Investigation into the Effectiveness of DNAPL Remediation Strategies in Fractured Media

EPA Grant Number: R825511C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R825511
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (1989) - Northeast HSRC
Center Director: Sidhu, Sukh S.
Title: Investigation into the Effectiveness of DNAPL Remediation Strategies in Fractured Media
Investigators: Culligan, Patricia J. , Germaine, John T.
Institution: Massachusetts Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: January 15, 1999 through May 31, 2001
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Hazardous Substance Research Centers , Land and Waste Management

Objective:

Contamination by Dense Non-Aqueous Phase Liquids (DNAPLs) such as chlorinated solvents, is an important environmental concern in many urbanized areas of the United States, including Federal Regions 1 & 2. DNAPLs are used in a wide variety of industries and are produced in large amounts. Accidental spills, poor storage facilities and inadequate disposal practices are factors that contribute to the release of these chemicals into the subsurface environment. Fig. 1 (no longer available) illustrates a typical DNAPL release at the ground surface. As shown in the figure, DNAPL has been able to migrate through the vadose zone an underlying aquifer, following a complex path that is dependent on the DNAPL self-weight and the heterogeneities of the aquifer, and generally uncoupled from the direction of groundwater flow. At the base of the aquifer, DNAPL has formed a pool on top of a fractured bedrock system, which it has invaded. The DNAPL has distributed itself throughout the fracture system in the form of DNAPL fracture pools, residual blobs and a dissolved aqueous phase species.

Once DNAPL enters a fracture system, the probability of encountering the non-aqueous phase liquid in a borehole where a sparse distribution of migration pathways exists will be very low. Thus, the site investigation of a contaminated fracture system will rarely delineate an accurate distribution of DNAPL within the fracture network. With little information on the probable distribution of DNAPL at a contaminated site, the planning of an effective remediation strategy is rendered virtually impossible. For this reason, the development of models for DNAPL invasion of fracture systems is a critical step towards improving DNAPL remediation performances in bedrock aquifers.

The goal of this project is to develop a model for DNAPL behavior in a rough-walled, vertical fracture system, toward the aim of formulating sensible DNAPL remediation strategies for fractured bedrock.

Approach:

Geotechnical centrifuge modeling is being used as the main experimental technique. Centrifuge modeling is an experimental method that facilitates small-scale physical modeling of problems affected by gravitational forces under realistic, but well-controlled boundary conditions. This is achieved by subjecting a scale model where all linear dimensions are reduced by a factor of n, to a centrifugal acceleration equivalent to n times the Earth's gravity (ng). For the particular case of DNAPL transport in fracture networks, centrifuge modeling allows us to physically model DNAPL transport in fractures that are of the order of meters in length. No other experimental technique can offer the same versatility of centrifuge modeling in this respect.

Expected Results:

The project is combining theoretical modeling with laboratory experiments and physical modeling using the geotechnical centrifuge. The rationale is to develop a good understanding of the mechanisms controlling DNAPL behavior in a single vertical fracture, before extending this understanding to DNAPL behavior in a complex natural environment. The use of the geotechnical centrifuge is allowing us to mimic the physical conditions that exist in nature, but at a reduced small scale and in a controlled laboratory environment (see below). Data from our centrifuge and laboratory experiments are being used to develop and validate a theoretical model that currently describes DNAPL invasion and migration in a single vertical fracture. The later extension of this model to multi-fracture behavior, will eventually enable us to investigate the feasibility of various site investigation and remediation strategies for contaminated bedrock.

Publications and Presentations:

Publications have been submitted on this subproject: View all 4 publications for this subprojectView all 131 publications for this center

Journal Articles:

Journal Articles have been submitted on this subproject: View all 2 journal articles for this subprojectView all 39 journal articles for this center

Supplemental Keywords:

DNAPL, Dense Non-Aqueous Phase Liquid, remediation, fractured rock., RFA, Scientific Discipline, Geographic Area, Waste, Remediation, Environmental Chemistry, Hazardous Waste, Environmental Monitoring, Ecological Risk Assessment, Hazardous, Environmental Engineering, EPA Region, fate and transport, hazardous waste management, hazardous waste treatment, advanced treatment technologies, in situ remediation, fractured media, cleanup, remediation technologies, DNAPLs, treatment, treatment technologies, technology transfer, Region 2

Progress and Final Reports:

  • 1999
  • 2000
  • Final Report

  • Main Center Abstract and Reports:

    R825511    HSRC (1989) - Northeast HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825511C001 Development of Mechanisms and Kinetic Models on Formation of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans from Aromatic Precursors
    R825511C002 Real-Time Monitoring and Control of Emissions from Stationary Combustors and Incinerators
    R825511C003 Development of Sampling Systems for Continuous Monitoring of Volatile Organic Compounds (VOCs)
    R825511C004 Investigation into the Effectiveness of DNAPL Remediation Strategies in Fractured Media
    R825511C005 Advanced Leak Detection and Location Research: Extending the SERDP-funded Technical Base
    R825511C006 Three-Dimensional Geostatistical Site Characterization with Updating
    R825511C007 Anaerobic Biodegradation of PAHs in Soils and Dredged Sediments: Characterizing, Monitoring and Promoting Remediation
    R825511C008 Substrate Accelerated Death and Extended Lag Phases as Causes of the Recalcitrance of Halogenated Compounds in Anoxic Environments
    R825511C009 Fate and Transport of Nonionic Surfactants
    R825511C010 In Situ Degradation of Petroleum Hydrocarbons and PAHs in Contaminated Salt Marsh Sediments
    R825511C011 Design and Operation of Surfactant-Enhanced Bioslurry Reactors
    R825511C012 Experimental Study of Overland Transport of Cryptosporidium parvum Oocysts
    R825511C013 Development of a Framework for Evaluation of Leaching from Solid Waste
    R825511C014 Use of a New Leaching Test Framework for Evaluating Alternative Treatment Processes for Mercury Contaminated Mixed Waste (Hazardous and Radioactive)
    R825511C015 Field Pilot Test of In Situ Ultrasonic Enhancement Coupled With Soil Fracturing to Detoxify Contaminated Soil
    R825511C016 Development of Sampling Systems for Continuous Monitoring of Volatile Organic Compounds (VOCs)
    R825511C017 Field Demonstration of the Use of Reactive Zero-Valence Iron Powder to Treat Source Zone Sites Impacted by Halogenated Volatile Organic Chemicals
    R825511C018 Technology Transfer of Continuous Non-Methane Organic Carbon (C-NMOC) Analyzer
    R825511C019 Field Sampling and Treatability Study for In-Situ Remediation of PCB's and Leachable Lead with Iron Powder
    R825511C020 Experimental and Modeling Studies of Chlorocarbon Incineration, PIC Formation, and Emissions Control
    R825511C021 Experimental Studies and Numerical Modeling of Turbulent Combustion During Thermal Treatment of Hazardous Wastes: Applied Research for the Generation of Design and Diagnostic Tools
    R825511C022 Electrochemical Sensor for Heavy Metals in Groundwater - Phase IV
    R825511C023 Novel Molecular Tools for Monitoring In-Situ Bioremediation
    R825511C024 Surfactant-Enhanced Bioremediation of Soils in the Presence of an Organic Phase
    R825511C025 Enhanced Microbial Dechlorination of PCBs and Dioxins in Contaminated Dredge Spoils
    R825511C026 Toward A Risk-Based Model for Bioremediation of Multicomponent NAPL Contaminants
    R825511C027 Removal and Recovery of VOCs and Oils from Surfactant-Flushed Recovered Water by Membrane Permeation
    R825511C029 Field Pilot Test of In-Situ Ultrasonic Enhancement Coupled With Soil Fracturing to Detoxify Contaminated Soil in Cooperation with McLaren/Hart Environmental Engineers at the Hillsborough, NJ Site
    R825511C030 In-Situ Field Test of Electroremediation of a Chromate-Contaminated Site in Hudson County, New Jersey
    R825511C031 Electrokinetic Removal of Heavy Metals and Mixed Hazardous Wastes from Partially and Fully Saturated Soils
    R825511C032 Effects of Clay Charge and Confining Stresses on Soil Remediation by Electroosmosis
    R825511C033 Assessment of Surfactant Enhanced Bioremediation for Soils/Aquifers Containing Polycyclic Aromatic Hydrocarbons (PAHs)
    R825511C034 In-Situ Bioremediation of Organic Compounds: Coupling of Mass Transfer and Biodegradation
    R825511C035 Investigation into the Effectiveness of DNAPL Remediation Strategies in Fractured Media
    R825511C036 Field Pilot Scale Demonstration of Trench Bio-Sparge: An In-Situ Groundwater Treatment Technology
    R825511C037 In-Situ Reductive Dehalogenation of Aliphatic Compounds by Fermentative Heterotrophic Bacteria
    R825511C038 The Effect of Carbon-Nitrogen Ratios on Bacterial Transport and Biodegradation Rates In Soils
    R825511C039 Ultrasonic Enhancement of Soil Fracturing Technologies for In-Situ Detoxification of Contaminated Soil
    R825511C040 Full Field Demonstration of Integrated Pneumatic Fracturing and In-Situ Bioremediation
    R825511C041 Determination of Adsorption and Desorption Behavior of Petroleum Products on Soils
    R825511C042 Evaluation of the Potential for Complete Bioremediation of NAPL-Contaminated Soils Containing Polycyclic Aromatic Hydrocarbons (PAHs)
    R825511C043 Characterization of Subsurface NAPL Distributions at Heterogeneous Field Sites
    R825511C044 Development of a Thermal Desorption Gas Chromatograph/Microwave Induced Plasma/Mass Spectrometer (TDGC/MIP/MS) for On-site Analysis of Organic and Metal Contaminants
    R825511C045 Using Trainable Networks for a Three-dimensional Characterization of Subsurface Contamination
    R825511C046 Application of Advanced Waste Characterization to Soil Washing and Treatment
    R825511C047 Electrochemical Sensor for Heavy Metals in Groundwater Phase III
    R825511C048 Improved Luminescence Sensors for Oxygen Measurement
    R825511C049 Preconcentration, Speciation and Determination of Dissolved Heavy Metals in Natural Waters, using Ion Exchange and Graphite Furnace Atomic Absorption Spectrometry
    R825511C050 Experimental and Modeling Studies of Chlorocarbon Incineration and PIC Formation
    R825511C051 PIC Emission Minimization: Fundamentals and Applications
    R825511C052 Project Title: Development of a Two Stage, Pulse Combustion, VOC Destruction Technology
    R825511C053 Development of Sampling Systems for Continuous Monitoring of Volatile Organic Compounds (VOCs)
    R825511C054 FTIR Analysis of Gaseous Products from Hazardous Waste Combustion
    R825511C055 Toxic Metals Volatilization for Waste Separation and Real-time Metals Analyses
    R825511C056 Mixed Metal Removal and Recovery by Hollow Fiber Membrane-Based Extractive Adsorber
    R825511C057 Removal of Volatile Organic Compounds (VOCs) from Contaminated Groundwater and Soils by Pervaporation
    R825511C058 Simultaneous SO2/NO Removal/Recovery by Hollow Fiber Membrane
    R825511C059 Superfund Sites and Mineral Industries Method
    R825511C060 Soil Washing of Mixed Organics/Metal Contamination
    R825511C061 Removal of Cesium, Strontium, Americium, Technetium and Plutonium from Radioactive Wastewater
    R825511C062 Development of a Method for Removal of Nonvolatile Organic Materials from Soil using Flotation
    R825511C063 Recovery of Evaporative Fuel Losses by Vapor Permeation Membranes
    R825511C064 Surfactant Selection Protocol for Ex Situ Soil Washing
    R825511C065 Biofiltration for the Control of Toxic Industrial VOCs Emissions
    R825511C066 Catalytic Oxidation of Volatile Organic Compounds in Water
    R825511C067 Soil Washing for Remediating Metal Contaminated Soils
    R825511C068 Aqueous Absorption and Kinetics of NO by Strong Oxidizing Agents
    R825511C069 Remediation of Dredging Spoils
    R825511C070 Freeze Concentration for Zero-Effluent Processes
    R825511C071 Life Cycle/Pollution Prevention Response to Executive Order 12856
    R825511C072 Faster Better, Cheaper Hazardous Waste Site Characterization and Cleanup: an Adaptive Sampling and Analysis Strategy Employing Dynamic Workplans
    R825511C073 Development of a Comprehensive Computer Model for the Pneumatic Fracturing Process
    R825511C074 Technology Demonstration and Validation of CFAST Field Analytical Instrumentation for Use in Hazardous Waste Site Characterization, Clean-up and Monitoring
    R825511C075 XFLOW: Training Software Simulating Contaminant Site Characterization and Remediation