The Remediation Technology Summit

February 26-28, 2019

Colorado Convention Center
Denver, CO

macbethTamzen Macbeth
Vice President
CDM Smith

Tamzen Macbeth is a Vice President at CDM Smith out of Helena, Montana. She has worked for CDM since 2009. Previously, she worked for 7 years at North Wind Inc. Tamzen is an environmental engineer with an interdisciplinary academic and research background in microbiology and engineering. She specializes in the development, demonstration and application of innovative, cost-effective technologies for contaminated groundwater. Specifically, she is experienced in all aspects of remedies from characterization to remediation for DNAPLs, dissolved organic, inorganic, and radioactive contaminants under CERCLA and RCRA regulatory processes. She has expertise in a variety of chemical, biological, thermal, extraction and solidification/stabilization remediation techniques as well as natural attenuation. Her current work focuses developing combined technology approaches, and innovative characterization techniques such as mass flux and mass discharge metrics. Since 2004, Tamzen has contributed to the ITRC as a team member and instructor for the ITRC’s Bioremediation of DNAPLs, Integrated DNAPL Site Strategy, Molecular Diagnostics and DNAPL Characterization teams. Tamzen earned a bachelor's degree in Microbiology in 2000 and a master’s degree in Environmental Engineering in 2002 both from Idaho State University in Pocatello, Idaho, and a doctoral degree from in Civil and Environmental Engineering in 2008 from the University of Idaho in Moscow, Idaho.


NAPL Characterization and Depletion: My Old Friend


Integrated DNAPL Site Characterization and Tools Selection

Sites contaminated with NAPLs present significant environmental challenges and have proven to be recalcitrant to remediation, especially where sites have been contaminated with DNAPLs. Our industry can no longer address DNAPL and dissolved phase contamination separately, but rather they need to be considered together. Experience gained at these sites has driven us to update overall our understanding of DNAPL and dissolved phase contamination. This includes the controlling role of small geologic heterogeneities on the fate and transport of DNAPL and associated dissolved phase contamination. This workshop will begin by presenting the new DNAPL Conceptual Site Model (CSM) based on this new understanding.

The workshop will then discuss properties of DNAPLs and associated aqueous, sorbed, and vapor phase contamination, and how they partition throughout the subsurface. Mechanisms that control the flow of DNAPLs in the subsurface including solubility, capillary entry pressure, saturation and residual saturation, wettability and interfacial tension will be discussed. Our workshop will present the DNAPL life cycle models of “higher” solubility DNAPLs such as chlorinated solvents, and the “lower” solubility DNAPLs such as coal tars and creosotes. We will also discuss the latest characterization approaches for sites contaminated with LNAPLs.

We will present a detailed module describing the objectives-based Integrated Site Characterization (ISC) process that will both clarify how to collect appropriate scale data, and what types of data are collected with an emphasis on geology where appropriate. We’ll discuss how to manage, analyze, and integrate the large geological-hydrogeological and contaminant data bases that can be developed using the ISC approach.

Finally, we will present a live demonstration of the ITRC Site Characterization Tools table that will help guide site characterization efforts as a resource that will resent many characterization tools, what they are used for, how geology affects tool choices, and references to more information on the tools.