.28, and 4.52. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in September 2004.The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area (WMA) T-TX-TY. This report is the second of two reports written to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from boreholes C4104 and C4105 in the T Tank Farm, and from borehole 299-W-11-39 installed northeast of the T Tank Farm. Finally, the measurements on sediments from borehole C4104 are compared with a nearby borehole drilled in 1993, 299-W10-196, through the tank T-106 leak plume.Sediments from borehole 299-W-11-39 were considered to be background uncontaminated sediments against which to compare contaminated sediments for the T tank farm characterization effort. However, during characterization of the sediments from 299-W11-39, numerous indications were found that suggest some nearsurface contamination may have occurred in the past such that the water extract information for sediments from 299-W11-39 may not represent natural background conditions. Therefore, most of the comparisons of the contaminated T tank farm boreholes to natural background conditions used the sediment characterization information from background borehole 299-W10-27, just northeast of the TX Tank Farm.This report also presents our interpretation of the data in the context of sediment types, the vertical extent of contamination, the migration potential of the contaminants, and the likely source of the contamination in the vadose zone and groundwater below the T Tank Farm. The information presented in this report supports the T-TX-TY Waste Management Area field investigation report (a) in preparation by CH2M HILL Hanford Group, Inc. Sediment samples from the boreholes were analyzed and characterized in the laboratory for the following parameters: moisture content, gamma-emitting radionuclides, one-to-one water extracts (which provide soil pH, electrical conductivity, cation, trace metal, radionuclide and anion data), total carbon and inorganic carbon content, and 8 M nitric acid extracts (which provide a measure of the total leachable sediment content of contaminants). Key radiocontaminants, technetium-99, actinides, fission products (including strontium-90, europium radioisotopes, ruthenium and molybdenum), cobalt-60, and uranium, along with other trace metals were determined in acid and water...

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Executive SummaryThis report was revised in September 2008 to remove acid-extractable sodium data from Table 4.8. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in June 2003.The overall goals of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are: 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid via collection of geotechnical information and data, future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank waste management areas. For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at the B-BX-BY tank farm waste management area are found in CH2M HILL (2000).To meet these goals, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses of vadose zone sediment, both uncontaminated and contaminated, from within B-BX-BY Waste Management Area.Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from the Resource Conservation and Recovery Act borehole 299-E33-338 that is near B-BX-BY Waste Management Area. This report is one in a series of three reports to present recent data collected on vadose zone sediment that provides a baseline to compare with information from two contaminated boreholes within B-BX-BY Waste Management Area: 1) borehole 299-E33-45, and 2) borehole 299-E33-46 northeast of tank B-110, which has been decommissioned. This document describes all the characterization data collected and interpretations for borehole 299-E33-338 assembled by the Applied Geology and Geochemistry Group within the Environmental Technology Division of the Pacific Northwest National Laboratory and is incorporated in the B-BX-BY field investigation report.The geology under the B-BX-BY Waste Management Area forms the framework through which the contaminants move, and as discussed in Serne et. al. 2002, provides the basis with which to interpret and extrapolate the physical and geochemical properties that control the migration and distribution of contaminants. Specifically, the identification of major lithological contacts and the interrelationships between the coarser-and finer-grained sediment facies are essential when combined with the geochemical profile for interpreting contaminant behavior in the subsurface. For this borehole, lithologic sections were constructed using detailed geologic descriptions, core photos, and geophysical logs. ...

Executive SummaryThis report was revised in September 2008 to remove acid-extractable sodium data from Table 4.22. The data was removed due to potential contamination introduced during the acid extraction process. The remaining text is unchanged from the original report issued in 2002.The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area B-BX-BY. This report is the first in a series of four reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole 299-E33-45 installed northeast of tank BX-102.This report also presents interpretation of the data in the context of the sediment lithologies, the vertical extent of contamination, the migration potential of the contaminants, and the likely source of the contamination in the vadose zone, perched water and groundwater east of the BX tank farm. The information presented in this report supports the Waste Management Area B-BX-BY field investigation report prepared by CH2M HILL Hanford Group, Inc. (a) Overall, the analyses identified common ion exchange and heterogeneous (solid phase-liquid solute) precipitation reactions as two mechanisms that influence the distribution of contaminants within that portion of the vadose zone affected by tank liquor. Significant indications of caustic alteration of the sediment mineralogy or porosity were not observed, but slightly elevated pH values between the depths of 79 to 141 ft below ground surface (bgs) were observed. X-ray diffraction measurements indicate no evidence of mineral alteration or precipitation resulting from the interaction of the tank liquor with the sediment. However, no samples were studied by scanning electron microscopy, a more sensitive technique for searching for faint evidence of caustic attack.The analyses do not firmly suggest that the source of the contamination in the groundwater east of the BX tank farm is the 1951 overfill event at tank BX-102. However, evidence is convincing that the fluids from the overfill event are present in the vadose zone sediments at borehole 299-E33-45 to a depth of 170 ft bgs.The near horizontally bedded, northeasterly dipping sediment likely caused horizontal flow of the migrating contaminants. At borehole 299-E33-45, there are several fine-grained lenses within the Hanford H2 unit at 74.5, 120, and 167 ft bgs that likely cause some horizontal spreading of percolating fluids. The 21-ft thick Plio-Pleistocene fine-grained silt/clay unit is also an important horizontal flow conduit as evidenced by the perched water zone between 227 and 232 ft bgs.The following are the key findings of the detailed characterization o...