Teach the Earth > > > Wooster Case Study - Capture Curve Analysis

# Wooster Case Study: Capture Curve Analysis

Terry Lahm
,
Capital University
Author Profile

This activity was selected for the On the Cutting Edge Exemplary Teaching Collection

Resources in this top level collection a) must have scored Exemplary or Very Good in all five review categories, and must also rate as “Exemplary” in at least three of the five categories. The five categories included in the peer review process are

• Scientific Accuracy
• Alignment of Learning Goals, Activities, and Assessments
• Pedagogic Effectiveness
• Robustness (usability and dependability of all components)
• Completeness of the ActivitySheet web page

#### Summary

This Excel based exercise has students calculate the shape of the capture zone of a contaminant recovery well. Students perform a sensitivity analysis by varying aquifer and pumping parameters to observe the impact of the capture-zone shape.

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## Context

#### Audience

This exercise is designed for undergraduate students enrolled in a hydrogeology, groundwater hydrology, or environmental geology courses where groundwater contamination is discussed.

#### Skills and concepts that students must have mastered

Students are expected to have been introduced to concepts of well capture zones, hydraulic gradient, hydraulic conductivity, and transmissivity. Basic working knowledge of Excel spreadsheets is needed. This exercise can also be used as a demonstration or learning tool in more introductory level courses dealing with groundwater pollution.

#### How the activity is situated in the course

This activity is designed to be hands-on experimentation in a computer laboratory setting. Ideally, students program the Excel spreadsheet to perform the calculations and then manipulate the spreadsheet to learn more about capture zone geometry as it relates to the groundwater hydrology and geology.

## Goals

#### Content/concepts goals for this activity

Strengthen and develop mathematical skills calculating the bounding flow line for a capture zone of a pumping well using Excel.

#### Higher order thinking skills goals for this activity

1. Experiment with the sensitivity of capture zone geometry based on geologic and hydrologic parameters using quantitative methods.
2. Learn how capture zone shape including maximum capture zone width and distance to the stagnation point for remediation wells in a case study approach.

## Description of the activity/assignment

This exercise uses an analytical method (Grubb, 1993) and Excel to calculate the capture zone shape for a TCE remediation well in Wooster, Ohio. The case study description given in an extensive PowerPoint presentation. The capture-zone equations are programmed by the student into an Excel worksheet and used to delineate the contributing area of a contaminant recovery well. Students can then experiment with by varying the pumping rate, hydraulic conductivity, and hydraulic gradient to better understand the sensitivity of these parameters on capture-zone shape.

## Determining whether students have met the goals

Learning outcomes are assessed based on the following:
1. Accuracy of Excel spreadsheet at determining capture-zone shape.
2. Answering conceptual questions used to guide students in exploration of capture-zone sensitivity to changing parameters. Answers to these questions are given in the instructor version of exercise.