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Title: Chapter 19 Notes

Chapter 19 Notes
  • Mrs. Sealy

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

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
  • 0-100drinking water, max of 200 for swimming

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
  • 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

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

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

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

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

Water Soluble Radioactive Isoptopes
  • Can be biologically magnified in tissues and
  • Ionizing radiation can cause birth defects,
    cancer and genetic damage

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

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

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

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.

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

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

Fig. 19.3, p. 479
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

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

Fig. 19.4, p. 481
  • 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.

  • 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)

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
Fig. 19.6, p. 483
Nipigon Bay
Jackfish Bay
Thunder Bay
Silver Bay
St. Marys R.
St. Lawrence R.
Spanish R.
St. Louis R.
Penetary Bay
Sturgeon Bay
Saginaw Bay
Niagara Falls
Saginaw R. System
Grand R.
Niagara R.
St. Clair R.
Thames R.
Buffalo R.
Detroit R. Rouge R. Raisin R.
Ashtabula R.
Cuyahoga R.
Maumee R.
Rocky R.
Black R.
Great Lakes drainage basin
Most polluted areas, according to the Great Lakes
Water Quality Board
Hot spots of toxic concentrations in water and
Eutrophic areas
Fig. 19.7, p. 484
Industrial pollution
Suffocated fish
Beaches closed
Sewage runoff
Dead algae
Low dissolved oxygen
Decreased fish population
Mercury- tainted fish
Fig. 19.8a, p. 485
Suburban sprawl
Lower water levels
Clear water
High dissolved oxygen
PCBs in sediment
Thriving fish population
Fig. 19.8b, p. 485
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

Ocean Hypoxia
  • The Dead Zone is an area of the ocean that is
    severely oxygen depleted due to cultural
  • 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

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

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)

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

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).

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.

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
  • 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.

Prevention and Reduction of Surface Water
  • 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 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.

Prevention and Reduction of Surface Water
  • Eliminate or reduce inorganic fertilizers and
    pesticides for golf courses, lawns and public
  • 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.

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.

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.

Sewage Treatment Plants
  • Secondary sewage treatment biological process in
    which aerobic bacteria are used to remove up to
    90 of biodegradable, oxygen demanding organic
  • 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

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

Waste lagoon, pond, or basin
Hazardous waste injection well
Mining site
Water pumping well
Buried gasoline and solvent tanks
Pumping well
Road salt
Cesspoll, septic tank
Leakage from faulty casing
Unconfined freshwater aquifer
Confined freshwater aquifer
Groundwater flow
Confined aquifer
Fig. 19.9, p. 487
  • 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
  • groundwater has smaller proportions of
    decomposing bacteria
  • cold temperatures slow decomposition

  • 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

VI. Drinking Water Quality
  • Protection of drinking water
  • UgtSgt Safe Drinking Water Act of 1974 tests fro 64
  • 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

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
  • 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.