1. Chapter 22 Topics:  Types of waste  Managing waste  Conventional waste disposal  Management tools  Industrial solid waste management  Managing hazardous waste

2. Types of waste  Waste = any unwanted material or substance that results from human activity or process  Municipal solid waste = non-liquid 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  Wastewater = from household, business, or industry; or polluted runoff from streets and storm drains

3. Waste management  The objective of waste management:  Minimize the amount of waste generated (source reduction)  Reuse or re-purpose  Recover waste materials and recycle/compost them  Dispose of waste safely and effectively  Source reduction is the preferred approach

4. The flow of waste  Waste stream = the flow of waste as it moves from its sources toward disposal destinations  Source reduction = use materials efficiently, consume less, buy goods with less packaging, use goods longer  Recovery (recycling, composting) = next best strategy in waste management  Recycling = sends used goods to facilities to manufacture into new goods (e.g., newspaper)  Composting = recovery of organic waste  But there will always be some waste left to dispose of

5. Municipal solid waste  Municipal solid waste also called “trash” or “garbage”  In the U.S., paper, yard debris, food scraps, and plastics are the principal components of municipal solid waste  Even after recycling, most solid waste is paper  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 1 ton/person each year

6. Disposal methods have improved  People used to dump their garbage wherever it suited them  Now, most industrialized nations bury waste in lined and covered landfills or burn it in incineration facilities  Recycling is reducing the pressure on US landfills

7. Sanitary landfills  Sanitary landfills = waste buried in the ground or piled in large, engineered mounds designed and constructed to prevent contamination and health threats  U.S. landfills are regulated 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 and infestation by pests  Closed landfills must be capped and maintained

8. Landfill leachate  Leachate = formed within a landfill as waste liquids and infiltration react chemically with the solid waste  Leachate management  Reduce leachate production by minimizing infiltration – this is done with landfill “covers” (soils and membranes)  Preventing the migration of leachate out of the bottom of the landfill – this is done with a “liner”  Collecting and treating the leachate that accumulates at the bottom of the landfill – this is done with a “collection system”

9. Landfill design features

10. Landfill gas recovery  Landfill gas = produced when bacteria decompose waste in a landfill’s oxygen-deficient  A mix of gases that consists of 50% methane  Can be collected, processed, and used like natural gas  When not used commercially, landfill gas is burned off to reduce odors and greenhouse emissions

11. Incineration  Incineration = a controlled process that burns garbage at very high temperatures  Incineration reduces the volume of waste  Incineration in specially constructed faculties can be an improvement over open-air burning of trash  The remaining ash must be disposed of in a hazardous waste landfill  Hazardous chemicals can be created and released

12. A typical solid waste incinerator

13. Waste-to-energy  Waste-to-energy (WTE) facilities = use the heat produced by waste combustion to create electricity  Over 100 facilities are in use across the U.S.  They process nearly 100,000 tons of waste per day  But they take many years to become profitable  Companies contract with communities to guarantee a minimum amount of garbage  Long-term commitments interfere with the communities’ efforts to reduce and recycle waste

14. Management tools – reduction  Source reduction = preventing waste in the first place  Avoids costs of recycling and disposal  Helps conserve resources  Minimizes pollution  Can save consumers and businesses money  Most waste consists of materials used to package goods – source reduction to address this issue would include  Using minimal packaging  Using recyclable packaging  Reducing the size or weight of goods and materials

15. Management tools – reuse  Reusing items keeps them out of the waste stream  Use durable goods used instead of disposable ones  Donate items to resale centers (e.g., Goodwill)  Rent or borrow items instead of buying them  Bring your own cup to coffee shops  Buy rechargeable batteries  Make double-sided copies

16. Management tools – composting  Composting = the conversion of organic waste into mulch or humus through natural decomposition  Home composting:  Householders place waste into composting piles, underground pits, or specially constructed containers  Heat from microbial action builds up and decomposition proceeds  Earthworms, bacteria, and other organisms convert waste into high-quality compost

17. Large-scale composting  Municipal composting reduces landfill waste by diverting food and yard waste from the waste stream to central composting facilities  Half of U.S. states now ban yard wastes from the municipal waste stream, accelerating the move to composting  The resulting mulch can be used for gardens and landscaping  Enriches soil and encourages soil biodiversity  Makes healthier plants and more pleasing gardens  Reduces the need for chemical fertilizers

18. Management tools – recycling  Recycling = collecting materials that can be broken down and reprocessed to manufacture new items  Recycling diverted 61 million tons of materials away from incinerators and landfills in 2008  Greenhouse gas emissions equal to 10 billion gallons of gas are prevented each year

19. Recycling must go full circle  There are three parts to recycling  collection and processing of recyclable materials through curbside recycling or designated locations  using recyclables to produce new goods  consumers purchasing goods made from recycled materials  All three parts are necessary

20. Recycling rates vary widely

21. Perspectives on recycling  Growth in recycling results from  Municipalities’ desire to reduce waste  The public’s satisfaction in recycling  Recycling is not always profitable  It is expensive to collect, sort, and process materials  The more material recycled, the lower the price  Market forces do not take fully into account  The health and environmental effects of not recycling  The enormous energy and material savings

23. Industrial waste  Waste from factories, mining, agriculture, petroleum extraction, etc.  U.S. industries generate 7.6 billion tons/year  97% is wastewater  State/local governments regulate industrial solid waste (with federal guidance)

24. Economics plays a bigger role  Most methods for industrial waste reduction, recycling, and disposal are similar to municipal solid waste  State/local regulations may not required permits, installation of liners or leachate collection systems, or monitoring groundwater for contamination  Industries are awarded for economic, not physical, efficiency  So they don’t have incentives to decrease waste  It may be cheaper to generate waste than to avoid it

25. “Industrial ecology”  Industrial systems could function like ecological systems, with little waste  Industrial ecology = redesigning industrial systems to reduce resource inputs while maximizing physical and economic efficiency  Life cycle analysis = examines the life cycle of a product to make the process more ecologically efficient  Waste products can be used as raw materials  Eliminates harmful products and materials  Creates durable, recyclable, or reusable products

26. An example of industrial ecology

27. Hazardous waste  Hazardous waste is a liquid, solid, or gas and is one of the following:  Toxic = harms human health when inhaled, ingested, or contact human skin  Reactive = chemically unstable and readily reacts with other compounds, often explosively or by producing noxious fumes  Ignitable = easily catches fire (natural gas, alcohol)  Corrosive = corrodes metals in storage tanks or equipment

28. Sources of hazardous waste  Industry produces most of our hazardous waste  Mining, manufacturing, agriculture, utilities, building demolition, and businesses all produce hazardous wastes  Industrial waste generation is highly regulated

29. Sources of hazardous waste  Households are the largest source of unregulated hazardous wastes, including paint, batteries, solvents, cleaners, and pesticides.  Since the 1980s, cities have designated sites or collection days to gather household hazardous waste

30. “E waste” – new to the scene  Electronic waste (“e- waste”) = waste from electronic devices such as computers, printers, cell phones, TVs, etc.  Americans discard 400 million devices/year – 67% are still in working  They should be treated as hazardous waste but are not

31. Chemistry of hazardous waste  Organic compounds and heavy metals are hazardous because their toxicity persists over time  Hazardous site investigations analyze for  Volatile organic compounds (VOCs) – solvents and fuels  Semi-volatile organic compounds (SVOCs) – plasticizers, tars, polycyclic aromatic hydrocarbons  Pesticides and PCBs (polychlorinated biphenyls)  Heavy metals (e.g., lead, chromium, arsenic, cadmium)

32. Hazardous waste disposal  Hazardous waste used to be discarded without special treatment  The degree of harm was not understood  “Dilution is the solution to pollution”  Hazardous waste generation and disposal in now regulated by the Resource Conservation and Recovery Act (RCRA) (1976, 1984)

33. “Cradle to grave”  Under RCRA, hazardous waste gets a “paper trail”  Generators of hazardous waste must obtain permits describing how the waste is generated, and how it is managed or stored on site before being shipped to a treatment or disposal facility  Transporters of hazardous waste must be licensed  Treatment and disposal facilities must obtain permits describing how the waste will be managed, and the measures taken to ensure waste constituents do not migrate into the environment

34. Disposal methods - landfills  Design and construction standards are stricter than for ordinary sanitary landfills  Must have several impervious liners and leachate removal systems  The hazardous character of the waste is not changed, but the waste is isolated from people, wildlife, and ecosystems

35. Disposal methods – impoundments  Surface impoundments, shallow depressions lined with plastic and clay, store liquid hazardous waste  The water evaporates and the residue is transported elsewhere for treatment or disposal

36. Disposal methods – injection  Deep-well injection = liquid waste is injected into a well drilled deep in the Earth, isolating it from the environment  The disposal layer has highly saline ground- water that is not suitable for drinking  Micro-earthquakes have been linked to this method

37. Radioactive waste  Radioactive waste is very dangerous and persistent  The U.S. has no designated single disposal site and waste is accumulating at individual power plants  The Waste Isolation Pilot Plant (WIPP) = the first underground repository for transuranic waste from nuclear weapons development  Caverns are 2,150 ft below ground in a huge salt formation thought to be geologically stable  WIPP became operational in 1999 and is receiving thousands of shipments of waste

38. CERCLA – Cleaning up the past  Many former military and industrial sites are contaminated with hazardous waste  Illegal dumping also created large numbers of sites contaminated with hazardous waste  Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (1980) “Superfund” established a federal program to clean up U.S. sites polluted with hazardous waste

39. The origins of Superfund  Two events spurred creation of Superfund  Love Canal, New York, families were evacuated after buried chemicals rose to the surface  Times Beach, Missouri, the town was evacuated after oil sprayed on roads was found to contain dioxin

40. The Superfund process  Once a potential Superfund site is identified, EPA scientists perform a Preliminary Assessment/Site Inspection (PA/SI) to determine:  How close the site is to human habitation  If wastes are currently confined or likely to spread  If the site threatens drinking water supplies  If an imminent hazard is posed, an expedited Immediate Removal action can be taken.

41. The Superfund process  Sites with the potential to pose long-term, continuing hazards are placed on the National Priority List (NPL)  Sites are investigated in detail (Remedial Investigation – RI)  Ranked by their level of risk to human health and the environment (Risk Assessment)  The feasibility of different cleanup options is evaluated and a remedial action is proposed (Feasibility Study – FS )

42. The Superfund process  Public hearings are held to inform area residents of the RI/RA/FS findings and to receive feedback on the proposed remedial action  The Remedial Action is performed as funds are available  Long-term monitoring of the Remedial Action is performed

43. Who pays?  Superfund was designed to operate under the principle that “the polluter pays”  If the responsible parties could be identified, they paid  If not, a trust fund (based on a federal tax on petroleum and chemical industries) was used  Congress allowed the tax authorization to expire and the trust fund is bankrupt  Taxpayers pay all investigation and cleanup costs  Fewer cleanups are being completed (341 have been cleaned up but 1,279 sites remain listed)