- G. Tyler Miller’s
- Living in the Environment
- 14th Edition
- Chapter 22
Water, Air, Land ….
- The solution to pollution is dilution.
Chapter 22 Key Concepts
- Types, sources, and effects of water pollutants
- Major pollution problems of surface water
- Major pollution problems of groundwater
- Reduction and prevention of water pollution
- Water makes us unique and gives life to Earth.
Section 1 Key Ideas
- What are major types and effects of water pollution?
- How do we measure water quality?
- Point versus Nonpoint sources
- What are the major sources of pollution?
What is water pollution?
- Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired usage.
What is water pollution?
- 3.4 million premature deaths each year from waterborne diseases
- 1.9 million from diarrhea
- U.S. 1.5 million illnesses
- 1993 Milwaukee 370,000 sick
What is water pollution? Need to study Table 22-1 Page 492
- Infectious Agents: bacteria and viruses often from animal wastes
- Oxygen Demanding Wastes: organic waste that needs oxygen often from animal waste, paper mills and food processing.
- Inorganic Chemicals: Acids and toxic chemicals often from runoff, industries and household cleaners
What is water pollution?
- Organic Chemicals: oil, gasoline, plastics, detergents often from surface runoff, industries and cleaners
- Plant Nutrients: water soluble nitrates, ammonia and phosphates often from sewage, agriculture and urban fertilizers
- Sediment: soils and silts from land erosion can disrupt photosynthesis, destroy spawning grounds, clog rivers and streams
- Heat Pollution and Radioactivity: mostly from powerplants
- Bacterial Counts: Fecal coliform counts from intestines of animals
- None per 100 ml for drinking
- >200 per 100 ml for swimming
- Sources: human sewage, animals, birds, raccoons, etc.
- See table 22-2 on page 493 for diseases transmitted by contaminated drinking water.
How do we measure water quality
- Dissolved Oxygen: BOD Biological Oxygen Demand…the amount of oxygen consumed by aquatic decomposers
- Chemical Analysis: looking for presence of inorganic or organic chemicals
- Suspended Sediment water clarity
How do we measure water quality
- Indicator Species: organisms that give an idea of the health of the water body.
- Mussels, oysters and clams filter water
Types, Effects and Sources of Water Pollution
- Refer to Tables 22-1 and 22-2 p. 492 and 493
Point and Nonpoint Sources
- Wastewater treatment plant
Major Sources of Water Pollution
- Agriculture: by far the leader
- Sediment, fertilizers, bacteria from livestock, food processing, salt from soil irrigation
- Industrial: factories and powerplants
- Mining: surface mining toxics, acids, sediment
Section 2-3 Key Ideas
- Freshwater pollution: What are major problems in streams?
- Developed versus Developing Countries
- Lake Pollution: Why are lakes and reservoirs more vulnerable?
- What is Eutrophication?
Freshwater Stream Pollution
- Flowing streams can recover from moderate level of degradable water pollution if their flows are not reduced.
- Natural biodegradation process
- Does not work if overloaded or stream flow reduced
- Does not work against non biodegradable pollutants
Pollution of Streams
- Factors influencing recovery
- What factors will influence this oxygen sag curve?
- Developed Countries
- U.S. and other developed countries sharply reduced point sources even with population and economic growth
- Nonpoint still a problem
- Toxic chemicals still problem
- Success Cuyahoga River, Thames River
- Developing Countries:
- Serious and growing problem
- Half of world’s 500 major rivers heavily polluted
- Sewage treatment minimal $$$
- Law enforcement difficult
- 10% of sewage in China treated
- Economic growth with little $$$ to clean up
India’s Ganges River
- Holy River (1 million take daily holy dip)
- 350 million (1/3rd of pop) live in watershed
- Little sewage treatment
- Used for bathing, drinking etc.
- Bodies (cremated or not) thrown in river
- Good news is the Indian government is beginning to work on problem
Freshwater Lake Pollution
- Dilution as a solution in lakes less effective
- Little vertical mixing
- Little water flow (flushing)
- Makes them more vulnerable
- Toxins settle
- Kill bottom life
- Atmospheric deposition
- Food chain disruptions
- Biomagnifications of PCBs in an aquatic food chain from the Great Lakes.
- See figure 22-6 on page 498
Eutrophication of Lakes
- Eutrophication: nutrient enrichment of lakes mostly from runoff of plant nutrients (nitrates and phosphates)
- During hot dry weather can lead to algae blooms
- Decrease of photosynthesis
- Dying algae then drops DO levels
- Fish kills, bad odor
Pollution of Lakes
Eutrophication in Lakes
- Advanced sewage treatment (N, P)
- Household detergents
- Soil conservation
- Remove excess weed build up
- Pump in oxygen or freshwater
Case Study: The Great Lakes
- Pollution levels dropped, but long way to go
- 95% of U.S. freshwater
- 30% Canadian pop, 14% U.S.
- 38 million drink
- 1% flow out St. Lawrence
- Toxic fish
Section 4: Groundwater
- Why is groundwater pollution a serious problem?
- What is the extent of the problem?
- What are the solutions?
- Groundwater can become contaminated
- No way to cleanse itself
- Little dilution and dispersion
- Out of sight pollution
- Prime source for irrigation and drinking
- REMOVAL of pollutant difficult
Groundwater Pollution: Causes
- Leakage from faulty casing
- Hazardous waste injection well
- Buried gasoline and solvent tank
- Unconfined freshwater aquifer
- Confined freshwater aquifer
- Pollution moves in plumes
- Soil, rocks, etc. act like sponge
- Cleansing does not work (low O, low flow, cold)
- Nondegradables may be permanent
- Prevention is the most effective and cheapest
Groundwater Pollution Prevention
- Strictly regulating hazardous waste disposal
- Store hazardous materials above ground
- Find less hazardous substitutes
Section 5 Ocean Pollution
- How much pollution can the oceans tolerate?
- Coastal zones: How does pollution affect coastal zones?
- What are major sources of ocean pollution and what is being done?
- Oils spills
- Oceans can disperse and break down large quantities of degradable pollution if they are not overloaded.
- Pollution worst near heavily populated coastal zones
- Wetlands, estuaries, coral reefs, mangrove swamps
- 40% of world’s pop. Live within 62 miles of coast
- Large amounts of untreated raw sewage (viruses)
- Leaking septic tanks
- Algae blooms from nutrients
- Dead zones NO DO
- Airborne toxins
- Oil spills
Case Study: Chesapeake Bay
- Slow “flushing” action to Atlantic
- Major problems with dissolved O2
- Preventing and reducing the flow of pollution from land and from streams emptying into the ocean is key to protecting oceans
- Sources: offshore wells, tankers, pipelines and storage tanks
- Effects: death of organisms, loss of animal insulation and buoyancy, smothering
- Mechanical cleanup methods: skimmers and blotters
- Chemical cleanup methods: coagulants and dispersing agents
Section 6: Prevention and Reduction
- How can we reduce surface water pollution: point and also nonpoint.
- How do sewage treatment plants work?
- How successful has the U.S. been at reducing water pollution? Clean Water Act
Solutions: Preventing and Reducing Surface Water Pollution
- Only apply pesticides and fertilizers as needed
- Buffer Zones Near Streams
- Most developed countries use laws to set water pollution standards.
- Federal Water Pollution Control Act (Clean Water Act 1972, ’77, ’87)
- Regulates navigable waterways..streams, wetlands, rivers, lake
Clean Water Act
- Sets standards for key pollutants
- Requires permits for discharge
- Requires sewage treatment
- Require permits for wetland destruction
- Does not deal with nonpoint sources well
- Goal All Waterways fishable and swimable
Technological Approach: Septic Systems
- Require suitable soils and maintenance
- Combined sewer overflow is a problem in many older towns
- EPA: 1.8 M to 3.85 M sick from swimming in water contaminated by sewer overflows
- EPA: $100 billion to fix
Technological Approach: Sewage Treatment
- Physical and biological treatment
- Primary: removes 60% of solids and 30-40% oxygen demanding wastes (physically)
- Secondary: uses biological processes to remove up to 90% of biodegradables
- Tertiary: advanced techniques only used in 5% of U.S. $$$$
- Disinfection: chlorine, ozone, UV
- What is not taken out???
Technological Approach: Advanced (Tertiary) Sewage Treatment
- Uses physical and chemical processes
- Removes nitrate and phosphate
- Sludge disposal…using as fertilizer
Technological Approach: Using Wetlands to Treat Sewage
The Good News
- Largely thanks to CWA:
- Between 1972 – 2002 fishable and swimmable streams 36% to 60%
- 74% served by sewage treatment
- Wetlands loss dropped by 80%
- Topsoil losses dropped by 1 billion tons annually
The Bad News
- 45% of Lakes, 40% streams still not fishable and swimmable
- Nonpoint sources still huge problem
- Livestock and Ag. Runoff
- Fish with toxins
Section 7 Drinking Water
- How is drinking water purified? High tech way.
- How can we purify drinking water in developing nations?
- What is the Safe Drinking Water Act?
- Is bottled water a good answer or an expensive rip-off?
- Maximum contaminant levels (MCLs)
- Purification of urban drinking water
- Protection from terrorism
- Purification of rural drinking water
Purification of urban drinking water
- Surface Water: (like Delaware River)
- Removed to reservoir to improve clarity
- Pumped to a treatment plant to meet drinking water standards
- Groundwater: often does not need much treatment
Purification of rural drinking water
- There can be simple ways to purify water:
- Exposing to heat and UV rays
- Fine cloths to filter water
- Add small amounts of chlorine
Safe Drinking Water Act
- 54 countries have drinking water laws
- SDWA passed 1974 requires EPA to set drinking water standards
- Maximum Contaminating Levels (MCLs)
Safe Drinking Water Act
- Privately owned wells exempt from SDWA
- SDWA requires public notification of failing to meet standards and fine.
- MCLs often stated in parts per million or parts per billion
- U.S. has the world’s safest tap water due to billions of $$$ of investment
- Bottle water 240 to 10,000 times more expensive than tap water
- 25% of bottle water is tap water
- 1.4 million metric tons of bottle thrown away each year
- Toxic fumes released during bottling
- Bottles made from oil based plastics
- Water does not need to meet SDWA
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