Do you get the groundwater picture yet?

What is an “aquifer”?

An underground formation that is capable of storing AND transmitting water

Some aquifers cover 100’s of square miles and be 100’s of square feet thick. Others may only cover a few square miles and be a few feet thick.

Water quality and water quantity vary from aquifer to aquifer, even vary sometimes within the same aquifer! (how can this happen?)

Some aquifers yield millions of gallons of water per day and maintain their water levels, while others may only be able to produce small amounts of water each day.

The rate of movement of ground water varies based on the rock material in the formation through which the water is moving. After water percolates down to the water table, it becomes ground water & starts to move slowly down gradient.

Water movement responds to differences in energy levels. The energies that cause ground water to flow are expressed as gravitational energy & pressure energy (both are forms of mechanical energy).

Gravitational energy comes from the difference in elevation between the recharge area (where water enters the ground water system) and discharge area (where water leaves the system).

Pressure energy (hydraulic head) comes from the weight of overlying water and earth materials.

Drilling wells is the best way to get the ground water picture!

You have a well log for 25 different wells. You are to illustrate your well data on a strip of paper.

USE PENCIL FOR THIS Mark off 1” sections on your strip of paper. Using your well data, draw the boundary lines for each substrate. Fill in the substrate sections with the appropriate markings.

We must all use the same colors: black line for the water table yellow – fine sand orange- medium sand red – coarse sand green – sandstone clay- brown dark blue – gravel purple - granite

If the horizontal scale of the cross section is 1 inch = 1 mile, and the vertical scale is 1 inch = 50 feet How many miles are horizontally represented in the cross section?

25 miles 25 miles

How many feet are vertically represented in the cross section? How many feet are vertically represented in the cross section?

600 feet

How many feet below the surface is the water table? How many feet below the surface is the water table? (yes, I know it varies, but from what depth to what depth??????????????) (yes, I know it varies, but from what depth to what depth??????????????)

12.5 to 250 feet 12.5 to 250 feet

Imagine a drop of water falling on the surface near well #8. What type of pollutants might enter the groundwater there? Imagine a drop of water falling on the surface near well #8. What type of pollutants might enter the groundwater there?

Fertilizers, pesticides, tractor fuel and POO POO!!!!!!!! Fertilizers, pesticides, tractor fuel and POO POO!!!!!!!!

Through which layer(s) would a drop of water move the fastest?

GRAVEL

Which layer would take the longest for a drop of water to get through? Which layer would take the longest for a drop of water to get through?

CLAY CLAY

Got a calculator? Get it out. If the groundwater has a flow rate of 100 feet per day, how long would it take the water in the sandstone formation to move from well #1 to well #15?

792 days or a bit over 2 years 792 days or a bit over 2 years

How deep is the zone of aeration at well #11? How deep is the zone of aeration at well #11?

150 feet 150 feet

How deep is the zone of saturation at well #6? How deep is the zone of saturation at well #6?

About 325 feet About 325 feet

Last question: Where would you label a “cone of depression” on the class chart? Last question: Where would you label a “cone of depression” on the class chart?

Between well #11 and well #19 Between well #11 and well #19

Are you “water-logged” yet??? Are you “water-logged” yet??? Get it? Ha, Ha, Ha Get it? Ha, Ha, Ha