Solid, Toxic and Hazardous Waste
Objectives
Identify the major components of the waste stream and how waste production has changed over time
Explain the difference between dumps, sanitary landfills and modern secure landfills
Summarize the benefits, problems, and potential of recycling and reusing wastes
Objectives
Analyze some of the alternatives for reducing the waste we generate
Understand what hazardous and toxic wastes are and how we dispose of them
Evaluate options for hazardous waste management
Solid waste
Waste stream is term that describes steady flow of wastes that we all produce
According to EPA, U.S. produces 11 billion tons of solid waste annually
–About half is agricultural waste, that are reused on farms
•Contribute to non-point source pollution
–More than one-third is mining related
•Much of this material is stored in place
Solid waste
–Industrial waste - 400 million metric tons
•15% is hazardous/toxic
–Municipal waste - 200 million metric tons
•Two-thirds of a ton per person
•Twice per capita as Europe or Japan
•Five to tens times as much as developing countries
Open dumps
Open, unregulated dumps are still the predominant method of waste disposal in developing countries
Over 20,000 people live and work on “SmokyMountain” in Philippines
Open dumps
Most developed countries forbid open dumping
–However:
•Estimated 200 million liters of motor oil are poured into the sewers or soak into the ground each year in the U.S.
–Five times volume of Exxon Valdez oil spill
Ocean dumping
Landfills
Landfills
–Sanitary landfills
•Refuse compacted and covered every day with a layer of dirt
•Dirt takes up as much as 20% of landfill space
•Since 1994, all operating landfills in the U.S. have been required to control hazardous substances
•Methane can be recovered from landfills as energy source
Landfills
Historically, landfills have been a convenient, inexpensive waste-disposal option
–Costs are increasing
–Suitable landfill sites are become scarce
–Increasingly, communities are rejecting new landfills
–Old landfills are quickly reaching capacity and closing
Exporting waste
Although most industrialized nations have agreed to stop shipping hazardous and toxic waste to less-developed countries, the practice still continues
–Indian reservations increasingly being approached to store wastes on reservations in US
–New York City sends its 11,000 tons of garbage per day to NJ, PA, VA and OH
Incineration and resource recovery
Also known as “waste-to-energy”
–Energy recovery - heat derived from incinerated refuse is a useful resource
–Steam used for heating buildings or generating electricity
–Reduces disposal volume by 80-90%
–Residual ash usually contains toxic material
Produce less waste
Best waste management practice
Excess packaging of food and consumer products is one of our greatest sources of unnecessary waste
–Paper, plastic, glass, and metal packaging material make up 50% of domestic trash by volume
–Use biodegradable or photodegradable plastic
Reuse
Cleaning and reusing materials in their present form is even better than recycling or composting
Reusable glass container makes an average of 15 round-trips between factory and customer before it has to be recycled producing less waste
–Buy beer in returnable bottles!
Shrinking the waste stream
Recycling
–Recycling is the reprocessing of discarded materials into new, useful products
•Currently, about two-thirds of all aluminum cans are recycled
–Half of all aluminum cans on grocery shelves will be made into another can within two months
Recycling
Potential problems
–Market prices fluctuate wildly
–Contamination
•Most of 24 billion plastic soft drink bottles sold annually in the U.S. are PET, which can be melted and remanufactured into many items
–But a single PVC bottle can ruin an entire truckload of PET if melted together
Recycling
Benefits
–Saves money, raw materials, and land
–Encourages individual responsibility
–Reduces pressure on disposal systems
•Japan recycles about half of all household and commercial wastes
–Lowers demand for raw resources
–Reduces energy consumption and air pollution
Recycling
Benefits example
–Recycling 1 ton of aluminum saves 4 tons of bauxite, 700 kg of coke and pitch, and keeps 35 kg of aluminum fluoride out of the air
•Producing aluminum from scrap instead of bauxite ore cuts energy use by 95%
–Yet we still throw away more than a million tons of aluminum annually!
Composting
Biological degradation of organic material
Every year we throw away the equivalent of 80 million barrels of oil in organic waste
Can be used for methane production
Demanufacturing
Disassembly and recycling of obsolete consumer products
“e- waste”
–A single personal computer has 700 different chemical compounds including toxic metals and valuable metals
European Union requires “cradle-to-grave” responsibility for electronic products
80% of US e-waste is sent to Asia for disposal or recycling, causing environmental degradation there
Hazardous and toxic wastes
EPA estimates US industries generate 265 million metric tons of officially classified hazardous wastes annually, more than 1 ton per person in the country
At least 40 million metric tons of toxic and hazardous wastes are released into the environment each year
Chemical and petroleum industries produce 70% of hazardous wastes
Federal Legislation - RCRA
Resource Conservation and Recovery Act (RCRA) - 1976
–Comprehensive program requiring rigorous testing and management of toxic and hazardous substances
•Cradle to grave accounting
Federal legislation - CERCLA
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
–Modified in 1984 by Superfund Amendments and Reauthorization Act (SARA)
•Aimed at rapid containment, cleanup, or remediation of abandoned toxic waste sites
•Toxic Release Inventory (TRI) - Requires 20,000 manufacturing facilities to report annually on releases of more than 300 toxic materials
Superfund sites
Superfund is a revolving pool designed to:
–Provide immediate response to emergency situations posing imminent hazards
–Clean-up abandoned or inactive sites
Formerly financed by special taxes on producers of toxic and hazardous wastes, but now funded by our taxes
Superfund sites
EPA estimates 36,000 seriously contaminated sites in the U.S.
1,400 sites had been placed on the National Priority List for cleanup with with Superfund financing
Studies of Superfund sites reveal minorities tend to be over-represented in these neighborhoods
Hazardous materials
Hazardous waste management options
Produce Less Waste
–Avoid creating wastes in the first place
–Recycle and Reuse
Convert to less hazardous substances
Store permanently
–Permanent retrievable storage
–Modern secure landfills
Bioremediation