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Warm-up. The U.S. Strategic Petroleum Reserve is currently 685 million barrels (and according to Nina, will be slowly increasing to 1.5 billion barrels over the next 20 years) U.S. petroleum consumption is 20,802,000 barrels/day. How many days will the current reserve last?
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Warm-up • The U.S. Strategic Petroleum Reserve is currently 685 million barrels (and according to Nina, will be slowly increasing to 1.5 billion barrels over the next 20 years) • U.S. petroleum consumption is 20,802,000 barrels/day How many days will the current reserve last? How many days will 1.5 billion barrels last? What do you think the Total world petroleum consumption is per day? What country is the top oil producer? Consumer?
What is water pollution? What is water quality? Water Pollution: • degradation of water quality (physical, chemical, or biological properties) Water quality: • how clean or pure water is • what its physical, chemical or biological properties are. • Does it meet water quality standards (Standards vary for different uses)
2. What standards are used to measure water quality? What is an MCL? Water Quality Standards • If standards exceeded, water cannot be used for intended purpose • Drinking water standards more stringent than those for rivers and streams MCL = Maximum Contaminant Level • Maximum level of contaminant allowed - if exceeded, water cannot be used for intended purpose and fines may be imposed)
3. On a separate paper, make an organized chart for the following types of water pollutants, including the following categories for each: a brief description of each; examples; the source of the pollutant; the effect on human health, wildlife, and the environment; how treated or cleaned up; and any especially interesting information you learned. • Biochemical oxygen demand (BOD) and dissolved oxygen • Pathogens (infectious agents) • Nutrients (N & P) • Oil • Sediment • Acids • Heavy metals • Organic compounds (pesticides, pharmaceuticals, food additives, etc.) • Thermal pollution
4. How can pollution from point and non-point sources be reduced?
4. How can pollution from point and non-point sources be reduced? Point source = Discharges of pollutants from a distinct, confined location Examples: sewage treatment plant discharges, industrial waste discharges from pipes into waterways • Reduction: • Permit process for any discharge into any water (NPDES = National Pollutant Discharge Elimination System) which limits pollutants and can levy penalties (RWQCB)
4. How can pollution from point and non-point sources be reduced? Non-point source = more diffuse and less confined • Examples: Runoff from roads, agricultural fields, feedlots, mines, clear-cut forests
4. How can pollution from point and non-point sources be reduced? Non-point source = more diffuse and less confined • Examples: Runoff from roads, agricultural fields, feedlots, mines, clear-cut forests
4. How can pollution from point and non-point sources be reduced? Non-point source = more diffuse and less confined • Examples: Runoff from roads, agricultural fields, feedlots, mines, clear-cut forests • More difficult to regulate and treat • Reduction • Good land use policy: vegetative buffers between agriculture land and waterways, catchment basins, artificial wetlands, keep erodable slopes covered with vegetation • Education
5. Describe the process that leads to cultural eutrophication Eutrophication High nutrients-->increased algae growth-->can include mats of algae at surface--> light level below surface drops or just too large a quantity of algae--> algae dies--> increased bacterial activity (increased BOD)--> lower oxygen concentration --> fish and other organisms die, which affects the whole ecosystem Cultural eutrophication (when humans add nutrients)
5. Describe three methods for controlling or cleaning up cultural eutrophication. Solutions: Decreased use of phosphate containing detergents, etc. Controlling agricultural runoff (better irrigation practices, using less fertilizer, buffers (strips of natural vegetation, wetlands) Controlling urban runoff (golf courses, parks, homes, landscaping) decreased fertilization, buffers, etc. Advanced treatment and use of wastewater
5. Draw an oxygen sag curve to illustrate what happens to dissolved oxygen levels in a stream below a point source of oxygen-demanding wastes. Explain the characteristic shape of the curve.
6. What are common sources of groundwater pollution? Explain how it can be cleaned up and explain why it is difficult to clean up. Describe three ways to prevent groundwater pollution Common sources of groundwater pollution Waste disposal sites, landfills (leachate) Leaking underground storage tanks Pesticides and fertilizer Septic tanks too close to aquifer (Los Osos) Saltwater intrusion Clean-up often difficult Pump and treat (water and vadose zone) Bioremediation PREVENTION IS MUCH BETTER
6. Describe three ways to prevent groundwater pollution PREVENTION Proper site location and lining of waste disposal sites Double lined underground storage tanks and use of above ground storage tanks with protective layer underneath and a berm. Decreased use of pesticides and fertilizers Use of sewage treatment rather than septic tanks in some locations with high ground water Avoid overdraft of groundwater (mining of water) in coastal areas
7. What is the twofold effect of sediment pollution? • Soil loss (erosion) • Degradation of water quality with sediment • Turbidity increases • Kills fish directly by clogging gills • Covers bottom of stream so can’t lay eggs or eggs smothered • Darker water --> increased temperature --> increased metabolism and need for oxygen and decreased dissolved oxygen in water • Blocks sunlight water plants need to grow • Suffocation of insect eggs and larvae
8. What was learned from the Exxon Valdez oil spill that might help reduce the number of future spills and their environmental impact? Need double-hulled tankers Off-load leaking tanker ASAP Soak up material on shore with absorbent material (don’t spray with hot water)
9. In the summer, you buy a house with a septic system that appears to function properly. In the winter, effluent discharges at the surface. What could the cause of the problem be? How could it be solved? • Cause • Increased water content of soil in winter does not permit proper drainage • Solution • Reduce volume of water through septic system by diverting “graywater” to other areas • Increase leach field area • Prevent by situating leach field in an area with adequate soil drainage and NOT where there is a high water table • In all cases, have tank pumped regularly
10. How does water that drains from a coal mine become contaminated with sulfuric acid? Why is this an important environmental problem? Coal mines contain rocks and coal with sulfur-containing minerals. Minerals react with water--> sulfuric acid Acid runoff into streams (ruin water quality and poison aquatic ecosystem) or seep into groundwater Acids also increase leaching of heavy metals to the water
12. In the Monterey Bay area some wastewater is dumped directly into the ocean. And some of it is used in a conservation plan. List the three ways that wastewater can be reused (but not for domestic use). What color is the delivery system for “recycled” water? • Uses (re-uses) • Agriculture • Golf courses • Parks and schools • Groundwater recharge • Drinking water (with adequate treatment and disinfection) • Color of pipe PURPLE
13. How is wastewater “treated” in a wetland? Which pollutants can be removed? • Wetland treatment wastewater flows through a wetland where it is cleaned naturally by organisms in the wetland • Which pollutants removed • Municipal wastewater • BOD, pathogens, nutrients (P, N), suspended solids, metals) • Stormwater runoff • Metals, nitrate, BOD, pesticides, oils • Industrial wastewater • Metals, acids, oils, solvents • Agricultural wastewater • BOD, nitrate, pesticides, suspended solids
OTHER WATER ISSUES: 1. Stream pollution continues to increase from industrial and sewage discharges. In developing countries there are no clean water laws. 20% of rivers in China are too polluted to use for irrigating crops. 2. Lakes are more prone to stratification which leads to low DO. The flushing and changing of water in lakes can take from 1 to 100 years. Concentrations of pollutants increase. 3. Eutrophication 4. Biomagnification = DDT, PCBs, lead, mercury become concentrated as it moves up the food chain.
OTHER WATER ISSUES: 5. Genetic pollution = the introduction of exotic species into lakes and rivers. Zebra mussel has no known predators in the Great Lakes now clogs water intact pipes for irrigation and power plants, grow on boat hulls, piers and other surfaces, deplete the food supply of other lake species. The quagga mussel is also in the Great Lakes. 6. Oil spills in the ocean are rare. After the huge oil tanker accidents, ships were required to have two hulls. More oil ends up in the ocean due to the dumping of ballast water or of waste water from ships. Each year, a volume of oil equalt to 20 times the amount spilled by the Exxon Valdez is imporperly disposed of by about 50 million U.S. motorists who change their own motor oil.
OTHER WATER ISSUES: 7. How to control non-point sources, primary culprit is agriculture? Reduce or eliminate pesticides and fertilizers. Use slow-release fertilizers. Plant buffger zones of permanent vegetation around cultivated fields to trap run-off. Livestock owners can treat their waste fluids. Reforest or replant denuded land to reduce soil erosion. 8. The Clean Water Act required that rivers, lakes and streams be cleaned up. However, many cities have antiquated sewage treatement facilitites.
OTHER WATER ISSUES: 9. Groundwater has been contaminated with pesticides and other toxins in many states, including California. Groundwater can be contaminated from leaky underground storage tanks, landfills, abandoned hazardous waste dumps, deep wells and livestock waste storage lagoons. Groundwater can be protected by monitorinjg aquifers, by requiring landfills to have plastic liners, requiring leak detection systems for undergound storage tanks, banning the disposal of hazardous wastes in deep wells, requiring liability insurance for companies that store hazardous wastes. 10. The problem with most water pollution/contamination is that there is little money available for clean up and very few inspectors. 11. How can water resources be used more sustainably? (1) source reduction of pollutants (2) reuse of wastewater (3) recycling of toxins rather than dumping them