Neven Kresic, Ph.D., PG is a Senior Principal and Hydrogeology Practice Leader at Amec Foster Wheeler with over 30 years of experience in hydrogeology and groundwater modeling, remediation, and resource development. He has worked with U.S. and international clients, including federal, state, and local agencies; industries such as water, transportation, and power utilities; and oil, petrochemical, chemical, mining, and construction companies. In addition to numerous scientific and professional papers, Dr. Kresic has authored best-selling textbooks Hydrogeological Conceptual Site Models: Data Analysis and Visualization by CRC/Taylor & Francis (2013), and Hydrogeology and Groundwater Modeling, Second Edition by CRC/Taylor & Francis (2007). He has instructed international workshops and academic courses in groundwater modeling, remediation and conceptual site development around the world, and is co-Chair of the Karst Commission of the International Association of Hydrogeologists, past Vice President for International Affairs of the American Institute of Hydrology, and committee member of the Groundwater Management and Remediation Specialty Group of the International Water Association.
Groundwater Remediation: From Hydrogeologic Site Concepts to Applied Numeric Models
The cleanup of various sites with groundwater contamination has been a major element of professional hydrogeology in the United States and, increasingly, in other countries around the world. It is likely that every professional hydrogeologist will work on a groundwater remediation project at some point in her or his career. The most critical element for success of such projects is development of hydrogeologic conceptual site models (CSM) which should be viewed as continuously evolving throughout the entire process, with every new piece of information. Similarly, a hydrogeologist evolves together with the CSM and accepts a possibility of initially “being wrong”. This flexibility is particularly important for groundwater remediation projects although CSMs for other, non-contaminated sites, share many of the same elements (e.g., where is the groundwater coming from, where is it going, how much of it, how fast…). At the same time, applied numeric models of groundwater flow and contaminant fate and transport have become an integral part of all phases of groundwater remediation projects including CSM development (remedial investigation) and remedy selection and implementation (feasibility study and remedial design). There is positive feedback between numeric groundwater models and CSMs – models can guide collection of additional data and also fill in the gaps between data that have been or will be collected at discrete time intervals, thus helping the hydrogeologist better understand and simulate transient (time-dependent) processes. This presentation focuses on different elements of CSM (groundwater and contaminant characterization) that are needed for numeric simulations of a variety of remedial alternatives including pump-and-treat or groundwater interception, natural attenuation, impermeable barriers or permeable reactive barriers, thermal remediation, and others. Models are crucial in answering critical questions in groundwater remediation: is the technology feasible, how long the remediation will last until it reaches its goal, and how much will it cost?