Chap 21: Water Pollution

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Chap 21 Water Pollution
Objectives Sources of water pollution. Types
of water pollution. Pollution of freshwater
streams. Pollution of freshwater
lakes Pollution of groundwater. Ocean
pollution. Preventing and reducing water
pollution. Drinking water quality. Read Case
Study Using Nature to Purify Sewage
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Water Pollution is any chemical, biological, or
physical change in water quality that has a
harmful effect on living organisms or that makes
water unsuitable for desired uses. See Table
21-1 for major categories of water
pollutants. What are some major diseases that
can be transmitted to humans through contaminated
drinking water? 1)______________________ 2)_____
_________________ 3)_______________________ How
many people die world wide each year due to
waterborne diseases?
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How do we measure water quality? Water that is
safe to drink should have no fecal coliform
bacteria. Most well water tests look only for
fecal coliform. Just as with air pollution there
are point and nonpoint sources for water
pollution. Point sources have identifiable
stationary discharge points. Nonpoint sources
cannot be traced to any single discharge
point. Agricultural activities are by far the
leading case of water pollution. Industrial
activities are another large source of water
pollution along with mining activities. For
____ of people in industrialized countries have
access to clean drinking water. _____ of
people in developing countries have access to
clean drinking water.
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However, this means that 1.4 billion people do
not have access to clean drinking water leading
to 9,300 deaths per day. If the world warms up
too much water or too little water could lead to
an increase in water pollution. What are the
major pollution problems for fresh water
streams? 1)___________________ 2)_______________
_____ 3)_____________________ 4)________________
______
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Pollution of fresh water lakes Why are lakes and
reservoirs more vulnerable to pollution than
streams? Also, food webs in lakes and reservoirs
are usually more complex. What is Cultural
Eutrophication? Approximately _______ of medium
to large lakes near major population centers in
the U.S have been affected by cultural
eutrophication. Are the Great Lakes more or less
polluted than they were in the 1960s?
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Pollution of Groundwater Why is groundwater
pollution such a serious problem? See figures
21-7 and 21- 8. What are some methods to protect
and cleanup groundwater? See figure 21-9
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Ocean Pollution Can the oceans effectively deal
with pollution? Coastal areas are more polluted
that non-coastal areas. Why? What about oil
spills? What can we do to protect coastal
areas? See figure 21-14
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What can we do to prevent and reduce surface
water pollution? The main thing is to prevent
runoff from agriculture. What are some of the
pollutants that come from farming? The Federal
Water Pollution Control Act of 1972, later
renamed the Clean Water Act, and the 1987 Water
Quality Act are the major efforts of the U.S. to
protect the countries surface waters. The Clean
Water Act set standards for allowed levels of key
water pollutants and requires permits for
discharges. In developing countries it is
estimated that 80-90 of raw sewage from cities
is discharged into rivers, streams, and
lakes. What can we do to reduce surface water
pollution?
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Drinking Water Standards Surface water supplies
used for drinking water are treated before being
distributed to users. 54 countries have drinking
water standards. Privately owned wells are not
required to federal drinking water
standards. What about bottled water?