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Waste Generation
With wealth comes high levels of waste. Compared to many other countries in the world, Canada is both wealthy and wasteful. Where does our waste come from? This section answers this question.
Q3.120
What are wastes? Wastes are substances or materials for
which the owner has no further use, and which are discarded. They can range from
household trash to the by-products of industrial processes. However, much of
what we consider to be 'waste' may still contain useful resources. Substances
and materials that really are of no further use to the current owner may be
useful to someone else. If not, it may be possible to recycle wastes into new
products, or to recover resources from them. An important part of waste
reduction is to re- examine what we consider to be 'waste'.
Q3.121
Do Canadians generate a lot of waste? Yes. It was estimated
that in 1988, for example, approximately 30 million tonnes of solid waste were
generated in Canada. North America as a whole, with only 8% of the world's
population, is responsible for 50% of its waste.
Q3.122
Why so much waste? There are a number of reasons why we
generate so much waste. First of all, we are a wealthy society; we enjoy a
relatively high standard of living and, on average, consume large quantities of
energy and materials. As well, affluence can reduce the incentive to use
products and resources efficiently. Finally, we have in the past taken our
natural resources and environment for granted we have not been aware of the true
costs of the waste we generate.
Did you know?
In 1988, Canadians generated an average of 1.7 kg of
solid waste per person per day. Per capita, this is about the same as our
American neighbours and twice as much as Sweden.
Q3.123
Why should Canadians care about waste management? Wastes do
not go 'away'. Everything we discard must go somewhere, and the disposal of
wastes has significant environmental and economic impacts. Landfills use up
valuable land, can leak contaminated water - leachate - into the environment,
and can release methane (a greenhouse gas). Incinerators can emit acid gases,
carbon dioxide, and toxic chemicals into the atmosphere. Transporting and
disposing of our garbage uses a great deal of energy, contributing to smog, acid
rain, and global warming. Planning, siting, and operating waste disposal
facilities also costs a great deal of money.
û focus
It is estimated that by 1995, existing landfill sites that
serve 71% of the Canadian population will be full. Planning new sites for
landfills and incinerators is a long and difficult process, made more difficult
by strong public opposition to siting proposals. Although we are world leaders
in the production of waste nobody wants a landfill or incinerator in their
neighbourhood.
Q3.124
What are 'solid wastes'? Solid waste is what we generally
think of as 'garbage'. It includes wastes from homes, offices, and industries,
with the exception of specific wastes that are designated as hazardous. Solid
waste is made up of things such as food and yard wastes, used paper products,
used packaging, discarded products (clothes, appliances, tires), as well as
wastes from construction.
Q3.125
What are 'hazardous' wastes? Hazardous wastes are wastes
that, due to their nature or quantity, are potentially hazardous to human health
and/or the environment. They require special disposal techniques to eliminate or
reduce the hazard. Hazardous wastes may be solids, sludges, liquids, or gases.
There are a number of reasons why a given waste may be considered hazardous. It may be corrosive, highly reactive, readily ignitable, or toxic. Exactly what constitutes a hazardous waste is strictly defined by provincial and federal regulations.
Q3.126
How are hazardous wastes generated? Hazardous wastes are
generated primarily by industry, mainly as by-products of manufacturing. The
manufacturing of many common products such as cars, textiles, paper, and
household products results in the generation of hazardous wastes.
Medical institutions and laboratories also generate hazardous wastes, although 'biomedical wastes' account for less than one half of one percent of all hazardous wastes. Most households, schools and other institutions, and commercial facilities generate small quantities of hazardous wastes, which are known as 'household hazardous wastes'.
Q3.127
Why are household hazardous wastes a matter of concern?
Individuals have generally disposed of household hazardous wastes by putting
them out with the garbage or by pouring them down the drain. However, most
municipal waste disposal and sewage systems were not designed to handle the
variety of chemical wastes that a typical Canadian household now produces. Since
sewage treatment plants do not destroy most of the household hazardous wastes
that go down the drain, many of them end up in rivers and lakes, contaminating
drinking water. Similarly, most existing municipal landfills are not designed to
handle these wastes, which can leach into groundwater. Municipal waste
incinerators, finally, are for the most part not equipped to handle the toxic
chemicals that can be found in household hazardous waste.
Waste Disposal
Where do our wastes go? What impacts do their disposal have on the environment? These questions are the subject of this chapter.
Q3.128
How are solid wastes currently disposed of in Canada? The
vast majority of solid wastes generated by Canadians end up in some sort of land
disposal facility, either sanitary landfills or dumps. Most of the remaining
solid wastes are incinerated.
Q3.129
What impact does land disposal have on the environment? The
major environmental concerns associated with land disposal relate to the
formation of leachate and landfill gas, and to the use of land which could
otherwise be used for purposes such as agriculture, wildlife habitat, housing,
or recreation. In addition, if improperly designed, land disposal sites can
generate odours, dust and litter, and attract scavenging birds and wildlife.
Q3.130
What is the difference between a dump and a sanitary
landfill? Although the terms are often used interchangeably, a sanitary landfill
is, in fact, very different from a traditional dump. At a dump, garbage is
generally left and allowed to degrade until covered with other loads of garbage.
Some garbage may be burned in a pit. At a sanitary landfill site, more
precautions are taken. Sites for new landfills are carefully chosen, access to
the site it limited, and loads of hazardous waste are not accepted. The wastes
that are accepted are spread and compacted by heavy machinery, and then covered
with soil or other materials. Burning is prohibited, litter is controlled, and
precautions are taken with respect to leachate and landfill gas. If a sanitary
landfill is properly designed and operated, its impacts on the environment
should be fairly minimal.
Q3.131
How do wastes break down in a land disposal site? Organic
wastes (such as food, leaves and yard wastes) can be gradually broken down or
decomposed by the action of bacteria. Inorganic wastes (such as glass and
metals) cannot.
When organic wastes are first put in a landfill, aerobic bacteria (bacteria that function in the presence of oxygen) begin to break them down into organic acids and other chemicals. As the wastes are covered by layers of more waste or soil, these aerobic bacteria quickly consume the available oxygen. Anaerobic bacteria (those that function in the absence of oxygen) then continue the work of decomposition.
While the rate of decomposition depends on many factors (such as moisture, acidity, and temperature), anaerobic decomposition is a very slow process. Under relatively dry conditions, like those in a sanitary landfill, decomposition may be negligible. At some landfills, excavations by 'garbage archaeologists' have unearthed food and paper wastes that have not decomposed since their disposal 10 to 20 years ago.
Q3.132
What is leachate? Leachate is contaminated water from a land
disposal site. It is formed when moisture percolates through layers of waste,
dissolving and carrying along various chemicals. the quantity of leachate
generated depends upon many factors, including levels of precipitation, the
amount of moisture in the wastes themselves, temperature, and subsurface water
movement. As leachate moves out of a land disposal site, the concentration of
contaminants in it may be reduced by natural processes, which are in many cases
sufficient to render the leachate harmless. Problems can occur, however, if
leachate contaminates groundwater or surface water supplies that are used for
drinking. Modern sanitary landfills are designed to prevent this from happening.
Q3.133
What is landfill gas? Landfill gas is a mixture of gases
produced when organic matter in wastes decomposes in the absence of air. It is
composed primarily of equal parts methane and carbon dioxide. Landfill gas is an
environmental concern since methane and carbon dioxide are greenhouse gases
(methane being the main concern due to its greater potency). There are also
safety concerns since methane is explosive when mixed with air in certain
concentrations.
Q3.134
When a product is labelled 'biodegradable', what does this
mean? A biodegradable product can be broken down by micro-organisms under
specific conditions. Until recently, it was commonly believed that such products
were better for the environment because they would break down naturally.
Following this reasoning, some advocates urged the use of paper rather than
plastic.
However, while many materials do ultimately degrade, the process is a lengthy one, especially if conditions are not right. Biodegradation takes place most rapidly in the presence of air and moisture. Wastes in a sanitary landfill are deprived of air and moisture, and so break down very slowly. If waste is destined for a landfill, the fact that a product is labelled as biodegradable is of little relevance. Of course, if waste is to be incinerated, biodegradability is of no relevance at all.
Q3.135
What is a solid waste incinerator? A solid waste incinerator
is a facility where solid waste is burned under controlled conditions. Just as a
state-of-the-art sanitary landfill differs from a traditional dump, a modern
incinerator bears little resemblance to an open burning pit. A modern
incinerator burns large quantities of solid waste at high temperatures under
highly controlled conditions. 'Energy-from-waste' incinerators allow the
recovery of energy from incineration.
Q3.136
What impacts do solid waste incinerators have on the
environment? The environmental impacts of an incinerator depend on the age and
design of the facility, and on how it is operated. Although the prospect of
waste incineration has caused considerable concern in some communities, much of
this concern is based on information about the emissions generated by old or
poorly operated facilities. If not properly controlled, incineration can emit
heavy metals such as lead and mercury, dioxins, and furans into the atmosphere,
as well as harmful organic chemicals and acid gases that contribute to acid
rain. The ash left over after incineration may be contaminated with toxic
organic chemicals and heavy metals.
Q3.137
Can the negative impacts associated with incinerators be
reduced? Yes. State-of-the-art incinerators operate at extremely high
temperatures, minimizing the formation of harmful organic chemicals. They also
have extensive control systems in place to prevent pollutants from being
released into the atmosphere. Ashes are tested and, if deemed hazardous,
disposed of at hazardous waste facilities. Finally, the recovery of energy from
waste can reduce our need for fossil fuels, the burning of which contributes to
smog, global warming, and acid rain.
Q3.138
What is the best way to dispose of household hazardous
wastes? Every effort should be made to reduce your generation of household
hazardous wastes. Before disposing of any that you do generate, check with your
municipality to see if there is a depot or collection system for them. If there
is no such system, call your provincial environment ministry for advice. In some
communities, the fire department may accept barbecue fluids, lighter fluids,
gasoline, and furnace oils.
Q3.139
Who pays for waste management? The costs of residential
solid waste management are paid primarily by municipal taxpayers through general
taxation. In most cases industries and institutions pay for private collection
and recycling of their solid wastes.
Q3.140
How much does it cost to dispose of solid waste? Costs vary
for different areas and different types of disposal facilities. A 1992 survey
indicated that on average municipal waste collection and disposal costs were
about $30 to $40 per capita per year; municipalities reported spending between 5
and 10% of their total budgets on waste management. Yet current municipal waste
management costs do not always reflect the full costs of waste disposal. The
full costs of waste disposal facilities include costs of planning, siting, and
mitigating environmental impacts and, for landfills, closing and monitoring the
landfill once full. In many municipalities, these costs are not factored into
current waste disposal costs.
Waste Reduction
There are many ways that we can reduce the amount of waste that we generate. Canadians have in fact made much progress in this area in recent years. This section looks at some of the issues relating to waste reduction in Canada today.
Q3.141
What are the four R's? The four R's are a hierarchy of
options for reducing the amount of waste requiring disposal. In order of
preference, the options are:
1. reduction at the source
2. re-use
3. recycling
and
4. recovery of resources from waste.
The order of the four R's is based on current understanding of the overall environmental impacts of the various options. In most cases, it is best to avoid generating waste in the first place this is 'reduction at source'. If waste is generated, the next best approach is to find a new use for it 're-use'. If this is not possible, recycling should be considered. Finally, it may be possible to recover energy or materials from waste.
Q3.142
What is 'reduction at the source'? 'Reduction at the source'
involves reducing the amount of waste generated in the first place. This means,
for example, buying only what you need and choosing products with less
packaging. For manufacturers, it involves using less material to produce and
package goods. While for the consumer, reduction at source is almost always the
best choice, the issue is more complicated for manufacturers; if reduced
material input leads to less durability for the product, the amount of waste
generated by consumers may increase.
Q3.143
What is 're-use'? This term refers to the repeated use of an
item in its original form (although not necessarily for its original purpose).
For consumers, this may be as simple as re-using grocery bags. An example in
industry would be the use of durable, re-usable crates rather than disposable
boxes to ship goods.
Q3.144
What is recycling? Recycling involves taking apart an old
product and using the material it contains to make a new product. What makes
recycling different from re-use is that the product must be reprocessed. This
extra step may have additional effects on the environment. Although recycling
helps conserve resources and reduces waste, it is important to remember that
there are still economic and environmental costs associated with the collection
and recycling of materials.
Q3.145
How much does it cost to recycle solid waste? The costs of
collecting and processing materials vary widely. The extent to which revenues
from the sale of recyclable materials offset costs depends on a number of
factors, including the market value of the materials collected, the costs of
collection and processing, and the distance that materials must be transported
to markets. In the case of high-value materials such as computer paper and
aluminum, revenues may offset costs. In other cases, the costs may greatly
exceed revenues.
The costs of residential recycling programs are also offset by financial benefits from the diversion of waste from disposal facilities. For municipalities that are running out of landfill space, and facing high costs to site, construct, and operate new disposal facilities, these benefits can be quite substantial. The same holds for businesses that must pay 'tipping fees' to dispose of their wastes.
Q3.146
What does the term 'post-consumer' mean? 'Post-consumer
material' is recycled material from households and commercial and institutional
facilities. It does not include recycled material from industry. For example,
recycled fibre made from fine paper collected in an office for recycling would
be considered post-consumer fibre. Recycled fibre made from wood scraps
collected from a printing industry would not. By purchasing products that
contain post- consumer recycled material, consumers can help to stimulate
markets for materials from residential and commercial recycling programs.
Q3.147
What is composting? Composting is a way of handling organic
waste materials such as food wastes, leaves, and grass clippings in order to
speed the natural process of decomposition. Composting speeds this process up by
creating the right conditions for naturally occurring aerobic bacteria and other
micro-organisms to break down organic wastes. The final product of composting is
a soil-like material called compost or humus. If composting is done properly,
the final compost is excellent for restoring organic content to soils.
Q3.148
How much solid waste can be composted? In theory, nearly all
the organic matter in municipal waste could be composted. About one third of the
municipal waste stream by weight is organic matter. Currently, much less than
this is composted.
Q3.149
What is 'resource recovery'? 'Resource recovery' involves
the extraction of valuable energy or materials from the waste stream. Modern
energy-from-waste plants, for example, have the ability to recover much of the
energy and heat value that go into the manufacturing of goods, while reducing
the amount of solid waste requiring disposal. This fourth R is primarily an
industrial practice, and there are few opportunities for individuals to practise
it.
Did you know?
In 1991, the cost to operate the residential `Blue
Box' program in Metropolitan Toronto was $193 per tonne of material collected.
Revenues from the sale of materials were estimated to offset about one- third of
the cost.
4. Putting Environmental Citizenship into Practice
What does environmental citizenship mean for the day-to-day life of an
individual or an organization? This chapter outlines an answer to this question.
