Systematic Approach to Capture Zone Analysis for Pump-and-Treat Systems
Luanne Vanderpool, Region 5, Superfund
U. S. Environmental Protection Agency
Co-Authors: Rob Greenwald, GeoTrans, Inc. and Yan Zhang, GeoTrans, Inc.
Abstract:
The presentation provides an overview of a systematic approach for the evaluation of capture zones at pump and treat systems, and highlights a document on the topic being developed by the U.S. EPA Office of Superfund Remediation and Technology Innovation (OSRTI) and U. S. EPA Office of Research and Development (ORD), in conjunction with the U.S. EPA Groundwater Forum. The presentation will define “target capture zones” and explain their use during capture zone analysis. The talk will discuss the importance of capture zone analysis during groundwater remediation, particularly for sites requiring containment. The steps associated with a systematic approach for capture zone analysis will be outlined.
These steps include the following:
• Step 1: Review site data, site conceptual model, and remedy goals
• Step 2: Define site-specific Target Capture Zone(s)
• Step 3: Interpret water levels
• Step 4: Perform appropriate calculations (flow budget calculation, capture zone width calculation and/or modeling)
• Step 5: Evaluate concentration trends at monitoring wells (and potentially tracer tests)
• Step 6: Interpret actual capture and compare to Target Capture Zone(s), assess uncertainties and data gaps
The use of “converging lines of evidence” and the iterative nature of the systematic approach will be explained.