HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Oostrom, M. Articles by Rohay, V. J. PubMed Articles by Oostrom, M. Articles by Rohay, V. J. GeoRef GeoRef Citation Agricola Articles by Oostrom, M. Articles by Rohay, V. J. Related Collections Flow Multi-Fluid Systems Multiphase Fluid Flow

SPECIAL SECTION: HANFORD SITE

Carbon Tetrachloride Flow and Transport in the Subsurface of the 216-Z-9 Trench at the Hanford Site

^a Environmental Technology Division, Pacific Northwest National Lab., P.O. Box 999, MS K9-33, Richland, WA 99352
^b Fluor Hanford, Inc., Richland, WA 99352
^* Corresponding author (mart.oostrom{at}pnl.gov).

Received 9 November 2006.

As a result of past practices, up to 580 m³ carbon tetrachloride (CT) was discharged to waste sites at the 200 West Area of the USDOE's Hanford Site near Richland, WA. Three-dimensional modeling was conducted to enhance the current conceptual model of CT distribution beneath the major disposal site (216-Z-9). The simulations, using the STOMP code, focused on migration of dense nonaqueous phase liquid (DNAPL) consisting of CT and codisposed organics under scenarios with differing sediment properties, sediment distribution, waste properties, and waste disposal history. Simulation results support a conceptual model for CT distribution where CT in the DNAPL phase migrated primarily in a vertical direction below the disposal site and where some CT DNAPL likely migrated across the water table into the regional aquifer. Results also show that the lower permeability Cold Creek unit retained more CT DNAPL within the vadose zone than other hydrologic units during the infiltration and redistribution process. Due to the relatively high vapor pressure of the CT, the resulting vapor plumes are extensive and influenced by density-driven advection. Any continued migration of CT from the vadose zone to the groundwater is likely through interaction of vapor phase CT with the groundwater and not through continued DNAPL migration. Additional simulations assessed the impacts of soil vapor extraction (SVE) as a remediation method. These simulations showed rapid CT removal associated with the assumed local equilibrium of CT between the phases. Additional efforts are needed to enhance the understanding of rate-limited volatilization to improve simulation of the SVE process and to provide a basis for refining the design and operation of SVE systems.

Abbreviations: CT, carbon tetrachloride • DNAPL, dense nonaqueous phase liquid • EV, EarthVision • NAPL, nonaqueous phase liquid • SVE, soil vapor extraction

This article has been cited by other articles:

				G. W. Gee, M. Oostrom, M. D. Freshley, M. L. Rockhold, and J. M. Zachara Hanford Site Vadose Zone Studies: An Overview Vadose Zone J., November 20, 2007; 6(4): 899 - 905. [Abstract] [Full Text] [PDF]