Water Pollution Chapter 11

Earth Science Review TIME!!!  You should know your water cycle.

Earth Science Review TIME!!!  You should know your watersheds.

Water, Air, Land …. The solution to pollution is dilution.

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  Drinking water quality

 Water makes us unique and gives life to Earth.

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? WHO:  3.4 million premature deaths each year from waterborne diseases.  1.9 million from dysentery (diarrhea).  U.S. 1.5 million illnesses.  1993 Milwaukee 370,000 sick. WHO:  3.4 million premature deaths each year from waterborne diseases.  1.9 million from dysentery (diarrhea).  U.S. 1.5 million illnesses.  1993 Milwaukee 370,000 sick.

What is water pollution?  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: Petroleum, 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 power plants.

 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. 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.  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

 Indicator Species: Organisms that give an idea of the health of the water body.  Mussels, oysters and clams filter water. How do we measure water quality?

Types, Effects and Sources of Water Pollution  Point sources  Nonpoint sources  Water quality

Point and Nonpoint Sources NONPOINT SOURCES Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES Fig p. 494

Major Sources of Water Pollution Agriculture: By far the leader.  Sediment,  Fertilizers,  Bacteria from livestock,  Food processing,  Salt from soil irrigation. Agriculture: By far the leader.  Sediment,  Fertilizers,  Bacteria from livestock,  Food processing,  Salt from soil irrigation.

Industrial: Factories and power plants. Mining: Surface mining toxics, acids, sediment. Major Sources of Water Pollution

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? (You should remember this)

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  Oxygen sag curve  Factors influencing recovery Fig p. 496  What factors will influence this oxygen sag curve?

Two Worlds 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 stories Cuyahoga River (Cleveland), Thames River Present

Two Worlds 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. 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 (1/3 rd 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. 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 Fig p. 499

Eutrophication in Lakes Solutions:  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.

Groundwater  Why is groundwater pollution a serious problem?  What is the extent of the problem?  What are the solutions?

Groundwater

Groundwater can become contaminated because:  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  Low flow rates  Few bacteria  Cold temperatures Coal strip mine runoff Pumping well Waste lagoon Accidental spills Groundwater flow Confined aquifer Discharge Leakage from faulty casing Hazardous waste injection well Pesticides Gasoline station Buried gasoline and solvent tank Sewer Cesspool septic tank De-icing road salt Unconfined freshwater aquifer Confined freshwater aquifer Water pumping well Landfill  Low oxygen Fig p. 502

Groundwater Pollution Prevention  Monitor aquifers  Leak detection systems  Strictly regulating hazardous waste disposal  Store hazardous materials above ground  Find less hazardous substitutes

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

Ocean Pollution 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.

Ocean Pollution  Large amounts of untreated raw sewage (viruses)  Leaking septic tanks  Runoff  Algae blooms from nutrients  Dead zones No DO  Airborne toxins  Oil spills  Large amounts of untreated raw sewage (viruses)  Leaking septic tanks  Runoff  Algae blooms from nutrients  Dead zones No DO  Airborne toxins  Oil spills

Case Study: Chesapeake Bay  Largest US estuary  Relatively shallow  Slow “flushing” action to Atlantic  Major problems with dissolved O 2 Fig p. 506

Preventing and reducing the flow of pollution from land and from streams emptying into the ocean is key to protecting oceans

Oil Spills  Sources: offshore wells, tankers, pipelines and storage tanks.  Effects: death of organisms, loss of animal insulation and buoyancy, smothering.  Significant economic impacts.  Mechanical cleanup methods: skimmers and blotters.  Chemical cleanup methods: coagulants and dispersing agents.

Oil Spills: Prince William Sound, Alaska, on March 24, 1989

Oil Spills: Prince William Sound, Alaska, on March 24, to 38 mill ion US gallons

Oil Spills: Deepwater Horizon oil spill 20 April 2010 in the Gulf of Mexico.  4.9 million barrels (210 million US gallons)

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 Nonpoint Sources Point Sources  Reduce runoff  Buffer zone vegetation  Reduce soil erosion.  Clean Water Act  Water Quality Act  Only apply pesticides and fertilizers as needed.

Nonpoint Sources Reduce runoff

Nonpoint Sources Buffer Zones Near Streams

Nonpoint Prevent soil erosion and only apply needed pesticides and fertilizers.

Point Sources 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, lakes.

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 swimmable

Technological Approach: Septic Systems  Require suitable soils and maintenance Fig p. 510  ¼ of all U.S. homes have Septic tanks. (Mine does!)  Can be used in parking lots, business parks, etc.

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 Fig p. 511

 Primary: Removes 60% of solids and 30-40% O 2 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, O 3 (ozone), UV.  What is not taken out???

Technological Approach: Advanced (Tertiary) Sewage Treatment  Uses physical and chemical processes  Removes nitrate and phosphate  Expensive  Not widely used

 Sludge disposal…using as fertilizer

Technological Approach: Using Wetlands to Treat Sewage Fig p. 513

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. 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 or swimmable.  Nonpoint sources still huge problem.  Livestock and Agricultural runoff.  Fish with toxins.  Huge die-offs.

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?

Drinking Water Quality  Safe Drinking Water Act  Maximum contaminant levels (MCLs)  Purification of urban drinking water  Bottled 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.  Aquifers = natural filter.

Purification of rural drinking water There can be simple ways to purify water:  Exposing to heat (boiling) and UV rays.  Fine cloths to filter water.  Add small amounts of chlorine. There can be simple ways to purify water:  Exposing to heat (boiling) 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.  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.

Bottle Water  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.

Bottle 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.  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.