Chapter 19 Notes

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Chapter 19 Notes

• Mrs. Sealy

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Types and Sources of Water Pollution

• 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 use

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Major Types of Water Pollution

• Disease causing agents (pathogens) bacteria,
  viruses, protozoa, and parasitic worms that come
  from sewage and untreated human and animal waste
• Indicator of water quality colonies coliform
  bacteria
• 0-100drinking water, max of 200 for swimming
  water

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Oxygen Demanding Waste

• Organic wastes that can be decomposed by aerobic
  bacteria. Bacteria deplete water of oxygen, which
  causes death to fish and other aerobic aquatic
  life
• BOD biological oxygen demand amount of oxygen
  needed by aerobic decomposers to break down
  organic matter in a certain volume of water over
  a five day period at twenty degrees Celsius

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Water Soluble Inorganic Chemicals

• Acids, salts, and compounds of toxic metals (Hg,
  Pb)
• High levels of these make water unfit to drink,
  harm fish, and other aquatic life, lower crop
  yields and accelerates metal corrosion

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Inorganic Plant Nutrients

• Water soluble nitrates and phosphates that cause
  excessive growth of algae and other aquatic
  plants, which die, decay and deplete water of
  oxygen, killing fish.
• Excessive levels of nitrates lower the oxygen
  carrying capacity of blood causing Blue Baby
  Syndrome

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Organic Chemcials

• Oil, plastic, gas, pesticides, solvents, and
  detergents
• Threaten human fish and aquatic life
• Just downright poisonous

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Sediment or suspended matter

• Clouds the water and reduces photosynthesis,
  which disrupts food webs and carries bacteria and
  pesticides
• It clogs and fills lakes, streams and harbors
• Decreases the efficiency of chlorine to disinfect
  water

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Water Soluble Radioactive Isoptopes

• Can be biologically magnified in tissues and
  organs
• Ionizing radiation can cause birth defects,
  cancer and genetic damage

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Thermal Pollution

• Heat absorbed by water to cool industrial and
  power plants which lowers the water quality by
  lowering dissolved oxugen leels making aquatic
  organisms more vulnerable to disease, parasites
  and toxic chemcials
• Causes fish kills
• Increases the growth rate of algae

Finland
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Genetic Pollution

• When aquatic ecosystems are disruoted by
  deliberate or accidental introduction of
  non-native species, which reduces biodiversity
  and causes economic loss.
• These species are usually introduced in the
  ballast water of ships

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Point source Pollution

• 1. Point sources discharge pollutants at
  specific locations (pipes, ditches, sewers at
  factories, sewage treatment plants, active and
  abandoned underground mines, offshore oil wells,
  oil tankers). These are controlled in developed
  countries and uncontrolled in developing
  countries.

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Non-point Source

• 2. Non Point Sources pollutants that cannot be
  traced to a specific site. These include
  large land areas that pollute due to runoff,
  subsurface flow, deposition from the
  atmosphere. Agriculture produces non-point
  pollution in the form of sediment, inorganic
  fertilizers, manure, salts dissolved in
  irrigation water and pesticides.

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II. Pollution Of Streams and Lakes

• A. Stream and River Pollution
• 1. Streams and rivers usually recover rapidly as
  long as streams are
• not overloaded with pollutants and flow is not
  reduced due to drought, damming, or diversion for
  agriculture and industry

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II. Pollution Of Streams and Lakes

• Oxygen Sag Curve when bacteria reduces or
  eliminates populations of organisms with high
  oxygen requirements. This depends upon stream
  volume, flow rate, temperature, pH level and
  volume of degradable wastes. This curve can also
  be done for thermal pollution

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Fig. 19.3, p. 479
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Reduction of Stream Pollution

• require cities to withdraw drinking water
  downstream rather than upstream, which improves
  water quality
• Water pollution laws of 1970 have increased the
  number and quality of wastewater treatment plants
  which in the US and other developed countries has
  reduced or eliminated point source pollution

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Lake Pollution

• Dilution is less effective
• Lakes and reservoirs contain stratified layers
  that undergo little vertical mixing.
  Stratification reduces levels of dissolved oxygen
  (especially on the bottom)
• Ponds contain small volumes of water
• Lakes are more vulnerable to contamination by
  plant nutrients, oil, pesticides, and toxic
  substances (Pb,Hg,Se) and acid deposition

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Fig. 19.4, p. 481
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Eutrophication

• Natural nutrient enrichment
• Cultural Eutrophicationwhen human activities
  near urban or cultural areas greatly accelerate
  the input of nutrients to a lake. Mostly nitrates
  and phosphates cause this.

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Eutrophication

• During hot weather, dense growths of algae,
  cyanobacteria, duckweed and hyacinths occur and
  dissolved oxygen is depleted which kills fish and
  other aquatic animals
• Excessive nutrients can cause anaerobic bactria
  to take over and produce gaseous decomposition
  products (CH4, H2S)

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Discharge of untreated municipal sewage (nitrates
and phosphates)
Nitrogen compounds produced by cars and factories
Natural runoff (nitrates and phosphates
Discharge of detergents ( phosphates)
Manure runoff From feedlots (nitrates
and Phosphates, ammonia)
Discharge of treated municipal sewage (primary
and secondary treatment nitrates and phosphates)
Runoff from streets, lawns, and construction lots
(nitrates and phosphates)
Lake ecosystem nutrient overload and breakdown
of chemical cycling
Runoff and erosion (from from cultivation, mining,
construction, and poor land use)
Dissolving of nitrogen oxides (from internal
combustion engines and furnaces)
Fig. 19.5, p. 482
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Fig. 19.6, p. 483
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CANADA
Nipigon Bay
Jackfish Bay
Thunder Bay
Silver Bay
St. Marys R.
St. Lawrence R.
Spanish R.
St. Louis R.
MICHIGAN
Penetary Bay
WISCONSIN
Sturgeon Bay
MICHIGAN
Saginaw Bay
NEW YORK
Niagara Falls
Saginaw R. System
Grand R.
MINNESOTA
Niagara R.
St. Clair R.
Thames R.
Buffalo R.
Detroit R. Rouge R. Raisin R.
Ashtabula R.
PENNSYLVANIA
IOWA
Cuyahoga R.
Maumee R.
Rocky R.
Black R.
ILLINOIS
INDIANA
OHIO
Great Lakes drainage basin
Most polluted areas, according to the Great Lakes
Water Quality Board
Hot spots of toxic concentrations in water and
sediments
Eutrophic areas
Fig. 19.7, p. 484
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Industrial pollution
Suffocated fish
Beaches closed
Sewage runoff
Dead algae
Low dissolved oxygen
Decreased fish population
Mercury- tainted fish
Fig. 19.8a, p. 485
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Suburban sprawl
Lower water levels
Clear water
High dissolved oxygen
PCBs in sediment
Thriving fish population
Fig. 19.8b, p. 485
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Ways To Prevent Cultural Eutrophication

• Use advanced sewage treatment
• Ban or limit phosphates in household detergents
  and other cleaners
• Practice soil conservation and land use control
  to reduce nutrient runoff

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Ocean Hypoxia

• The Dead Zone is an area of the ocean that is
  severely oxygen depleted due to cultural
  eutrophication
• Caused by plant nutrients that get washed down
  rivers into the ocean causing algal blooms and
  fish kills
• Examples Chesapeake bay and the Gulf of Mexico

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Ocean Pollution

• How coastal areas are effected
• 1. wetlands, estuaries, coral reefs, mangrove
  swamps bear the majority of the enormous wastes
  we ad to the ocean
• 2. Most sewage in developing countries is
  dumped directly into the ocean without treatment
• sewage and agricultural wastes introduce
  large quantities of nitrogen and phosphorus to
  the water which causes algal blooms

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Ocean Pollution

• Pollutants that are dumped into the ocean
• 1. dredge spoils or materials full of toxic
  chemicals scraped from the bottom of harbors and
  rivers to maintain channels are dumped from
  barges and ships at 110 sites in the Pacific,
  Atlantic and Gulf Coasts
• 2. sewage sludge-gooey, mud like mixture of
  toxic chemicals, infectious agents and settled
  solids removed from wastewater at sewage
  treatment plants (banned in the US since 1992)

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Ocean Pollution

• Sewage and garbage from merchant marine fleets
• Highly toxic pollutants and high level
  radioactive wastes

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Ocean Pollution

• Effects of oil on ocean ecosystems
• Crude petroleum (oil from ground) and refined
  petroleum (fuel oil, gasoline, other petroleum
  products) pollution comes from normal operation
  of offshore wells, washing tankers, releasing
  oily water and from pipeline and storage tank
  leaks onto the land or into sewers by cities,
  individuals and industry (1000Xs that spilled by
  the Exxon Valdez).

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Ocean Pollution

• Tar like globs that float on the surface coat
  feathers of diving and other birds and the fur of
  marine mammals, which destroys their insulation
  and buoyancy, which causes death due to the loss
  of body heat.
• Oil that sinks to the bottom smothers bottom
  dwelling organisms (crabs, oysters, mussels,
  clams) and can kill coral reefs.
• Overall- it is a low risk ecological problem.

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Prevention of Ocean Pollution

• Reduce oil waste and shift to renewable energy
  resourcesReduce flow of pollution from the land
  streams into the oceans.
• Prevent and control air pollution (33 of
  pollutants come from emissions).
• Prevention
• Discourage sludge dumping and hazardous dredged
  material.
• Reduce or curtail development of oil drilling and
  oil shipping in coastal areas.
• Develop land use planning in coastal areas.
• Require double hulls in oil tankers by 2002.
• Recycle used oil
• Reduce genetic pollution in ballast water.

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Prevention and Reduction of Surface Water
Pollution

• Nonpoint pollution
• 1.Leading causeagriculture. Farmers can reduce
  fertilizer runoff onto surface waters and
  into aquifers by.
• Reducing or eliminating the amount of fertilizer
  use.
• Use slow release fertilizers.
• Alternate crops between row crops and nitrogen
  fixation crops
• Plant buffer zones between cultivated fields and
  nearby surface waters.
• Apply pesticides only when needed.
• Use biological controls for pests.

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Prevention and Reduction of Surface Water
Pollution

• Eliminate or reduce inorganic fertilizers and
  pesticides for golf courses, lawns and public
  lands.
• Livestock growers could manage animal density
  (reducing manure). Planting buffers, and
  locating feed lots.
• Create detention basins for animal runoff and
  reapply fertilizers to croplands or forestlands.
• Reforest critical watersheds (reduces soil
  erosion and the severity of flooding and slows
  global warming and the loss of wildlife habitants.

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Point Pollution and the Legal Approach

• 2 of the sewage is treated in Latin American,
  15 in China, and 30 in India The Clean Water
  Act of 1977 and the Water Quality Act of 1987
  form the basis of the U.S. effort to control
  pollution of the countrys surface waters.
• The main goalsafe waters for fishing and
  swimming by 1983 and restore and maintain
  chemical, physical, and the biological integrity
  of the nations waters.
• Discharge Trading Policy of 1995 uses market
  forces to reduce water pollution. Credits can be
  sold for excess reductions- like air pollution
  control and SO.

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Sewage Treatment Plants

• Primary sewage treatment a mechanical process to
  screen out debris (sticks, stones, rages, etc.),
  and suspended solids which settle out as sludge
  in a settling tank.

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Sewage Treatment Plants

• Secondary sewage treatment biological process in
  which aerobic bacteria are used to remove up to
  90 of biodegradable, oxygen demanding organic
  wastes.
• Trickling filters aerobic bacteria degrade
  sewage as it seeps through a bed of crushed
  stones covered which bacteria and protozoa.
• Activated sludge processsewage is pumped into a
  large tank, mixed for hours with bacteria and air
  to facilitate degradation by microorganisms.
  Then suspended solids settle out as sludge.
• Sludge from both primary and secondary treatment
  is broken down in an anaerobic digester and then
  incinerated, dumped into the ocean, or used as
  fertilizer.

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Sewage Treatment Plants

• Advanced Sewage Treatment series of chemical and
  physical processes that remove pollutants left in
  the water after primary and secondary treatment.
• Advanced sewage treatment removes nitrates and
  phosphates which contribute to eutrophication of
  lakes, slow moving streams, and coastal waters.
• These advanced plants cost twice as much to build
  and four times as much to operate. Water from
  primary, secondary, and advanced treatment plants
  is bleached and disinfected by chlorinating.
• Sewage Sludge (36 by weight) is applied to
  farmland as fertilizer for crops used for animal
  feed and human food.
• 38 is dumped into landfills16 is incinerated
  9 is composted

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Waste lagoon, pond, or basin
Hazardous waste injection well
Mining site
Water pumping well
Buried gasoline and solvent tanks
Pumping well
Road salt
Sewer
Landfill
Cesspoll, septic tank
Leakage from faulty casing
Unconfined freshwater aquifer
Groundwater
Confined freshwater aquifer
Groundwater flow
Discharge
Confined aquifer
Fig. 19.9, p. 487
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Groundwater

• IV. Groundwater prime source of drinking water
  and irrigation water. Groundwater cannot cleanse
  itself like surface water does.
• Reasons for pollution
• groundwater flow is slow, not turbulent
• contaminants are not effectively diluted and
  dispersed
• groundwater has smaller proportions of
  decomposing bacteria
• cold temperatures slow decomposition

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Groundwater

• Reasons for Pollution
• underground storage tanks
• landfills
• abandoned waste dumps
• deep well disposal of liquid hazardous waste
• industrial and livestock waste storage lagoons
  located near aquifers
• industrial waste ponds without liners to prevent
  toxic liquid wastes from seeping into aquifers

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VI. Drinking Water Quality

• Protection of drinking water
• UgtSgt Safe Drinking Water Act of 1974 tests fro 64
  contaminants
• Strengthening Safe water Act
• improving water treatment by combining smaller
  water systems for larger ones
• strengthening and enforcing public notification
  requirements about violations
• banning all lead in new plumbing pipes, faucets
  and fixtures

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Bottled Water

• International Bottled Water Association tests for
  181 contaminants
• National Sanitation Foundation certification by
  this agency requires tests for 200 chemical and
  biological contaminants
• EPA does not test or approve water-filtering
  devices
• One/fourth of it is tap water
• 40 is contaminated by bacteria and fungi
• 1.5 million tons of plastic thrown away
• Oil used to make plastic would power 100,000 cars
  for a year.
•