The Prototype Plume Busters Software:

A New Tool for Computer Assisted Instruction P. Allen Macfarlane,

Geoffery Bohling, Margaret Townsend

Kansas Geological Survey

Steve Case and Tom BakerKU Center for Science Education

Ken ThompsonDepts. of Physical SciencesEmporia State University

Teaching Ground-water Science Concepts

• The concepts and earth material properties that govern ground-water flow are abstract.

• Ground-water systems are typically not observed directly.

The River Basin Hydrologic Cycle

Stagnant ? ? ?Stagnant ? ? ?

Hydrogeology: What is it?• Hydrogeology examines the interrelationships

of geologic materials and processes with water

• This is not what a hydrogeologist does:

• An NSF-funded product

• A role-play to help students develop a better understanding of how ground-water concepts are applied using simulation and games.

Setting for the SimulationStream-Aquifer System

A

A' A'

Bedrock

A

Alluvialaquifer

MissouriRiverWater

table

Environmental Consultant Role Play

Your RoleYou have been hired by the pipeline owner solve this environmental problem.

Your objective is to eliminate the contamination from the aquifer in the shortest amount of time for the least cost to the pipeline owner.

Every action you take in this simulation will cost you time & money

The SituationA chemical spill from a ruptured pipeline has contaminated a shallow aquifer. A plume of contamination is moving toward the river.

If unchecked, the contaminants will seep into the nearby Buffalo River and render River City’s downstream water supply unusable.

Software Features

Software Structure• Locate the Plume• Remediate the Plume

Interaction with the Software• Information provided on a series of linked HTML pages• User interacts with ground-water model through the Map View screen

Locating the Plume

• The ships of the each player’s fleet are distributed on a game board before play begins.

• Ships remain fixed in their positions on the board throughout the game.• Each player tries to “guess” the location of the opposing player’s ships so

they can be destroyed and sunk.

Locating the Plume

Source

Ground-waterFlow

BuffaloRiver

Where is the plume in the aquifer at any given time?

Assumption: The plume is moving in the same direction and with the same constant speed as the ground-water.

Problem Solution: Distance = Speed x Time

Porosity Definition

Earth Material Bulk Volume (VT) =

Volume of the Matrix (VM) + Volume of the Voids (VV)

Porosity = VV

VT

x 100%

All earth materials contain void space or porosity

Hydraulic Conductivity The ease with which fresh water passes through an earth material.

Hydraulic conductivity is a measure of the connectedness of the pores in the sediment or the rock and

it is sensitive to the:• Tortuousity &• Number & distribution of pathways through the earth material

Hydraulic HeadA Measure of Ground-water Potential Energy

Sea-level Datum

Hydraulic Head (h) = 0

h

Water table

Datum

h1

h2

ΔLΔh

HydraulicGradient

= Δh/ΔL

Hydraulic Gradient

Darcy’s Law

Q/A = K x (Δh/ΔL)

SpecificDischarge

= HydraulicConductivity

X HydraulicGradient

Average Ground-water Velocity

Average Groundwater = Specific discharge/Aquifer porosityVelocity

Darcy’s Law q = K X (Δh/ΔL)Specific

Discharge= Hydraulic

ConductivityX Hydraulic

Gradient

Locating the Plume

Average Speed = Specific discharge/Aquifer porosity

2 times of interest:• When the contaminants first

entered the aquifer

• When the source stopped adding contaminants to the aquifer

Distance = Speed x Time

Locating the Plume

Source

Plume

Ground-waterFlow Corridor

When contaminants last entered

When contaminants first entered

Target area for monitoring well placement

Remediate the Plume

Pump and Treat Technology

Remediate the Plume

Ground-water flow

Ground-water flow

Plume

Plume

Capture Zone

Production Well

Injection Well

Capture Zone