Water

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Chapter 21

• Water Soil Pollution

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Types of Water Pollution

• Sewage
• Disease-causing agents
• Sediment pollution
• Inorganic chemicals
• Radioactive substances
• Thermal pollution

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Eutrophication

• Nutrient enrichment of a standing water ecosystem
• Ex Many of the lakes in our area!!

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Eutrophication
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Eutrophication

• As nutrient levels rise, algal numbers also
  increase. Then, dead and dying cells rot,
  decomposers consume them and use up the oxygen.
  BOD or biological oxygen demand increases and
  life is choked out (hypoxia).

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Controlling Artificial Eutrophication

• H2O, sunlight, carbonate CO3, N, P, other
  inorganic compounds are the main requirements for
  algal growth (limiting factors).
• If we limit the P (and even the N), we can slow
  eutrophication.

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Organic Compounds

• Polychlorinated Biphenyls (PCBs), Benzene,
  Chloroform, Dioxins, Vinyl Chloride are
  examples that can be found in polluted water.

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Lead (Pb)

• Pb based paint was banned (for sale) in the U.S.
  in 1978.
• Pb additives were removed from U.S. gasoline in
  1986.
• Pb enters the soil groundwater from incinerator
  ash that is dumped into landfills.
• Pb enters your body via pesticides fertilizers
  on produce, canned foods, dinnerware.
• Middle-aged men, pregnant women, young kids
  face the greatest threat.

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Mercury (Hg)

• Liquid at room temp. can vaporize.
• Liquid ? Gas ? Precipitation ?Contaminates Water
• Coal-fired power plants release the largest
  amount of Hg (33).
• Technology is there to remove the Hg out of coal
  emissions but it is expenive.
• Municipal incinerators medical waste incinerators
  contribute as well.

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Mercury (Hg)

• Bacteria convert the Hg in the sediments to
  methyl mercury. These compounds are highly toxic
  remain in the environment for long periods of
  time.
• They accumulate into organisms found at the top
  of the food chain. Tuna, Shark, Swordfish,
  marine mammals.
• 40 out of 50 states have released health
  advisories on Hg tainted seafood.

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Red Tides

• Algal blooms due to marine algae.
• These can produce toxins that directly kill fish
  birds, work their way up the food chain to
  marine mammals people.
• Causes?
• Increasing temp?
• Coastal Pollution?

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Red Tides
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Dead Zone in the Gulf Of Mexico

• Fertilizers flow from the mighty Mississippi into
  the Gulf of Mexico from Iowa, Wisconsin,
  Illinois (31 states) every spring summer.
• This Dead Zone causes Hypoxia and creates an area
  of no life, the size of New Jersey. Poses a
  serious threat to commercial fishing in the area.

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Radioactive Substances

• These isotopes emit radiation.
• Originate from mining of Uranium Thorium,
  nuclear plants, medical scientific research
  facilities, Radon from the earths crust.
• 12 sewage treatment plants have tested positive
  for low level radiation in the U.S. since the
  1980s.

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Thermal Pollution

• Water is used to cool industrial plants (steam
  generated electric power plants) is returned to
  waterways significantly warmer.
• This speeds decomposition and allows less oxygen
  to dissolve in the water. Fish become stressed,
  need more food, have to ventilate their gills
  more and thus have a shorter lifespan.

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Sources of Water Pollution

• Point Source vs. Non-point Source
• Agriculture
• Municipal sources
• Industrial wastes

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Sources of Water Pollution

• Point Source This is discharged into the
  environment through pipes, sewers, or ditches
  from specific sites like factories or sewage
  treatment plants.
• Ex Cyanide spill in Feb. 2000 contaminated the
  Tisza Danube Rivers.

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Sources of Water Pollution

• Nonpoint Source (polluted runoff) is caused by
  land pollutants that enter bodies of water over
  broad areas (not a single point.)
• Precipitation carries pollutants and deposits
  them into lakes rivers, wetlands, groundwater,
  the ocean.
• Soil erosion is a major source.

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Sources of Water Pollution

• Agriculture 72 of water pollution comes from
  agriculture.

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Sources of Water Pollution

• Municipal sources contribute urban runoff from
  storm sewers and city streets. Runoff contains
  salt, garbage,sediments, traffic emissions.

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Sources of Water Pollution

• Industrial wastes
• Food industries ? organic wastes
• Papermills pulp mills ? sludge chlorine
• Electronics ? Cu, Pb, Mn, other heavy metals
  (can be filtered)

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Improving Water Quality

• Purification of drinking water through reservoirs
  (surface water source).
• Aluminum sulfate used to take particulates out
• Sand used to filter smaller particulates.
• Activated carbon used sometimes
• Disinfection via Chlorine, O3, or UV radiation.

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Improving Water Quality

• Municipal Water pollution has a nonpoint source
  in urban runoff from sewers. This runoff is
  often worse than sewage itself.
• It contains asbestos, chlorides, copper,
  cyanides, grease, hydrocarbons, Pb, motor oil,
  organic wastes, phosphates, sulfuric acid, and
  Zn.
• Combined sewer systems (NY, San Francisco,
  Pittsburgh, Boston) mix human industrial wastes
  with urban runoff. If too much rain drains into
  the runoff then the system cant handle it. Thus
  combined sewer overflow flows into waterways
  without being treated.

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Groundwater Pollution

• 50 of the U.S. population receives water
  directly from untreated groundwater.
• Pesticides, fertilizers, organic compounds,
  landfill seepage, underground storage tanks,
  backyards, golf courses, agriculture all flow
  into our groundwater supply.
• 250,000 petroleum tanks are presently seeping
  into groundwater (conservative estimate).

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Individual Septic Systems
Involve the use of Septic tanks and Leach fields
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Laws Controlling Water Pollution

• Safe Drinking Water Act of 1974
• Clean Water Act of 1972, 1981, 1987
• Refuse Act of 1899 (Used in Hudson River case!)
• 40 of Americas waters fail to meet Clean Water
  Act standards.
• 218 million Americans live within ten miles of
  polluted water.

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The Great Lakes hold 1/5th of the worlds
fresh surface water!
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Soil Pollution and Remediation

• Is any change in the physical or chemical
  composition of the soil that adversely affects
  living organisms.
• Includes salts, petroleum products, metals,
  fertilizers, and pesticides.
• Salinization of irrigated soils occurs over a
  long period of time but can lead to very poor
  soil conditions.
• In the past, the only way to clean soil was to
  incinerate it.

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Effects of salt on plant roots
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Current methods of cleaning soil

• Now, there are other methods of cleaning soil
• Dilution (Rinsing it)
• Vapor extraction (Air is pumped in to remove
  volatile compounds)
• Bioremediation (Use of bacteria to clean soil)
• Phytoremediation (Use of plants to clean soil)