Water Pollution and Its Prevention

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Water Pollution and Its Prevention
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Water Pollution

• The presence of a substance in the environment
  that, because of it chemical composition or
  quantity, prevents the functioning of natural
  processes and produces undesirable environmental
  and health effects
• as defined by the EPA

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Water Pollution

• Pollutant any material that causes the pollution

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Two sources of water pollution

• Point source -pollution occurs when harmful
  substances are emitted directly into a body of
  water

• Nonpoint source - delivers pollutants indirectly
  through environmental changes

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Biological Pollution

• Pathogens are agents that causes disease, a
  living microorganism such as a bacterium or
  fungus

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Pathogens Carried by Sewage

• Salmonella typhi Typhoid fever

• Vibro cholerae - Cholera

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Pathogens Carried by Sewage

• Salmonella species - Salmonellosis

• Escherichia coli
• Campylobacter species
• Cryptosporidium parvum Diarrhea/Dysentery

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Pathogens Carried by Sewage

• Hepatitis A virus Infectious hepatitis

• Poliovirus - Poliomyelitis

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Pathogens Carried by Sewage

• Shigella species
• Entamoeba histolytica

• Giardia intestinalis - Giardiasis

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Pathogens Carried by Sewage

• Roundworms Numerous parasitic diseases

• Flatworms - Numerous parasitic diseases

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Public Health

• The connection between disease and sewage-carried
  pathogens was recognized in the mid-1800s

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Public Health

• Public-health measures are taken to prevent the
  cycle of disease
• Purify and disinfect public water supply
• Sanitary collection and treatment of sewage waste
• Maintain sanitary conditions where food is
  prepared for public consumption
• Public education

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Water Sanitation Statistics

• Over 1 billion people do not have access to safe
  drinking water
• 2.5 billion people live in areas having poor or
  no sewage collection or treatment
• Over 3 million people died each year due to
  waterborne diseases

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Types of Non-Biological Water Pollution

• Chemical Pollutants
• Inorganic Pollutants
• Organic Pollutants
• Sediments
• Chemical Nutrients

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Chemical PollutantsInorganic Chemicals

• Heavy metals (lead, mercury, cadmium, nickel)

• Acids from mine drainage (sulfuric acid)
• Acid precipitation (sulfuric nitric acid)
• Road salts (sodium calcium chlorides)

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Chemical PollutantsOrganic Chemicals

• Petroleum
• Pesticides
• Industrial chemicals (PCB, cleaning solvents, and
  detergents)

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Chemical Pollutants

• Many chemical pollutants are toxic even at low
  concentrations
• Some pollutants may concentrate and move up the
  food chain
• Higher concentrations of pollutants may make the
  bodies of water useless except for navigation

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Sediments

• Causes of increased sediments entering waterways
• Erosion from farmland
• Deforested slopes
• Overgrazing rangelands
• Construction sites
• Mining sites

• Effects of large amounts of sediments
• 1. Reduce light penetrating the water
• 2. Clogs gills and feeding structures
• 3. Kills eggs of fish and other aquatic
  organisms

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Reducing Sediments

• Modern storm-water management has designed
  retention ponds

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Chemical Nutrients

• Inorganic chemicals nutrients
• Nitrogen
• Phosphorus
• Source of chemical nutrients
• Sewage outfall
• Agricultural runoff

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Eutrophication

• Eutrophication is the increase of chemical
  nutrients into an ecosystem.
• Effects increase of plant growth and decay
  leading to poor water quality
• Low dissolved oxygen concentrations
• Very little sunlight

• Oligotrophic bodies of water have clear water and
  low biological productivity.

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Process of Eutrophication

1. Chemical nutrients (phosphorus and nitrogen)
   enters a body of water (lakes, rivers, streams,
   estuaries)
2. The increase in chemical nutrients causes
   excessive growth in
3. algae found at the surface of the water
4. submerges aquatic plants found at the bottom of
   the body of water

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Process of Eutrophication
Algae (found at the surface of the water)
RAPID GROWTH
Submerged Aquatic Plants (found at the bottom of
the lake, river, stream)
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Process of Eutrophication

• 3. Algae start to cover up the entire surface
• Submerged aquatic plants die

Algae prevent sunlight from reach the bottom of
the body of water
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Process of Eutrophication

1. Bacteria, already living in the water, decompose
   the dead submerged aquatic plants and algae.

Bacteria feed on dead plant matter
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Process of Eutrophication

• The bacteria populations increase because of an
  accumulation of nutrients (dead algae and
  submerged aquatic plants).

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Process of Eutrophication

• The large populations of bacteria start to use up
  the dissolved oxygen.
• Fish and other aquatic organisms die due to a
  lack of oxygen. (Cause of death Suffocation)

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Combating Eutrophication

• Attacking the symptoms
• 1. Chemical treatment
• 2. Aeration
• 3. Harvesting aquatic weeds
• 4. Drawing water down

• Getting to the root causes
• Identify the point and nonpoint sources
• Develop and implement strategies for correction

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Questions?