An Efficient Reliability-Based Approach to Aquifer Remediation Design

EPA Grant Number: R827126
Title: An Efficient Reliability-Based Approach to Aquifer Remediation Design
Investigators: Reeves, Howard W. , Dowding, Charles H. , Igusa, Takeru
Institution: Northwestern University
EPA Project Officer: Lasat, Mitch
Project Period: September 1, 1998 through August 31, 2000 (Extended to June 30, 2001)
Project Amount: $142,198
RFA: Exploratory Research - Environmental Engineering (1998) RFA Text |  Recipients Lists
Research Category: Engineering and Environmental Chemistry , Sustainability , Land and Waste Management

Description:

The working hypotheses of the proposed research are: 1) that both site characterization uncertainty and the impact of this uncertainty on the results of the performance model must be considered in site exploration and evaluation the reliability of a remedial design, and 2) that hydrogeologic unit boundary uncertainty strongly impacts the uncertainty in the computation of contaminant fate and transport at a site. These hypotheses will be tested through the implementation of a computationally-efficient algorithm to estimate the uncertainty in simulated concentrations at complex three-dimensional sites based on limited site data

Approach:

A three-dimensional finite element model that simulates groundwater flow and contaminant transport will be modified by to produce sensitivity matrices that relate changes in predicted concentration throughout the domain to changes in the underlying geological model for the site. A Taylor series approach will be applied to estimate modeled concentration uncertainties from site uncertainties developed either through a classic geostatistical or a conditional probability approach. Results from each approach will be compared to illustrate the important practical differences arising from the application of either method. The uncertainties from the site and from the modeled concentrations will be combined with the sensitivity matrices to produce an importancy matrix. This importancy matrix indicates where new data should be collected at the site to reduce uncertainty in the modeled concentrations. The uncertainties also are manipulated to estimate the reliability of the simulated remedial design.

Expected Results:

A practical approach for quantitative evaluation of the reliability of remedial design options for complex three-dimensional field sites will be developed. Application of this approach will address the motivating questions for the research: Are there enough field data to analyze the performance and reliability of various remedial alternatives ? and Where should the next data be collected to increase confidence in the remedial design ? By addressing questions of the performance or reliability of a remedial design, and by integrating site exploration into the design process, the ability to design economical and effective remedial systems will be enhanced.

Publications and Presentations:

Publications have been submitted on this project: View all 10 publications for this project

Supplemental Keywords:

groundwater modeling, contaminant transport, water quality, site assessment, Scientific Discipline, Air, Waste, Hydrology, Remediation, Environmental Chemistry, Ecological Risk Assessment, Groundwater remediation, Engineering, Chemistry, & Physics, fate and transport, computationally efficient algorithm, contaminant transport, three dimensional transport model, hydrogeologic unit boundry, remedial design, groundwater flow, aquifer remediation design, water quality

Progress and Final Reports:

  • 1999 Progress Report
  • 2000
  • Final Report