1. Water

2. Global Water Distribution ► 71% of Earth’s surface is water ► 97% is salt water in oceans and seas ► 3% is fresh water  77% of fresh water is frozen in glaciers & polar ice caps & polar ice caps  13% is available some is deep in aquifer or as vapor in atmosphere some is deep in aquifer or as vapor in atmosphere not always where it is needed not always where it is needed

3. Watersheds ► Area of land drained by a river

4. Porosity of Soils ► For water to get into groundwater, it must pass through soil ► Porosity- the amount of space between the particles that make up soil or a rock

5. Water Quality ► Pollution anywhere in watershed can pollute river ► Ex: Plastic blow out of trash cans in city, goes into drainage and rain washes them into ocean.

6. Permeability of Soils  Permeable  the ability of soil or rock to allow water to flow through Sandstone, limestone, sand, gravel are permeable Sandstone, limestone, sand, gravel are permeable Clay & Granite are impermeable Clay & Granite are impermeable Impermeable soils are reason why LV has flash floods Impermeable soils are reason why LV has flash floods

7. Recharge Zone ► The area of the Earth’s surface where water percolates down Subsidence in LV- we were drawing water out of groundwater causing valley to sink -10 feet in downtown Now they recharge groundwater in Winter from Lake Mead Now they recharge groundwater in Winter from Lake Mead

8. Water Uses ► Vast differences between countries US uses 300 L/day (80 gallons)US uses 300 L/day (80 gallons)  only half used inside home, rest used outdoors for lawns, etc India uses 41 L/dayIndia uses 41 L/day See Table 1 p. 277 See Table 1 p. 277

9. Water Pollution ► The introduction of chemical, physical or biological agents into water that degrade water quality and adversely affects the organisms that depend on that water

10. Main Causes ► Industrialization ► Rapid Human Growth

11. Prevention ► Point Source Source can be identified and origin located Source can be identified and origin located Enforcing clean up is difficult, Enforcing clean up is difficult, ex: Perchlorates ex: Perchlorates ► Non-Point Source Controlling is difficult Controlling is difficult Ex: highway construction & maintenance Ex: highway construction & maintenance storm water runoff, litter storm water runoff, litter

12. Pollution Types and Sources for Point Source Pollution ► 23 million septic tank systems ► 190,000 storage lagoons for polluted waste ► 9,000 municipal landfills ► About 2 million underground storage tanks containing pollutants such as gasoline ► Thousands of public and industrial wastewater treatment plants

13. Pollution Types and Sources for Non-Point Source Pollution ► Pesticides from crop land ► 50 million tons of fertilizer applied to crops and golf courses each year ► 10 million tons of dry salt applied to highways for snow & ice removal every yr.

14. Thermal Pollution ► Increase in temperature of a body of water ► Decreases the amount of oxygen the water can hold ► Fish and aquatic organisms may suffocate and die ► Below Dam- decrease in temp cause native fish to be endangered species fish to be endangered species

15. Groundwater Pollution ► Pollutants enter when surface water percolates down from the Earth’s surface ► Pollution can enter & affect groundwater Clean upClean up -recharge is slow (can take hundreds to -recharge is slow (can take hundreds to thousands of years) thousands of years) -difficult to decontaminate -difficult to decontaminate

16. Ocean Pollution  Activities on land cause 85% of ocean pollution pollution ex: oil, toxic wastes, medical wastes  Ships can legally dump wastewater & garbage overboard in some parts of ocean ex: Cruise ship pollution

17. Read: Read: Ecofact on Cruise Ship Pollution

18. River Comes from same root word as Rival Wars fought over water sources

19. Issues for Water Conservation ► Conservation may not be enough to prevent water shortages  Desalinization ► Problems changes salinity in ocean areachanges salinity in ocean area expensiveexpensive  Transporting Fresh Water ► Problems  Expensive  Greek Islands

20. Solutions For the Future Solutions For the Future

21. Water Conservation ► In Agriculture  use of drip irrigation & computer programs to coordinate watering times  Know why the water savings from Math Practice: Israeli Agriculture

22. Water Conservation ► In Industry  Golf courses use “gray water” in LV; takes less energy  Recycling of cooling and wastewater

23. Water Conservation ► In Home  Low flow toilet & shower heads  Landscaping-water at night to prevent evaporation and/or use xeriscaping

24. Homework ► Study for the TEST