Water Pollution

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Water Pollution
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Polluted Waterways

• 44 of lakes, 37 of rivers, 32 estuaries
  unsafe for recreational activities
• 75 of H2O pollution in US comes from
• Soil erosion
• Atmospheric deposition
• Surface runoff

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Less Developed Countries

• Less- developed countries dump 95 of all sewage
  into waterways
• Lack of
• Rapid urbanization
• Explosive population
• More-developed countries shift industry for cheap
  labor

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Groundwater

• 50 of US depends on GW
• 43 of US agriculture water
• 100,000 LUSTs (Leaking Underground Storage Tanks)
  leak chemicals into GW
• 60 of most hazardous liquid waste injected into
  GW wells
• Remains for average of 1400 years
• Cleanup of 300,000 sites could cost 1 trillion

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Pollutants

• Biological
• Physical
• Chemical
• Physical, or chemical change that has a negative
  impact on human health or the environment

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Biological Pollutants
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Biological Pollutants

• Consists of pathogens (disease-causing agents)
• Come from sewage
• Diseases include
• Typhoid, cholera, dysentery, polio, infectious
  hepatitis, salmonella, E-Coli bateria
• 1993 Milwaukee Wisconsin 370,000 developed
  diarrhea from water-borne pathogen in public
  drinking water supply

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Fish need oxygen to breath DISSOLVED OXYGEN
or DO. When the DO is low the fish may suffocate
result fishkill. Likewise if the DO is too
high, DO in the fishs blood begins to bubble
causing Gas Bubble Disease. Many factors
effect the DO in aquatic environments
temperature, water movement, aquatic plant life
Pollutants in the water may indirectly effect
these three important factors temperature,
water movement and aquatic plant life, resulting
in low water quality
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DO (dissolved oxygen)

• DO gets into the water by
• 1) moving water (riffles, rapids, water falls,
  etc.)
• 2) photosynthesis of aquatic plants
• Gases do not readily dissolve in liquids with
  high temperatures.
• ?T ? ? DO

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BOD

• BOD Biological Oxygen Demand
• The amount of oxygen needed for microorganisms to
  break down waste material
• High BOD indicates high levels of organic
  contaminants in the water
• Sewage organic wastes decomposers work to
  break down the waste which takes oxygen
• ? BOD ? ? DO
• Sewage also contains many pathogens fecal
  coliform test performed on water samples

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Physical Pollutants
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Temperature

• Referred to as Thermal Pollution
• Gases do not readily dissolve in liquids with
  high temperatures.
• ?T ? ? DO
• Power plants sometimes use waterways to cool
  their equipment. Replaced waters are warmer than
  they were before causing DO ?
• Cooling towers can be build to cool the water
  before they are discharged back into the water
  body.

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Sedimentation

• Excessive amounts of suspended solids in water.
• Come from soil erosion
• Increases turbidity which reduces the amount of
  sunlight that penetrates the water ?
• ? photosynthesis ? ? DO

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Sedimentation

• Carries toxic pollutants, disease-causing agents
• Filling in waterways (reduces depth)
• Slows water flow ? ?DO
• Disrupts food chain
• Clogs gills
• a turbidity test is performed to determine the
  amount of suspended solids in water

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Chemical Pollutants
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Chemical Pollutants

• pH
• plant nutrients
• heavy metals
• radioactive substances

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pH

• 3.0 3.5 toxic to most life
• 3.5 4.0 lethal to trout and other fish
• 4.0 4.5 fish eggs dead lake
• 5.0 6.0 changes ecology (biodiversity, ,
  decline is fish species, high aluminum, slow
  decomposition, nutrients trapped at bottom, algae
  disappears, crystal clear,
• 6.5 9.0 mostly harmless
• 9.0 harmful to lethal as pH goes up to 11.5

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• Nitrites/nitrates phosphorous
• increases plant growth
• sources fertilizers, sewage
• causes algal bloom eutrophication
• ? plant life ? blocks sunlight ? ? photosynthesis
  ? plants die ? ?BOD ? ?DO ? fish kill
• cultural eutrophication same as above caused by
  human sewage

Plant Nutrients
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Heavy Metals
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Mercury (Hg)

• Sources
• leaching of soil due to acid rain, burning coal,
  industrial, household and mining wastes.
• Health Concerns
• damages nervous system, kidneys, vision, Minimata
• 1932 1968 Co dumped 27 tons mercury compounds
  into Minimata Bay Hg converted to methyl
  mercury ingested by eating fish 43 people died

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Lead (Pb)

• Sources
• paint, mining, incinerator ash, lead pipes and
  solder (contaminate water), auto exhaust
• Health Concerns
• damage to kidneys, nervous system (brain),
  ability to learn, depressed biosynthesis of
  proteins, nerves, red blood cells anemia,
  irritability

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Cadmium (Cd)

• Sources
• electroplating, mining, plastic industries,
  sewage
• Health Concerns
• kidney disease

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Arsenic (As)

• Sources
• herbicides, wood preservatives, mining industry
• Health Concerns
• Damage to eyes, skin, GI tract, liver cancer

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Aluminum (Al)

• Sources
• leaching due to acid rain
• Health Concerns
• anemia, loss of bone strength possible role in
  dementia, and Alzheimers

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Radioactive Substances

• oceans become contaminated by nuclear waste from
  illegal dumping, bomb tests, and nuclear accidents