Answer Key
Unit 4 Managing and
Reducing Waste
Chapter 7 Solid and Liquid Waste Management
Answers to Pause and Reflect Questions
(Student textbook page 217)
1. Agriculture, industries, and municipalities are the main
sources of solid waste.
2. A landfill is a disposal site for solid waste that is built
into or on top of the ground that isolates the waste
from the surrounding ground and water resources.
An impermeable liner is buried underground and
alternating layers of waste and soil are added over time;
eventually the layers become compressed.
Leachate is liquid from landfill that contains chemicals
from the decomposing waste that could escape and
pollute local water and soil. Landfill gas is produced
from the decomposition of materials and is composed
of methane and carbon dioxide, which are both
greenhouse gases.
3. Increases could be due to population growth; increases
in the purchase of products per person; the increase
in production and purchase of disposable products;
people replacing products such as cellphones,
computers, and televisions with the latest models and
throwing away the old ones.
4. Answers should clearly state an opinion about the
location of a landfill that is supported by at least two
statements based on science.
Sample answers: No, I would not support a landfill in
my community. Landfills are unsightly, and leachate
and gas may escape into our water, soil, and air. Also, I
think we should put money into recycling more things
instead of building more landfills. or Yes, I support a
landfill in my community. Communities should deal
with the waste they produce. Our community has areas
of bedrock that can prevent leachate from getting into
our water, and we can use the landfill gas to supply
electricity for the community.
(Student textbook page 219)
5. The three types of thermal treatment of waste differ
according to the temperatures used and the amount of
oxygen present.
6. Some kinds of thermal treatment are called energy
recovery or waste-to-energy technology because
energy is produced when the waste is burned. The
resulting steam is used to heat buildings.
7. Answers should clearly state an opinion about the
export of solid waste to foreign countries that is
supported by at least one statement.
Sample answers: No, I do not support the export of
solid waste because we lose control over how that waste
is treated and cannot ensure it does not contribute
to the world’s pollution. or No, I do not support
the export of solid waste because its transportation
generates too much greenhouse gas. or No, I do not
support the export of solid waste because the countries
receiving it tend to be poor and the people who work
at the sites have very little protection. or Yes, I support
the export of solid waste because there are no suitable
sites in my community and the facility in the receiving
community is designed to use the waste to generate
clean energy.
(Student textbook page 221)
8. Resource recovery refers to removing materials from the
waste stream that could be used to make new products.
9. Answers should include two of each of the following.
•Benefits: Compost is rich in nutrients, helps soil
retain water, and limits sediment run-off; it decreases
the amount of organic waste that goes into landfills,
which reduces costs of waste management and
the amount of greenhouse gases emitted into
atmosphere; it makes people more aware of all the
organic waste they generate.
•Concerns: Many compost sites have odours and attract
vermin; compost produces leachate, which can leak
into the surrounding area; people working at large-scale
facilities may be exposed to harmful concentrations
of micro-organisms; composting regularly takes
commitment many people do not want to make.
10. Answers should clearly state an opinion on the options
that is supported by at least one statement related to
the environment or science.
Sample answers: Yes, I think the green bin program
is a good idea because it reduces the waste going to
landfills. or No, I think the green bin program is a
poor use of tax dollars because the organic waste will
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decompose relatively quickly anyway, while plastic will
not. We would be better off reducing the amount of
plastic going into landfills.
(Student textbook page 229)
11. Wastewater is any waste in liquid form.
12. Sewage can be treated by either septic systems (used in
rural areas) or municipal sewage treatment plants.
13. It is important for municipalities to maintain and
monitor sewage treatment plants because the water is
eventually returned to the soil or local water systems
and that water must be free of waste and toxins.
Answers to Caption Questions
Figure 7.3 (Student textbook page 215): Answers could
include the following points:
•Many communities still do not collect organic
material for composting and people do not want to
carry out their own composting.
•Many people still throw out paper and organic waste
that can be diverted from landfills because it is easier
for them and it has become a habit.
•Food waste continues to be an issue in the
community.
Figure 7.9 (Student textbook page 223): Answers should
clearly state an opinion about responsibility for waste that
is generated, supported by at least one statement.
Points could include:
•Waste should be the responsibility of the owner of the
item because consumers need to be more aware of the
life cycle of the products they buy. This might mean
that consumers will demand products that produce
less waste; it might also mean an increase in illegal
dumping.
•Waste should be the responsibility of the retailer
because they are the ones delivering the items to the
community. This might mean that retailers will need
to increase their overhead costs in order to deal with
the waste materials returned to them.
•Waste should be the responsibility of the
manufacturer because they created the product and
should be responsible for it over the item’s life cycle;
manufacturers may be able to reclaim some of the
materials to make more product. This might mean
that manufacturers will increase the cost of their
goods to pay for the waste management.
•Waste should be the responsibility of the community/
municipality because managing waste is a large-scale
and expensive activity that can only be done at the
municipal level. This might mean an increase in
landfills around the community, an increase in taxes
or fees to pay for waste management, or both.
Figure 7.11 (Student textbook page 227): Antimicrobial
cleaners and chlorine bleach should never be poured down
the drain in a home with a septic system because the septic
system depends on micro-organisms to digest the organic
components of the wastewater. Cleaners and bleach would
kill these micro-organisms.
Figure 7.12 (Student textbook page 229): A municipal
sewage treatment system is more suitable for highly
populated areas than a septic system because a sewage
treatment system can handle larger volumes of wastewater
and sewage than a septic system can.
Answers to Section 7.1 Review Questions
(Student textbook page 225)
1.Answers should indicate an understanding that a waste
stream is the movement of solid waste from the source
to its final destination.
Sample answer: Waste stream refers to the path garbage
follows when it is thrown away. Like a river, the
waste moves (flows) from an original source through
different places until it reaches its final location (a
landfill or incinerator).
2.Answers should clearly state an opinion about manure
that is supported by at least two statements related
to environmental science. Answers should disagree,
noting that manure comes from the digestive tracts
of animals and contains pathogens that could harm
human health if it gets into local water sources; manure
also contains nutrients that can enter run-off that ends
up in local water sources (causing algal blooms).
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3.a)Diagrams should include the following labels: water
table, liner, leachate collection system, ground water
monitoring well, refuse, methane monitoring, gas
recovery system, cap, leachate treatment system.
Diagrams should roughly follow Figure 7.4 on page
216 of the student textbook.
How a Modern Landfill Works
gas recovery
system
methane
monitoring
cap
leachate
treatment
system
refuse
ground water
monitoring well
liner
leachate
collection
system
water table
b) Leachate is the liquid from landfills. It is composed
of chemicals from the breakdown of garbage, which
are dissolved in water that seeps down into the
landfill, potentially moving the leachate into the
water table below. Leachate is contained by rubber
or impermeable clay liners placed at the bottom
of the landfill to prevent it from entering the local
ecosystem. The leachate can be collected and treated
before it enters the water system. Leachate is also
contained by ensuring that landfill sites are far from
local waterways.
c)Landfill gas (methane and carbon dioxide) can be
captured and burned to generate electricity.
4.Sources and Composition of Solid Waste
Type of
Solid Waste
Sources
Composed Mostly
of
Agricultural
farms, ranches,
feedlots,
slaughterhouses
animal waste and organic
matter left over after
harvesting and processing
crops and animals
Industrial
manufacturing,
construction,
mining, other
industries
chemicals, mine tailings,
construction materials
Municipal
homes, office
buildings,
institutions
food and other organic
waste, paper, metal, glass,
plastic
5.Three waste treatment alternatives to landfill sites that
use thermal treatment are
•incineration: complete combustion at high
temperatures (over 850°C)
•pyrolysis: thermally processed in the absence of
oxygen at lower temperatures than incineration
(350°C to 850°C)
•gasification: thermally treated with limited oxygen
and lower temperatures than incineration (over
650°C)
Advantage: reduces volume of the waste by 10 to 20%;
some facilities are used to produce energy
Disadvantage: residue (ash or solids) must still be
disposed of; if air pollutants (CO2 or syngas) are
generated, they must be treated
6.Answers should clearly state an opinion about the
transport of solid waste that is supported by at least
two statements related to the environment or science.
Sample answers: I am against the transport of solid
waste because environmental controls are weak
in places that are likely to take it. or I am against
transporting solid waste to other places because its
transport generates greenhouse gas. or I am against
transporting solid waste to other places because we
need to be reminded that our efforts should go toward
reducing the amount of waste made to begin with. or I
am in favour of transporting solid waste because there
are no suitable sites in my community and the facility
in the receiving community is designed to use the
waste to generate clean energy.
7.a)The three Rs are all are concerned with minimizing
the amount of waste that goes to landfills or
incinerators. The three Rs are different in their
approach to dealing with the solid waste: they deal
with different aspects of a product life cycle.
b)Source reduction of solid waste focusses on reduce
and re-use, which are about reducing consumption
of materials and hence reducing the amount of waste
generated. Source reduction addresses. how products
are designed, manufactured, purchased, used, and reused
8.Answers should include any examples of solid waste that
students typically use on a daily or weekly basis. Answers
should also show an understanding of how this waste can
be reduced, for example, through minor repairs, reducing
food waste, or purchasing fewer products that are meant
to replace items that are still usable.
9.Answers should clearly state an opinion about
programs that collect household organic waste
and composting it that is supported by at least two
statements. Answers should include information in a
style that is appropriate for the general public and that
will get or retain their attention.
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10. a) Answers could include many lunch items, such as
cookies that are individually wrapped, drink boxes,
bottles of water, yogurt, cheese and crackers, cheese
strings, dessert items, granola bars or energy bars,
sandwiches, salads, soups, coffee, and tea.
b) Advantages can include any two of: the food stays
fresher longer, since it is still wrapped even though
the larger package is open; single servings reduce
the amount of food waste; single servings are more
suitable for eating “on the go” or packing portable
meals.
c)Disadvantages include: single servings produce
more solid waste from the packaging; packaging is
often less biodegradable than organic waste; single
servings may still lead to food waste as uneaten food
and half-filled bottles of water or cups of coffee litter
the landscape.
11. a) The term disposable society suggests that as a society
we throw many things out when they are still useful
or simply replace items (and throw out the damaged
ones) rather than repairing them.
b) Answers should clearly state an opinion about their
own consumption habits as well as those of others
that is supported by at least one statement.
Sample answers: Yes, I think it is true for me and
many people in my community and country. Many
people want the newest models of items to replace
versions they have, such as televisions, computers,
and cellphones. The old ones are thrown away. or I
do my best to avoid wasting food, and I re-use and
recycle my clothes and tools, but I know lots of other
people who do not. The piles of waste across Canada
indicate that many people in the country prefer
disposable things.
Answers to Section 7.2 Review Questions
(Student textbook page 231)
1.Storm water consists of rain and melting snow that
drains from lawns, driveways, roads, and urban
surfaces, as well as liquid waste that is poured down
storm sewers.
2.a)A septic system is a localized system that uses
mirco-organisms to treat sewage from a single
house.
b)The flowchart should show the following: wastewater
is first drained into a septic tank; grease and oils rise to
the top and solids settle to the bottom; bottom solids
are decomposed by micro-organisms; liquid waste
leaves the tank and is channelled through a drain
field, which is a series of pipes with holes in them that
are embedded in gravel and just below the surface
of the soil; excess water evaporates; periodically the
remaining solids in the tank are removed.
c)Septic systems must be located away from areas
where they will be disturbed and placed where a
drain field can be built.
d) Laundry bleach and similar products must not be
added to septic systems because they will kill the
micro-organisms that help decompose the organic
waste.
e)Other types of agricultural wastewater include
run-off from farmland and feedlots that contains
nutrients, organic matter, and bacteria, as well as
run-off from irrigation and rainfall that contains soil
and sediment.
3.a)Residential sources make the largest contribution to
wastewater (65%).
b) For communities that rely on septic systems, there
would be less residential wastewater going into
municipal sewers because wastewater from toilets
and drains would be going into septic systems rather
than municipal facilities.
c)Answers should base the argument on the fact that
most wastewater in sewer systems comes from
residential sources; therefore, whatever is added
by each household sewer system does contribute
significantly. Another way to look at individual
impact is to suggest that because of the power
of magnification, if each household cut their
wastewater by a small percentage, the savings for the
system would be very large.
d) Pie graphs should have a title such as Sources of
Wastewater in Municipal Sewers. The circle should
be divided into four sections. The relative sizes of the
sections should reflect the percentage contribution
of the source, each being a percentage of the 360° of
the circle. Labels should be Residential; Industrial,
commercial, and institutional; Storm water; and
Ground water infiltration.
4.Liquid wastes are not disposed of in landfills because
they increase the amount of leachate produced and can
make the landfill structurally unstable.
5.Answers should include a well-developed descriptive
paragraph covering primary treatment to physically
separate large solids from sewage; secondary treatment
to facilitate the biological breakdown of dissolved
organic compounds; and tertiary treatment to remove
nitrates, phosphates, and other inorganic substances.
Pages 228-29 and Figure 7.12 in the student textbook
can be referred to for supporting details.
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6.Storm drains often divert water that enters them
directly into nearby waterways, without treatment of
the storm water. Therefore, soapy wastewater from car
washing would be polluting the local waterway.
volume of waste before it is covered, which reduces the
space needed to store waste; landfills are designed to
reduce offensive odours that would develop if garbage
was just dumped in a pile.
7.Logos should convey that storm drains, sewer systems,
and waterways are interconnected. Logos could be
assessed in terms of images, legibility, and content.
12. Landfills are built into or on top of the ground and
include a large, impermeable liner that is buried deep
underground. The waste is then added and buried over
time between layers of soil that are bulldozed on top
of it. Alternating layers of soil and waste are eventually
compressed. The landfill will have a cap, as well as
mechanisms to monitor methane, safety of ground
water, and collection and treatment of leachate.
8.Disadvantages of separate storm drains and sewers
include that storm drains move water directly
into waterways, which can introduce pollutants;
increased flow of water into local waterways can cause
erosion of stream banks and increased sediment
pollution; warmer storm water can cause an increase
in temperature in the waterway and a decrease in
dissolved oxygen in the water, which can kill fish and
other aquatic life.
Comparison of Processes and End Products
Answers to Chapter 7 Review Questions
Type
(Student textbook pages 239–41)
1.a
3.d
5.c
7.b
2.b
8.c
4.a
6.e
13. a) Thermal treatment refers to processing solid waste at
high temperatures.
b) The three types of thermal treatment are
incineration, pyrolysis, and gasification.
9.A waste stream is the movement of solid waste from
one or several sources through a variety of other
places before reaching its final destination—usually
a landfill or incinerator. Solid waste enters the waste
stream from three main sources: agriculture, industry,
and municipalities. Examples of agricultural waste
include animal waste (manure) and organic materials
left over from crop harvesting. Examples of industrial
waste include waste from manufacturing, mining,
construction, and other industrial activities. Examples
of municipal solid waste include recycling materials,
compost/organic waste such as food waste, electronic
waste, plastics, and many other waste items that are
generated in homes, businesses, and institutions.
10. The number of landfills is declining because many
landfills have reached their capacity and have been
closed; in other cases, poorly run landfills have been
closed because they were not meeting regulations;
in addition, new landfills are not being developed
because many people do not want them built in their
communities.
11. Answers may include any four of the following:
landfills are an immediate solution for solid waste
management (they prevent waste from entering
ecosystems directly); when built properly, landfills
isolate waste from ground water, air, and soil; some
landfills use gases produced by waste to generate
electricity; landfills use compactors to reduce the
Process
End Products
carbon dioxide and water
Incineration complete combustion
vapour, bottom ash, and
(in the presence of
oxygen) at temperatures other air pollutants
over 850°C
Pyrolysis
thermal processing in
the absence of oxygen
at lower temperatures
(350–850°C)
syngas and a solid residue
Gasification
uses an intermediate
amount of oxygen,
but not enough for
complete combustion
syngas and solid residue
c)Two advantages of thermal treatment are that it
reduces the volume of waste that would normally
end up in a landfill, and it can be used to produce
energy.
14. The export of solid waste is controversial because
it is expensive to transport. Also, transporting
waste involves burning fossil fuels, which generates
greenhouse gases. Political and social controversies
also exist. Many people believe that shipping waste to
distant locations is not the right thing to do because
then someone else has to deal with the consequences of
waste and potential toxic residue.
15. Source reduction involves preventing or limiting
the production of waste in the first place. It involves
designing, manufacturing, purchasing, using, and
re-using products in ways that reduce the amount or
toxicity of waste created.
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16. Storm water includes rain and melting snow that
drains from driveways, roofs, lawns, and roads. It
also includes liquid waste that is poured down storm
sewers. Storm water often contains sediments and
organic matter, as well as harmful chemicals. Sewage
includes any materials that are rinsed down a drain or
flushed down a toilet. Most sewage is organic matter,
which includes flushed urine and feces, food scraps,
and water from washing clothes and dishes. Hundreds
of other chemicals are also found in municipal sewage.
These include plasticizers, pesticides, medicines, and
flame retardants.
17. Storm water is usually routed to a sewage treatment
facility rather than being discharged directly into
waterways. Storm sewers should be separate from
sanitary sewers when large volumes of water need to be
treated, such as after a storm. Otherwise, excess water
can cause raw sewage to back up into people’s homes
and harmful run-off to enter waterways.
18. a) Sources of liquid wastes are agricultural activities,
which generate liquid waste as run-off from farms;
industrial activities, such as mining and petroleum
production; and municipal activities, such as
flushing toilets and taking showers. All materials
disposed down a building’s drain, including paints,
cleaners, cooking oils, and motor oils, are considered
to be liquid wastes.
b)Liquid wastes from these sources are considered
harmful to human health and the environment
because agricultural run-off includes chemicals from
fertilizers and pesticides; industrial liquid wastes
include heavy metals, nutrients, and sediments; and
municipal liquid wastes could include pathogens, or
toxic chemicals that have been improperly disposed of.
19. a) Septic systems are used in rural areas where
population densities are low. Rural areas have the
space to accommodate septic systems (including the
required drainage area), which are suitable to service
one dwelling. Also, it would be expensive (on a per
capita basis) to install a municipal sewage system in
a scarcely populated area, where houses are far apart.
b) Septic systems are not a good option for urban
settings because they require more space for
drainage that is available around urban dwellings.
Additionally, there are more people in urban areas,
and septic systems would fill up faster than the
bacteria could decompose the solid organic waste.
c)Septic systems and municipal sewage systems are
similar in that they both involve the treatment
of wastewater by separating the liquid waste by
settlement and then by decomposition by bacteria.
They are different in the processes used to treat the
waste. Septic systems treat the waste at the source
of production through a relatively simple process.
They are designed for relatively small volumes of
liquid waste. Municipal systems treat large amounts
of liquid waste at a location further away from the
many sources.
20. Examples may include activities related to the
purchase of disposable consumer products that are not
essential. Ways to decrease this waste include limiting
materials purchased or the type of consumer products
purchased, as well as donating used items instead of
throwing them in the garbage.
21. a) Workers would monitor the landfill site for leachate,
which contains chemicals, and high levels of
micro-organisms. Also, landfill gas that is still being
generated needs to be monitored.
b) Sample answer: Safe former landfill sites could be
used for recreational activities and/or parks.
22. Untreated wastewater may contain feces, which
carry pathogens that could cause diseases and harm
ecosystems where the sewage is discharged; untreated
wastewater also contains nutrients that could
contribute to algal blooms. Discharge of untreated
wastewater likely happens because of financial costs. If
proper pipes to carry the waste to a treatment facility
are not in place, or there is no treatment facilities.
These are both expensive to install.
23. a) Single family dwellings use the most water. Reasons
include the area is composed mostly of single family
houses; there many different sources of water use
in single family homes; there are more likely to be
children in single family homes, which generates
more water use; and there is greater potential for
water wastage in single family homes.
b) The three highest uses of water are outdoor (21%),
toilets (15%), and faucets and laundry (each 14%).
c)Use of water is very closely related to production
of wastewater—likely all the outdoor water used
becomes wastewater, and so is water from toilets,
laundry, and most water from faucets.
d) Water used outdoors will end up in wastewater
treatment plants as run-off from gardens, lawns, and
driveways.
e)Sample answer: Families can reduce their production
of sewage and wastewater by using rain barrels
to collect water to use for watering gardens and
washing cars; converting gardens to native plants
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that require less water; washing cars less often;
washing fewer loads of laundry; running the
dishwasher only when full; and making sure all
faucets seal properly so none leak.
24. a) In 2011, the population of Ontario was 13.5 million
and of Canada was 34.5 million
b) Ontario: (13 500 000)(2 kg) = 3 × 107 kg; Canada:
(34 500 000)(2 kg) = 7 × 107 kg
c)Ontario: (0.004 m3)(27 000 000 kg) = 1 × 105 m3,
therefore 1 × 105 m high
Canada: (0.004 m3)(69 000 000 kg) = 3 × 105 m3,
therefore 3 × 105 m high
25. Answers should include a well-thought-out proposal
with a clear recommendation that considers the
practical requirements of implementing it. Headings
could include Program Description, Costs, Materials
Needed, Approvals Required, Potential Challenges, and
Communication Plan.
26. Assuming the toilet is in a home that is part of a
municipal sewage system, the water travels into
the sewer system through pipes from the house,
and then networks of pipes take it to the treatment
facility where it goes through primary, secondary, and
tertiary treatment. Then the water is released into the
environment. Answer may include details of primary,
secondary, and tertiary treatment found on pages 228
and 229 of the student textbook.
27. Answers should reflect students’ considerations of
consumer products they use and creative thinking in
redesigning the packaging. Answer should reflect the
functions of the current packaging, which could be
preserving freshness, protection of fragile materials,
ease of packing for transport, public safety, branding
and advertising, and/or anti-theft features. The revised
packaging must fulfill the same functions while
reducing packaging waste.
28. Answers should include the following key points:
•Biosolids are created from the municipal treatment of
sewage and are now used for fertilizer in many parts
of the world, including Canada. They are used to
promote plant growth and for adding nutrients back
into soil that has become depleted over time. They
are also purchased as compost. The fertilizer is used
by farmers, home gardeners, and some municipalities
for landscaping.
•The uses and applications of biosolids are regulated
in places such as Canada. Many countries, such as
China, have been using biosolids for thousands of
years.
•In Canada, regulation occurs at the provincial and
territorial level. These regulations control the quality
of biosolid produced and used, as well as how much
is applied in an area.
•Use is controversial because some treated biosolids
may still contain chemicals and heavy metals that
pose a risk to the environment.
•Also, as the global population continues to grow,
more and more biosolid waste is being generated, and
there is a need to find more uses for it.
29. a) “We” could include the scientific community, federal
and/or provincial and territorial governments, the
general public, and product manufacturers.
b) Answers should clearly state an opinion about a
waste management crisis that is supported by at least
one statement.
Sample answer: I think all groups mentioned in part
a) should feel there is a waste management crisis,
because each group plays a role in managing and
trying to find ways to reduce the amount of waste
our society generates.
30. Answers should clearly state an opinion about which of
the three Rs is most important that is supported by at
least one statement.
Sample answer: I think reducing is the most effective
way because it focusses on reducing the amount of
waste that is made in the first place. I believe it is the
most effective because the less waste that is initially
made, the less effort has to go into recycling or
developing methods to encourage re-use of things.
31. a) Answers should include the name and contact
information for each of the three sources used.
Advantages of using phytoremediation include that
it is less expensive than removing and later treating
water; less expensive than digging out and removing
soil in a contaminated area; involves simply
planting trees or other plant material; requires little
maintenance; it is more visually appealing than
digging out the site for chemical treatment; plant life
will support ecosystem and wildlife development
in the area; solar energy is used for the cleaning
process.
Disadvantages include it is only effective in areas
with low contamination levels; it is only effective in
areas where contamination is not below where the
roots of the plants grow; the presence of chemicals
in plants may affect the food chain in the ecosystem;
if plants used in phytoremediation are burned, the
chemicals that the process has cleaned up may be
released and contaminate the air.
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b) Answers should clearly state an opinion about
the use of wetlands for phytoremediation that
is supported by at least one statement related to
science or the environment.
Sample answer: I think the use of wetlands for
phytoremediation is a good idea because they are
a natural part of the environment, their use does
not add chemicals or other harmful things to the
environment, and they can support local ecosystems.
or I do not think we should be using wetlands
for phytoremediation because the chemicals will
damage the food chain in the ecosystem.
32. Answers should reflect students’ knowledge of the
many products that do not decompose and will be
in landfills for generations. Answers may indicate
archeologists will infer that many products are
consumed per person, and many of those products are
disposed of.
33. Answers should reflect students’ considerations of
many products and creative thinking in terms of ideas
for re-use of materials.
34. Answers should clearly state an opinion about the
saying “Use it up, wear it out, make it do, or do
without” that is supported by at least one statement.
Sample answer: Although it would not be really
difficult to do it, I would have to adjust what I actually
do because I tend to throw things away that are still in
good condition and could be used some more. or It is
important to me to have things that are new, fresh, or
up to date, so I would have trouble with this. I would
prefer to find ways to pass things on.
Pause and Reflect Students should provide at least one
example of how they would incorporate what they have
learned about one or more of the following:
•what items municipal solid waste is composed of
•how waste is disposed of or dealt with to divert it
from landfills
•how source reduction can be carried out
•wastewater and why it is important to consider what
is flushed down the toilet or drains
Chapter 8 Managing Hazardous Wastes
Answers to Pause and Reflect Questions
(Student textbook page 245)
1.A hazardous substance is something that can cause
harm to the environment or organisms and, therefore,
requires special handling. A hazardous waste is
material being discarded that contains a hazardous
substance (a substance that is flammable, corrosive,
reactive, and/or toxic).
2.Toxic substances are a group of hazardous substances.
Any substance that causes harm is a hazardous
substance, while toxic substances are hazardous
substances that are poisonous to organisms.
3.Medicines such as painkillers and anti-inflammatories
may contain small amounts of toxic substances that, in
large enough amounts accumulated in landfills, can be
poisonous to people and other organisms.
(Student textbook page 249)
4.Three sources of hazardous waste are agriculture,
industry and manufacturing, and municipalities (i.e.,
communities, homes).
5.Answers should cite any two sources of chlorinated
hydrocarbons: persistent pesticide called DDT,
polyvinylchloride products (such as pipes), solvents, or
synthetic rubber products.
6.Suggestions could include: donate electronic devices
to charities; develop recycling programs to re-use
electronic components in other equipment; adjust
expectations so that we are not always purchasing new
products when those we have still meets our needs.
(Student textbook page 254)
7.The highest priorities in the pollution-prevention
hierarchy are reduce and re-use.
8.Re-using hazardous substances can save industry the
costs of purchasing new materials and of disposing of
hazardous wastes. Re-use also lessens the impact on
the environment because less hazardous material is
introduced into communities, and thus less hazardous
waste, which can cause damage to the environment,
needs to be disposed of. This reduction also saves money
municipalities would have to spend on handling and
disposing of the hazardous wastes.
9.Possible reasons and counter-arguments include
•disposable batteries are less expensive than
rechargeable batteries; counter argument: in the long
run, rechargeable batteries cost less because they can
be re-used
•disposable batteries are available in more places
and, therefore, are easier to find; counter argument:
rechargeable batteries are much more common now,
and since you do not need to buy them as frequently
as disposable ones, less convenience is not a great
disadvantage
•disposable batteries can be used immediately,
while rechargeable ones must be charged first;
counter argument: planning can help reduce the
inconvenience of waiting to recharge the batteries
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(Student textbook page 256)
10. EPR stands for extended producer responsibility, which
is the idea that the producer of a product is responsible
for a product’s life cycle, including its disposal. EPR
helps in the management and collection of hazardous
wastes because it encourages industry to design
products to minimize such waste and creates resources
that help municipalities deal with hazardous waste
management, which can be expensive.
11. Answers should include one of the following methods:
Table 8.2 Types of Hazardous Waste Treatment
Type of Treatment
Description
Chemical
Treatment involves chemically converting hazardous wastes into less hazardous
substances. Chemical treatment can also reduce the volume of the waste prior to disposal.
Physical
Physical force and/or mechanical devices are used to isolate hazardous wastes for disposal.
For example, filters can remove hazardous substances from liquid wastes. Physical
treatment can also decrease the volume of hazardous waste.
Biological
The use of organisms, including micro-organisms, to reduce or remove contaminants from
a site is called bioremediation. Bioremediation degrades organic wastes so that they are
less harmful, and it is used to treat many types of wastes. In some situations, it may be used
to treat hazardous wastes. For example, bioremediation may be used to treat agricultural
soils and soils around mining sites that have been contaminated with hazardous wastes.
Thermal
Treatment exposes hazardous waste to extreme heat, which makes the substance less
hazardous or no longer hazardous. The volume of waste is also greatly reduced.
Immobilization
Treatment fuses wastes at high temperature in glass, ceramics, or cement. These
impermeable materials trap the wastes so they can be placed into long-term storage
without threatening the environment.
Stripping
A process that separates volatile chemicals from water and collects them for further
treatment or disposal.
Precipitation
Also called flocculation, this approach is used mostly for treating sewage. It binds the
hazardous components of sewage to chemicals that clump and settle out, making them
easy to filter, collect, and dispose.
Carbon absorption
Activated carbon particles bind to hazardous chemicals in waste gases or liquids. Wastes
may be removed for disposal. The carbon can be cleaned and re-used.
Phytoremediation
This is a type of bioremediation that uses plants. It often makes use of natural or
constructed wetlands to treat sewage before it is released into the environment.
12. Answers should clearly state an opinion about
thermal treatment that is supported by at least one
statement. The benefits of thermal treatment that
can be cited include hazardous substances can be
made less hazardous; hazardous substances could be
made harmless; and the volume of hazardous waste is
reduced.
Answers to Caption Questions
Figure 8.1 (Student textbook page 244): Control of
hazardous wastes is challenging because so many different
activities involve the production and transport of
hazardous substances. In addition, there are few controls
on the creation of new products that may result in the
production of hazardous wastes.
Figure 8.2 (Student textbook page 245): The insecticide
pictured is hazardous because it is designed to poison
organisms.
Figure 8.4 (Student textbook page 247): Answers should
include harmful to organs and tissues; increased risk of
cancer; skin and respiratory tract irritation and illnesses;
harmful effects on organisms in ecosystems throughout the
environment.
Figure 8.6 (Student textbook page 249): Hazardous waste
should be classified by trained individuals because the
waste must be disposed of according to its properties. Only
individuals trained to identify those properties can direct
the waste to the process designed to safely handle and
dispose of it.
Answers to Section 8.1 Review Questions
(Student textbook page 252)
1.a)Industry examples include heavy metals, chlorinated
hydrocarbons, ammonia, organic residues, acids, and
dyes. All of these wastes can damage the health of
organisms and harm the environment.
b) Agriculture examples include pesticides (chlorinated
hydrocarbons), such as DDT, which can cause
harm to the nervous systems and reproductive
systems of organisms; and harmful organic material,
such as manure, which can contain bacteria that
contaminates water systems.
c)Municipal examples include various household
hazardous wastes, such as cleaners, used oil and
gasoline, paints, glues, polishes, and medications.
They can all damage the environment and the health
of many organisms.
2.E-waste is electronic waste, such as cellphones,
calculators, TVs, and computers. Some e-waste is
considered hazardous because the electronics include
heavy metals such as lead, particularly in the cathode
ray tube (CRT).
3.a)dangerously reactive: material can react easily with
other materials, air, or water, and may explode if not
handled properly
b) corrosive: material can corrode other materials,
including human skin
4.Answers should look like this:
5.a)Suggestions could include promoting curbside
pickups or organizing more drop-off facilities;
advertising the pickup and drop-off facilities;
sending out information pamphlets to educate
people about identifying household hazardous
wastes and the harm they can do.
b) Samples should show an understanding of the
harmful effects of hazardous substances and why
they should not be disposed of in regular garbage.
Encourage students to be creative in their designs
and how the information is conveyed.
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6.Answers can include any incident discussed in the
student textbook or that students have read about
or seen on television. The textbook examples (pages
250–51) include heavy-metal contamination, soil
contamination, chemical waste dumping, acidic waste
spill, Arctic hazardous waste, and hazardous mine
leakage; students may know of local examples of these
type of events. Other possible examples could relate to
E. coli contamination (Walkerton Ontario, 2000), oil
spills, tire storage facility fires, or train derailments.
7.
Product
Possible Hazardous Waste from Its
Production
Paint
heavy metals, pigments, solvents, organic residues
Leather
heavy metals, organic solvents
Fabric
heavy metals, dyes, organic chlorine compounds,
solvents
Plastics
organic chlorine products
8.a)Biohazardous waste is waste that includes blood
products, body organs, and used bandages, needles,
and syringes.
b) The regulations are strict because these products can
carry diseases that could be spread to people.
c)People who work as maintenance staff in medical
facilities need to be trained in how to handle
the material being disposed of, and the material
needs to be clearly marked that it is biohazardous.
In addition, those responsible for handling and
disposing of the materials must have proper
equipment and facilities to do so.
9.Toxic waste is a type of hazardous waste; hazardous
waste is considered harmful in general, while toxic
waste is harmful in a particular way—it is poisonous.
10. The effect of a hazardous substance depends on its
toxicity, the duration of exposure to it, the amount of
exposure, and the route of exposure.
Answers to Section 8.2 Review Questions
(Student textbook page 258)
1.Answers should summarize the pollution-prevention
hierarchy shown in Figure 8.9 (textbook page 253). The
four key strategies (in decreasing order of importance)
are
•reduce the amount of waste at its source
•recycle wastes whenever possible
•treat wastes to reduce the hazard and/or volume
•dispose of wastes on land or incinerate them (as a last
resort)
2.Answers should show an understanding of what
common household and personal care products are
considered hazardous wastes.
Sample answer: I will only use rechargeable batteries
instead of using disposable batteries. This will result in
less hazardous waste because I will be able to recharge
and re-use the same batteries instead of having to send
them to landfill.
3.Answers should reflect research into alternative
cleaning products that are made of common
ingredients found in many kitchens, such as, using
paste of vinegar and baking soda to remove rust stains,
vinegar and water to wash windows, or lemon juice to
bleach white fabrics.
4.Answers should show an understanding of what
common household and personal care products are
considered hazardous wastes.
Sample answer: I can choose to purchase products
from companies that support recycling or that design
products to limit production of hazardous waste.
5.The three Rs can be applied in a similar way to
how they apply to regular waste, with some careful
consideration for safety.
Sample answer:
•reduce—products can be designed and manufactured
in a manner that reduces the production of
hazardous waste
•re-use—industries can re-use hazardous substances
that are wastes in one process by cleaning them and
using them for another process
•recycle—hazardous substances such as old paint can
be recycled and made into new paint
6.Extended producer responsibility (EPR) is the idea
that the producer of a product is responsible for
that product during its life cycle, including product
disposal. This policy encourages industry to design
products to minimize hazardous waste throughout
their life cycle, which should reduce the amount of
hazardous waste that must be managed.
7.A hazardous waste landfill is lined with an
impermeable liner and several layers of clay, gravel
between the clay, and pipes to collect escaped leachate.
Leachate and landfill gas must be collected because
they contain hazardous substances that are very
dangerous and must be prevented from entering local
soil and water sources.
8.a)Phytoremediation uses plants to treat hazardous
waste. Often this involves using wetlands to treat
sewage before it is released.
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b) Bioremediation is the use of organisms to
reduce or remove harmful wastes; when plants
are the organisms used, it is referred to as
phytoremediation.
9.a)Physical methods, precipitation (flocculation),
and stripping are all ways to reduce the volume of
hazardous waste.
b) Biological treatment, phytoremediation, carbon
absorption, and immobilization all convert
hazardous waste to non-hazardous waste.
c)Chemical, physical, and thermal methods all convert
hazardous waste to non-hazardous and reduce the
volume of the waste.
10. Answers should clearly state an opinion on the
hazardous waste storage facility that is supported by at
least one statement.
Sample answer: Yes, I would support locating a
retrievable storage facility in my community because
the money could be used for many needed services.
I think that such facilities need to go somewhere,
and I trust that the people in my area would properly
monitor the facility to ensure it is safe.
Answers to Chapter 8 Review Questions
(Student textbook pages 265–67)
1.b
3.b
5.a
7.c
2.c
8.a
4.e
6.d
9.Hazardous waste is any discarded solid, liquid, or gas
that is, or contains, substances known to be flammable
(ignitable), corrosive, reactive, or toxic and that can
cause harm to organisms and the environment. The
three main sources of hazardous wastes are agriculture,
industry and manufacturing, and municipalities
(households).
10. The four main categories of hazardous waste are
•ignitable and flammable (can ignite easily when
exposed to heat and can produce harmful particulate
matter and smoke)
•corrosive (includes acids and bases that can corrode
metal and skin)
•reactive (can explode if improperly handled, may
react dangerously with water and air, and often
destabilize with heat and/or shock to produce
harmful gases)
•toxic (can cause serious illness or death to people and
other organisms)
11. a) DDT belongs to the class of organic compounds
known as chlorinated hydrocarbons.
b) DDT is considered to be persistent because it does
not degrade easily; therefore it remains in the
environment for decades and contaminates soil for
a long time. In addition, it is taken up by organisms
and passed up the food chain.
c)Use of DDT is allowed in certain parts of the world
because it is effective in combating mosquitoes,
which can cause diseases such as malaria. Therefore,
DDT prevents the spread of the disease and saves
many lives. DDT is banned in most countries
because malaria is not a threat to their populations.
12. Answers should include two of the following:
medicines, paints, petroleum products, metals, leather,
many electronics, and textiles. Heavy metal wastes are
problematic because absorption of heavy metals into
tissues harms the health of living organisms; heavy
metals do not degrade and therefore remain in the
environment for a long time; and heavy metals are
waste products of so many manufacturing/industrial
processes.
13. Any two of production, transportation, use, or
disposal.
Sample answers: The production of consumer goods
often involves hazardous waste production through
the manufacturing processes. Products may also
contribute to generating hazardous waste when they
are transported and used. Upon disposal, many
consumer products release harmful substances into
the environment. Some examples include batteries,
cleaners, polishes, electronics, and paints.
14. Answers should name older electronic wastes such
as televisions, appliances, cellphones, and computers.
PCBs are a type of chlorinated hydrocarbon found
in many older e-waste devices. PCBs are hazardous
because they accumulate in animal and human tissues
and can harm the immune, nervous, respiratory,
reproductive, and urinary systems. They can also cause
cancer.
15. Suggestions for why hazardous wastes continue to be
disposed of in landfills could include
•lack of knowledge about the hazards associated with
these wastes
•lack of awareness of programs such as drop-off sites
and curb pickup arrangements that help manage the
waste
•people do not want to make the extra effort to
dispose of these waste properly
Examples of what can be done to reduce disposal in
landfills include
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•education about how dangerous hazardous wastes
can be
•greater awareness of programs available to help
manage the hazardous waste in the community
16. Factors that determine the nature and severity of health
effects include
•level of toxicity (how harmful the substance is)
•duration of exposure (how long a person is exposed
to it)
•the amount of exposure (how much of it a person is
exposed to)
•the route of exposure (whether it is inhaled, ingested,
or absorbed)
17. The purpose of P2 is to emphasize the importance of
reducing the amount of hazardous waste produced by
society. The strategies are
•Reduce the amount of waste at its source.
•Recycle wastes whenever possible.
•Treat wastes to reduce their hazard or their volume.
•Dispose of wastes on land or incinerate them as a last
resort.
18. Source reduction of hazardous municipal wastes can
include the following:
•redesigning processes or products so that fewer
hazardous wastes are produced when a consumer
product is disposed of
•reducing consumerism, so people only buy the
amount of product that they expect to use
•sharing excess substances in order to reduce the
amount of hazardous household substances being
disposed of
•making changes in the household cleaning substances
and other products that are used to reduce hazardous
waste
19. Hazardous substances used in one industrial process
can be cleaned and re-used in that same process or
in a different process. Examples include waste oils
produced by one industry can be cleaned and used
to fuel power plants, and chemicals used in one
manufacturing process can be cleaned and re-used for
another process.
20. Possible reasons for a decline in the cellphone recycling
rate include
•People are keeping their old cellphones instead of
turning them in for recycling.
•More people are throwing them in the regular
garbage.
•More people are selling or donating their old
cellphones.
Examples of how to improve cellphone recycling rates
include
•Provide convenient and common drop-off sites.
•Use financial incentives, such as payment of a deposit
when the cellphone is purchased that is reimbursed
when the cellphone is returned to the store for
recycling.
•Require manufacturers to take back old cellphones.
21. Advantages of EPR programs include
•Producers will design more sustainable, less toxic,
more easily recycled products.
•Products will be designed to last longer because
manufacturers are financially responsible for the
disposal at end of life.
•The amount of hazardous waste in landfills will be
reduced.
•Health and environmental problems related to
hazardous wastes in landfills will be reduced.
Disadvantages include
•Some complex electronics are difficult to recycle
safely and processes will not be regulated.
•The cost of electronic devices will increase because
manufacturers will include a disposal fee in the cost
of the item.
•Some companies may try to resell used electronics that
were collected instead of recycling them.
•Some companies may improperly dispose of items in
landfills to reduce costs.
22. Answers should clearly state an opinion about
responsibility that is supported by at least one
statement.
Sample answer: I think the manufacturers of the
product are responsible for changing the labelling. I
could post information concerning this issue in the
schools and ask local stores to post your information;
write to consumer advocate groups that support
changes that assist consumers; and/or write to
government ministries responsible for the environment
and/or consumer product safety
23. A study of the life cycle of a consumer product is
useful for establishing sustainable waste management
strategies because it provides information about
where wastes are generated and how processes can be
changed to reduce waste that is produced. Examples
could include the study of the life cycle of electronics
in order to understand where e-waste is generated or
what hazardous materials go into the production of the
product.
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24. When selecting a non-retrievable storage site for
hazardous wastes, it is important to consider the
locations geology (type of bedrock), soil types
(preferably clay), distance to water sources (preferably
far away), and general stability (e.g., not near
earthquake-prone areas).
25. Answers should clearly state an opinion about
nuclear waste disposal that is supported by at least
one statement that shows an understanding of the
advantages and disadvantages of nuclear energy and
the waste that is generated.
Sample answer: I would support a new reactor being
installed, as long as the community was properly
informed about potential concerns about how the
radioactive waste was going to be dealt with and the
proper procedures to deal with accidental release of
radioactive or other hazardous waste.
26. Answers should clearly state an opinion about the
statement that is supported by at least one statement.
Sample answer: I think Rachel Carson is deliberately
exaggerating to draw attention to the topic of the
environment. I think the statement means that
although we may be able to get used to some
conditions, it does not mean we should not try to fix
them or that we can ignore them.
27. Answers should clearly state an opinion about
responsibility in the face of natural disasters that is
supported by at least one statement.
Sample answers: I think that in the case of natural
causes of environmental damage, governments should
be responsible for the restoration of the environment. It
is not fair to have industries cover the costs, since they
were not responsible. They could provide technological
support, if needed. or I think that industries should
be responsible for disaster planning that includes
environmental damage due to natural disasters such
as earthquakes or tornadoes if there is reason to
believe that this could happen in the area in which the
company is operating.
28. Students can use a graphic organizer such as a PMI
chart describing a particular strategy or a flowchart
showing events flowing from a letter-writing campaign.
Examples of ideas include selective purchasing
of products that support reduction of hazardous
waste production; developing or becoming part of
a grassroots initiative to educate the public about
different ways some products can be made to reduce
hazardous waste and to inform the public about why
this is important; or starting an e-campaign to connect
concerned consumers with the manufacturer.
29. Lists should show a variety of activities during the day,
from personal care to household chores to recreational
activities. Answers about reducing the impact on the
environment should reflect an understanding of what
household and personal products are considered
hazardous waste, and what actions can be taken to
reduce the use of hazardous waste–generating products
or what alternatives can be used. For example, use one
of the many household cleaning product alternatives,
use recycled paints, and purchase second-hand
products instead of new ones.
30. A diagram such as a simple flowchart may be
the most effective way to explain the process of
phytoremediation to younger students. Answers should
include a basic description of phytoremediation as
the use of plants to remove hazardous waste from the
environment and a brief description of the process.
(Plants absorb the heavy metals through their roots,
removing them from the soil. The heavy metals move
up through the plants’ tissues. The plant is eventually
removed from the area, taking the heavy metals with it,
and destroyed.)
31. Hazards: car battery contains battery acid; oil base
paint contains solvent, volatile organic compounds;
furniture polish container may be an explosion hazard
if it is an aerosol can. Community hazardous waste
disposal instructions should include documentation
of the source(s) of the information. The public service
announcement should describe hazardous waste and
give clear instructions on how to dispose of it in the
community.
32. a) Students may suggest common items such as
cleaning products or paints. The names of the
hazardous chemicals should come from the
ingredients list on the label. If there is no WHMIS
symbol on the label, students may need to research
the disposal information, which should follow the
principles for disposing of flammables/combustibles,
corrosives, reactives, or toxic/infectious waste, most
of which must be disposed of by taking it to the
municipal hazardous waste depot.
b) Pamphlets should reflect the information obtained
for part (a); encourage students to be creative and
to consider the purpose of the pamphlet and its
audience.
c)Many alternatives to chlorine bleach can be used,
which are just as effective. These include borax,
vinegar, baking soda, and lemon juice.
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33. Answers should clearly state an opinion about the
suitability of incineration that is supported by at least
one statement.
Sample answer: I would support incineration of
municipal waste, but not medical or industrial. Medical
waste contains biohazards and perhaps radioactive
waste that requires special handling, so it is not suitable
for treatment at a local incinerator. Industrial waste
can contain many different hazardous wastes in larger
quantities, and could be more harmful than municipal
wastes.
34. a) In brownfield sites, hazardous waste has
contaminated the soil and perhaps water in the
area, which could affect anyone working or living
on the land; these could be absorbed, ingested, or
inhaled by people. Potential buyers of brownfield
sites must consider the costs related to cleaning up
the site before it can be used, as well as the potential
environmental damage to surrounding air and water
during the clean-up.
b) Governments could encourage the clean-up of
brownfield sites by providing technological and/or
financial support to municipalities that want to clean
up the areas.
35. a) Pesticides are hazardous waste when they are left
over and in storage. Residual pesticide in equipment
used to spray or in storage containers is also
hazardous waste.
b) Pesticides are hazardous substances designed to kill
organisms; they must be stored carefully and used
properly, whether they are waste or not.
Pause and Reflect Students should provide at least one
example of how they would incorporate what they have
learned about one or more of the following:
•what hazardous waste is and what the different
sources are
•how hazardous wastes must be disposed of
•how to reduce the amount of hazardous waste
generated
Answers to Unit 4 Review Questions
(Student textbook pages 272-3)
1.b
3.c
2.a
5.e
4.e
6.a)Major sources of solid waste include agriculture
(animal waste, organic matter), industry (chemicals,
construction waste materials, mine tailings), and
municipal (paper, organic, metal, glass, plastic)
b) Landfills are where solid waste is buried. Landfills
are built on top of the ground to isolate waste from
ground water, air, and soil, and have an impenetrable
liner; waste is buried in layers between layers
of soil, which is then compressed; leachate and
landfill gas produced is collected. Benefits include
immediate solutions for solid waste management
that avoids waste being dumped in ecosystems; some
landfills use gases produced to generate electricity;
compactors reduce the volume of waste.
c)NIMBY stands for Not In My Backyard. Local
people can be generally supportive of landfills, but
they are resistant to landfill sites being placed in
their communities because of concerns over ground
water contamination, disease-carrying rats, odours,
and truck traffic.
d) Solid waste disposal alternatives to landfills include
thermal treatment, which is the processing of solid
waste at high temperatures by methods such as
incineration, pyrolysis, and gasification; exportation,
which is the transport of solid waste to another region.
7.The three Rs are
•reduce, which is reduction of waste production
at the source (products are redesigned or the
manufacturing process is changed to result in less
waste); it can also simply mean using less materials
(for example, only cooking enough food for a meal)
•re-use of products rather than replacing them with
something new; this includes choosing re-useable
rather than disposable products (for example,
refilling a plastic bottle instead of buying a new bottle
of water)
•recycle, which is the collecting of waste materials
and reprocessing them to make new products (for
example, waste paper is used to make new paper,
waste plastic is used to make fleece clothing, waste
glass is used to re-surface roads)
Advantages:
•reduction of materials going into the waste stream
•municipalities save money because less waste needs
to be managed
•promotes manufacturing and consumer responsibility
•fewer raw materials are needed for new products
Disadvantages:
•initial investment is required to change design of
manufacturing processes (reduction), or to create
facilities and systems for recycling
•a behaviour change is required, since people
must make different consumer choices or handle
manufacturing or consumer waste differently
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•there can be cross-contamination of materials that
can add to the problems of recycling
•the demand for recycled materials is driven by the
market, which can change over time
8.a)Sewage is any material that is poured down the drain
or flushed down the toilet; storm water is wastewater
that drains from lawns, driveways, roofs, and other
surfaces in cities.
b) Sewage can be treated by septic systems or large
municipal facilities. Septic systems are used
mainly in rural areas and involve treating sewage
by collecting wastewater in a septic tank on the
property, where solids settle to the bottom, oils
and grease float to the surface, and clarified liquid
wastes are channelled through pipes to a septic field,
where water evaporates. Municipal sewage treatment
facilities treat sewage in cities, which involves
primary (removal of solids), secondary (removal of
organic material and killing of micro-organisms),
and tertiary steps (removal of inorganic nutrients).
c)If sewage systems back up in homes after a heavy
rainfall, it can be inferred that the sewer and stormwater systems are connected. Sewage backing up in
homes after a heavy rainfall indicates that the high
volume of rainwater has overwhelmed the system.
d) Storm water contains nutrients, chemicals, and other
materials that could pollute the local waterways
if it is diverted directly into them. Storm water is
warmer than the water in local waterways; it causes
an increase in temperature of the waterways, which
can harm ecosystems. Storm water can also cause
erosion of stream banks and increases in sediment
of waterways, which can harm aquatic life.
9.Answers should include any two of
•flammable and combustible (i.e., are a fire hazard that
could easily ignite or produce smoke and particulate
matter, and can be unstable)
•corrosive (i.e., can corrode materials, including skin)
•reactive (i.e., can explode if improperly handled, and
can react easily with other materials, air, or water to
produce harmful gases)
•toxic and infectious (i.e., can kill or cause harm to
people and other organisms)
10. a) Answers could show any two of common household
products, such as insecticides, pesticides, cleaning
or polishing products, oil and petroleum products,
batteries, older electronics, paint, glue, and some
personal care products (e.g., nail polish, some
medications). Reasons cited for why the products
are hazardous should be based on whether they are
flammable and combustible, corrosive, reactive, or
toxic and infectious.
b) Household hazardous waste collection is encouraged
through curbside pickup in a community and
organized drop-off locations where people can take
materials.
11. a) The reduce strategy is the same for both types of
waste because it is about design and manufacturing
processes that reduce the amount of waste generated
at source. The re-use strategy can be used for both
types of waste—waste from one process can be
cleaned and re-used or household products can be
re-used instead of thrown away. The recycle strategy
applies to both, for example, the recycling of old
paint to produce a new paint product.
b) Re-using and recycling strategies are more limited
for hazardous waste, especially for hazardous
household wastes. Hazardous waste must be handled
and disposed of safely, which is often not possible
for the general public, and so re-using hazardous
materials or recycling them can become dangerous.
12. Source reduction is considered to be the most
effective because it reduces the amount of waste that
is generated when the products are made. Answers
should reflect an understanding of how students’
choices and habits influence the amount of waste they
generate.
Sample answer: I will carry a re-usable water bottle
instead of buying disposable plastic bottles of water.
13. a) organics (food, grass, and gardening waste)
b) organics: purchase less food so not so much is
wasted or compost; paper: recycle or use more
electronic forms; plastic: recycle or use re-useable
containers; glass and metal: recycle or purchase
fewer products packaged in jars; other: recycle or
donate to charity
c)Wastes are diverted from the waste stream through
recycling (collecting and reprocessing materials
into new products), composting (decomposition of
organic matter using worms, insects, or bacteria),
source reduction (reducing waste through changes
in manufacturing, design, and re-use of products),
and re-using (using both sides of paper, re-using
plastic bags or bottles).
14. Answers should clearly state an opinion about the
proposed landfill installation that is supported by
social, political, and economic considerations.
Sample answer: No, I would not support the installation
of a landfill in our community. I think the money that
would go into building and maintaining it should be
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used for promoting composting and for educating
more people on how the choices they make can help to
reduce the amount of waste they generate. I think the
presence of a landfill would reduce the value of many
homes in the area, and it would be difficult to attract
new people and businesses to the community due to
concerns about landfills, such as the odours or that the
landfill can attract disease-carrying rats. Also, landfills
can cause environmental problems if they are not well
maintained.
15. Answers should include the following key points:
•Greywater is household wastewater, except water
from toilets and kitchen sources, that is recycled
through storage and treatment. It is used for outdoor
irrigation and for flushing toilets.
•Greywater should not be used for drinking water (i.e.,
do not drink water from outdoor taps).
•Chemicals or other hazardous materials should not
be poured down the bathroom drains because this
is one source of the greywater that will be used to
maintain the property.
16. Answers should reflect an understanding of how
students’ choices and habits influence the amount
of waste they generate. Examples may include use
of different cleaning products, choice in personal
care products, choice in products that can be reused instead of disposed of after a single use, and
the amount of waste that their general consumption
generates.
17. Answers should include the following:
•the flow of waste through the waste stream, from
the original source of the waste through purchase,
discard into home waste container, and pickup and
transport to municipal waste disposal sites, including
final destinations of landfills and incinerators
•diversions, including smarter use of products,
recycling, and composting
•source reduction involves reducing the waste
generated by redesigning products or manufacturing
processes, as well as re-using products
18. Answers should clearly state an opinion about the
effectiveness of recycling that is supported by at least
two reasons based on current science, technology,
economics, or knowledge of human behaviour.
Sample answer: I do not agree that recycling
and composting will solve all of our solid waste
management problems because not everything can be
recycled or composted. Also, both of these methods
have disadvantages, such as requirement for energy
resources and production of harmful materials during
the processes. I think it would be better to place more
emphasis on reducing the amount of waste people
generate in the first place.
19. Answers should clearly state an opinion about the
pesticide ban that is supported by at least two reasons.
Sample answers: I do not agree with banning the
use of all pesticides on home lawns and gardens
because people may purchase other products that
are not as well regulated; also, if pesticides are not
used, organisms that can be harmful to lawns and
trees may overtake people’s yards and cause a great
deal of destruction in the community. or I agree with
the banning of all pesticides because the run-off is
damaging our waterways. Gardeners and lawn care
specialists can use alternative methods to control pests
and weeds that are as effective.
20. Children are more vulnerable to hazardous substances
because their bodies are still developing and their
immune systems cannot defend against invasion by
pathogens; their tissues are more easily damaged by
chemicals and other harmful substances.
21. a) DDT is a hazardous substance because it is a type
of chlorinated hydrocarbon, which causes damage
to nervous and reproductive systems. DDT is a
persistent pesticide because it does not break down
easily; instead, it accumulates in tissues and is
passed up the food chain.
b) Heavy metals include arsenic, lead, and mercury.
Sources of heavy-metal waste include mining
operations; oil and gas exploration and use; and the
production, use, and disposal of medicines, paints,
leather, and textiles.
c)Answers should note that First Nations conducted
an education campaign for communities along the
shipping route; they joined with municipalities to
protest; they mobilized citizens along the route and
gave them tools such as petitions, letter writing
tips, Facebook groups, organized events to attend,
and visible ways to show their support (the Blue
Ribbons for Our Life Source campaign); and they
were part of formal presentations to the House
of Commons Standing Committee on Natural
Resources to protest the transport of the generators.
Students’ reasons for the protest should focus on
the continued commitment of First Nations to
the protection of Mother Earth, the First Nations’
sense of connectedness in their assertion “We Are
the Land,” their arguments based on the amount
of radiation under consideration and the potential
for accidents along the transport route, and their
concern about setting a precedent for an approved
route for shipping hazardous waste.
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