1. Groundwater

2. Porosity & Permeability Porosity: - the percentage of the total volume of a rock consisting of voids. - pore spaces: spaces between mineral gains, fractures, solution cavities, vesicles - for example: vesicles & fractures in a basalt = 30-40% solution cavities in limestone = 30% spaces between grains in cemented sandstone = 5% spaces between grains in conglomerate = 20% fractures in granite = <1% Permeability: - the capacity of a rock to transmit fluids - depends on the size of the voids, and whether the voids are interconnected. - a rock can have high porosity but low permeability if the voids are not connected so as to allow water to flow. - velocity of gw averages 1 m/day to 1 m/year.

3. Water Table

4. Flow Groundwater flows downhill and into areas of low pressure. Stream beds are areas of low pressure: Natural springs.

5. Effluent and Influent Water table drops below level of stream bottom Water table is at or above level of stream bottom.

6. Spring

7. Spring Pic

8. Well Picture Groundwater Well: An artificial area of low pressure

9. Wells

10. Cone of Depression

11. Contaminated Wells

12. Vermillion GW flows N to S Town wells Wastewater treatment plant

13. Ogallala Ogallala Formation: A trillion gallons of water put in the ground by melting glaciers 10K years ago. This water is used for irrigation in the midwest.

14. Center Pivot 128 Acres

15. Center Pivot II

16. Circles

17. Garden City, Kansas

18. San Joaquin Valley

19. Subsidence

20. Artesian Water Pressurized groundwater rises from an aquifer

21. Blow Out

22. Water Tower

23. Water Reservoir Table Rock Reservoir, South Carolina

24. New York Drought 52% decrease in capacity in two years One reservoir in the Catskill Mountains

25. Lake Mead

27. Wastewater Treatment

28. Karst Topography

29. Karst I Limestone Bedrock Acidic groundwater slowly dissolves bedrock

30. Karst II

31. Small Sink

32. Medium Sink

33. Large Sink

34. Stalactite Water percolating through the ground leaves behind calcite (CaCO 3 ) deposits.

35. Cave Stalactite Stalagmite Column

36. Cave II

37. Geysers & Hot Springs

38. Geyser Formation Groundwater percolates downward; as it approaches magma at depth, it heats up. When it flashes into steam, the steam rushes back up to the surface forming a geyser. Then the process repeats. Sometime this process repeats at a regular interval, sometimes not.

39. Old Faithful

40. Colorado River Delta River ends here Only 10% of river water makes it into Mexico

41. Aral Sea Reduced in size by 60% in 30 years Commercial fishing eliminated

42. Lake Chad

43. 1/20th of its size 20 yrs ago!