Solid_ Toxic and Hazardous Waste

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					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 “Smoky Mountain” 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

				
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