Types of U.S. solid waste
Municipal urban solid waste
• Solid waste/person/day: ~5 lbs
• By economic sector (%):
• demolition (building materials) 40%,
• residential 30,
• commercial 20,
• industrial 2,
• misc 8%.
Types of Municipal solid waste
•
• paper (38%)
• building, rubber, textiles (15%),
• plastic (8%),
• glass (7%),
• yard clippings (18%),
• food (7%).
Methods of disposal
1) Isolation by
• sealing (e.g. landfills),
• burial (deep wells- liquid waste),
• geologic repository (solid nuclear waste).
• 2) Attenuation by
• dilution (e.g. add water)
• or spreading thin (farm waste).
• 3) Recycling
Landfills
Waste Groups
• Group I. Toxic liquids, solids, fertilizers, pesticides, heavy metals, brines, toxic
chemicals.
• Group II. Household and commercial garbage
• Group III. Non-soluble solid waste: concrete, glass, rubber etc.
Classes of landfills
• Class I: totally impermeable to and away from groundwater. Takes Group I waste.
• Class II: near groundwater but sealed. Takes Group II waste.
• Class III. No protection from groundwater. Takes Group III waste only.
From dumps to landfills
• Bottom of landfill lined w/ plastic or clay
• Each days trash compacted by tractors and isolated with 6” clay soil cover.
• Pile consists of “cells” of daily trash.
• Landfill covered with 20” clay.
• Leachate tank- collects liquid from pile and recycles or stores.
Ocean dumping
• Ocean dumping common prior to 1991 Ocean dumping act.
• Sludge in coastal waters:
• Organic pollutants
• Heavy metals
• Pesticides and fertilizers
Nuclear waste
• High level radiation from spent fuel.
• Alpha, beta and gamma radiation.
• Need long term isolation (10,000 yrs).
• Geological repository (Yucca Mt, Nevada ).
• Will be operative 2010 ? (currently in water filled pools).
• Stored 300 below ground, but above water table in pyroclastic volcanic rock.
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