Water pollution

1. Water Pollution
L .Guna Vardhan Reddy
2211CS010324
G7B-35

2. Lake Washington
 Sewage dumped into Lake
Washington from Seattle
 1955: Edmondson discovered
cyanobacteria (blue-green algae) in
the lake
 Algae grew, died, darkened waters,
foul smell
 Chief nutrient – phosphorus,
coming from the sewage treatment
plants
 Public pressure led to cleanup of
the lake
 New pollution challenges

3. Causes and Effects of Water Pollution
Water pollution causes illness and death in humans and
other species and disrupts ecosystems.
The chief sources of water pollution are agricultural
activities, industrial facilities, and mining, but growth in
population and resource use make it increasingly worse.

4. Water Pollution Comes from Point and
Nonpoint Sources
 Water pollution : chemical,
biological or physical change
in water quality
 Point sources
• Located at specific places
• Easy to identify, monitor,
and regulate
• Examples
 Nonpoint sources
• Broad, diffuse areas
• Difficult to identify and
control
• Expensive to clean up
Nonpoint sediment from
unprotected from farms

5. Water Pollution Comes from Point and
Nonpoint Sources
 Agriculture activities: leading
cause of water pollution
• Sediment eroded from the
lands
• Fertilizers and pesticides
• Bacteria from livestock and
food processing wastes
 Industrial facilities-inorganic and
organic
 Mining – disturbs the land
Point source

6. Water Pollution Comes from Point and
Nonpoint Sources
 Other sources of water pollution
• Parking lots-grease, toxic materials and sediments that
collect on their impervious surface
• Prevents rain from soaking in, worsens flooding-
• Human-made materials
• E.g., plastics – polymers break down very slowly
• Climate change due to global warming
• some areas get more precipitation than others
• Intense downpours flushes more harmful chemicals
• Prolonged drought reduces river flows that dilute
waste

7.  Infectious disease organisms: contaminated drinking water
• 500 disease causing bacteria that can be transferred
from wastes of human and animal waste
 The World Health Organization (WHO)
• 3 Million people die every year, mostly under the age of
5, from drinking contaminated water
• 1.2 billion people have no access to drinking water
• Diarrhea caused mostly by polluted water – kills a
young child every 18 seconds
Cons of Major Water Pollutants

8.  Water Pollution and Skin Diseases
 Water Pollution and Cancer
 Water Pollution and Child Health
 Carbonated water damages teeth
 Environmental concerns
 One major issue surrounding mineral water involves the
container. The large-scale production of plastic bottles
causes pollution and has serious consequences for the
environment.
 Women of reproductive age.
Cons of Major Water Pollutants

9. Testing Water for Pollutants…….
 Variety of tests to determine water quality:
 Coliform bacteria: Escherichia coli, significant levels,
found in fecal waste
• 100 ml of water no colonies for drinking
• 100 ml of should contain no more than 200 colonies
 Level of dissolved oxygen (DO) – excessive inputs of
oxygen-demanding wastes can deplete DO levels in water
 Chemical analysis – determine the presence and
concentrations of specific organic pollutants

10. Testing Water for Pollutants ……
 Indicator species
• Cattails from areas contaminated with fuels,
solvents
• Bottom dwellers (mussels) feed by filtering water
through their bodies
 Bacteria and yeast glow in the presence of a
particular toxic chemical, such as heavy metals,
carcinogens in food
 Color and turbidity of the water – sediment
measured by colorimeters and turbidimeters

11. Water Quality as Measured by Dissolved
Oxygen Content in Parts per Million

12. Major Water Pollution Problems in
Streams and Lakes
 While streams are extensively polluted worldwide by
human activities, they can cleanse themselves of many
pollutants if we do not overload them or reduce their
flows.
 Addition of excessive nutrients to lakes from human
activities can disrupt lake ecosystems, and prevention of
such pollution is more effective and less costly than
cleaning it up.

13. Individuals Matter: The Man Who Planted
Trees to Restore a Stream
 John Beal: restoration of Hamm Creek, Seattle, WA,
U.S. – 15 year clean up.
 Planted trees
 Persuaded companies to stop dumping
 Removed garbage

14. Highly Polluted River in China
1/3 rd of China’s rivers
judged unfit for
agricultural use
2007 – ½ of the
population including
278 cities do not have
access to drinkable
water

15. Trash Truck Disposing of Garbage
into a River in Peru
• Most streams
passing through
urban or industrial
areas suffer from
severe pollution
• Garbage also
dumped into rivers
in some places

16.  2007 State of the Great
Lakes report
• New pollutants-PCB’s
• Wetland loss and
degradation
• Declining of some
native species
• Native carnivorous fish
species (lake trout)
declining
• Ban use of toxic
chlorine compounds-
bleach (paper)
Pollution in the Great Lakes

17. The Seattle, Washington Area, U.S.