Water Resources & Pollution Chapters in Textbook: 9, 14Key Concepts:
Water availability ★ Only 3% of world’s water is fresh...and only 1% is available for use
Groundwater★ Unconfined Aquifers: ○ More likely to be contaminated by anthropogenic chemicals
○ Quicker to recharge (weeks-years)★ Confined Aquifers: ○ Concealed beneath impermeable rock, and therefore less likely to
be contaminated○ Slow to recharge because of the impermeable rock (10,000-20,000
years)○ May have an area near the surface the allows it to recharge (called a
recharge area). ○ Artesian Wells are wells that tap water from a confined aquifer. The
Confined aquifer is under a lot of pressure from the impermeable layer of rock above it that the water, when a well is created bursts out and is flowing. No pump is needed.
★ Problems with Overuse○ Salt Water Intrusion: Pumping water faster than it can recharge can harm water quality. Rapid
pumping near the coast can cause saltwater to displace the freshwater.
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○ Cone of Depression:An area where there is no longer groundwater due to rapid pumping of a well.
★ Regulated by the Safe Drinking Water Act (which also regulates surface waters) ○ sets maximum contaminant levels in drinking water sources for 77 different substances.
Surface Waterpage 1
Water Resources & Pollution Chapters in Textbook: 9, 14
★ Water visible on the earth’s surface★ Regulated under the Clean Water Act of 1972
○ CWA was borne from the Federal Water Pollution Control Act of 1948
Water Diversion★ Levees and Dikes (New Orleans)★ Dams (Hoover and Three Gorges Dams)★ Aqueducts (Colorado River Aqueduct)
Desalination★ Distillation★ Reverse Osmosis★ Issues of brine disposal
Water Uses:
★ Agricultural○ Furrow (65% efficiency)○ flood (70% efficiency)○ Spray (75% efficiency)○ Drip (95% efficiency)
★ Industry○ genergating electricity○ cooling machinery○ refining paper
★ Household○ toilets○ lawn watering○ showers, sinks, pools
Conservation: What steps can you do to conserve water?★ Reuse Grey Water (using wastewater from sinks, showers and washing machine)★ Xeriscape the landscape by planting native to reduce need to water lawns
POLLUTIONWater Pollution: Any chemical, biological or physical change in water quality that has a harmful effect on living organisms (including humans!) or makes it unusable for agriculture
★ Point Sources - Discharge pollution from specific locations (single point). ○ EASY TO MONITOR/REGULATE○ Factories, power plants, oil wells
★ Non-Point Sources - Scattered or diffused, having no specific location of discharge. ○ HARDER TO CONTROL!!○ Agricultural fields, feedlots, golf courses
Major Water Pollutants★ Human wastewater
○ Excess nutrients (N & P) eutrophication➔○ Biological Oxygen Demand: amount of oxygen a
quality of water uses over a periods of time at a specific temperature
■ low BOD: less polluted by wastewater■high BOD means less oxygen available to
other organisms (can create Dead Zones)○ Disease-causing organisms (esp. Fecal coliform, a
mostly harmless group of bacteria, is an indicator species. It could indicate that the water is polluted with harmful bacteria such as E. Coli & Cholera)
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Water Resources & Pollution Chapters in Textbook: 9, 14
★ Metals (Pb, Hg, As, Cd)
★ Acid (Acid mine drainage)
★ Synthetic Organics (pharma; pesticides; others)
★ Oil (Think about the effects of the Deepwater Horizon spill)
★ Solid Waste (especially plastic!)
★ Sediment (runoff from construction is a common cause of sediment pollution)
★ Thermal (often from nuclear power plants)
★ Noise pollution (underwater war ships training)
Wastewater Treatment (see your video worksheet from class)★ Septic System
○ Sewage enters septic tank, where floating materials will form a scum layer along the top, solids will settle onto the bottom and bacteria will break the sludge down and the liquid portion (septage) moves to the drain field, where will will slowly sink into the ground.
★ Sewage System○ Primary Treatment
■ solid waste removal○ Secondary Treatment
■ biological treatment in which bacteria break down organic material, converting it into CO2 and inorganic nutrients (such as nitrogen and phosphorus)
■ Final step in secondary treatment is UV radiation or Chlorine to kill any remaining pathogens.
○ Tertiary Treatment■ Uncommon….it is the final step of removal of nutrients (NPK)
Case Studies:Three Gorges Dam on the Yangtze River in China is the largest dam in the world. It can generate 85 billion kWh per year (11% of China’s electricity). It is over a mile wide, 600 feet tall, and its reservoir is 410 miles long.
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Water Resources & Pollution Chapters in Textbook: 9, 14
They began construction on the dam in 1993 and completed the dam in 2006. In the process, over 1.3 million people were displaced. It disrupts the natural migration of fish and river dolphins. Fish ladders have alleviated the problem with fish by allowing them to swim upstream from the dam.
Colorado River fed by snowmelt in the Rockies, flows through seven states and supplies much of the West Coast with freshwater. Along its path are 14 major dams, and many aqueducts to help control flooding and supply cities, and rural areas with electricity and water. The Colorado River Aqueduct supplies all of Los Angeles. SWo much of the water is diverted and used that very little of this water reaches the end of its natural path--the Gulf of California.
Minamata Bay in Japan had over 27 tons of mercury containing compounds dumped into it by a chemical company that was producing products of mercury. It was thought that mercury; a fairly inert chemical would not hurt the bay. Bacteria in the bay turned the mercury into methylmercury, which is highly toxic. Algae, zooplankton, fishes, etc. Bioaccumulation caused people to get very sick eating the fish from the Bay. Fifty two people were badly poisoned and 17 died. To this day, mercury poisoning is called Minamata disease. It causes retardation in children, kidney failure and nervous disorders. Too much mercury causes insanity.
Relevant FRQ’s:
1999 (1) - water quality tests2001 (4) - farm water pollution2002 (2) - Colorado River diversion2004 (1) - mercury & seafood2007 (1) - sewage treatment2008 (2) - Landfill leachate
2009 (3) - Colorado River & impacts of climate change on hydrology,coastal ecosystems2011 (2) - ocean acidification2014 (2) - sewer systems2015 (1) - Everglades
(3) - Oil Spills 2017 (1) - microbeads, plastic pollution, wastewater
(3) - effects of deforestation on water quality (4) - dams, water diversions
Vocabulary
Aquifer
Unconfined aquifer
Confined aquifer
Water table
Groundwater recharge
Floodplain
Oligotrophic lake
Mesotrophic lake
Eutrophic lake
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Water Resources & Pollution Chapters in Textbook: 9, 14
Levee
Dike
Dam
Fish ladder
Aqueduct
Distillation
Reverse osmosis
Furrow irrigation
Flood irrigation
Spray irrigation
Drip irrigation
Hydroponics
Gray water
Point sources
Nonpoint sources
Wastewater
Biochemical oxygen demand (BOD)
Dead zones
Eutrophication
Septic tank
Leach field
Primary treatment
Secondary treatment
Tertiary treatment
Disinfection (Chlorine/UV)
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Water Resources & Pollution Chapters in Textbook: 9, 14
Manure lagoon
Acid mine drainage
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