Water pollution is a serious global problem impacting human and environmental health. Several key points about water pollution include: 1) It has various sources such as agricultural runoff containing excess fertilizers and pesticides, untreated sewage, and industrial waste. 2) It harms living organisms and renders water unsuitable for uses like drinking and recreation. Pollution has caused millions of preventable deaths from waterborne diseases each year. 3) Successful prevention and reduction of water pollution requires strategies like improved sewage treatment, regulation of industrial discharges, and management of nonpoint sources of pollution from agriculture and urban runoff. 4) While laws like the Clean Water Act have made progress in reducing water pollution in

1. Water Pollution
The pollution saga of
the nectar of life…

2. The Blue Marble or
the Blue Sapphire!
“Our liquid planet glows like a soft blue sapphire in the hard-
edged darkness of space. There is nothing else like it in the solar
system. It is because of water.” - John Todd

3. Water and Water issues
• Water is an essential thing for life.
• Without water life is impossible
• How much water is required per person per day?
• As per universal standards(Average)
* For drinking 5 litres
* sanitation 20 litres
* Bathing 15 litres
* Food preparation 10 litres

4. Some facts on water
 Only 2.5 % of the total water on earth is fresh water
 About 80 countries or 40% of the world’s population suffering
from water shortages
 By 2025, 66% of the world population may suffer from serious
water problems
 Still, 1 billion people lack access to safe drinking water and 2.4
billion lack access to proper sanitation
 Agriculture accounts for more than 70% of the fresh water
• Fewer than 35% of the cities in the developing world treat their
waste water
• Many countries lack adequate legislation and policies for
efficient water management

5. Water management problems
• There is sufficient water in the world.
• It is not managed well
• Water security was a subject to all the world
countries during the World summit, 2002
• Water policy is required by all the nations

6. What is water pollution?
Any chemical, biological,
or physical change in
water quality that has a
harmful effect on living
organisms or makes
water unsuitable for
desired usage.

7. What is water pollution?
Infectious Agents: bacteria and viruses often
from animal wastes
Inorganic Chemicals: Acids and toxic chemicals
often from runoff, industries and household
cleaners

8. What is water pollution?
Organic Chemicals: oil, gasoline, plastics,
detergents often from surface runoff, industries
and cleaners
Plant Nutrients: water soluble nitrates, ammonia
and phosphates often from sewage, agriculture
and urban fertilizers
Sediment: soils and silts from land erosion can
disrupt photosynthesis, destroy spawning
grounds, clog rivers and streams
Pollution and Radioactivity: mostly from
powerplants

9. Impact of water pollution
As per WHO:
• 3.4 million premature
deaths each year from
waterborne diseases
• 1.9 million die from
diarrhea

10. Types, Effects and Sources of Water
Pollution
Point sources
Nonpoint sources
Water quality

11. Point and Nonpoint Sources
NONPOINT SOURCES
Urban streets
Suburban
development
Wastewater
treatment
plant
Rural homes
Cropland
Factory
Animal feedlot
POINT
SOURCES

12. Major Sources of Water Pollution
Agriculture: by far the
leader
• Sediment, fertilizers,
bacteria from livestock,
food processing, salt from
soil irrigation
Industrial: factories and
powerplants
Mining: surface mining
toxics, acids, sediment

14. Freshwater Stream Pollution
Flowing streams can recover from
moderate level of degradable
water pollution if their flows
are not reduced.
• Natural biodegradation
process
• Does not work if
overloaded or stream flow
reduced
• Does not work against non
biodegradable pollutants

15. Pollution of Streams
 Oxygen sag curve Factors influencing recovery
What factors will influence this oxygen sag curve?

16. Two Worlds
Developed Countries
U.S. and other developed
countries sharply reduced
point sources even with
population and economic
growth
• Nonpoint still a problem
• Toxic chemicals still
problem
• Success Thames River

17. Two Worlds Developing Countries:
Serious and growing
problem
• Half of world’s 500 major
rivers heavily polluted
• Sewage treatment
minimal $$$
• Law enforcement difficult
• 10% of sewage in China
treated
• Economic growth with
little $$$ to clean up

18. India’s Ganges River
• Holy River (1 million take
daily holy dip)
• 350 million (1/3rd
of pop) live
in watershed
• Little sewage treatment
• Used for bathing, drinking etc.
• Bodies (cremated or not)
thrown in river
• Good news is the Indian
government is beginning to
work on problem

20. Pollution of Lakes
Eutrophication

21. Eutrophication of Lakes
Eutrophication: nutrient
enrichment of lakes
mostly from runoff of
plant nutrients (nitrates
and phosphates)
• During hot dry weather can
lead to algae blooms
• Decrease of photosynthesis
• Fishes killed, bad odour

22. Eutrophication in Lakes
Solutions:
• Advanced sewage
treatment (N, P)
• Household detergents
• Soil conservation
• Remove excess weed
build up
• Pump in oxygen or
freshwater

23. Case Study: The Great Lakes
•Pollution levels
dropped, but
long way to go
•95% of U.S.
freshwater
•30% Canadian
pop, 14% U.S.
•38 million drink
•1% flow out St.
Lawrence
•Toxic fish

25. Section 4: Groundwater
• Why is groundwater pollution a serious
problem?
• What is the extent of the problem?
• What are the solutions?

27. Groundwater
Groundwater can become
contaminated
• No way to cleanse itself
• Little dilution and
dispersion
• Out of sight pollution
• Prime source for
irrigation and drinking
• REMOVAL of
pollutant difficult

28. Groundwater Pollution: Causes
 Low flow rates  Few bacteria
 Cold temperatures
Coal strip
mine runoff
Pumping
well
Waste lagoon
Accidental
spills
Groundwater
flow
Confined aquifer
Discharge
Leakage from faulty
casing
Hazardous waste injection well
Pesticides
Gasoline
station
Buried gasoline
and solvent tank
Sewer
Cesspool
septic tank
De-icing
road salt
Unconfined freshwater aquifer
Confined freshwater aquifer
Water pumping
well Landfill
 Low oxygen
Fig. 22-9 p. 502

30. Groundwater
• Pollution moves in
plumes
• Soil, rocks, etc. act
like sponge
• Cleansing does not
work (low O, low
flow, cold)
• Nondegradables may
be permanent

31. Prevention is the
most effective and
cheapest

32. Groundwater Pollution Prevention
 Monitor aquifers
 Leak detection systems
 Strictly regulating hazardous waste disposal
 Store hazardous materials above ground
 Find less hazardous substitutes

34. Ocean Pollution
• How much pollution can the oceans tolerate?
• Coastal zones: How does pollution affect
coastal zones?
• What are major sources of ocean pollution and
what is being done?
• Oils spills

35. Ocean Pollution
Oceans can disperse and
break down large
quantities of degradable
pollution if they are not
overloaded.
• Pollution worst near heavily
populated coastal zones
• Wetlands, estuaries, coral
reefs, mangrove swamps
• 40% of world’s pop. Live
within 62 miles of coast

36. Mangrove Swamp

37. Estuaries

38. Ocean Pollution
• Large amounts of untreated
raw sewage (viruses)
• Leaking septic tanks
• Runoff
• Algae blooms from
nutrients
• Dead zones NO DO
• Airborne toxins
• Oil spills

39. Ocean Pollution
Fig. 22-11 p. 504

41. Case Study: Chesapeake Bay
 Largest US
estuary
 Relatively shallow
 Slow “flushing”
action to Atlantic
 Major problems with dissolved O2
Fig. 22-13 p. 506

42. Preventing
and reducing
the flow of
pollution from
land and from
streams
emptying into
the ocean is
key to
protecting
oceans

43. Oil Spills
 Sources: offshore wells, tankers, pipelines and
storage tanks
 Effects: death of organisms, loss of animal
insulation and buoyancy, smothering
 Significant economic impacts
 Mechanical cleanup methods: skimmers and
blotters
 Chemical cleanup methods: coagulants and
dispersing agents

44. Oil Spills

47. Prevention and Reduction
• How can we reduce surface water pollution:
point and also nonpoint.
• How do sewage treatment plants work?
• How successful has the U.S. been at reducing
water pollution? Clean Water Act

48. Solutions: Preventing and Reducing
Surface Water Pollution
Nonpoint Sources Point Sources
Reduce runoff
Buffer zone
vegetation
Reduce soil erosion
Clean Water Act
Water Quality Act
 Only apply pesticides and fertilizers as needed

49. Nonpoint Sources
Reduce runoff

50. Nonpoint Sources
Buffer Zones Near
Streams

51. Nonpoint
Prevent soil erosion and only apply
needed pesticides and fertilizers

52. Point Sources
Most developed countries
use laws to set water
pollution standards.
• Regulates navigable
waterways..streams,
wetlands, rivers, lake

53. Clean Water Act
• Sets standards for key
pollutants
• Requires permits for
discharge
• Requires sewage treatment
• Require permits for
wetland destruction
• Does not deal with
nonpoint sources well
• Goal All Waterways
fishable and swimable

54. Technological Approach: Septic
Systems
Require suitable soils and maintenance
Fig. 22-15 p. 510
•¼ of all U.S. homes
have Septic tanks
•Can be used in
parking lots, business
parks, etc.

55. Combined sewer
overflow is a
problem in many
older towns
•EPA: 1.8 M to
3.85 M sick from
swimming in
water
contaminated by
sewer overflows
•EPA: $100 billion
to fix

56. Technological Approach: Sewage
Treatment
Physical and biological treatment
Fig. 22-16 p. 511

58. Primary: removes 60% of
solids and 30-40% oxygen
demanding wastes
(physically)
Secondary: uses biological
processes to remove up to
90% of biodegradables
Tertiary: advanced
techniques only used in 5%
of U.S. $$$$
Disinfection: chlorine,
ozone, UV
What is not taken out???

60. Technological Approach: Advanced
(Tertiary) Sewage Treatment
Uses physical and chemical processes
Removes nitrate and phosphate
Expensive
Not widely used

61. Sludge disposal…using as fertilizer

62. Technological Approach: Using
Wetlands to Treat Sewage
Fig. 22-18 p. 513

63. Rain Water HarvestingRain Water Harvesting
• Rain Water Harvesting RWH- process of collecting, conveying &
storing water from rainfall in an area – for beneficial use.
• Storage – in tanks, reservoirs, underground storage-
groundwater
• Hydrological Cycle

64. Appropriate Technology
Water conservation
and groundwater
recharge techniques
Water harvesting cum
supplementary
irrigation techniques

65. The Good News
Largely thanks to CWA:
• Between 1972 – 2002
fishable and swimmable
streams 36% to 60%
• 74% served by sewage
treatment
• Wetlands loss dropped by
80%
• Topsoil losses dropped by
1 billion tons annually

66. The Bad News
• 45% of Lakes, 40% streams
still not fishable and
swimmable
• Nonpoint sources still huge
problem
• Livestock and Ag. Runoff
• Fish with toxins

69. Drinking Water
• How is drinking water purified? High tech
way.
• How can we purify drinking water in
developing nations?
• What is the Safe Drinking Water Act?
• Is bottled water a good answer or an expensive
rip-off?

70. Drinking Water Quality
 Safe Drinking Water Act
 Maximum contaminant levels (MCLs)
 Purification of urban drinking water
 Bottled water
 Protection from terrorism
 Purification of rural drinking water

71. Purification of urban drinking
water
Surface Water:
• Removed to reservoir to
improve clarity
• Pumped to a treatment
plant to meet drinking
water standards
Groundwater: often does
not need much
treatment

73. Purification of rural drinking
water
There can be simple ways
to purify water:
• Exposing to heat and
UV rays
• Fine cloths to filter water
• Add small amounts of
chlorine

74. Safe Drinking Water Act
• 54 countries have
drinking water laws
SDWA passed 1974
requires EPA to set
drinking water
standards
Maximum Contaminating
Levels (MCLs)

75. Safe Drinking Water Act
• Privately owned wells
exempt from SDWA
SDWA requires public
notification of failing to
meet standards and fine.
MCLs often stated in
parts per million or
parts per billion

76. Bottle Water
U.S. has the world’s
safest tap water due to
billions of $$$ of
investment
Bottle water 240 to
10,000 times more
expensive than tap
water
25% of bottle water is tap
water

77. Bottle Water
1.4 million metric tons of
bottle thrown away
each year
Toxic fumes released
during bottling
Bottles made from oil
based plastics
Water does not need to
meet SDWA