- Rock layers and the water table
- Springs and geysers
- Explain how water enters an aquifer.
- Explain how water leaves an aquifer.
- Define aquifer, and give an example.
- Define springs and geysers.
- State the purpose of wells and how they work.
aquifer: permeable layer of underground rock that is saturated with groundwater
groundwater: fresh water below Earth’s surface
spring: place where the water table meets the surface so groundwater bubbles out of the ground onto the surface
water table: top of an underground rock layer that is saturated with groundwater
well: circular hole dug or drilled down into an aquifer to allow people to access groundwater
Introducing the Lesson
Introduce groundwater with the lesson at the following URL from the National Groundwater Association. The lesson introduces students to important groundwater concepts and demonstrates the concepts with a groundwater simulator. Problems with groundwater pollution are also introduced.
With the activity at the URL below, groups of students can build a model of groundwater using simple materials. The model-building activity is a follow-up activity to the groundwater introduction and demonstration described above under “Introducing the Lesson.” Students will be able to use their model to investigate the effects of different sediments on recharge rates, permeability, and porosity.
Building Science Skills
Use the hands-on activity “Where Does All the Water Go?” (see URL below) so students can actually see how groundwater flows. In the activity, they will explore a groundwater model and find the velocity of groundwater flow through the model.
Help students understand lesson vocabulary as well as learn a skill for understanding other unfamiliar terms. First define the word permeable (“able to be penetrated by water”). Then explain that the prefix im- or in- generally means “not.” Therefore, the word impermeable means “not permeable,” or “not able to be penetrated by water.” Challenge the class to think of other examples of words that are negated by the addition of the prefix in- or im- (e.g., secure/insecure, valid/invalid, mature/immature).
Challenge a few students to design and create a model of an aquifer. Have them use their model to show the class how an aquifer is recharged.
Use the classroom activity at the URL below so students can investigate groundwater and how sites for drinking-water wells are selected. Students will create their own groundwater well model using a coffee can and wire screening. They will also add food coloring to see how a pollutant can migrate through groundwater into drinking water resources.
Students may hold the misconception that groundwater flows in underground rivers. Explain that this is uncommon and that most groundwater seeps slowly through cracks and pores in rocks and sediments. Demonstrate how groundwater moves by pouring water through a sieve that is full of a mixture of sand, pebbles, and gravel. Let students observe as the water slowly drips out of the bottom of the sieve.
Question: Like water through a sieve, water seeps through rocks underground only in one direction: from the top down. Why?
Answer: Gravity pulls water down toward the center of Earth.
Reinforce and Review
Copy and distribute the lesson worksheets in the CK-12 Earth Science for Middle School Workbook. Ask students to complete the worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions listed at the end of the lesson in the FlexBook®.
Check students’ mastery of the lesson with Lesson 13.3 Quiz in CK-12 Earth Science for Middle School Quizzes and Tests.
Points to Consider
Fresh water is needed by many living things on Earth. However, most of Earth’s water is not fresh. Instead, it is salt water in the oceans. What do you know about Earth’s oceans? For example, how deep are they? And why is their water salty?
Ocean water moves in waves, tides, and currents. Do you know what causes these ocean water movements?