17 Lecture Presentation lecture will help you understand: • The types of waste we generate • Managing waste • The scale of the waste dilemma • Conventional waste disposal •

Chapter

17

Lecture Presentations prepared byReggie Cobb

Nash Community College© 2015 Pearson Education, Inc.

Managing Our Waste

© 2015 Pearson Education, Inc.

This lecture will help you understand:

• The types of waste we generate • Managing waste • The scale of the waste dilemma • Conventional waste disposal • Ways to reduce waste • Industrial solid waste

management • Managing hazardous

waste


Central Case Study: A Mania for Recycling on Campus• In 2001, Ohio University and Miami University of

Ohio competed in a 10-week recycling event • The first Recyclemania

• In 2014, 461 colleges competed for many awards


Central Case Study: A Mania for Recycling on Campus (cont’d)• Recyclemania is the biggest of a growing number of

campus competitions in the name of sustainability • The Campus Conservation Nationals is gaining

momentum • Students on campuses across the country compete to

see who can save the most water and energy • 109 colleges participated

• Campus sustainability is thriving • Students, faculty, staff, and administrators are doing the

right things • Competing in these competitions adds to the fun


Approaches to waste management

• Waste • Any unwanted material or substance that results from a

human activity or process • Municipal solid waste

• Nonliquid waste from homes, institutions, and small businesses

• Industrial solid waste • From production of goods, mining, agriculture, petroleum

extraction and refining • Hazardous waste

• Solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive


We have several ways to manage waste

• Minimize the amount of waste generated (source reduction)

• The preferred approach • Recover waste materials

and recycle them • Dispose of waste safely

and effectively • Waste stream

• The flow of waste as it moves from its sources to its disposal destinations


Municipal solid waste

• Most U.S. municipal solid waste (“trash” or “garbage”) consists of paper, yard debris, food scraps, and plastics

• Food scraps and plastics are the largest components • Most municipal solid waste comes from packaging

and nondurable goods (discarded after a short time of use)

• As we get more goods, we generate more waste • U.S. citizens generate 7.1 lb/person each day • Critics label the U.S. the “throwaway society” • U.S. waste decreased slightly from 2005 to 2012


The U.S. municipal solid waste stream


Developing nations are producing waste

• Consumption is greatly increasing in developing nations

• Rising standard of living, more packaging, poor-quality goods

• Wealthy consumers discard items that can still be used

Poor people support themselves by selling items they scavenge from dumps


Disposal methods have improved

• Wealthier nations invest in waste collection and disposal

• Efforts minimize impacts on health and the environment • Recycling and composting are decreasing pressure on

landfills

In 2012 in the U.S., 35% of waste was recycled or composted


Landfills provide our main method of disposal

• Sanitary landfills • Waste buried in the ground or piled in large mounds to

prevent contamination and health threats • U.S. landfills must meet the EPA’s national standards

under the Resource Conservation and Recovery Act (RCRA) of 1976

• Waste is partly decomposed by bacteria and compresses under its own weight to make more space

• Soil layers reduce odor, speed decomposition, reduce infestation by pests

• Closed landfills must be capped and maintained


Landfills provide our main method of disposal (cont’d)• Leachate

• Liquid from trash dissolved by rainwater • It is collected and

treated in landfills • Collection systems

must be maintained for 30 years after a landfill is closed


Frequently Asked Question

• How much does garbage decompose in a landfill?


Landfills have drawbacks

• Despite improved technology, liners can be punctured

• Leachate collection systems won’t be kept up • It takes decades for waste to decay • The not-in-my-backyard (NIMBY) syndrome:

residents don’t want landfills in their areas • Wealthy, educated people have the political clout to

prevent landfills from being sited in their neighborhoods • Landfills are disproportionately sited in poor and minority

communities


Landfills can be transformed after closure

• In 1988, the U.S. had 8000 landfills • Today there are fewer than 2000, but they are large

• Cities have converted closed landfills into public parks, stadiums, gardens, wetlands, and festival events


Weighing the Issues

• Environmental Justice? • Do you know where your trash goes? • Where is your landfill or incinerator located? • Are 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 neighborhood

protested against the introduction of the landfill or incinerator?


Incinerating trash reduces pressure on landfills

• Incineration • A controlled process that burns garbage at very high

temperatures • Metals are removed, and the rest is burned in a furnace • The remaining ash is toxic and must be disposed of in a

hazardous waste landfill • Hazardous emissions are created and released

• Scrubbers • Chemically treat emissions to remove hazardous

chemicals and neutralize acidic gases • Fly ash – particulate matter that can be very toxic • Baghouse – huge filters that physically remove fly

ash


We can gain energy from trash

• Incineration reduces the volume of waste and can generate electricity

• Waste-to-energy (WTE) facilities • Use the heat produced by waste combustion to create

electricity • Landfill gas

• Bacterial decomposition creates a mix of gases that consists of 50% methane

• Can be collected, processed, and used like natural gas


Waste-to-energy incinerator


Reducing waste is our best option

• Source reduction • Preventing waste in the first place • Avoids costs of disposal and recycling • Helps conserve resources and minimizes pollution • Can save consumers and businesses money

• Most waste consists of materials used to package goods

• To reduce waste, use minimal or recyclable packaging • Buy unwrapped fruit and vegetables • Reduce the size or weight of goods and materials • Choose products that motivate producers to create

longer-lasting goods


Reducing waste is our best option (cont’d)

• Some local governments are trying to reduce plastic bags

• Grocery bags can take centuries to decompose • They choke and entangle wildlife and cause litter • 100 billion of them are discarded each year in the U.S.

• Many governments have banned nonbiodegradable bags

• Tax on bags gives financial incentives to use other bags

• Consumers bring their own bags


Reuse is a main strategy to reduce waste

• Actions we all can take to reduce the waste we generate:


Composting recovers organic waste

• Composting • The conversion of organic waste into mulch or humus

through natural decomposition • It can be used to enrich soil

• Home composting • Householders place waste into composting piles,

underground pits, or specially constructed containers • Heat from microbial action builds up and spurs

decomposition • Earthworms, bacteria, and other organisms convert waste

into high-quality compost


Composting recovers organic waste (cont’d)

• College campus composting programs • Ball State University, Indiana

• Shreds surplus furniture and wood pallets to make mulch to nourish on campus plants

• Ithaca College, New York • Composts 44% of its food waste / saves $11,500 disposal fees • Plantings also grow better with the compost mix


Composting recovers organic waste (cont’d)

• Municipal composting programs • These programs divert food and yard waste from the

waste stream to central composting facilities • People can use the mulch in gardens and landscaping

• Half of U.S. states now ban yard wastes from the municipal waste stream

• Accelerating the move to composting


Recycling consists of three steps

• Step 1: collection and processing of recyclable materials through curbside recycling or designated locations

• Materials recovery facilities (MRFs): workers and machines sort, clean, shred, and prepare items

• Step 2: using recyclables to produce new goods • Glass, metal, paper, plastics use recycled materials

• Step 3: consumers buy goods made from recycled materials

• Incentives for further recycling • Facilities are built or expanded


Recycling consists of three steps (cont’d)


Recycling has grown rapidly

• 9000 recycling programs serve 50% of Americans • U.S. recycling rates vary

• Depending on the product and state • Businesses see that they can save money • Entrepreneurs can start

new businesses

The U.S. recycles 26% of its waste stream


Recycling has grown rapidly (cont’d)

• Recycling rates vary greatly depending on the product or material


Recycling has grown rapidly (cont’d)

• Many college students are getting involved in Recyclemania, “trash audits,” and “landfill on the lawn”

• Louisiana State University recycled 68 tons of refuse • University of North Carolina at Greensboro

performed a trash audit to show how many recyclable items are thrown away needlessly


Recycling has grown for many reasons

• Municipalities want to reduce waste • The public takes satisfaction in recycling • Recycling may not be profitable, however

• To collect, sort, and process materials is expensive • The more material that is recycled, the lower the price • Transportation costs to recycling facilities may be high

• But market forces do not take into account the health and environmental effects of not recycling

• Recycling offers enormous savings in energy and materials


The Science Behind the Story

• Tracking Trash • Researchers from the SENSEable City Lab at

Massachusetts Institute of Technology (MIT) placed tracking devices on various kinds of trash in New York City and Seattle

• Movements of the items were tracked


The Science Behind the Story (cont’d)

• Tracking Trash • Hazardous waste items and electronic waste items

tended to travel farthest because they were sent to special facilities for handling

• This raises the question, of whether special handling is worthwhile, given the impacts of extra gasoline use and greenhouse gas emissions required

• These data will be used to improve the ways we handle waste


Weighing the Issues

• Costs of Recycling and Not Recycling • Should governments subsidize recycling programs even if

they are run at an economic loss? • What types of external costs do you think would be

involved in not recycling aluminum cans? • Do you feel these costs justify sponsoring recycling

programs even when they are not financially self-supporting?

• Why or why not?


We can recycle materials from landfills

• Businesses are weighing the benefits of salvaging materials in landfills that can be recycled

• Metals (steel, copper) • Organic waste for compost • Wastes can be incinerated in WTE facilities • Harvesting methane from open dumps (Asia, Africa)

• But costs and regulatory requirements have made investing in landfill mining risky

• Rising prices and better technologies will change this


Financial incentives help address waste

• “Pay-as-you-throw” approach: residents are charged according to how much trash they put out

• The less waste, the less a person has to pay • Bottle bills

• Consumers receive a refund for returning used bottles and cans to stores

• These bills are effective and popular • Container litter is reduced 69–84% • Total litter is reduced by 30–64% • States are beginning or expanding their programs


Industrial solid waste

• Industrial solid waste • Is not municipal or hazardous waste • Comes from factories, mining, agriculture, petroleum

extraction, etc. • U.S. industries generate 7.6 billion tons of waste per

year • 97% is wastewater

• The federal government regulates municipal solid waste

• States and local governments regulate industrial solid waste (with federal guidance)

• State and local rules are less strict than federal rules


Regulation and economics each influence industrial waste generation• Most methods and strategies of waste disposal,

reduction, and recycling are similar to those for municipal solid waste

• Industries may not be required to have permits or install liners or leachate collection systems

• Or even to monitor groundwater for contamination • It may be cheaper to generate waste than to avoid it

• Industries are awarded for economic, not physical, efficiency

• Once government or the market makes it efficient, businesses gain incentives to reduce their waste


Industrial ecology seeks to make industry more sustainable• Industrial ecology

• Involves redesigning industrial systems to reduce resource inputs while maximizing physical and economic efficiency

• Based on principle that industrial systems should function like ecological systems, with little waste

• Life-cycle analysis • Examines the life cycle of a product to make the process

more ecologically efficient • Industrial ecology examines how waste products can

be used as raw materials • Eliminates harmful products and materials • Creates durable, recyclable, or reusable products


Businesses are adopting industrial ecology

• Businesses are saving money while reducing waste • Interface, a carpet tile company, asks customers to

return used tiles for recycling and reuse • Reduced waste and adapted its boilers to use landfill gas

for energy • Cut waste generation by 80%, fossil fuel use by 45%, and

water use by 70% • Saved $30 million/year, held prices steady, and raised

profits by 49%


An example of industrial ecology

• Swiss Zero Emissions Research and Initiatives (ZERI) helps businesses—such as breweries—create goods and services without generating waste


Hazardous waste

• Hazardous waste • A liquid, solid, or gas that is either:

• Ignitable • Easily catches fire (natural gas, alcohol)

• Corrosive • Corrodes metals in storage tanks or equipment

• Reactive • Chemically unstable and readily reacts with other

compounds • Often explosively or by producing noxious fumes

• Toxic • Harms human health when inhaled, ingested, or touched


Hazardous wastes are diverse

• Industry produces the largest amount of hazardous waste

• But waste generation and disposal are highly regulated • Households: the largest source of unregulated

hazardous waste • Paint, batteries, solvents, cleaners, pesticides, etc.

• Many hazardous substances become less hazardous over time

• But others may be especially persistent (e.g., radioactive waste, organic compounds, heavy metals)


Organic compounds can be hazardous

• Synthetic organic compounds resist bacterial, fungal, and insect activity

• Plastics, tires, pesticides, solvents, wood preservatives • Keep buildings from decaying, kill pests, and keep stored

goods intact • Their resistance to decay makes them persistent

pollutants • They are toxic because they are readily absorbed through

the skin • They can act as mutagens, carcinogens, teratogens, or

endocrine disruptors


Heavy metals can be hazardous

• Lead, chromium, mercury, arsenic, cadmium, tin, and copper

• Used widely in industry for wiring, electronics, metal plating and fabrication, pigments, and dyes

• Enter the environment when they are disposed of improperly

• Heavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnify


E-waste is growing

• Electronic waste (e-waste) • Waste involving electronic devices • Computers, printers, cell phones,

TVs, MP3 players • Americans discard 300 million

devices per year • 3/4 still work

• They are put in landfills but should be treated as hazardous waste

• Valuable trace minerals can be recovered – the 2010 Olympic medals were made from e-waste!


E-waste is growing (cont’d)

• Electronic waste is increasing


Several steps precede the disposal of hazardous waste• Communities designate sites, collection days, or

facilities to gather household hazardous waste • Waste is then transported for treatment and disposal


Several steps precede the disposal of hazardous waste (cont’d)• Under the Resource Conservation and Recovery Act

(RCRA): the EPA sets standards, but the… • States manage hazardous waste

• Large generators of hazardous waste must obtain permits

• Materials must be tracked “from cradle to grave”

• Intended to prevent illegal dumping


Several steps precede the disposal of hazardous waste (cont’d)• Hazardous waste disposal is costly

• Often results in illegal dumping • Illegal dumping creates health risks

• Along with financial headaches for dealing with it • Industrial nations illegally dump in developing

nations • The Basel Convention, an international treaty, should

prevent dumping, but it still happens • High costs also encourage companies to invest in

reducing their hazardous waste • Incineration, bacterial and plant decomposition, etc.


We use three disposal methods for hazardous waste

• Landfills do not lessen the hazards of the substances

• But they help keep the substance isolated from people, wildlife, and ecosystems

• Hazardous waste landfills • Their design and construction standards are stricter than

those for ordinary sanitary landfills • Must have several impervious liners and leachate

removal systems • Must be located far from aquifers


We use three disposal methods for hazardous waste (cont’d)• Surface impoundments

• Store liquid hazardous waste • Shallow depressions are lined with plastic and clay • The liquid or slurry evaporates • The residue of solid hazardous waste is transported

elsewhere for disposal • This storage method is only temporary

• The clay layer can crack and leak waste • Rainstorms cause overflow, contaminating nearby areas


We use three disposal methods for hazardous waste (cont’d)• Deep-well injection

• A well is drilled deep beneath the water table • Waste is injected into it • A long-term disposal method • The well is isolated from

groundwater and humans • But the wells can corrode

and leak waste


Contaminated sites are being cleaned up

• Thousands of former military and industrial sites are contaminated with hazardous waste

• Dealing with these messes is hard, time-consuming, and expensive

• Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (1980)

• Superfund is administered by the EPA • Established a federal program to clean up U.S. sites

polluted with hazardous waste


Contaminated sites are being cleaned up (cont’d)

• The EPA must also clean up brownfields • Lands whose reuse or development is complicated by the

presence of hazardous materials • Two events spurred creation of Superfund

legislation • In Love Canal, Niagara Falls, New York, in 1978–1980,

families were evacuated after buried chemicals rose to the surface

• Times Beach, Missouri, was evacuated after contamination with dioxin from oil sprayed on roads


The Superfund process

• Once a Superfund site is identified, EPA scientists note:

• How close the site is to human habitation • Whether wastes are currently confined or likely to spread • Whether the site threatens drinking water supplies

• Harmful sites are placed on the National Priority List • Ranked by their level of risk to human health • Cleanup occurs as funds are available

• The EPA must hold public hearings to inform area residents of its findings and to receive feedback


Who pays for cleanup?

• CERCLA operates under the polluter-pays principle: charge polluting parties for cleanup

• However, the responsible parties often can’t be found

• A trust fund was established by a federal tax on the petroleum and chemical industries

• The fund is bankrupt, and Congress has not restored it; taxpayers now pay all costs of cleanup

• Fewer cleanups are being completed • 1326 sites remain, and only 375 have been cleaned up • Each cleanup costs $25 million and takes 15 years


Conclusion

• We have made great strides in addressing our waste problems

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

• Recycling and composting are growing rapidly • But our prodigious consumption has created more

waste than ever before • The best solution to our waste problem is to reduce

generation of waste

Documents

17 Lecture Presentation lecture will help you understand: • The types of waste we generate • Managing waste • The scale of the waste dilemma • Conventional waste disposal •