1. Municipal Solid Waste: Disposal and Recovery
CHAPTER 21
Municipal Solid Waste: Disposal and Recovery

2. An introduction to municipal solid waste
Danehy Park is in North Cambridge, Massachusetts
Its 50 acres hosts thousands of people
A red light in the bathroom warns if methane has built up
The park is built on an old landfill that was once a blight on the neighborhood
In the 1970s and 1980s, closing old landfills created a “solid waste crisis” that turned out to be temporary
Many have been converted to parks, golf courses, and nature preserves
We are running out of space to put all of our garbage

3. From landfills to playing fields

4. Solid wastes: landfills and combustions
Municipal solid waste (MSW): total of all materials (trash, refuse, garbage) thrown away from homes and small businesses
It is collected by local governments
It is different from hazardous waste and nonhazardous industrial waste
Nonhazardous industrial waste: generated by industries
Demolition and construction wastes, agricultural and mining wastes, sewage sludge, industrial wastes
States, not the EPA, oversee these wastes

5. Disposal of municipal solid waste
The amount of MSW generated in the U.S. is increasing
More people, changing lifestyles, excessive packaging
In 1960, the average MSW was 2.7 lbs/person/day
In 2007: 4.6 lbs/person/day
In 2007, the U.S. generated enough garbage to fill 96,000 garbage trucks/day
We generate huge amounts of MSW and it is harder to dispose of in an environmentally sound and healthy way
MSW varies depending on the generator, neighborhood, and time of year

6. U.S. MSW composition

7. Electronic Waste: A Growing Problem
E-waste consists of toxic and hazardous waste such as PVC, lead, mercury, and cadmium.
The U.S. produces almost half of the world's e-waste but only recycles about 10% of it.
Figure 22-4

8. Whose job?
Many local governments are responsible for collecting and disposing of MSW
They own trucks and hire workers
Or contract with a private firm
Who pays for the cost of waste pickup?
Taxes
Pay-as-you-throw: charges by the amount of trash
Collectors bill households
State and federal regulations begin to apply at disposal

9. Past sins Until the 1960s MSW was burned and buried in dumps
Smoldering dumps smelled and attracted flies and rats
Incineration (combustion facilities): burn waste completely
May cause air pollution
Open dumps and incinerators were phased out
Public pressure and air pollution laws
Replaced by landfills
In the last 10 years, landfills and combustion have declined
Recycling has increased
Patterns of disposal differ in countries

10. U.S. MSW disposal

11. Approaches to Pollution Management
Human activity producing pollutant
Altering human activity through education incentives and penalties to promote:
Development of alternative technologies
Adoption of alternative lifestyles
Reducing, reusing, recycling
Release of pollutant into environment
Regulating and reducing the pollutant at the point of emissions by:
Setting and imposing standards
Introducing measures for extracting the pollutant from waste emissions
Long-term impact of pollutant on ecosystem
Cleaning up the pollutant and restoring ecosystems by:
Extracting and removing the pollutant from the ecosystem
Replanting and restocking with animal populations

12. INTEGRATED WASTE MANAGEMENT
We can manage the solid wastes we produce and reduce or prevent their production.
Figure 22-5

13. Landfills
Landfill: waste is put on or in the ground and covered with earth
Minimizing air pollution and vermin
But managers did not understand ecology, the water cycle, or products of decomposition
They did not have regulations to guide them
So landfills were put on any cheap land outside of town
Natural gullies, abandoned quarries, wetlands, old dumps

14. Secure landfills
Secure landfill: a reasonably safe landfill that is lined
It also has a leachate-removal system
It is monitored and properly capped
But the barriers are subject to damage and deterioration
Surveillance and monitoring systems are needed to prevent leakage

15. Pipes collect explosive methane as used as fuel
When landfill is full,
layers of soil and clay
seal in trash
Topsoil
Electricity
generator
building
Sand
Clay
Methane storage
and compressor
building
Leachate
treatment system
Garbage
Probes to
detect
methane
leaks
Pipes collect explosive methane as used as fuel
to generate electricity
Methane gas
recovery well
Leachate
storage
tank
Compacted
solid waste
Garbage
Groundwater
monitoring
well
Leachate
pipes
Leachate pumped
up to storage tank
for safe disposal
Sand
Synthetic
liner
Leachate
monitoring
well
Sand
Clay and plastic lining
to prevent leaks; pipes
collect leachate from
bottom of landfill
Groundwater
Clay
Subsoil
Fig , p. 532

16. Secure landfill

17. New Orleans dump

18. Problems of landfills: leachate and groundwater pollution
Leaching: chemicals dissolve in and are transported by water
Leachate: water with various pollutants
A “witches brew” of pollutants
Organic matter, heavy metals, chemicals
Can enter groundwater aquifers
All states have, or will have, landfills contaminating groundwater
Florida has 145 sites on the Superfund list (sites where groundwater contamination threatens human health)

19. Problems of landfills: methane
Buried wastes undergo anaerobic decomposition
Producing biogas (methane, CO2 and hydrogen)
Biogas is highly flammable
Seeping horizontally through soil, it can enter homes and cause explosions
Seeping to the surface, it kills vegetation
Biogas can be captured, purified, and used as fuel
In 2008, commercial landfill gas produced electricity and gas for 1.4 million homes
Reducing greenhouse gas emissions and fossil fuel use

20. Westminster landfill

21. Problems of landfills: incomplete decomposition
Plastics in MSW resist decomposition
Petroleum-based polymers resist microbial digestion
Biodegradable plastic polymers have been developed
Using cornstarch, cellulose, lactic acid, soybeans
They are more expensive
They are used by organic manufacturing companies
Even biodegradable materials degrade very slowly
Newspapers buried 30 years ago are still readable
Decomposition requires water
But water produces toxic leachates

22. Problems of landfills: settling
Waste settles as it compacts and decomposes
Buildings have never been put on landfills
Where landfills have been converted to playgrounds and golf courses, shallow depressions or deep holes are created
Monitoring the facility and using fill to restore a level surface solve the problem

23. Improving landfills
The EPA upgraded siting and construction requirements
New landfills are sited on high, stable ground above the water table, away from airports
Water drains into a leachate-collection system
Tile, plastic liners, and compacted soil collect leachate
The fill is built up in the shape of a pyramid and capped with earthen material and soil and reseeded
The site is surrounded by groundwater monitors
Abandoned landfills can become recreational facilities
Attractive golf courses and wildlife preserves

24. Features of a modern landfill

25. Siting new landfills
Between 1988 and 2007, landfills decreased from 8,000 to 1,754
The EPA does not think capacity is a problem
But people don’t want landfills near them
It is hard to find areas to build new landfills
Any potential site is met with protests and lawsuits
LULU (locally unwanted land use); NIMBY (not in my backyard); NIMTOO (not in my term of office)
BANANA (build absolutely nothing anywhere near anything)

26. Outsourcing Undesirable consequences of the siting problem
Drives up costs of waste disposal
Inefficient and objectionable transfer to private landfills
Transfer of waste may occur across state or national lines
Resentment and opposition from citizens
11 U.S. states export > 1 million tons/year (#1: New York)
13 states import > 1 million tons/year (#1: Pennsylvania)
Desirable consequences of siting problems: it encourages recycling and stimulates combustion of MSW

27. Advantages of combustion
89 U.S. facilities burn 32 million tons/year of MSW
A waste reduction process, not disposal
Ash must still be disposed of
Combustion reduces weight of trash by 70% and volume by 90%
Fly ash contains most of the toxic substances
It is landfilled
Bottom ash: is used as fill in construction or roadbeds
Converted to concrete

28. More advantages of combustion
No changes are needed in collection or people’s behavior
Two-thirds of combustion facilities are waste-to-energy (WTE)
Untreated MSW releases 35% as much energy as coal when burned
Producing electricity for 2.3 million homes
Wasted energy going to landfills equals 9.4 billion gallons of diesel oil/year
Many facilities add resource recovery
Separating and recycling materials before and after burning

29. Drawbacks of combustion
Air pollution: has decreased through strict regulations
Odor pollution: plants are isolated from residential areas
Facilities are expensive to build
Siting: facilities are located in industrial areas
Toxic ash must be disposed of in secure landfills
The facility must have a continuous supply of MSW
Agreements with municipalities decreases flexibility in waste management options
The process wastes energy and materials
Combine burning with recycling and recovery

30. An operating facility
A facility serving 1 million gets 3,000 tons of MSW/day
Waste comes in by rail and truck
Communities pay $65/ton tipping fees
Waste processing is efficient: 80% is burned for energy
12% is recovered; 8% is landfilled
If 1 million tons of MSW are processed
40,000 tons of metals are recycled
Electricity for 65,000 homes is generated
Opponents cite air pollution, traffic, and property values as concerns against WTE facilities

31. The Waste To Energy process
Incoming waste is inspected and recyclables are removed
Shredders reduce waste particles to 6 inches or less
Magnets remove metals for recycling
Waste is blown into boilers for burning
Water circulating through the boilers produces steam for electricity
Metals are separated from bottom ash
Combustion gases are treated to reduce emissions
Fly ash and bottom ash are taken to landfills

32. Waste-to-energy combustion facility

33. Costs of municipal solid-waste disposal
Costs of disposing of MSW are increasing
Design features of landfills
Expenses in acquiring sites and transportation
Tipping fees average $42/ton (but New York City’s is $263/ton—$1 billion/year!)
One consequence: illegal dumping
Some towns charge $5/bag for MSW, $1/tire, etc.
Wastes are appearing in many areas
Buildings put padlocks on dumpsters
Many states track down midnight dumpers

34. Better solutions: source reduction
Source reduction: reducing waste at its source
The best solution for domestic wastes
Designing, manufacturing, purchasing, or using materials to reduce the amount/toxicity of trash
U.S. waste has leveled off at 4.5 lbs/person
Due to lifestyle changes
Measured by measuring consumer spending, which reflects goods and products that become trash
In 2000, 55 million tons did not go into the waste stream

35. Examples Reducing the weight of items
Steel cans are 60% lighter than they used to be
Reducing paper waste via electronic communication, data transfer, the Internet
Reusing durable goods: reselling items
eBay, Craigslist, Freecycle Network
Designing products to last longer and be easier to repair
Staying off of bulk mailing lists
Composting yard wastes

36. Waste reduction by reuse

37. The recycling solution
More than 75% of MSW is recyclable
Primary recycling: the waste is recycled into the same material
Recycling newspapers into newspapers
Secondary recycling: waste is made into different products that may or may not be recyclable
Recycling newspapers into cardboard

38. Benefits of recycling Recycling saves energy and resources
One ton of recycled steel saves 2,500 pounds of iron ore, 1,000 lbs of coal, 5,400 BTUs of energy
Recycling decreases pollution
Making recycled paper uses 64% less energy, creates 74% less air, and 35% less pollution
A recycling program that processes 1 ton of waste eliminates 620 lbs of CO2, 30 lbs of methane, 5 lbs of CO, 2.5 lbs of particulates

39. What gets recycled?
Paper (47%): paper, cardboard, insulation, or is composted
Glass (28%): new containers, fiberglass or used in highway construction (glassphalt)
Plastic (12%): carpet, clothes, irrigation drainage tiles, building materials, sheet plastic
Metals: recycling aluminum (39%) saves 90% of the energy to make cans from ore
Saves energy, creates jobs, reduces the trade deficit
Yard wastes (64%) are composted

40. Deck made from Trex

41. Other items that are recycled
Textiles (17%): strengthen recycled paper products
Old tires (35%): incorporated into highway asphalt
Over 1 million tires/year are burned in combustion plants
People recycle out of environmental and economic motivations
The Global Recycling Network is an information exchange promoting recycling and ecofriendly products

42. Municipal recycling
Recycling is the most direct and obvious way to become involved in environmental issues
Almost every state has recycling goals, with varying degrees of success
33.4% of MSW was recycled in 2007
There is great diversity in recycling programs
Recycling centers, curbside recycling, incentives, etc.

43. State recycling rates

44. MSW recycling in the U.S.

45. Successful recycling programs
Have a strong incentive to recycle
PAYT charges, but no charges for recycling
Have mandatory regulations, with warnings or sanctions for violators
Offer curbside residential recycling
60% of people in the U.S. have curbside programs
Have drop-off sites for large items (e.g., sofas)
Have ambitious, yet clear and feasible, recycling goals
Involve local industries
Have an experienced, committed recycling coordinator

46. Curbside recycling

47. Economics of recycling
Cities have different recycling rates
New York City, 16%; San Francisco, 70%
Recycling costs are often higher than alternatives
Markets fluctuate wildly; low tipping fees
Recycling critics say that recycling must pay for itself
Environmental assessments should compare energy costs of recycling with costs of landfill or combustion
Life cycle analysis: comparing energy costs of making products from recycled goods vs. from scratch

48. Recycling has taken a hit
The 2008–2009 recession caused demand for recyclable products to plummet
Berkeley, California received $200/ton for recyclables in 2008, but it got $35/ton in 2009
But support for recycling is strong
Two-thirds of households will participate in curbside recycling
Even more recycle if a PAYT program exists or participants are rewarded
Dover, New Hampshire’s MSW went from 6 lbs/person (1991) to 2.3 lbs/person (1997)

49. Paper recycling Newspapers: the most important item that is recycled
78% of newspaper is recycled
What is meant by “recycled paper”?
Recycled paper: routinely recovered and rerouted back into processing
Postconsumer recycled paper is what’s important
It is almost impossible to tell recycled from virgin paper
The market is a critical factor in recycled paper
Is there a demand?

50. The market for recycled paper
The market for recycled paper fluctuates widely
During the late 1980s, municipalities had to pay to get rid of paper
In 1995, at $160/ton, paper was being stolen!
In 1996, the market collapsed
Cities had to pay to have paper hauled away
But it is still less expensive than paying tipping fees
There is a lively international trade in used paper
Forest-poor countries buy wastepaper

51. Wastepaper exports

52. Glass recycling and bottle laws
Most MSW glass: containers for beverages
The U.S. drinks 28 billion gallons/year
Most drinks come in single-serve containers that are thrown away
Glass = 5.3% of MSW, but 50% of nonburnable MSW
Mining and manufacturing create pollution
Hidden problems: litter, injuries, flat tires, etc.
Bottle laws: require a deposit on all beverage containers
Retailers must accept used containers and pass them on for reuse or recycling

53. Bottle laws Are fiercely opposed by beverage and container industries
Cite lost jobs and higher costs of beverages
Well-financed lobbying has defeated bottle laws
11 states have adopted bottle laws
Jobs are gained and costs have not risen
A high percentage of bottles is returned
There is a marked reduction in litter
A national bottling law has been unsuccessful
It would increase recycling
It would employ tens of thousands

54. Plastics recovery Plastics have a bad reputation
They have a rapid throughput (packaging, diapers, etc.)
The are conspicuous in MSW and litter
They do not decompose in landfills
Bottled water: the number one “new” drink
8.9 billion gallons were sold in the U.S. in 2007
Only two states with bottle laws include bottled water
People pay 10,000 times more than for tap water
Only 1 in 6 bottles is recycled
But there is a real market demand for plastic

55. PETE and HDPE
Numbers and letters on the bottom of plastic bottles tell the type of plastic polymer in the bottle
PETE (polyethylene terephthalate): code 1
Recycled into carpets, jackets, film, strapping, new PETE bottles
HDPE (high-density polyethylene): code 2
Recycled into irrigation drainage tiles, sheet plastic, recycling bins
Recycling plastic makes economic and environmental sense

56. Plastic bags
Plastic bags are everywhere: hanging from trees, blowing along highways, clogging sewers, in oceans
Killing thousands of marine animals and turtles yearly
Each year, the U.S. uses 100 billion (world: 1 trillion!)
Hard to recycle and almost indestructible
China has banned ultrathin bags
San Francisco banned plastic bags in 2007
The plastic industry is fighting back with lawsuits
Use cloth, paper bags, or thicker plastic bags

57. Regional recycling options
As landfills close and MSW is transferred to other places, transfer stations that transfer wastes to larger vehicles are set up
Materials recovery facilities (MRFs, “murfs”)
Converted transfer stations
567 MRFs in the U.S. handle 91,000 tons/day
After recyclables are collected by curbside collection or collecting stations, MSW is trucked to the MRF
Workers inspect and sort the MSW to prepare it for the recyclable-goods market
Glass, cans, paper, plastic

58. Materials recovery facility

59. MRFs MRF’s advantages: economies of scale
It produces a high-quality end product for recyclable materials market
People know where to bring their wastes
Some MRFs use high technology to sort waste
Magnets, optical sensors, air sorters
Mixed waste processing facilities: less common
Waste is sorted for recovery of recyclables before being landfilled or combusted
The U.S. has 34 facilities handling 43,000 tons/day

60. Composting mixed waste and yard trimmings
Some facilities compost MSW after removing large items and metals
Co-composting: mixing treated sludge with MSW provides bacteria and nutrients
Facilities are plagued with flies and fire
They may also be combined with a MRF
Yard-trimmings composting programs are more common
3,500 U.S. programs handle 57,000 tons/day

61. Integrated waste management
It is not necessary to use one method of handling MSW
Source reduction, waste-to-energy, combustion, recycling, MRFs, landfills, composting all have roles
Integrated waste management uses several processes
Waste reduction: the U.S. produces the most waste
We are a “throwaway society”
True management of MSW begins at home
WasteWise: an EPA-sponsored program that partners with local governments, schools, corporations
Partners design their own waste-reduction programs

62. The throwaway society

63. Pay-as-you-throw trash pickup

64. Waste disposal issues There will always be MSW
Landfilling will decrease and more MSW will go to WTE combustion facilities and recycling
Policy makers have opted for short-term solutions with low political costs
Resulting in long-distance hauling of MSW
Areas required to handle their own trash will find suitable landfill sites and use the best technologies
People don’t want trash from other areas
It will take an act of Congress to address this problem

65. Recycling and reuse Recycling is the wave of the future
Making more durable goods is overlooked and underutilized
Banning the disposal of recyclables in landfills and at combustion facilities makes sense
Massachusetts bans yard wastes, metals, glass, paper, and plastics
A national bottle law would be a giant step forward
Closing the “recycling loop” would encourage recycling

66. Closing the recycling loop
Set minimum postconsumer levels of recycled content for newsprint and glass containers
Require purchases of certain goods that include recycled products
Even if they are more expensive
Require that all packaging be reusable or made of recycled materials
Tax credits or incentives encourage the use of recycled or recyclable materials in manufacturing
Help develop recycling markets

67. Municipal Solid Waste: Disposal and Recovery
CHAPTER 21
Municipal Solid Waste: Disposal and Recovery
Active Lecture Questions

68. Review Question-1
True or False: Municipal solid waste (MSW) is the same as hazardous waste.
a. True
b. False

69. Review Question-1 Answer
True or False: Municipal solid waste (MSW) is the same as hazardous waste.
a. True
b. False

70. Review Question-2
“Gas wells” in landfills tap into the ______ naturally produced within the landfill by the decomposition process.
a. carbon dioxide
b. oxygen
c. methane
d. water vapor

71. Review Question-2 Answer
“Gas wells” in landfills tap into the ______ naturally produced within the landfill by the decomposition process.
a. carbon dioxide
b. oxygen
c. methane
d. water vapor

72. All of the following are drawbacks of combustion except
Review Question-3
All of the following are drawbacks of combustion except
a. air pollution.
b. reduction of garbage volume.
c. combustion facilities are expensive.
d. combustion ash must be disposed of as hazardous waste.

73. Review Question-3 Answer
All of the following are drawbacks of combustion except
a. air pollution.
b. reduction of garbage volume.
c. combustion facilities are expensive.
d. combustion ash must be disposed of as hazardous waste.

74. Review Question-4
The two recyclable plastics in most common use are ______ (code 2) and ______ (code 1).
a. HDPE; PETE
b. HDL; LDL
c. MSW; MRF
d. LDL; MSW

75. Review Question-4 Answer
The two recyclable plastics in most common use are ______ (code 2) and ______ (code 1).
a. HDPE; PETE
b. HDL; LDL
c. MSW; MRF
d. LDL; MSW

76. a. recycling and composting. b. materials recovery facilities.
Review Question-5
Integrated waste management calls for having the following processes in operation:
a. recycling and composting.
b. materials recovery facilities.
c. landfills.
d. all of the above.

77. Review Question-5 Answer
Integrated waste management calls for having the following processes in operation:
a. recycling and composting.
b. materials recovery facilities.
c. landfills.
d. all of the above.

78. Interpreting Graphs and Data-1
According to Fig. 21-3, most of the municipal solid waste in the United States is disposed by
a. recycling.
b. composting.
c. burying in landfills.
d. burning.

79. Interpreting Graphs and Data-1 Answer
According to Fig. 21-3, most of the municipal solid waste in the United States is disposed by
a. recycling.
b. composting.
c. burying in landfills.
d. burning.

80. Interpreting Graphs and Data-2
According to Fig , in what year did MSW recycling begin to increase dramatically?
a. 1965
b. 1990
c. 2000
d. 2007

81. Interpreting Graphs and Data-2 Answer
According to Fig , in what year did MSW recycling begin to increase dramatically?
a. 1965
b. 1990
c. 2000
d. 2007

82. Thinking Environmentally-1
The accumulation of televisions, computers, DVD players, cell phones, and the like has contributed to a new kind of waste called
a. techno-waste.
b. EZ-waste.
c. MSW.
d. e-waste.

83. Thinking Environmentally-1 Answer
The accumulation of televisions, computers, DVD players, cell phones, and the like has contributed to a new kind of waste called
a. techno-waste.
b. EZ-waste.
c. MSW.
d. e-waste.

84. Thinking Environmentally-2
The type of material that contributes most to the municipal solid waste in the United States is
a. wood.
b. food waste.
c. plastics.
d. paper.

85. Thinking Environmentally-2 Answer
The type of material that contributes most to the municipal solid waste in the United States is
a. wood.
b. food waste.
c. plastics.
d. paper.