WASTE GENERATION

Designed By:Kishan Mishra

Introductory Presentation

Upon successfully completing this chapter, you will be able to:

• Summarize and compare the types of waste we generate• List the major approaches to managing waste• Delineate the scale of the waste dilemma • Describe conventional waste disposal methods: landfills and incineration• Evaluate approaches for reducing waste: source reduction, reuse, composting,

and recycling• Discuss industrial solid waste management and principles of industrial ecology• Assess issues in managing hazardous waste

18-2

Central Case: The Beare Road Landfill

• 1968 - 1983: The Beare Road pit received municipal garbage for Toronto’s ever-increasing garbage

• 1983: landscape restoration was undertaken• 1996: began to collect the methane-rich gas being generated by the

decomposting garbage (LFGTE, landfill gas-to-electricity)

“We can’t have an economy that uses our air, water, and soil as a garbage can.”

–David Suzuki

18-3

Approaches to Waste Managment

18-4

Approaches to waste management

• Municipal solid waste = non-liquid waste that comes from homes, institutions, and small businesses

• Industrial solid waste = waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining

• Hazardous waste = solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive

• Wastewater = water used in a household, business, or industry, as well as polluted runoff from our streets and storm drains

18-5

We have several aims in managing waste

• Three main components of waste management

– Minimizing the amount of waste we generate (source reduction)

– Recovering waste materials and finding ways to recycle them– Disposing of waste safely and effectively

18-6

18-7

We have several aims in managing waste (cont’d)

• Waste stream = flow of waste as it moves from its sources toward disposal destinations.– More efficient use of materials, consume less, buy goods with

less packaging, reusing goods • Recovery (recycling, composting) = next best strategy in

waste management.– Recycling = sends used goods to manufacture new goods– Composting = recovery of organic waste

18-8

Municipal Solid Waste

18-9

Patterns in the municipal solid waste stream vary from place to place

• Municipal solid waste is also referred to as trash or garbage• In Canada, paper, organics, and plastics are the principal components of

municipal solid waste– Even after recycling, paper is the largest component of solid waste– In 2008, 2.2 kg per person per day

• In developing countries, food scraps are the primary contributor to solid waste– Wealthy nations invest more in waste collection and disposal

18-10

18-11

18-12

Waste generation is rising in all nations

• Since 1960, waste generation has increased in North America by 300%.

• Plastic has accounted for greatest relative increase.• Waste generation in Canada has kept pace with population

growth.• In many industrialized nations, per capita waste generation rates

have leveled off or decreased in recent years.• Increase popularity of recycling.

Open dumping in the past has given way to improved disposal methods ...

• Historically people dumped their garbage wherever it suited them

• Most industrialized nations now bury waste in lined and covered landfills or burn it in incineration facilities

• Diversion rates are increasing in Canada– Recycling or composting increased from

21% to 27% in 2008

Waste disposal is regulated by three levels of government

• Municipal:– Collection, diversion, and disposal of solid waste– Drop-off facilities for hazardous waste

• Provincial and territorial:– Movement of waste materials within the jurisdiction– Licensing of treatment facilities– Legislation and guidelines for landfill sites

• Federal government:– International agreements about waste– Transboundary movements of waste materials

Sanitary landfills are engineered to minimize leakage of contaminants

• Sanitary landfills = waste buried in the ground or piled in large, engineered mounds

• Leachate = liquid that results when trash dissolves in water as rainwater percolates downward

18-16

Landfills can be transformed after closure

• Many landfills lie abandoned.• Managers closed smaller landfills and made fewer larger

landfills.• Decommissioning = shutting down an industrial site

and getting it ready for cleanup and repurposing.• Growing cities converted closed landfills into public

parks– Rouge Park in Toronto– Fresh Kills in New York

18-18

Landfills have drawbacks• Experts believe that leachate (toxic fluid) will eventually

escape– The liner will become punctured– Leachate collection systems eventually aren’t

maintained• It is hard to find places suitable for landfills

– The Not-In-My-Backyard (NIMBY) syndrome• The “garbage barge” case

– 1987: Islip, New York’s landfills were full, and a barge traveled to empty the waste in North Carolina, which rejected the load, as did Louisiana and Mexico

– It returned to Queens to incinerate the waste, after a 9,700 km journey

18-19

Incinerating trash reduces pressure on landfills• Incineration = a controlled process in which mixed

garbage is burned at very high temperatures; often used in Europe to also generate energy; proposed for Duke Point.

• Incineration in specially constructed faculties can be an improvement over open-air burning of trash– But, the remaining ash must be disposed of in a

hazardous waste landfill– Hazardous chemicals are created and released

during burning• Scrubbers = chemically treat the gases produced in

combustion to remove hazardous components and neutralize acidic gases

18-20

18-21

Many incinerators burn waste to create energy

• Waste-to-energy facilities (WTE) = use the heat produced by waste combustion to create electricity– Waste generates about 35% of the energy

generated by burning coal• Companies contract with communities to

guarantee a minimum amount of garbage– Long-term commitments interfere with the

communities’ later efforts to reduce waste

18-22

Landfills can produce gas for energy

• Bacteria can decompose waste in an oxygen-deficient environment

• Landfill gas = a mix of gases that consists of roughly half methane – Can be collected, processed, and used like natural gas – When not used commercially, landfill gas is burned off in

flares to reduce odors and greenhouse emissions• More than 40 operational projects in Canada collect

landfill gas and convert it into energy 18-23

Garbage justice?

• Do you know where your trash goes? • Where is your landfill or incinerator located? • Are the people who live closest to the facility wealthy, poor, or middle class? • What race or ethnicity are they? • Do you know whether the people of this neighbourhood protested against the introduction of the landfill or incinerator?

18-24

Reducing waste is a better option

• Source reduction = preventing waste generation in the first place

• Avoids costs of disposal and recycling• Helps conserve resources• Minimizes pollution• Can save consumers and businesses money

• Strategies– Reduce packaging– Ban or per-bag charges for plastic grocery bags– Increase the longevity of goods

18-25

Reuse is one main strategy for waste reduction

• Donate used items to charity• Reuse boxes, paper, plastic, wrapping paper, and

so on• Buy groceries in bulk• Decline bags at stores and bring cloth bags

shopping• Bring your own cup to coffee shops• Buy rechargeable batteries• Select goods with less packaging• Compost kitchen and yard wastes• Rent or borrow items instead of buying them

18-26

Reducing Packaging: Is It A Wrap?

Reducing packaging cuts down on the waste stream, but how, when, and how much should we reduce? Packaging can serve very worthwhile purposes, such as safeguarding consumer health and safety. • Can you think of three products for which you would not want to see less packaging?•Can you name three products for which packaging could easily be reduced without ill effects to the consumer?•Would you be any more or less likely to buy these products if they had less packaging?

18-27

Composting recovers organic waste

• Composting = the conversion of organic waste into mulch or humus through natural biological processes of decomposition

• There are now more than 350 centralized composting programs in Canada

• 28% of the Canadian solid waste stream is made up of materials that can easily be composted

• 57% of Canadian households do some form of composting

18-28

18-29

Recycling has grown rapidly and can expand further

• 95% of Canadian households have access to recycling programs

• Recycling rates vary from one product or material type to another and from one location to antoher

• Increase has been driven by – Economic forces– Desire to reduce waste

18-30

Financial incentives can help address waste• Pay-as-you-throw = uses financial

incentives to influence consumer behavior– The less waste a house generates the less it

is charged for trash collection • Return-for-refund = consumers pay a

deposit, and receive a refund for returning used bottles– Greatly reduced beverage container litter– All provinces and territories in Canada except

for Nunavut

18-31

Costs of Recycling and Not Recycling

• Should recycling programs be subsidized by governments even if they are run at an economic loss?

• What types of external costs—costs not reflected in market prices— do you think would be involved in not recycling, say, aluminum cans?

• Do you feel these costs justify sponsoring recycling programs even when they are not financially self-supporting? Why or why not?

Edmonton showcases reduction and recycling

• Edmonton, Alberta, has created one of the world’s most advanced waste management programs– Waste: 35% sanitary landfilled,

15% is recycled, 50% is composted

– 88% of the people participate in curbside recycling

18-33

Industrial Solid Waste

18-34

Industrial solid waste

Industrial waste = waste from factories, mining, agriculture, petroleum extraction, etc.

18-35

Regulation and economics each influence industrial waste generation

Most methods and strategies of waste disposal, reduction, and recycling are similar to municipal solid wasteThe amount of waste generated by a manufacturing process is one measure of its efficiency Physical efficiency is not equal to economic efficiencyIt can be cheaper to generate waste than to avoid wasteThe rising cost of waste disposal encourage industries to decrease waste and increase physical efficiency

18-36

Industrial ecology seeks to make industry more sustainable

Industrial ecology = redesigning industrial systems to reduce resource inputs and to minimize physical inefficiency while maximizing economic efficiency

Life cycle analysis = examine the life cycle of a product and look for ways to make the process more ecologically efficient

Pollution prevention (P2) strategies = aimed at reducing waste and preventing pollution at its source

18-37

Businesses are adopting industrial ecology

InterfaceModified tile design and production methods to reduce wasteCut waste generation by 80%, fossil fuel use by 45%, and water use by 70%, while raising profits by 49% Canadian TireAuto parts return initiativesXeroxTake-back/lease programsENVIRx programReturn unused medications to pharmacies for disposal

18-38

Waste exchanges are an offshoot of industrial ecology

Concept of industrial ecology is based on a “closed loop”Wastes are recycled back through the system

Waste exchange = a network service with the goal of linking producers of waste with industries or individuals that can make use of the waste as raw materials

The Waste Exchange of Canada www.recyclexchange.net

18-39

Hazardous Waste

18-40

Hazardous waste

• 1999: Canadian Environmental Protection Act:– Flammable = substances that easily catch fire– Corrosive = substances that corrode metals in storage

tanks or equipment– Reactive = substances that are chemically unstable and

readily react with other compounds, often explosively or by producing noxious fumes

– Toxic = substances that harm human health when they are inhaled, are ingested, or contact human skin

18-41

Hazardous wastes have diverse sources

• Households currently are the largest source of unregulated hazardous waste– Household hazardous waste (HHW)– Paints, batteries, oils, solvents, cleaning agents, pesticides

• Canadians improperly dispose of 27 000 tonnes of HHW each year– Average home has close to 45 kg of hazard wastes– Two classes are particularly hazardous– Organic compounds– Heavy metals

18-42

Organic compounds and heavy metals can be hazardous

Organic compounds – are particularly hazardous because their toxicity persists over time

and synthetic organic compounds resist decomposition• Keep buildings from decaying, kill pests, and keep stored goods

intact • Their resistance to decay causes them to be persistent pollutants• They are toxic because they are readily absorbed through the skin• They can act as mutagens, carcinogens, teratogens, and

endocrine disruptors

18-43

Organic compounds and heavy metals can be hazardous (cont’d)

• Heavy metals– Lead, chromium, mercury, arsenic, cadmium, tin, and copper – Used widely in industry for wiring, electronics, metal plating,

pigments, and dyes– They enter the environment when they are disposed of

improperly– Heavy metals that are fat soluble and break down slowly are

prone to bioaccumulation

18-44

“E-waste” is a new and growing problem

• Electronic waste (e-waste) = waste involving electronic devices – Computers, printers, VCRs, fax machines, cell phones – Disposed of in landfills, but should be treated as hazardous

waste (6% of a typical computer is composed of lead)– Some people and businesses are trying to use and reuse

electronics to reduce waste– Serious concerns about health risks to workers

18-45

Several steps precede the disposal of hazardous waste

• For many years, hazardous waste was discarded without special treatment– Public did not know it was

harmful to human health– Assumed the substances

would disappear or be diluted in the environment

– Since the 1980s, cities designate sites or special collection days to gather household hazardous waste

18-46

There are three disposal methods for hazardous waste

• Secure landfills• Surface impoundments• Deep-well injection• These methods do nothing to lessen the

hazards of the substances but do keep the waste isolated

18-47

Secure landfills

• Must have several impervious liners and leachate removal systems– Design and construction standards are

stricter than for ordinary sanitary landfills– Must be located far from aquifers

18-48

Surface impoundments• Surface impoundments =

store liquid hazardous waste

• Shallow depressions are lined with plastic and clay

• Residue of solid hazardous waste is transported elsewhere

• The underlying clay layer can crack and leak waste

• Rainstorms cause overflow, contaminating nearby areas

18-49

Deep-well injection• Deep-well injection

= a well is drilled deep beneath the water table and waste is injected into it– Long-term disposal– The well is intended to

be isolated from groundwater and human contact

– Wells become corroded and leak waste into soil

18-50

Radioactive waste is especially hazardous• Radioactive waste is particularly dangerous and

persistent

• Geologic isolation = using the absorptive capacity and impermeability of naturally occurring rock to block contaminants

• Multiple-barrier approach = engineering the facility to place as many barriers as possible, both physical and chemical, in the pathway of any escaping contaminants

18-51

Contaminated sites are being cleaned up, slowly

• 18,000 Canadian contaminated sites, including priority sites for cleanup activities:– Faro Mine, Yukon ($14.6 million)– Canadian Forces Base Esquimalt, British

Columbia ($4.56 million)– Port Radium Mine, Northwest Territories ($7.1

million)– Belleville Small Craft Harbour, Ontario ($6.8

million)

• Brownfields = sites that have been contaminated but have the potential to be cleaned up and remediated

18-52

Conclusion

• Modern methods of waste management are far safer for people and gentler on the environment

• Recycling and composting are making rapid progress• Canada has changed from virtually no recycling to

diverting nearly 25% of all solid waste• Our prodigious consumption habits have created more

waste than ever before • Finding ways to reduce, reuse and efficiently recycle the

materials and goods that we use stands as a key challenge for this century

18-53