Water Pollution

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Water Pollution
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Questions for Today

• What are examples of point and nonpoint pollution
  sources for water?
• What are the Major Types of Water Pollutants and
  Diseases transmitted in Water?
• What are two measurements used to determine clean
  waters in lakes and rivers?
• Compare and Contrast Oligotrophic Lakes with
  Eutrophic Lakes.

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Questions for Today

• What major sources of pollution for ground water?
• What laws are in effect for our drinking water?
• What are major sources of pollution for ocean
  water?

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Sources of Water Pollution

• Remember
• Point sources are pollutions sources where you
  can identify the sole polluter and/or pollutant
• Nonpoint sources are sources where you cannot
  identify the polluter or the pollutant can come
  from many anonymous sources.

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Top Three polluters

• Agricultural Activities
• Sediment eroded from agricultural lands
• Fertilizers and pesticides
• Industrial Wastes
• Organic and inorganic wastes
• Heat
• Mining
• Erosion of Sediments and Toxic Chemicals

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Top areas of nonpoint pollution

• Parking Lots
• Prevent absorption of water back into the water
  table
• Increases flooding and erosion
• Plastic
• Polymers are forever!

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Major Water Pollutants

• Aside from the different chemicals, inorganic and
  organic, that enter our water supply, infectious
  disease is one of the major water pollutants.
• Identified over 500 types of diseases
• The World Health Organization (WHO)
• Each year, approximately 3.2 million people die
  prematurely from water-borne infectious diseases.
• 1 child every 18 seconds die due to diarrhea
  alone!

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Water Quality

• Two of the biggest measures for water quality
  are
• Dissolved Oxygen
• Amount of Oxygen ready to use in the water
• Biochemical Oxygen Demand
• Amount of Oxygen needed for organic growth.
• When both measurements are graphed we get a
  oxygen sag curve.

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Oligotrophic vs Eutrophic

• Oligotrophic lakes are lakes with low nutrient,
  clear water, BIG fish, and Cold, High DO, low BOD
• Eutrophic Lakes high nutrient, murky/brackish
  water, small fish and bugs, warm, Low DO, High
  BOD
• Oligotrophic lakes -gt Eutrophic Lakes
• Cultural Eutrophism

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Major sources of groundwater pollution

• Remember that half of the US Drinking water comes
  from groundwater sources like aquifers.
• Common Pollutants include
• Hydrocarbons
• Inorganic Chemicals
• Organic Solvents

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Major Sources of GW Pollution

• The Problem
• Once contaminant hits the water supply, the GW is
  essentially ruined.
• Groundwater flows slower than surface water so it
  cannot naturally biodegrade the pollutant as well
  as a river or stream.

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Laws protecting our Water

• U.S. Safe Drinking Water Act of 1974
• Requires the EPA to establish a Maximum
  Contaminant Level for any contaminant entering
  our water.
• Clean Water Act
• Many provisions guarding our water supplies
• Requires treatment facilities for municipal water
  and regulates the amount of pollutants entering
  our water.

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Pollution in the Ocean

• Most of the Open Oceans are considered clean
  due to the vastness and the deep waters.
• Most of the pollution problems are located closer
  to the coastlines and shores due to agricultural
  runoff and access to sunlight.

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Industry Nitrogen oxides from autos and
smokestacks, toxic chemicals, and heavy metals in
effluents flow into bays and estuaries.
Cities Toxic metals and oil from streets and
parking lots pollute waters sewage adds nitrogen
and phosphorus.
Urban sprawl Bacteria and viruses from sewers
and septic tanks contaminate shellfish beds and
close beaches runoff of fertilizer from lawns
adds nitrogen and phosphorus.
Construction sites Sediments are washed into
waterways, choking fish and plants, clouding
waters, and blocking sunlight.
Farms Runoff of pesticides, manure, and
fertilizers adds toxins and excess nitrogen and
phosphorus.
Red tides Excess nitrogen causes explosive
growth of toxic microscopic algae, poisoning fish
and marine mammals.
Closed shellfish beds
Closed beach
Oxygen-depleted zone
Toxic sediments Chemicals and toxic metals
contaminate shellfish beds, kill spawning fish,
and accumulate in the tissues of bottom feeders.
Oxygen-depleted zone Sedimentation and algae
overgrowth reduce sunlight, kill beneficial sea
grasses, use up oxygen, and degrade habitat.
Healthy zone Clear, oxygen-rich waters promote
growth of plankton and sea grasses, and support
fish.
Fig. 20-15, p. 548
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Ocean Pollution

• Aside from Agricultural, a major pollutant is oil
  that is leaked off of rigs and tanker ships and
  industrial and city runoff.
• The Exxon Valdez crash in 1989
• Cost roughly 6.5 billion dollars
• The Prestige Crash in 2002
• The BP Oil Spill
• Industrial Runofff accounts for 37 of the oil
  pollution in the ocean

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Gulf of Mexico and Pollution

• The Gulf Coast has some of the worst water in the
  nation due to its low DO count.
• Why?
• How many states drain waste into the Gulf of
  Mexico

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