1. Water Pollution
Chapter 20

2. Water Pollution Comes from Point Sources
Any chemical, biological, or physical change in water quality that harms living organisms or makes water unsuitable for desired uses.
Point sources
Located at specific places
Easy to identify, monitor, and regulate
Examples:
Ditches, sewer lines, drain pipes, oil tankers, undergound mines

3. Point Source of Polluted Water in Gargas, France

4. Water Pollution Comes from Nonpoint Sources
Broad, diffuse areas from which pollutants enter bodies of surface water or air
Difficult to identify and control
Expensive to clean up
Examples
Runoff (chemical or biological) from feedlots, cropland, lawns, golf courses, logged forests, urban streets & parking lots (THINK BIG AREA)

5. Nonpoint Sediment from Unprotected Farmland Flows into Streams

6. Biggest Sources of Water Pollution
Agriculture activities
***Sediment eroded from agricultural land***
Fertilizers and pesticides
Bacteria from livestock and food processing wastes
Industrial facilities
Organic and inorganic chemicals
Mining
Sediment from eroding soil
Toxic chemicals

7. Waste water runoff from strip mining flowing into the Ohio River

8. Other Sources of Water Pollution
Parking lots
Build up of toxins on surface
Human-made materials
E.g., plastics – release polymers as they break down
Climate change due to global warming
will affect precipitation and change amounts of pollutants washing into the hydrological cycle

9. Major Water Pollutants Have Harmful Effects
Infectious disease organisms: contaminated drinking water
Over 500 disease-causing agents can be spread through water vectors
The World Health Organization (WHO)
3.2 Million people die every year from water diseases or clean water shortages (most under 5)
In the developing world, diarrheal diseases kill a child under 5 every 18 SECONDS
1.2 Billion people (1 out of 6) worldwide have no access to clean drinking water

10. Major Water Pollutants and Their Sources

11. Common Diseases Transmitted to Humans through Contaminated Drinking Water

12. Testing Water for Pollutants
Variety of tests to determine water quality:
Coliform bacteria: Escherichia coli, significant levels
Chemical analysis of Fecal Coliform (per 100 mL)
For drinking = NO colonies
For swimming < 200 colonies
Raw sewage contains several million colonies
Level of dissolved oxygen (DO)
Can indicate the presence of oxygen demanding bacteria – a sign that the water is polluted by potentially disease causing agents

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

14. Testing Water for Pollutants
Indicator species
Examples: cattails, mussels
Genetic engineering
Bacteria and yeast glow in the presence of a particular toxic chemical
Measuring sediment
Color and turbidity of the water
Turbidity – cloudiness of the water

15. Threats to Streams
Streams can cleanse themselves if we do not overload them
Dilution is a natural recovery process
Hindered by drought, damming, water diversion (reduces flow)
Biodegradation of wastes by bacteria
takes time – and cannot break down non-degradable pollutants (like mercury or DDT)
Oxygen sag curve shows the demands of oxygen-demanding wastes on a stream or river that has been polluted

16. Stream Pollution in Developed Countries
1970s: Water pollution control laws
Must eliminate or reduce point source discharge
Successful water clean-up stories
Ohio Cuyahoga River, U.S.
Thames River, Great Britain
Room for improvement – large fish kills
Contamination of toxic inorganic and organic chemicals by industries and mines
Malfunctioning or overloaded sewage treatment plants
Runoff from agriculture/feedlots (fertilizer, pesticides, manure)

17. Cuyahoga River Fire, 1969

18. Global Outlook: Stream Pollution in Developing Countries
Half of the world’s 500 rivers are polluted
Most of these are in developing countries
Cannot afford waste treatment
Cannot enforce water pollution laws
Untreated sewage
Developing countries dump 80-90% of waste raw
Industrial waste
Pollutes 2/3 of India’s rivers
China’s rivers
1/3 unsafe for agricultural & industrial use
300 million people without access to drinkable H20

19. Natural Capital Degradation: Highly Polluted River in China

20. Trash Truck Disposing of Garbage into a River in Peru

21. Low Water Flow and Too Little Mixing Makes Lakes Vulnerable to Water Pollution
Less effective at diluting pollutants than streams
Stratified layers
Little vertical mixing
Little of no water flow

22. Cultural Eutrophication Is Too Much of a Good Thing
Natural nutrient enrichment of a lake over time
Oligotrophic lake
Low nutrients, clear water
Cultural eutrophication
Accelerated nutrient enrichment due to human activites involving mostly nitrate- and phosphate- containing effluents
Sources: feedlots, farmland, suburban yards, mining sites, untreated sewage

23. How Cultural Eutrophication Happens
During hot weather or droughts
More nutrients
Algal blooms
Algal death
Increased bacteria – decomposing
Fish die (suffocation)
Anaerobic bacteria take over producing hydrogen sulfide and methane

24. Cultural Eutrophication Is Too Much of a Good Thing (3)
Prevent or reduce cultural eutrophication
Remove nitrates and phosphates
Diversion of lake water
Clean up lakes
Remove excess weeds
Use herbicides and algaecides; down-side?
Pump in air

25. Case Study: Pollution in the Great Lakes (1)
1960s: Many areas with cultural eutrophication
1972: Canada and the United States: Great Lakes pollution control program
What was done?
Problems still exist
Raw sewage
Nonpoint runoff of pesticides and fertilizers
Biological pollution
Atmospheric deposition of pesticides and Hg

26. Case Study: Pollution in the Great Lakes (2)
2007 State of the Great Lakes report
New pollutants found
Wetland loss and degradation; significance?
Declining of some native species
Native carnivorous fish species declining
What should be done?

27. The Great Lakes of North America

28. Case Study: India’s Ganges River: Religion, Poverty, Population Growth, and Health (1)
Holy river: religious customs
Pollution
Sewage
Human remains
Painted statues
Government intervention
Waste treatment plants
Crematoriums
Snapping turtles

29. India’s Ganges River

30. Ground Water Cannot Cleanse Itself Very Well
Source of drinking water for ½ of US and 95% rural areas
Common pollutants
Fertilizers and pesticides
Gasoline
Organic solvents
Pollutants dispersed in a widening plume

31. Ground Water Cannot Cleanse Itself Very Well
Slower chemical reactions in groundwater due to
Slow flow (less than 1 ft per day): contaminants not diluted
Less dissolved oxygen
Fewer decomposing bacteria
How long will it take to cleans itself of
Slowly degradable wastes (like DDT)
Take decades to thousands of years
Nondegradable wastes (like lead and arsenic)
Permanent pollution

32. Groundwater Pollution Is a Serious Threat
China: many contaminated or overexploited aquifers
9 out of 10
U.S.: FDA reports of toxins found in many aquifers
EPA survey of 26,000 industrial waste ponds and lagoons found that 1/3 had no liners
2/3 of America’s liquid hazardous wastes are injected into disposal wells and leak into aquifers
EPA has cleaned up 350,000 of 460,000 underground tanks

33. What’s in those leaky tanks?
What about leaking underground storage tanks:
Gasoline
Oil
Methyl tertiary butyl ether (MTBE)
A suspected carcinogen
Nitrate ions
Can cause cancer or “blue baby syndrome”
Bottom Line: Wastes we think we have thrown away or stored safely can escape and come back to haunt us 33

34. Case Study: A Natural Threat from Arsenic in Groundwater
Source of As in the groundwater
Natural AND human (mining)
Human health hazards: cancer
Skin
Lungs
Bladder
Northern Chile – 3 to 14 times higher cancer rates than normal

35. There Are Many Ways to Purify Drinking Water
Reservoirs and purification plants
Improve quality by letting suspended matter settle
Protecting watersheds is cheaper than treating
Process sewer water to drinking water
El Paso, TX gets 40% of its water this way
Works well, but expensive & people think its gross
Expose clear plastic containers to sunlight (UV)
Takes 3 hours to kill bacteria
Has decreased childhood diarrhea by 30-40%
Nanofilters
The LifeStraw

36. The LifeStraw: Personal Water Purification Device

37. Case Study: Protecting Watersheds Instead of Building Water Purification Plants
New York City water
Reservoirs in the Catskill Mountains
Protect the watershed instead of water purification plants
Spent $1.5 billion on revegetation & protection
Purification would cost $6 billion plus $300 million per year in filtration cost

38. Using Laws to Protect Drinking Water Quality
1974: U.S. Safe Drinking Water Act
Sets maximum contaminant levels for any pollutants that affect human health
The BAD news
5.6 million Americans drink water that does not meet EPA safety standards for 1 or more pollutants
1 in 5 American’s drink water from a plant that has violated one or more safety standards during the year

39. Using Laws to Protect Drinking Water Quality
Health scientists say strengthen the law
More notification for violations
Ban lead in plumbing pipes
Still allowed to sell plumbing line w/ 10% lead as “lead-free”
Water-polluting companies: weaken the law
Want “waivers” to violate standards when it is too expensive to comply
Want to eliminate national tests and reduce notifications (usually you’re parents get one every year from your water utility company) 39

40. Is Bottled Water the Answer?
U.S.: some of the cleanest drinking water
Bottled water
¼ is regular tap water
40% is contaminated by bacteria
Costs 240 to 100,000 times more than tap water
Fuel cost to manufacture the plastic bottles
Recycling of the plastic
Consumers spend $1-2 billion in US
Growing back-to-the-tap movement
If you’re worried have an INDEPENDENT test

41. Ocean Pollution Is a Growing and Poorly Understood Problem (1)
Coasts bear the brunt
40% of the world’s population live on or near the coast
Of the world’s 15 largest metropolitan areas – 14 are on the coast
2006 Study by UN EP: State of the Marine Environment
80% of marine pollution originates on land
Sewage

42. Ocean Pollution: Cruise Ships
Cruise line pollution: what is being dumped?
Human waste
Dry cleaning solutions
Garbage
Used oil
It is illegal in US waters, but most do it at night
Solution: tourists are picking cruise lines based on ship waste management
Outside of US waters, it is up to each ship’s country of origin – most are flagged from nations without strict employment or environmental laws

44. US Beaches U.S. coastal waters Beach goers
Raw sewage
Sewage and agricultural runoff: NO3- and PO43-
Beach goers
Ear infections, sore throats, eye irritation, respiratory diseases, gastrointestinal disease
1 in 4 beaches is “unsuitable” for swimming 44

45. Pollution effects Harmful algal blooms Oxygen-depleted zones
Red, brown or green tides
Cause airborne toxins to be release killing birds, marine mammals
Poisons seafood
Reduces Tourism
Oxygen-depleted zones
“Dead Zones”
Nitrates and Phosphates 45

46. A Red Tide

47. Science Focus: Oxygen Depletion in the Northern Gulf Of Mexico
Severe cultural eutrophication
Mississippi watershed drains 2/3 of the US land
Oxygen-depleted zone
Overfertilized coastal area
Preventive measures
Reduce fertilizer use (or use below ground)
Improve flood prevention
Replanting vegetation
Will it reach a tipping point?

48. A Large Zone of Oxygen-Depleted Water in the Gulf of Mexico Due to Algal Blooms

49. Ocean Oil Pollution Sources
Largest source of ocean oil pollution
Urban and industrial runoff from land
1989: Exxon Valdez, oil tanker ran aground in Prince William Sound, Alaska
Price to clean up - $2.5 billion ($4 billion after lawsuits)
2002: Prestige, oil tanker, sank off the coast of Spain
Leaked oil for 2 years (twice the amount of the Valdez)

51. Ocean Oil Pollution Problems
Volatile organic hydrocarbons
Kill many aquatic organisms
Especially vulnerable larval forms
Tar-like globs on the ocean’s surface
Coat animals
Loss of buoyancy and death results from drowning
Heavy oil components sink
Affect the bottom dwellers (clams, crabs, oysters)

52. Recovery from Oil Spills
Faster recovery from crude oil than refined oil
Crude oil: 3 years
Refined oil: years
Economic impact to tourism
Cleanup procedures
Floating booms, skimmer boats, absorbent bacteria
Only gets 15% of oil
Methods of preventing oil spills
Use double hulls

53. Reduce Surface Water Pollution from Agriculture
Reduce erosion
Keep cropland covered with vegetation
Reduce the amount of fertilizers
Especially on sloped land
Plant buffer zones of vegetation
Use organic farming techniques
Use pesticides prudently
Control runoff
Tougher pollution regulations for livestock operations
Deal better with animal waste

54. Case Study: The U.S. Experience with Reducing Point-Source Pollution
Numerous improvements in water quality
# of people served by community H2O meeting federal health standards went from 79% to 94%
Some lakes and streams are not safe for swimming or fishing
From 36% to 60%
High levels of Hg, pesticides, and other toxic materials in fish
Treated wastewater still produces algal blooms

55. Dealing with Sewage to Reduce Water Pollution
Septic tank system
Underground tank for treating wastewater from a home in rural and suburban areas. Bacteria in the tank decompose organic wastes, and the sludge settles to the bottom of the tank. The effluent flows out of the tank into the ground through a field of drainpipes.
Issues:
Settling tank must be pumped every few years
Not maintained can cause sewage to back-up into the home or pollute nearby groundwater
Chemicals can kill the bacteria

56. Solutions: Septic Tank System

57. Dealing with Sewage to Reduce Water Pollution
Wastewater or sewage treatment plants
STEP 1: Primary sewage treatment
Physical process
Goal: Removal of solids
Screens, grit chamber, settling tanks
Result: 60% reduction in suspended solids & 30 to 40% reduction in oxygen-demanding waste
DOES NOT REMOVE:
Pathogens, phosphates, nitrates, salts, radioisotopes, pesticides 57

58. Solutions: Primary and Secondary Sewage Treatment58

59. Dealing with Sewage to Reduce Water Pollution
Wastewater or sewage treatment plants
STEP 2: Secondary sewage treatment
Biological process
Goal: remove oxygen demanding waste
Result: 90% of dissolved and biodegradable wastes are removed, 70% of toxic metals, phosphorous and 50% of nitrogen
DOES NOT REMOVE:
Most isotopes
Persistent organic substances (pesticides)
Pathogens 59

60. Solutions: Primary and Secondary Sewage Treatment60

61. Dealing with Sewage to Reduce Water Pollution
Wastewater or sewage treatment plants
STEP 3: Tertiary or advance sewage treatment
Chemical
Goal: remove specific pollutants
VERY HIGH COST, not widely used
BEFORE DISCHARGE (LAST STEP)
Bleaching or chlorination to remove color and disease-causing bacteria
Result: very successful, but carries some risk from the chemicals (cancer, miscarriage, endocrine disruptors)
DOES NOT REMOVE: some viruses 61

62. Solutions: Primary and Secondary Sewage Treatment

63. Sewage Treatment in the US
Law requires primary and secondary treatment
You can exempt secondary if it is an “excessive financial burden”
Separate pipes for sewage and storm runoff
Reduces cost of treating waste water (less of it)
More expensive to install
Health risks of swimming in water with blended sewage wastes

64. We Can Improve Conventional Sewage Treatment
Use composting toilet systems
Now waterless and odorless (?)
Wetland-based sewage treatment systems
Ideal for some developing countries

66. Options!

67. Solutions: Water Pollution, Methods for Preventing and Reducing Water Pollution

68. What Can You Do? Water Pollution, Ways to Help Reduce Water Pollution