CHAPTER 20
Water Pollution
Core Case Study: Lake Washington
1. What was being dumped into Lake Washington by the mid 1950s?
2. What did the growth of cyanobacteria do to the lake?
3. What was done to help rectify the situation?
20-1: What are the Causes & Effects of Water Pollution
Define water pollution: _____________________________________________________
__________________________________________________________________________
Point
WATER POLLLUTION
Non-Point
What Is It?
Examples
What are the 3 biggest sources of water pollution?
1. __________________ activities
 _____________ from agricultural lands
 ______________ & ________________
 Bacteria from ___________________ & ___________________
2. __________________ facilities
 ________________ &________________ chemicals
3. Mining
 __________________ & toxic chemical
How have parking lots become a major source of nonpoint pollution?
One of the major water pollution problems people face is exposure to ____________________
through _________________________________________________.
How many diseases can be spread through water vectors? __________
_______________________ die every year from water diseases. Most are under age ____.
______________ worldwide have no access to clean drinking water (this is __ in every __)
Looking at Tables 20-1 and 20-2:
Describe one major water pollutant and its source(s).
List 4 diseases transmitted through water that cause diarrhea:
Science Focus: Testing Water for Pollutants
1. Fecal coliform bacteria indicate water contamination. To be deemed safe for
drinking,water can have ______ colonies, for swimming __________.
sewage has _____________.
2. Levels of _____________________ (____) can indicate the presence of bacteria.
Raw
3. Two indicator species for water pollution are ____________ and _______________.
4. Define turbidity: ________________________________________________________
20-2: What are the Major Water Pollution Problems in Streams and Lakes?
Rivers and streams can naturally recover from wastes through ____________________
and __________________________ by bacteria.
This recovery process does not work when:
What is an oxygen sag curve?
Draw and label a diagram of the oxygen sag curve below:
Stream Pollution in Developed Countries
Water pollution laws were set in the __________s.
Successful clean ups of the _________________ River and ______________ River.
Room for improvement: toxic chemicals by _________________________, overloaded
sewage treatment plants, runoff from agriculture/feedlots (__________________,
______________________ & ____________________)
Stream Pollution in Developing Countries
Most of the world’s polluted river are in developing countries because they cannot
________________________________ and/or ________________________________.
_____% - _____% of raw sewage is dumped
_______________ waste pollutes 2/3 of India’s rivers
In China _______________________ people do not have access to drinkable water
India’s Ganges River:
According to the Hindu people, the Ganges is a ________ river. People use it to _______,
________ from or take a dip. But it is highly polluted by the people and the industries in
the _____ cities in the basin. Complicating the situation, Hindus believe they must
__________ the dead. Putting the ashes in the Ganges increases chances of getting to
heaven. But, many people cannot afford enough _______ for cremation. So the bodies
are _____________ ________________ and mingle with livestock. _________________ of
the bodies decreases ____________________ and adds disease causing _____________
and _____________ to the water. To clean up the river, the government plans to build
_________________________ in the basin’s cities and 32 electric
_____________________. Also, they released 25,000 ____________________________ to
devour ________________. Another religious custom is to throw
______________________ into the river. Often these contain ___________________ like
_________ & ______________.
Describe why lakes are more vulnerable to water pollution.
Define: EutrophicationOligotrophicThe most common culprits for cultural eutrophication are ___________ and ___________
containing compounds.
Explain how cultural eutrophication kills fish: (Remember we’ve done this before!)
What two lessons can be learned from the story of Lake Washington?
Briefly describe the history of the Great Lakes as far as being affected by water
pollution.
20-3: What Are the Major Pollution Problems Affecting Groundwater and Other Drinking
Water Sources?
Name several common pollutants that pollute groundwater.
Describe why it is difficult and costly to remove contaminants from groundwater.
Toxins dumped underground pose a risk to our aquifers:
The EPA says that __/__ of the industrial waste ponds in the US have no liners.
__/__ of our liquid hazardous wastes are injected into the ground.
Inside those leaky tanks are: gasoline, oil, _____ (letters only), and _____ ions.
 The last 2 are known carcinogens (cause ______________) and nitrate ions
can cause ______________________ which kills infants
How does drinking water become polluted with arsenic?
Arsenic can cause:
Describe one prevention and one cleanup solution to groundwater pollution.
Describe how each purifies drinking water:
Developed Countries Sewer Wastewater
Tropical Countries
The LifeStraw
How has New York City protected its watershed in order to have pure water?
What is the US Safe Water Drinking Act? Is it working?
Is drinking bottled water worth it?
List a few harmful impacts bottled water has on the environment.
20-4: What are the Major Water Pollution Problems Affecting Oceans?
______% of the world lives on or near the coast, with _____ of the world’s 15 largest
metro areas being on the coast.
______% of marine pollution is from the land.
Using Figure 20-15, pick 3 to describe below:
3 Examples of Sources of Marine Pollution
1.
2.
3.
How are cruise ships contributing to marine pollution?
What causes oxygen-depleted zones?
Ocean Oil Pollution:
What happened to the Exxon Valdez oil tanker in 1989?
What is actually the largest source of ocean oil pollution?
What affect does oil have on marine life?
Describe one prevention and one cleanup solution to coastal water pollution.
20-5: How Can We Best Deal With Water Pollution?
Ways to reduce water pollution from nonpoint sources:
What is the Clean Water Act and what types of improvements has it led to?
Some homes have septic tanks. Describe how this works. A picture could be helpful.
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Many homes send their wastewater to sewage treatment plants. The steps are:
STEP ONE: _________________ Sewage treatment is a ________________ process
 Goal: ____________________________________________________________
 Pieces: __________________________________________________________
 Does not remove: ___________________________________________________
STEP TWO: _________________ Sewage treatment is a ________________ process
 Goal: _____________________________________________________________
 Pieces: __________________________________________________________
 Does not remove: ___________________________________________________
STEP THREE: _________________ Sewage treatment is a ________________ process
 Goal: _____________________________________________________________
 Pieces: __________________________________________________________
 Does not remove: ___________________________________________________
BEFORE DISCHARGE: water is subject to _______________ or __________________ to remove
______________ & ________________________________.
Describe a few issues that may arise in wastewater treatment plants in the US.
What is a composting toilet system?
Why is a wetland-based sewage treatment plant better?
Science Focus: Treating Sewage by Working with Nature
1. Describe John Todd’s “living machine”.