Activity 4_groundwaterediting

GEOL 101 Name: Michael HW 4 Groundwater Contamination DUE Monday, 10/30 Objectives: 1) To use water elevations to construct a groundwater flow map. 2) To use the flow map to make predictions about where contaminants will flow from point sources. 3) To analyze scientific data, interpret the data and present your conclusions. Background: In Dec 1989, the residents of houses A and E observed a gasoline smell in their basements. Over the next year, the residents in house B and F (April 1990), G and C (August 1990) and H and D (Dec 1990) also began to smell gasoline in their basements. The residents of these houses contracted the Crunchy Environmental Consultants (CEC) to determine where the source of the gasoline is located. CEC installed nine monitoring wells in the blocks around the houses, including one each at the Brachio Fuels and Biagas Gasoline stations. Both of these wells contained various amounts of gasoline-related compounds. You, the CEC geologist, need to determine the direction of groundwater flow in order to determine who is responsible for the gasoline odors. Problems to do in class : • Complete the table below to determine the elevation of the water table at each monitoring well location (shown on map on the third page): Monitoring Well Elevation of the top of the well (ft above sea level) Depth to water (ft) Elevation of water table (ft a.s.l.) 1 215 15 200 2 214 23 191 3 213 24 189 4 219 26 193 5 209 32 177 6 212 22 190 7 205 25 8 194 23 9 200 31 • Write the elevation of the water table next to each monitoring well. Draw water table elevation contours with an interval of 10 ft starting at 200 ft asl and ending at 170 ft asl. • What general direction is the water flowing? Write the general direction here and make an arrow that indicates the general direction of flow on the map. Writing Assignment to be completed outside of class: After you have completed your analysis of the water flow direction, write a 400-500 word essay that addresses the following items: In paragraph 1, fully explain the evidence you used to determine the direction of water flow (refer to the textbook chapter on groundwater to further your explanation).