1. Teacher Earth Science Education Programme
PARTNERS
PRINCIPAL
PLATINUM
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GOLD

2. This slide must be displayed before talk commences
Teacher Earth Science Education Programme
PARTNERS
Teacher Earth Science Education Programme
PARTNERS
SILVER
The Australian National University
Department of Primary Industries, Vic
Earth Science Western Australia
Pitney Bowes Business Insight
PowerWorks
Queensland Resources Council
Rob Kirk Consultants
The University of Sydney
The University of Tasmania
BRONZE
Anglo Coal
Australian Nuclear Science and Technology Organisation
CS Energy
Department of Sustainability and Environment, Vic
Essential Petroleum
Flinders University
Gordon Wakelin King
Great Artesian Basin Coordinating Committee
Hot Dry Rocks
Macquarie University
Sandy Menpes
Monash Energy
Museum Victoria
Our Water Our Future, Vic
Petroleum Geo-Services
Primary Industries and Resources SA
Stanwell Corporation
Velseis
ZeroGen
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3. Teacher Earth Science Education Programme Learning about Groundwater
Wet Rocks –
Learning about Groundwater
Using “Gnasty Gnomes” game as a teaching tool
This talk discusses how to use the “tectonic island” game as an aid to teaching some basic groundwater principles.
Prepared by Chris McAuley, Principal Hydrogeologist, Department of Sustainability and Environment, Victoria.
Support figures sourced from:
Lectures given by Chris McAuley
Referenced sources

4. Gnasty Gnomes – protect groundwater from pollution
Key concepts:
Many people are dependent on groundwater as their primary source of water
There are many things that contaminate groundwater
This game is designed to communicate that preventing contamination is more cost effective than fixing it!
Three contamination management options are included: prevention, bioremediation (for organic contaminants) and drill (dig and dump).
In order to assist in teaching about groundwater, a series of games have been developed that each have a basic groundwater concept.
Gnasty Gnomes represents a city or town that uses groundwater as its primary supply of water. Contamination is entering the soil, and ultimately the groundwater. Unless stopped, the water quality deteriorates until it can no longer be used.

5. Game framework Cash for clean-up options Remediation options
Source of contamination
This is the basic layout of the game. The challenge is to keep the water quality ok for use for as long as possible! Of course Gnomes are known as a leading source of contamination!
Fresh groundwater
Supply bore

6. Threats of pollution on groundwater
Provision of what we now consider to be basic necessities is built on extensive industrial development and supply and distribution systems. There is a legacy of this development. Invariably practices in the past (and many continue today) result in chemicals from industrial processes entering the groundwater. Where this groundwater is used by others for water supply, industry or by the environment, the presence of these chemicals can make it no longer “fit for purpose”.
The many sources of contamination to groundwater 6

7. A complex picture...
Processes of contamination are particularly complex. Once a contaminant enters the soil, its interaction with the soil will determine how it moves through it. Likewise once it enters the groundwater, its movement is constricted by the pathways available, and the interaction with both the soil material it is passing through and the groundwater itself.
The four key processes that dictate how a contaminant moves through the groundwater are advection, mechanical dispersion, decay / degradation and retardation. 7

8. Advective processes, concentrations – single point source1 C0 C t1 1 C0 C
Advective movement of a contaminant means that the contaminant will move at the source concentration at a uniform velocity through the aquifer. The velocity term is known as the average linear velocity, and is a product of the hydraulic conductivity, the gradient driving flow and the porosity of the material.
If a one-off “pulse” or spill enters the groundwater, then under advective processes, the source concentration would move through the aquifer without any form of reduction. t2 1 C0 C t3
Distance (x) 8

9. Concentrations – continuous point source
At t2 1 C0 C
If a continuous source of contamination is added into the groundwater system, then a “stream” of the source concentration will move through the aquifer.
Distance (x)
Distance (x) 9

10. Mechanical Dispersion
Longitudinal
Transverse
Dispersivity is a function of the porous media
Mechanical dispersion occurs because not all the flow pathways through rock and soil are of the same length. If you think about a soil or rock, the pattern of the spaces between the grains (porosity) and the pathways that connect them (permeability) will be highly variable. As a contaminant moves through the soil or rock, parts of the contaminant will travel by different pathways through the pores and connecting passageways. As this occurs, the contaminant starts to disperse – that is the source concentration starts to diminish. However, if the total mass of contaminant does not change (it is not reacting with the soil or rock) then as its concentration decreases, the volume of the aquifer in which there is contaminant increases. 10

11. Dispersion of the solute
Continuous point source
Transverse (t)
Longitudinal (l)
At t2
Results in spreading of the front 1
For a continuous source of contamination, what we see is a change in concentration of the contaminant down the flow path, particularly at the contaminant front. C0 C
Distance (x) 11

12. Dispersion effect Instantaneous point source t1 t2 t3 1 t1 1 t2 1 t31 C0 C t2
For a point source, the effect is to have a gradual reduction in the concentration down the flow path, but an increase in the area over which the contaminant occurs. 1 C0 C t3
Distance (x) 12

13. Cleaning it up
Bioremediation – for organic chemicals (what are these?), often there are really small bugs (eg. microbial bacteria) that love to eat them. If you can find the right bugs and give them the right conditions, they can eat up the contamination. But be careful …. What the bugs produce can sometimes be as nasty as the contaminant in the first place!
Chemical treatment – sometimes the best way to treat a contaminant (especially the inorganic ones (what are these?) is to add another chemical that reacts with them. This can assist in getting rid of the contaminant. 13

14. Cleaning it up Digging and dumping
This basically digs up the contamination, and then moves it somewhere else
It solves the problem here, but what might be some of the consequences …….. 14

15. Use in the class room
Unstructured observation 10 to 15 minutes of ”play”, recording and or discussing observations at the conclusion. Some observations may be:
Can keep the water quality ok longer if you stop the Gnomes from dropping pollution! Drilling is cool, but expensive What do the bugs do? What do the chemicals do?
Groundwater is a significant water resource. Although surface water is commonly thought of as the main supply of water for drinking, agriculture and the environment, in fact there is much more groundwater available. In some parts of the world, groundwater is the only reliable source of water.
Of the available groundwater, a significant proportion is suitable for drinking water. This far outstrips the available surface water.

16. Use in the class room
Competitive “games” Who can keep groundwater safe for the longest!
Groundwater is a significant water resource. Although surface water is commonly thought of as the main supply of water for drinking, agriculture and the environment, in fact there is much more groundwater available. In some parts of the world, groundwater is the only reliable source of water.
Of the available groundwater, a significant proportion is suitable for drinking water. This far outstrips the available surface water. 16

17. Links to other topics
Permeability and porosity Water resource management Concepts of sustainability
Groundwater is a significant water resource. Although surface water is commonly thought of as the main supply of water for drinking, agriculture and the environment, in fact there is much more groundwater available. In some parts of the world, groundwater is the only reliable source of water.
Of the available groundwater, a significant proportion is suitable for drinking water. This far outstrips the available surface water. 17