Water Pollution

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Chapter 14 Water Pollution
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Water Pollution

• Water pollution- the contamination of streams,
  rivers, lakes, oceans, or groundwater with
  substances produced through human activities and
  that negatively affect organisms.
• Point sources- distinct locations that pump waste
  into a waterway. These are easily identified
• Nonpoint sources- diffuse areas such as an entire
  farming region that pollutes a waterway. These
  are more expensive and difficult to clean up.

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Can you identify which of these is point
source Pollution?
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Categories of Water Pollution

• Sewage
• disease-causing agents
• sediment pollution
• inorganic plant and algal nutrients
• organic compounds
• inorganic chemicals
• radioactive substances
• thermal pollution
• Noise pollution

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Water Pollution is a Problem Worldwide
Half of the worlds major rivers are seriously
depleted and polluted They poison surrounding
ecosystems Threaten the health and livelihood of
people The invisible pollution of groundwater has
been called a covert crisis
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Water Pollution

• Over two-thirds of U.S. estuaries and bays are
  severely degraded because of nitrogen and
  phosphorous pollution
• Every year almost 25 of U.S. beaches are closed
  at least once because of water pollution
• Over 73 different kinds of pesticides have been
  found in the groundwater that we eventually use
  to drink
• 1.2 trillion gallons of sewage, storm water and
  industrial waste are discharged into U.S. waters
  every year
• A large number of U.S. rivers are too polluted
  for aquatic life to survive
• Americans use over 2.2 billion pounds of
  pesticides every year, which eventually washes
  into our rivers and lakes

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Leading causes of water pollution

• Agriculture activities
• Sediment eroded from the lands
• Fertilizers and pesticides-almost all waters are
  polluted with pesticides
• Bacteria from livestock and food processing
  wastes
• Industrial facilities- heavy metals, corrosive
  materials organic and non-organic chemicals
• Mining- acid drainage pollutes water by leeching
  out heavy metals

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Agriculture major source of water pollution

• Agriculture is leading source of water pollution
  in US
• Animal wastes and plants residues have high BOD
• Chemical pesticides can leach into groundwater
• Almost all streams and rivers are polluted with
  agricultural pesticides

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Agricultural Runoff is the main cause of the Dead
Zone in the Gulf of Mexico The U.N. documented
250 dead zones worldwide in 2005
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Sediment runoff from farmland is the
highest Pollution from agriculture by weight.
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Eutrophication

• Eutrophication is an abundance of fertility to a
  body of water.
• Eutrophication is caused by an increase in
  nutrients, such as fertilizers.
• Eutrophication can cause a rapid growth of algae
  which eventually dies, causing the microbes to
  increase the BOD and oxygen levels to fall
  eventually may cause a die-off of all organisms.

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Solutions to Reduce Eutrophication

• Phosphate-free detergents
• Planting vegetation to increase nutrient uptake
• Treat wastewater
• Reduce fertilizer application

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Different industries add different pollutants

• Food processing plants- high BOD
• Paper mills- High BOD and toxic compounds
• Textile industry-the World Bank estimates that
  17-20 percent of industrial pollution comes from
  textile industry with 72 toxic chemicals being
  added to water

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According to Greenpeace, the discharge from these
factories includes heavy metals and hazardous
and persistent chemicals with hormone-disrupting
properties were found being discharged from
China s factories
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Heavy Metals and Other Substances that can
threaten human Health and the Environment

• Lead
• Arsenic
• Mercury
• Acids
• Synthetic compounds (pesticides, pharmaceuticals,
  and hormones)

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More on heavy metals

• Lead
• Found in old paint, industrial pollutants, leaded
  gasoline
• Mercury
• Mercury bioaccumulates in the muscles of top
  predators of the open ocean

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Arsenic found naturally in rocks and water

• When arsenic is found in water, it may be from
  natural causes
• Highest levels of arsenic in U.S. found in upper
  Midwest and West
• Individual wells dug in Southeast Asia-many are
  contaminated by arsenic causing arsenic posioning

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World Mercury Production from Human Activities
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Pharmaceuticals and Hormones Found in Water
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Industrial Compounds

• Chemicals used in manufacturing
• Local examples include PCBs in Hudson River from
  General Electric Co. and cadmium from foundry in
  Cold Spring
• PCBs cause brain damage, are lethal and
  carcinogenic

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Oil Pollution
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Marine pollution threatens resources

• Even into the mid-20th century, coastal U.S.
  cities dumped trash and untreated sewage along
  their shores
• Oil, plastic, chemicals, excess nutrients make
  their way from land into oceans
• Raw sewage and trash from cruise ships
• Abandoned fishing gear from fishing boats

In 2006, 359,000 Ocean Conservancy volunteers
from 66 nations picked up 3.2 million kg (7
million lbs.) of trash
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Ways to Remediate Oil Pollution

• Containment using booms to keep the floating oil
  from spreading.
• Chemicals that help break up the oil, making it
  disperse before it hits the shoreline.
• Bacteria that are genetically engineered to
  consume oil

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Water Pollution from Mining

• Acid Mine Drainage-low pH of water causes iron to
  precipitate from pyrite and cause a rusty red
  color
• Heavy metal contamination and leeching
• Mine waste and tailings
• Processing chemicals pollution
• Sedimentation of waters and erosion

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Mining often pollutes waters
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Other Water Pollutants

• Solid waste pollution (garbage)
• Sediment pollution (sand, silt and clay)
• Thermal pollution
• Radioactive pollution
• Noise pollution

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Solid Waste Pollution

• Much solid waste is garbage
• North Pacific Gyre-Great Pacific Garbage Patch
• Plastic waste is dangerous to marine animals and
  humans
• Found in the stomachs of dead baby sea birds as
  parent birds think the small pieces of plastic is
  phytoplankton.

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Plastic rubbish deposits
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Plastic Pollution of Water

• Plastics can release harmful chemicals into the
  water
• Plastic is a synthesized organic compound
  (carbon-hydrogen bonds) that does not decompose
• Plastic breaks up into extremely tiny pieces that
  is mistaken for food by many organisms.

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Sediment Pollution

• Excessive amounts of suspended soil particles
• Originates from erosion of agricultural lands,
  forest soils exposed by logging, degraded stream
  banks, overgrazed rangelands, strip mines, and
  construction
• Problems
• Limits light penetration
• Covers aquatic animals and plants
• Brings insoluble toxins into waterways

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Land disturbance results in poor water quality
Clear-cutting, mining, poor cultivation
practices Dramatically changes aquatic habitats,
and fish may not survive Solutions better
management of farms and forests avoid
large-scale disturbance of vegetation
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Radioactive Substances

• Contain atoms of unstable isotopes that
  spontaneously emit radiation
• Sources
• Mining
• Processing radioactive materials
• Nuclear power plants
• Natural sources

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Thermal Pollution

• Occurs when heated water produced during
  industrial processes is released into waterways
• Temperature affects digestive rates, heart rates,
  and respiration rates
• Warmer water holds less dissolved oxygen
• Removing streamside cover also raises water
  temperature

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Noise Pollution

• Sounds from ships and submarines
• Sonar equipment could negatively affect whales,
  causing them to be beached
• U. S. Military exempt from environmental laws
  related to sonar use

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Organic Compounds found in Polluted Water
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Human Wastewater

• Water produced by human activities such as human
  sewage from toilets and gray water from bathing
  and washing clothes or dishes.

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Why human and animal waste water needs to be
treated
Pathogens and toxins enter water supply via
inadequately treated human waste and animal waste
via feedlots Causes more human health problems
than any other type of water pollution
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Three reasons scientists are concerned about
human wastewater

• Oxygen-demanding wastes like bacteria that put a
  large demand for oxygen in the water
• Nutrients that are released from wastewater
  decomposition can make the water more fertile
  causing eutrophication
• Wastewater can carry a wide variety of
  disease-causing organisms.

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Biochemical Oxygen Demand (BOD)

• BOD- the amount of oxygen a quantity of water
  uses over a period of time at a specific
  temperature.
• As BOD increases Dissolved Oxygen (DO) decreases
• Lower BOD values indicate the water is less
  polluted and higher BOD values indicate it is
  more polluted by wastewater.

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Sewage and pollutants in drinking water
Currently, 1.1 billion people are without safe
drinking water 2.4 billion have no sewer or
sanitary facilities Mostly rural Asians and
Africans An estimated 1.6 to 5 million people
die per year from unsafe drinking water
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Common Diseases from Human Wastewater
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Major Water Pollutants and Their Sources
Table 20-1, p. 532
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Solutions

• Treat sewage
• Disinfect drinking water
• Public education to encourage personal hygiene
• Government enforcement of regulations

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Treatments for Human and Animal Wastewater

• Septic systems- a large container that receives
  wastewater from the house.

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Treatments for Human and Animal Wastewater

• Sewage Treatment Plants- centralized plants in
  areas with large populations that receive
  wastewater via a network of underground pipes.
• Test for human and animal waste using fecal
  coliform bacteria test

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Levels of Treatment and Success

• Primary treatment Some pathogenic bacteria and
  some solids removed
• Secondary treatment some viruses, more waste
  solids, more pathogenic bacteria, and some
  dissolved organics removed, BOD lowered
• Tertiary treatment Phosphorous and nitrogen
  levels lowered, dissolved organics and pathogenic
  bacteria lowered, waste solids completely removed
• Chlorination treatment Pathogenic bacteria
  completely removed, nitrogen amounts lowered
  further, viruses lowered further

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Tertiary treatment of waste water often includes
Chlorine treatment

• Chlorine Dilemma
• Chlorine byproducts are linked to numerous
  cancers, miscarriages and birth defects
• Peru stopped using chlorine
• 1991 huge cholera epidemic that infected 300,000
  people
• Fluoridation
• Prevents tooth decay
• Linked to cancer, kidney disease

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Treatments for Human and Animal Wastewater

• Manure lagoons- large, human-made ponds line with
  rubber to prevent the manure from leaking into
  the groundwater. After the manure is broken down
  by bacteria, it is spread onto fields as
  fertilizers.

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Problems with Manure Lagoons

• Containment of lagoons may burst if containment
  walls break.
• During high precipitation events lagoons may
  overflow bringing pathogenic bacteria to water
  supply

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We have better methods- We can improve
traditional sewage treatment

• Use of natural wetlands
• Remove toxic wastes before sewage enters
  treatment plants
• Use composting toilets
• Reduce use of toxic materials

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Using Nature to Purify our waste water and sewage
water

• Natural water purification system
• Sewage flows into anaerobic digester
• Cleaner water then passes through artificial
  marsh to remove some nutrients
• water flows into a passive greenhouse
• Solar energy and natural processes remove and
  recycle nutrients
• Diversity of organisms used

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Use of a Living Machine to purify waste water
Omega Center in Rhinebeck NY
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Water Laws

• Clean Water Act- (1972) supports the protection
  and propagation of fish, shellfish, and wildlife
  and recreation in and on the water.
• Issued water quality standards that defined
  acceptable limits of various pollutants in U.S.
  waterways.
• Effectively improved water quality from point
  sources

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Water Laws

• Safe Drinking Water Act- (1974, 1986, 1996) sets
  the national standards for safe drinking water.
• It is responsible for establishing maximum
  contaminant levels (MCL) for 77 different
  elements or substances in both surface water and
  groundwater.

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Indicators of water quality

• Scientists measure properties of water to
  characterize its quality
• Biological indicators presence of fecal coliform
  bacteria and other disease-causing organisms
• Chemical indicators pH, nutrient concentration,
  taste, odor, hardness, dissolved oxygen
• Physical indicators turbidity, color,
  temperature

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Streams Can Cleanse Themselves If We Do Not
Overload Them

• Dilution of pollutants does help
• Biodegrading of wastes by bacteria (takes time)
  Some substances are not biodegradable
• Higher human population stresses natural system
  of cleansing
• Prevention is less costly and more effective and
  cleanup

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Dilution and Decay of Degradable,
Oxygen-Demanding Wastes in a Stream
Fig. 20-7, p. 534
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Solutions Methods for Preventing and Reducing
Water Pollution
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What Can You Do? Reducing Water Pollution