1. Chapter 29: Waste Management

2. Early Concepts of Waste Disposal
Start of Industrial Revolution, the volume of waste produced in the US was relatively small.
Managed through the concept of “dilute and disperse.”
Factories located near water.
Easy transport of materials by boat
Sufficient water for processing and cooling
Easy disposal of waste into the river
Few factories and a sparse population
Method was sufficient to remove the waste from the immediate environment.

3. Early Concepts of Waste Disposal
As industrial and urban areas expanded, the concept became “concentrate and contain”
Containment not always achieved.
Containers leak or break and allow waste to escape.
People are facing a serious solid-waste disposal problem.
We are producing a great deal of waste and the acceptable space for permanent disposal is limited.
Difficult to site new landfills (NIMBY).

4. Modern Trends
Environmentally correct concept is to consider wastes as resources out of place.
Waste would be a resource to be used again.
Referred to as the “zero waste” movement.
Industrial ecology
Study of relationships among industrial systems and their links to natural systems.
Waste from one part of the system would be a resource for another part.

5. Modern Trends Countries have moved to cut waste by imposing taxes.
Taxation of waste in all its various forms, from emissions from smokestacks to solids delivered to landfills.
As taxes increase people produce less waste.
Landfills produce methane gas which can be burned as fuel.

8. Integrated Waste Management
A set of management alternatives that includes:
Reuse
Source reduction
Recycling
Composting
Landfill
Incineration

9. Reduce, Reuse, Recycle
Ultimate objective of the three R’s is to reduce.
Study of the waste stream in areas that utilize IWM technology suggests that the amount of refuse disposed of in landfills or incinerated can be reduced by at least 50%
Reduction facilitated by
Better design of packaging to reduce waste, an element of source reduction (10% reduction).
Large-scale composting programs (10% reduction).
Establishment of recycling programs (30% reduction).

10. Reduce, Reuse, Recycle
Recycling is a major player in the reduction of urban waste stream.
Estimated that as much as 80-90% of the US waste stream might be recovered through intense recycling.
Partial recycling can provide a significant reduction ~50%.
Simplified by single stream recycling.

12. Public Support for Recycling
Encouraging signs
An increase in the willingness of industry and business to support recycling on a variety of scales.
People are now more likely to purchase products that can be recycled or that come in containers that are more easily recycled or composted.

13. Markets for Recycled Products
In communities where recycling has been successfully implemented, it has resulted in glutted markets for the recycled products.
If recycling is to be successful,
markets and processing facilities will also have to be developed to ensure that recycling is a sound financial venture.

14. Recycling of Human Waste
The use of human waste or “night soil” on croplands is an ancient practice.
Early uses of human waste for agriculture occasionally spread infectious diseases.
One of the major problems of recycling human waste today is that thousands of chemicals and metals flow through our waste stream.
Because many toxic materials are likely to be present with the waste, we must be very skeptical of utilizing sewage sludge for land application.

15. Materials Management
Futuristic waste management has the goal of zero production of waste.
Consistent with the ideals of industrial ecology.
Goal will require more sustainable use of materials combined with resource conservation in what is being termed materials management.

16. Materials Management The goal could be pursued in the following ways:
Eliminate subsidies for extraction of virgin materials.
Establish “green building” incentives that encourage the use of recycled-content materials and products in new construction.
Assess financial penalties for production that uses negative materials management practices.

17. Materials Management
Provide financial incentives for industrial practices and products that benefit the environment by enhancing sustainability.
Increase the number of new jobs in the technology of reuse and recycling of resources.

18. Solid-Waste Management
Continues to be a problem in many parts of the world.
Many practices inadequate.
Open dumps, illegal roadside dumping
Social problem as much as a physical one, because many people are simply disposing of their waste as inexpensively and as quickly as possible.

19. Composition of Solid Waste
Paper is by far the most abundant content.
Excavations into modern landfills using archeological tools have cleared up some misconceptions concerning other items.
Fast-food packaging accounts for about 0.25% of the average landfill
Disposable diapers, approximately 0.8%
Polystyrene products, about 0.9%

21. On-Site Disposal
A common on-site disposal method in urban areas is the mechanical grinding of kitchen food waste.
Garbage-disposal devices are installed at the kitchen sink, and the garbage is ground and flushed into the sewer system.

22. Composting
Biochemical process in which organic materials decompose to a rich, soil-like material.
The process involves rapid partial decomposition of moist solid organic waste by aerobic organisms.
As a waste management option, large-scale composting is generally carried out in the controlled environment of mechanical digesters.

23. Incineration
Combustible waste is burned at temperatures high enough (900°–1,000°C, or 1,650°–1,830°F) to consume all combustible material.
Leaving only ash and non-combustibles to dispose of in a landfill.
Process of incineration can be used to supplement other fuels and generate electrical power.
In modern incineration facilities, smokestacks are fitted with special devices to trap pollutants.

24. Open Dumps
In the past, solid waste was often disposed of in open dumps, where the refuse was piled up without being covered or otherwise protected.
Located wherever land is available, without regard to safety, health hazards, or aesthetic degradation.
Common sites
Abandoned mines and quarries, natural low areas, such as swamps or floodplains; and hillside areas above or below towns.

26. Sanitary Landfills
Designed to concentrate and contain refuse w/o creating a nuisance or hazard to public health or safety.
Confined to the smallest practical area
Reduced to the smallest practical volume
Covered with a layer of compacted soil at the end of each day of operation.

27. Leachate
The most significant hazard from a sanitary landfill is pollution of groundwater or surface water.
If waste comes into contact with water, leachate is produced.
noxious, mineralized liquid capable of transporting bacterial pollutants

28. Site Selection
A number of factors must be taken into consideration when selecting a site, including:
Topography
Location of the groundwater table
Amount of precipitation
Type of soil and rock
Location of the disposal zone in the surface water and groundwater flow system.
Best sites are arid sites

29. Site Selection
The waste is buried above the water table in relatively impermeable clay and silt soils.
Leachate produced remains in the vicinity of the site and degrades by natural filtering action.
Site selection also involves important social considerations.
Chosen where they expect local resistance to be minimal or where they perceive land to have little value.
Frequently located in areas of low socioeconomic status

31. Monitoring Pollution in Sanitary Landfills
Once a site is chosen for a sanitary landfill and before filling starts, monitoring the movement of groundwater should begin.
Accomplished by periodically taking samples of water and gas from specially designed monitoring wells.
Monitoring the movement of leachate and gases should continue as long as there is any possibility of pollution.

32. How Pollutants Can Enter the Environment from Sanitary Landfills
1. Methane, ammonia, hydrogen sulfide, and nitrogen gases can be produced from compounds in the soil and the waste and can enter the atmosphere.
2. Heavy metals, such as lead, chromium, and iron, can be retained in the soil.

33. How Pollutants Can Enter the Environment from Sanitary Landfills
3. Soluble materials, such as chloride, nitrate, and sulfate, can readily pass through the waste and soil to the groundwater system.
4. Overland runoff can pick up leachate and transport it into streams and rivers.

34. How Pollutants Can Enter the Environment from Sanitary Landfills
5. Plants growing in the disposal area can selectively take up heavy metals and other toxic materials.
Passed up the food chain as people and animals eat the plants.
6. If plant residue return toxic substances to the soil.

35. How Pollutants Can Enter the Environment from Sanitary Landfills
7. Streams and rivers may become contaminated by waste from groundwater seeping into the channel (3) or by surface runoff (4).
8. Toxic materials can be transported to other areas by the wind.

36. How Pollutants Can Enter the Environment from Sanitary Landfills
Modern sanitary landfills are engineered to include multiple barriers:
Clay and plastic liners to limit the movement of leachate
Surface and subsurface drainage to collect leachate
Systems to collect methane gas
Groundwater monitoring to detect leaks of leachate below and adjacent to the landfill.

39. Federal Legislation for Sanitary Landfills
Resource Conservation and Recovery Act of 1980.
Legislation intended to strengthen and standardize design, operation, and monitoring of sanitary landfills.
Landfills that cannot comply with regulations face closure.
States may choose between two options:
1. Comply with federal standards.
2. Seek EPA approval of solid-waste management plans, which allows greater flexibility.

40. Federal Legislation for Sanitary Landfills
Provisions of federal standards include the following:
Landfills may not be sited on floodplains, wetlands, earthquake zones, unstable land, or near airports.
Landfills must have liners.
Landfills must have a leachate collection system.
Landfill operators must monitor groundwater for many specified toxic chemicals.
Landfill operators must meet financial assurance criteria to ensure that monitoring continues for 30 years after the landfill is closed.

41. Federal Legislation for Sanitary Landfills
EPA approval of its landfill program:
Groundwater monitoring may be suspended.
Alternative types of daily cover over the waste.
Alternative groundwater protection standards and schedules for documentation are allowed.
Under certain circumstances, landfills in wetlands and fault zones are allowed.
Alternative financial assurance mechanisms are allowed.

42. Reducing the Waste You Produce

43. Hazardous Waste
In the US, approximately 1,000 new chemicals are marketed each year, and about 70,000 chemicals are currently on the market.
35,000 chemicals used are classified as definitely or potentially hazardous to the health of people or ecosystems.
The US currently produces about 700 million metric tons of hazardous chemical waste per year, referred to more commonly as hazardous waste.

44. Hazardous Waste
Uncontrolled dumping of chemical waste has polluted soil and groundwater in several ways:
Chemical waste may be stored in barrels.The barrels eventually corrode and leak.
When liquid chemical waste is dumped into an unlined lagoon, contaminated water may percolate through soil and rock to the groundwater table.
Liquid chemical waste may be illegally dumped in deserted fields or even along roads.

47. Resource Conservation and Recovery act
Passed in 1976
Identification of hazardous wastes and their life cycles.
“Cradle to grave” management
The act classifies hazardous wastes in several categories:
Materials highly toxic to people and other living things;
Wastes that may ignite when exposed to air;
Extremely corrosive wastes
Reactive unstable wastes that are explosive or generate toxic gases or fumes when mixed with water.

48. Comprehensive Environmental Response, Compensation, and Liability Act
Passed in 1980
Act defined policies and procedures for release of hazardous substances into the environment.
Mandated development of a list of the sites where hazardous substances were likely to or already had produced the most serious environmental problems
Established a revolving fund (Superfund) to clean up the worst abandoned hazardous-waste sites.

49. Comprehensive Environmental Response, Compensation, and Liability Act
Strengthened by amendments that made the following changes:
Improved and tightened standards for disposal and cleanup of hazardous waste.
Banned land disposal of certain hazardous chemicals.
Initiated a timetable for phasing out disposal of all untreated liquid hazardous waste in landfills or surface impoundments.
Increased the size of the Superfund.

50. Hazardous-Waste Management Land Disposal
Management of hazardous chemical waste involves several options, including:
Recycling
On-site processing to recover by-products with commercial value
Microbial breakdown
Chemical stabilization
High-temperature decomposition
Incineration
Disposal by secure landfill or deep-well injection

52. Secure Landfill A secure landfill for hazardous waste is designed to:
Confine the waste to a particular location
Control the leachate that drains from the waste
Collect and treat the leachate
Detect possible leaks
This type of landfill is similar to the modern sanitary landfill.

54. Land Application: Microbial Breakdown
Intention application of waste materials to surface soil.
May be a desirable method of treatment for certain biodegradable industrial wastes.
A good indicator of the usefulness of land application for a particular waste is the biopersistence of the waste.
How long the material remains in the biosphere.
Greater the biopersistence, the less suitable for land application

55. Land Application: Microbial Breakdown
Land application of biodegradable waste works because,
when materials are added to the soil, they are attacked by microflora that decompose the waste material in a process known as microbial breakdown.

56. Surface Impoundment
Both natural topographic depressions and human-made excavations formed primarily of soil or other surface materials but lined with manufactured materials such as plastic.
Examples include aeration pits and lagoons at hazardous-waste facilities.
Prone to seepage, resulting in pollution of soil and groundwater.
Evaporation from surface impoundments can also produce an air pollution problem.

57. Deep Well Disposal
A deep well penetrates to a depth below and completely isolated from all freshwater aquifers.
Waste is injected into a permeable rock layer several thousand meters below the surface in geologic basins.
Capped by relatively impervious, fracture-resistant rock such as shale or salt deposits.

58. Deep Well Disposal Important control of water pollution in oil fields.
Injection of oil field brine.
Should not be viewed as a quick and easy solution to industrial waste problems.

59. Alternatives to Land Disposal of Hazardous Wastes
Advantages to source reduction, recycling, treatment, and incineration include the following:
Useful chemicals can be reclaimed and reused.
Treatment of wastes may make them less toxic and therefore less likely to cause problems in landfills.
The actual waste that must eventually be disposed of is reduced to a much smaller volume.
Because a reduced volume of waste is finally disposed of, there is less stress on the dwindling capacity of waste-disposal sites.

60. Alternatives to Land Disposal of Hazardous Wastes
Source Reduction
The object is to reduce the amount of hazardous waste generated by manufacturing or other processes.
Recycling and resource Recovery
May contain materials that can be recovered for future use.

61. Alternatives to Land Disposal of Hazardous Wastes
Treatment
Waste can be treated by a variety of processes to change the physical or chemical composition of the waste and so to reduce its toxic or hazardous characteristics.
Incineration
Destroyed by high-temperature incineration.
Incineration is considered a waste treatment rather than a disposal method because the process produces an ash residue, which must then be disposed of in a landfill.

62. Ocean Dumping
Oceans have long been dumping grounds for many types of waste, including industrial waste, construction debris, urban sewage, and plastics
Many locations in the world’s oceans are
Accumulating pollution continuously
Have intermittent pollution problems
Or have potential for pollution from ships in the major shipping lanes

64. Ocean Dumping
Marine pollution has a variety of specific effects on oceanic life, including the following:
Death or retarded growth, vitality, and reproductivity of marine organisms.
Reduction in the dissolved oxygen content necessary for marine life because of increased BOD.
Eutrophication caused by nutrient-rich waste in shallow waters of estuaries, bays, and parts of the continental shelf.
Habitat change caused by waste-disposal practices that subtly or drastically change entire marine ecosystems.

65. Ocean Dumping Microlayer
The upper 3 mm of ocean water.
Planktonic life abundant (base of the marine food chain)
Home to young fish and shellfish in the early stages of their life.
Microlayer also tends to concentrate pollutants, such as toxic chemicals and heavy metals.
Fear that disproportionate pollution will have especially serious effects on marine organisms.

66. Ocean Dumping
Marine pollution can have major impacts on people and society.
Contaminated marine organisms may transmit toxic elements or diseases to people who eat them.
When beaches and harbors become polluted there may be damage to marine life as well as a loss of visual appeal and other amenities.
Economic loss is considerable.
Tourism and fishing industry

67. Pollution Prevention
Involves identifying ways to prevent the generation of waste rather than finding ways to dispose of it.
Approaches include:
Purchasing the proper amount of raw materials so that no excess remains to be disposed of.
Exercising better control of materials used in manufacturing processes so that less waste is produced.

68. Pollution Prevention
Substituting nontoxic chemicals for hazardous or toxic materials currently in use.
Improving engineering and design of manufacturing processes so that less waste is produced.