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If withdrawal exceeds recharge , the groundwater table drops.

If withdrawal exceeds recharge , the groundwater table drops. Water Quality Problems. Bacteria Heavy metals (lead, mercury, chromium, arsenic) Gasoline & Diesel Solvents (carbon tetrachloride and TCE) Nitrate Salt-water intrusion. Percentage of total disease burden caused

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If withdrawal exceeds recharge , the groundwater table drops.

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  1. If withdrawal exceeds recharge, the groundwater table drops.

  2. Water Quality Problems Bacteria Heavy metals (lead, mercury, chromium, arsenic) Gasoline & Diesel Solvents (carbon tetrachloride and TCE) Nitrate Salt-water intrusion

  3. Percentage of total disease burden caused by unsafe water Skin lesions caused by arsenic poisoning

  4. With the help of wealthy western nations, hundreds of thousands of wells were installed to deliver bacteria-free drinking water to residents of Bangladesh. This effort to combat water-borne disease has resulted in a second tragedy in Bangladesh: the groundwater in many areas of the country is now known to be rich in arsenic and mercury… This has been described as “the worst mass poisoning case in history”. Latest idea: rain-water harvesting (cisterns) Arsenic poisoning in Bangladesh update 2005

  5. Pyrite FeS2“fools gold” Pyrite forms in environments where there is little oxygen. When pyrite is exposed to weathering or when coal containing pyrite is burned, it generates sulfuric acid, and is the main cause of acid rain and acid mine drainage. Arsenic, mercury, cadmium, and other toxic metals can substitute for iron in pyrite. mercury in fish

  6. Electron microprobe elemental maps for arsenic and sulfur showing arsenic-rich (6-7 wt. %) pyrite occurs as the second of 3 pyrite generations.

  7. ASARCO American Smelting and Refining Company 5th and Douglas, Omaha From: Two-Mile Time Machine by Richard Alley, p. 190

  8. Geo-hero: Clair Patterson Patterson was a geochemist at Cal Tech who did pioneering work in the 1960’s on the age of the Earth. While developing the uranium/ lead technique, he came to realize that lead contamination of recent origin was ubiquitous--in the air, in the soil, and in human flesh. His findings and his activism lead to the banning of tetraethal lead in gasoline. History of Lead Poisoning and Medical Geology

  9. Aquifer-a permeable layer below the Earth’s surface through which groundwater flows. Aquifers (especially those in “unconsolidated sand and gravel”) are vulnerable to contamination.

  10. X X X

  11. “Comedy of Errors” concerning groundwater flow, groundwater quality and city planning.

  12. Nitrate (NO3=) is abundant in animal waste and runoff from fertilized fields, and is linked to “Blue Baby” Syndrome. EPA limit is 10 parts per million

  13. Heron Island, a tiny part of the Great Barrier Reef How much groundwater?

  14. A surprising amount of fresh groundwater is present below islands because fresh water is less dense than saltwater. The aerated zone is also known as the vadose zone. Fresh groundwater

  15. Withdrawal of groundwater has caused subsidence in many areas--especially Mexico City, New Orleans, Houston,Venice, and Pisa. Withdrawal of groundwater from aquifers causes adjacent mud to compact.

  16. Withdrawal of groundwater has caused serious problems with earth fissures in southern Arizona, New Mexico, and Nevada.

  17. Shoreline Systems-- Chapter 15

  18. Low, rolling waves in deep water are called swell. L L/2 In deep water, circular motion ceases at a depth equal to half the wave length (L/2). When waves come on shore, they “touch bottom” at this depth and change their shape. 21

  19. Wind Speed Wind Duration Fetch (distance of wind-water interaction) Size and Energy of Waves depends on: 22

  20. summer, La Jolla, CA 23

  21. winter, La Jolla, CA 24

  22. Longshore drift takes place when waves approach shore at an angle. 25

  23. 26

  24. Longshore drift Waves approaching shore at an angle 27

  25. Cape Cod, MA 28

  26. Groins or jetties (arrows) are built to slow the movement of sand on a beach. In which direction has sand been moving since construction of the groins? 29

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