Optimal Search Strategy for the Definition of a DNAPL Source
Abstract
DNAPL (Dense Non-Aqueous Phase Liquid) contamination poses a major threat to the groundwater supply; thus, successful remediation of the contaminated sites is of paramount importance. Delineating and removing the DNAPL source is an essential step that renders remediation successful and lowers the estimated remediation time and cost significantly. This work addresses the issue of identifying and delineating DNAPL at its source. The methodology employed here is based upon the rapidly evolving realization that it is unlikely to identify and adequately define the extent of a DNAPL source location using field techniques and strategies that focus exclusively on directly locating separate phase DNAPL. The goal of this work is to create an optimal search strategy in order to obtain, at least cost, information regarding a DNAPL source location. The concept is to identify, prior to a detailed site investigation, where to initially sample the subsurface to determine the DNAPL source characteristics and then to update the investigative strategy in the field as the investigation proceeds. The search strategy includes a stochastic groundwater flow and transport model that is used to calculate the concentration random field and its associated uncertainty. The model assumes a finite number of potential source locations. Each potential source location is associated with a weight that reflects our confidence that it is the true source location. After a water quality sample is selected, an optimization algorithm is employed that finds the optimal set of magnitudes that corresponds to the set of potential source locations. The simulated concentration field is updated using the real data and the updated plume is compared to the individual plumes (that are calculated using the groundwater flow and transport simulator considering only one source at a time). The comparison provides new weights for each potential source location. These weights define how the concentration realizations calcu
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2009
- Accession Number
- ADA520462
Entities
People
- George Pinder
- James Ross
- Zoe Dokou
Organizations
- University of Vermont