What is Groundwater?

1. What is Groundwater? Students will: Understand how water collects and flows underground. Explain how underground water reaches the surface in springs and by wells. Create a model in a experiment to show how the ground can filter water.

2. What is groundwater? • It is water held underground. • The ground under HTMS may seem too solid to hold water, but it is likely that groundwater sits or moves under the surface.

3. What is the difference between permeable and impermeable? • The ground beneath our feet is made up of both of these materials. • Permeable - substance that liquids can flow through • Like a coffee filter • Examples: soil, sand and gravel (there are spaces between the particles) • Impermeable– substance that liquids cannot flow through; causes water to collect in permeable material above it - Examples: solid granite, clay

4. What is a water table? • A water table is the top of the region that is saturated, or completely filled with water. • The saturation region below the water table is a called the saturation zone.

5. What is an aquifer? • An aquifer is an underground layer of permeable rock or sediment that contains water. -Some aquifers lie deep under layers of impermeable rock. -Others lie just beneath the topsoil. • Importance of Aquifers • They can filter out bacteria and other small organisms • Can remove some harmful chemicals and minerals • Can make groundwater clear and ready to drink • If it is not polluted, the groundwater may not need expensive treatment.

7. How does an aquifer form? For an aquifer to form, three things are needed: • A layer of permeable rock holds the water. Groundwater is stored in the pore spaces of gravel, sand or rock. • A neighboring area of impermeable rock keeps the water from draining away. (Either above or below ) • A source of water replenishes or refills the aquifer. Like any body of water, an aquifer can be emptied.

8. Where in Alabama can aquifers be found?

9. Quick Questions • What is a water table? • Through what kind of materials can water sink? • When does water stop sinking? • What forms the upper boundary of the water in an aquifer? • What forms the bottom of an aquifer? • What holds the water in place?

10. Investigation • Procedures: • Gather your materials and wait for your group to get settled. • Cap the top of the bottle. Invert it and add to it a layer of gravel, then a layer of sand, then a layer or soil. • Slowly pour water onto the soil until a water table becomes visible in the sand beneath it. • Add the pollutants pepper, cocoa, and food coloring to the bottle. Slowly unscrew the cap so that the water trickles into the bucket. • Observer the water that filtered through. • Pour more water onto the soil and let it trickle out.

11. Aquifer Reflection • Which pollutants were filtered out before reaching the aquifer? • Which ones reached the aquifer? • What effect does pollution have on drinking water that comes from aquifers? • What could you do to clean up an aquifer? • Is this like the real world? How?