It's Water-Wise Wednesdays with Frannie the Fish! {TAPS Manual Part 4: Sinkholes}

Frannie's friends at the Groundwater Foundation recently published the second edition of the Training About Protecting the Source (TAPS) Manual. The manual guides users through hands-on activities that explore potential threats to groundwater and challenges them to think about what can be done to protect this key drinking water source.

This manual can be used inside the classroom and is aligned to the national Next Generation Science Standards, but Frannie loves just learning about groundwater, no matter where she is. For the next few weeks, you can join her as she works through the different activities. 

Frannie will be using the Groundwater Foundation's Awesome Aquifer Kit, but if you don't have one, you can follow along with materials that might be found around your home. This is the second part of Frannie's exploration of the TAPS Manual. You can follow the link to see what she learned about leaky underground storage tanks, improperly abandoned wells and the over-application of fertilizer.

Today's activity is....Sinkholes.

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A sinkhole is a depression that is formed as underlying limestone or a similarly soft rock is dissolved by groundwater. Typically, sinkholes form slowly so that the top layer of land stays intact for a while after the rock below dissolves. Sinkholes vary greatly in area and depth and can be small and shallow or they may be very large. Sinkholes form a direct path to groundwater through which contaminants can easily enter.

For this activity, you will need:

• Awesome Aquifer Kit, OR
• Plastic box
• Gravel
• Sugar cubes (at least 12 cubes)
  
• 16 oz cup of water slightly above room temperature
• Small plastic toy or house (optional)

Activity Steps

1. Read through all the instructions first before you begin to build the model. Make sure you have all the needed materials and supplies.

 

2. Fill the plastic box with gravel until it is about ¼ full.

 

3. Add water so that half of the rocks are covered. (This will represent an aquifer.)

 

4. Place sugar cubes on the gravel, next to one side of the plastic box. The sugar cubes should be at least three cubes across, two cubes wide, and two layers deep. The sugar cubes simulate layers of limestone.

 5. Add more gravel on top to cover the sugar cubes completely. You can either create a hill over the sugar cubes or continue to add gravel so that surface of the model is level.

 

6. If you have a small plastic toy animal or house, place it on top of the gravel directly above the sugar cubes.

  

7. Pour or spray water (preferably warm water) over the buried sugar cubes to simulate rain. Watch and wait.

Frannie noticed that the warm water slowly dissolved the sugar cubes beneath the gravel. The surface of the gravel remained level for a little bit, but eventually it collapsed into the vacuum that was left by the sugar. Like sugar cubes, soluble geologic materials can dissolve over time due to natural causes or human impacts such as over-pumping and over development. Once a sinkhole appears, it can become a direct line for contaminants to enter the water below.

It's Water-Wise Wednesdays with Frannie the Fish! {TAPS Manual Part 3: Leaky Underground Storage Tanks}

Frannie's friends at the Groundwater Foundation recently published the second edition of the Training About Protecting the Source (TAPS) Manual. The manual guides users through hands-on activities that explore potential threats to groundwater and challenges them to think about what can be done to protect this key drinking water source.

This manual can be used inside the classroom and is aligned to the national Next Generation Science Standards, but Frannie loves just learning about groundwater, no matter where she is. For the next few weeks, you can join her as she works through the different activities. 

Frannie will be using the Groundwater Foundation's Awesome Aquifer Kit, but if you don't have one, you can follow along with materials that might be found around your home. This is the second part of Frannie's exploration of the TAPS Manual. You can follow the link to see what she learned about improperly abandoned wells and the over-application of fertilizer.

Today's activity is....Leaky Underground Storage Tanks.

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An underground storage tank system (UST) is a tank and any underground piping connected to the tank that has at least 10 percent of its combined volume underground. Underground storage tanks can contain fuels, chemicals, and wastes. According to the US Environmental Protection Agency there are over 550,000 underground storage tanks that store fuels or other hazardous substances. These tanks may leak and when they do, they can contaminate surrounding soil, groundwater, surface waters, and even affect indoor air quality.

For this activity, you will need:

• Awesome Aquifer Kit, OR
• Plastic box
• Gravel
• Plastic tube
• Hand pump or Syringe
• Nylon
• Rubber band
• Food dye
• Small plastic container with lid (ex. a film cannister, sprinkles or spice container, etc.)
• 16 oz cup of water

Activity Steps

1. Read through all the instructions first before you begin to build the model. Make sure you have all the needed materials and supplies.

 

2. Fill the plastic box with gravel until it is about ¼ full.

 

3. Add water so that half of the rocks are covered. (This will represent an aquifer.)

 

4. Create a well by covering the end of the plastic tube with nylon, securing it with a rubber band.

 

5. Insert the well, with the well screen on the bottom, near one corner of the plastic box. Push the well down so that it reaches the bottom of the model.

 

6. Add more gravel until the box is about ½-¾ full. The surface of the gravel should be fairly level across the box.

 

7. Dye about 1.5 oz of water with three or four drops of food coloring and use it to fill the plastic container. Seal the container when full.

   

8.Using a tack, carefully poke holes in one end of the film canister or container.

 

9. Dig a small hole in the gravel on the opposite side of the model from the well. Place the canister/container inside the hole. The end of the container with the holes poked in it should be facing down. Cover the container, either partially or entirely, as long as at least 10% of it is underground.

 

10. Pour water on the surface of the gravel to simulate rain. Observe what happens to the colored water inside the storage tank after it rained. 

 

11. Pump the well by inserting the tip of the syringe into the well (plastic tube) or attaching and pumping the hand pump.

Frannie observed that once the water "rained" over her aquifer, the red water, which was contained in the storage unit, leaked out into the aquifer below. As it rained more and more, even more leachate entered the aquifer. Very quickly, the whole aquifer becomes contaminated  and when Frannie tried to pump water up from the aquifer, it was pink from the contaminant. 

Storage tanks are a common and useful way of storing and disposing of toxic waste, but they must be monitored carefully to prevent contamination of our drinking water sources, crops, and livestock.