Dense Nonaqueous Phase Liquids (DNAPLs)Chromium VI
Dense Nonaqueous Phase Liquids (DNAPLs)
1,4-Dioxane
Dioxins
Mercury
MTBE
Perchlorate
POPs
PCBs
TCE
Other Contaminants
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Detection and Site Characterization
Partioning Interwell Tracer Technique
The following discussion is taken from Site Characterization Technologies for DNAPL Investigations, EPA 542-R-04-017
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The partitioning interwell tracer test (PITT) is an in situ technique for estimating the volume and percent saturation of DNAPLs in both the vadose and saturated zones.
In the vadose zone application, a line of injection wells is drilled on one side of the contaminant mass, and a second line of extraction wells is placed on the other side. Two types of tracer gases—partitioning and conservative—are introduced into the injection wells and removed from the extraction wells. The partitioning gases are chosen so that they will be slowed down at different rates by the DNAPLs they contact as they move through the soil. Conservative gases are chosen that will be minimally affected by the DNAPLs and hence travel more quickly to the extraction wells. DNAPL volumes can be calculated based on breakthrough curves for the tracers across the well line. The time frame for the actual test is in the range of one week, depending on the geology and distance between wells, but it can be much longer.
The concept is the same for the saturated zone application. Partitioning tracer chemicals are chosen that will move through the ground water and soil matrix relatively easily under pumping conditions, but will preferentially and reversibly attach themselves to DNAPLs. Conservative chemicals are chosen that will react minimally with both the natural matrix and the DNAPLs. By using the arrival times of both the partitioning and conservative chemicals in extraction wells, the amount of DNAPLs present can be estimated.
For Further Information
DNAPL Site Characterization Using a Partitioning Interwell Tracer Test at Site 88, Marine Corps Base Camp Lejeune, North Carolina
Naval Facilities Engineering Service Center, Port Hueneme, CA, 131 pp, 1999
A PITT was completed at Site 88, the location of the Morale, Welfare, and Recreation Dry Cleaners at the Marine Corps Base Camp Lejeune, North Carolina. The PITT was conducted to estimate the saturation, volume, and spatial distribution of tetrachloroethene that is present as a DNAPL within the selected test area. The PITT results provided characterization of the initial DNAPL conditions at the site in preparation for a surfactant-enhanced remediation demonstration to remove DNAPL from the shallow aquifer.
In-Situ Characterization of Dense Non-Aqueous Phase Liquids Using Partitioning Tracers
G.A. Pope, D.C. McKinney, A.D. Gupta, R.E. Jackson, and M. Jin.
DOE/ER/14720, 219 pp, 2000
This report describes the issues involved in using partitioning tracers as well as a demonstration of using them in connection with a surfactant flood of a DNAPL.
Partitioning Tracers for In-Situ Measurement of Nonaqueous Phase Liquids in the Subsurface
M.L. Brusseau, et al.
DOE/ER/14722, 37 pp, Sep 2000
This project explores the use of partitioning tracer tests for the detection and quantification of NAPLs in subsurface systems, as well as the influence of factors such as physical heterogeneity, non-uniform NAPL distribution, and dilution effects on NAPL/water mass transfer. This latter issue is important with respect to both the efficacy of the partitioning tracer method and the dissolution behavior of NAPLs. Lastly, the use of gas-phase partitioning tracer tests to measure soil-water content and fluid-fluid interfacial areas is evaluated.
Tracer Techniques for DNAPL Source Delineation and In Situ Flushing Techniques for Enhanced Source Removal: Pilot Scale Demonstrations at the Dover National Test Site
M.C. Brooks, M.D. Annable, S.C. Rao.
NTIS: ADA410848, 293 pp, Sep 2001
This report evaluates the performance of innovative tracer techniques for DNAPL characterization and in situ cosolvent and surfactant flushing for DNAPL removal in an isolated test cell (3.0m x 4.5m x 12.3m) located at the Dover National Test Site, Dover AFB, DE.
Abstracts of Journal Articles
Analysis of Partitioning Interwell Tracer Tests
Analytical Method Developments to Support Partitioning Interwell Tracer Testing
The Applicability of Dissolved Helium and Neon as Dense Nonaqueous Phase Liquid (DNAPL) Partitioning Tracers
Application of Gas-Phase Partitioning Tracer Tests to Characterize Immiscible-Liquid Contamination in the Vadose Zone Beneath a Fuel Depot
Characterization of Tetrachloroethene DNAPL in Low-Permeability Coastal Plain Sediments, North Carolina
Controlled Release, Blind Tests of DNAPL Characterization Using Partitioning Tracers
Diffusive Partitioning Tracer Test for Nonaqeous Phase Liquid (NAPL) Detection in the Vadose Zone
Effect of Mass Transfer Rate Limitations on the Use of Partitioning Tracers for the Characterization of DNAPL Micropools in the Subsurface
Evaluation of the Partition Interwell Tracer Technique for Possible Characterization of DNAPL Pools
Helium and Neon Groundwater Tracers to Measure Residual DNAPL: Laboratory Investigation
Krypton and Sulfur Hexafluoride as Non Aqueous Phase Liquid Partitioning Tracers in the Saturated Zone
Monitoring Partitioning Tracer Testing and Surfactant Flooding by In-Line Gas Chromatography Techniques
Non-Invasive Imaging of NAPL/Partitioning Tracer Interaction in Porous Media
Numerical Simulations of Radon as an In Situ Partitioning Tracer for NAPL Quantifying Contamination Using Push-Pull Tests
Radon as a Natural Partitioning Tracer for Locating and Quantifying DNAPL Saturation in the Subsurface
Simulation and Performance Assessment of Partitioning Tracer Tests in Heterogeneous Aquifers
Tracer Interaction Effects during Partitioning Tracer Tests for NAPL Detection
Design of Aquifer Remediation Systems: (1) Describing Hydraulic Structure and NAPL Architecture Using Tracers
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Last updated on Monday, November 10, 2008