Geology 2 Spring 1997

Name:

Lab day & time:

PRELAB #3. GROUNDWATER

This prelab assignment is due at the beginning of your lab session. You will not be allowed to participate in the lab if you have not completed this prelab exercise. Read about groundwater in Chapter 14 in Chernicoff.

Define/describe the water table (page 275).

Define porosity and permeability and tell how they differ.

Describe the porosity and permeability you would expect to find in a sedimentary layer composed of fine grained, clayey mud.

Would you expect the hydraulic conductivity of a clayey mud bed to be high or low?

What does the presence of a lake tell you about the depth of the water table?

If you lived in the country and needed to drill a water well for your water supply, would you choose a hilltop site or a valley site? Why?

Define/describe an aquifer and an aquitard.

Describe (or sketch) how the pumping of water from a well alters the shape of the water table in the vicinity of the well.

Describe (or sketch) how excessive pumping of fresh water from wells in a coastal community can cause the ground water to become contaminated by salt water.