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<br />Action: Use the wash bottle with clear water to represent rain. Squirt <br />water over the lake and over the sand. Students will see how <br />precipitation is part of the water cycle because the water will enter <br />. the lake as well as soak into the sand/ground. <br /> <br />Discussion: The model demonstrates the inter-relationship of <br />groundwater and surface water. Groundwater often feeds lakes and <br />streams. The place where groundwater becomes surface water is a <br />discharge area. Precipitation (from the wash bottle) and water from the <br />lake (surface water) infiltrate the ground to become groundwater, thus <br />recharQinQ the aquifer. <br /> <br />CONCEPT 7: The soil and rock below the earth's surface normally consists of <br />both a saturated and an unsaturated zone. The top of the saturated zone is <br />called the water table. A type of monitoring well called a piezometer can be <br />used to define the top of the saturated zone. <br /> <br />Action: Looking at the model, notice the water level in all of the <br />piezometers and pumping wells ~xcept for the two that penetrate the <br />confining layer. <br /> <br />Discussion: Depth to the water table varies. . Use a grease pencil or <br />dry erase marker to draw the water table on the model (connect water <br />levels in each of the piezometers and pumping wells in the unconfined <br />aquifer). Note the water table slopes from the inlet to the outlet. <br /> <br />CONCEPT 8: Water in confined aquifers is under Dressure. This pressure <br />causes the water level in wells penetrating the confined aquifer to rise above <br />the top of the aquifer. <br /> <br />Action: Looking at the model, notice the water level in the piezometer <br />and the pumping well that penetrate the confining layer and end in the <br />confined aquifer. <br /> <br />Discussion: The confined aquifer in the model is under pressure because <br />the confining layer significantly retards water movement upward. The <br />aquifer has a recharge area but no obvious discharge area. Pressure in <br />the aquifer allows water to move upward through the confining layer. <br /> <br />CONCEPT 9: The Dotentiometric surface is the level to which water will rise <br />in a well penetrating a confined aquifer. <br /> <br />Action: Observe the water levels in the piezometer and pumping well <br />that penetrate the confining layer. <br /> <br />Discussion: In the confined aquifer, the potentiometric surface is <br />above the top of the aquifer, and may actually be above the water table <br />in the overlying unconfined aquifer. <br /> <br />3 <br />