April 2021 Virtual Meeting

Monday, April 12, 2021
6:00 - 7:30 pm

Note: ETGS members will receive an email with info for logging into the meeting.

April Presentation

Development of a Regional Groundwater Flow Model for the U.S. Department of Energy Oak Ridge Reservation:
Numerical Model using MODFLOW-USG



Dr. Alauddin Khan



A regional scale groundwater flow model (GFM) with dimensions of approximately 40 x 16 km (25 x 10 miles) has been developed for the DOE Oak Ridge Reservation (ORR). The model implements a key recommendation of the ORR Groundwater Strategy, which is an interagency approach for addressing legacy groundwater contamination from past operations at ORR facilities. The strategy was agreed to by DOE, EPA, and TDEC in FY 2014. The calibrated flow model will serve as the framework for future, smaller scale, modeling efforts to support cleanup actions and decisions under CERCLA/FFA (6 watershed-scale groundwater RODs are planned). The Oak Ridge site is located in a geologically complex region and encompasses three large government facilities, including the Y-12 National Security Complex (Y-12), Oak Ridge National Laboratory (ORNL), and the East Tennessee Technology Park (ETTP). The GFM, in conjunction with smaller scale modeling, has played a role in the following:

  • Analysis of regional flow systems and simulation of changes

  • Additional characterization and placement of monitoring wells to delineate the extent of plumes, including optimization of the long-term monitoring network

  • Visualization of extent and movement of groundwater and contaminants

  • Conducting "what-if" testing to evaluate potential on-site and off-site migration flow paths

  • Engineering studies to identify remediation alternatives, as well as the follow-on engineering design work

  • Assessment of potential short- and long-term risks

  • Final watershed groundwater decisions that may include monitored natural attenuation or Technical Impracticability waivers

The presentation will cover aspects of the general conceptual site model, numerical model construction, model boundary conditions, model calibration and results, particle track results and conclusions.


Dr. Khan is a senior environmental modeler with more than 30 years of diversified experience in chemical/environmental engineering, water resource engineering and project management. He has extensive experience in soils, sediments and groundwater investigation and remediation projects with expertise in groundwater and surface water modeling, and project management. He has managed projects and conducted contaminant fate and transport modeling within a diverse array of hydrogeologic settings using a wide range of software packages for CERCLA RI/FS, RCRA RFIs, NEPA SEIS, and LUST projects. He has supported development of risk based corrective actions (RBCA), Environmental Impact Statements (EIS), feasibility study reports, remedial design projects, and research and development efforts. Other experience includes free product recovery modeling and system design, modeling of deep well injection of hazardous waste, well performance and pump test analysis, data analysis using statistical methods, database management, and software development. He has conducted workshops and training seminars related to use of particular models and case study applications. He obtained a M.S. and Ph.D. in Chemical Engineering from the University of Oklahoma, Norman, and a B.S., Chemical Engineering, Bangladesh University of Engineering and Technology, Dhaka.

Greetings, and welcome to the March 8, 2021 ETGS virtual meeting. We hope you, your family, and your colleagues are staying healthy and well. 

As a courtesy, please mute your cell phone or the microphone in your laptop/tablet to minimize background noise and feedback echoes. We will try to mute all participants until the presentation is finished. Please use the chat feature to type comments or questions during the presentation. We recommend that you send questions for the speaker to "everyone" so all participants can see the question. After the presentation, the speaker will answer questions.  During this Q&A period, you may unmute if you wish to ask a question verbally.

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Thank you for your patience and understanding as we continue adapting to this virtual format. As always, we welcome and appreciate your feedback and suggestions for improvement.



Page updated March 18, 2021