Press Release

GEI’s Derek Tomlinson to Teach ITRC LNAPL Training Courses

May 4, 2017

On May 4th and May 11th, Derek Tomlinson will be co-teaching Parts 1 and 2 of the Interstate Technology & Regulatory Council (ITRC) Light Non-Aqueous Phase Liquid (LNAPL) training. The online trainings are hosted by U.S. EPA’s Contaminated Site Clean-Up Information (CLU-IN) training portal. The ITRC LNAPL training courses help users set appropriate LNAPL remedial objectives in the context of a site-specific LNAPL conceptual site model, provide tools to screen LNAPL remedial technologies to identify an optimal LNAPL remedial technology to achieve the objectives, and provide example performance metrics that would be set to gauge remedial effectiveness and demonstrate achievement of the objectives. Natural source zone depletion (NSZD) for LNAPLs is also summarized, including the processes involved, their rates, and potential for long-term progress.

Further details on Parts 1 and 2 of the ITRC LNAPL internet-based training is summarized below, and more information and registration details can be found here – ITRC Internet-Based Training Registration.

LNAPL Training Part 1: An Improved Understanding of LNAPL Behavior in the Subsurface – State of Science vs. State of Practice [May 4, 1 – 3:15 PM, EDT]

A sound LNAPL understanding is necessary to effectively characterize and assess LNAPL conditions and potential risks, as well as to evaluate potential remedial technologies or alternatives. Unfortunately, many environmental professionals have a faulty understanding of LNAPL conditions based on outdated paradigms. The Part 1 internet-based training aids to improve the general understanding of LNAPLs. Better understanding leads to better decision making. Additionally, this training provides a necessary technical foundation to foster effective use of the ITRC LNAPLTechnical and Regulatory Guidance document, Evaluating LNAPL Remedial Technologies for Achieving Project Goals (LNAPL-2, 2009).

Part 1 explains how LNAPLs behave in the subsurface and examines what controls their behavior. Part 1 also explains what LNAPL data can tell you about the LNAPL and site conditions. Relevant and practical examples are used to illustrate key concepts.

LNAPL Training Part 2: LNAPL Characterization and Recoverability – Improved Analysis – Do you know where the LNAPL is and can you recover it? [May 11, 1 – 3:15 PM, EDT]

Part 2 addresses LNAPL characterization and site conceptual model development as well as LNAPL recovery evaluation and remedial considerations. Specifically, Part 2 discusses key LNAPL and site data, when and why those data may be important, and how to get those data. Part 2 also discusses how to evaluate LNAPL recoverability, and an overview of remedial approaches.

About Derek Tomlinson: 

Derek Tomlinson, P.E., P.Eng., BCEE is a Principal and Science, Engineering and Technology Leader with GEI Consultants based in their Philadelphia area office, with more than 20 years of experience, specializing in development of strategies for managing sites with non-aqueous phase liquids (NAPLs). His graduate training at the University of Waterloo focused on contaminant hydrogeology including the characterization and remediation of NAPLs using high-resolution characterization techniques to understand multi-phase fluid transport within the subsurface. Derek’s technical expertise includes development of innovative site characterization methods for refinement of robust CSMs, which he has used in proper design, implementation, and operation of a range of in situ remediation technologies within both porous media and fractured bedrock geologic settings. He has worked at various types of sites under USEPA CERCLA and RCRA programs, nationally in several state and regional led voluntary programs, and internationally. In addition, he has provided expert witness and testimony in matters related to NAPL releases.


About GEI: GEI’s multidisciplinary team of engineers, scientists, and planners deliver integrated water resources, environmental, ecological, geotechnical and waterfront engineering solutions to diverse clientele nationwide. The firm has provided a broad range of consulting and engineering services on over 50,000 projects in 50 states and 22 countries. For more information on GEI, please visit

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