Nearly everything we do leaves behind some kind of solid waste.  Although it can include a wide variety of materials and come in many forms, solid waste in general is comprised of two major components:

• Municipal Solid Waste (MSW) - trash generated by residents, businesses, institutions and municipalities, but not including hazardous waste or other industrial by-products - is the first and largest component of the solid waste stream.  MSW typically contains a wide variety of discarded materials: food scraps, yard wastes, paper and paperboard products, plastics, metal, rubber, leather, textiles, wood, glass, and other miscellaneous materials.  The pie chart to the right shows the proporitions of these materials typically found in MSW generated across the United States.
  
  While households and businesses in other states generally produce the same kinds and proportions of wastes, solid waste generated in Massachusetts may contain slightly higher or lower proportions of some materials.  For example, glass and plastic bottles used for soda and other carbonated beverages are usually recycled due to the Bottle Bill, so Massachusetts waste may contain a lower percentage of glass and plastic than other states' waste does.  Also, there may be regional variations in the quantities and timing of leaf and yard waste produced, due to differences in vegetation around the country.  In general, MassDEP believes that municipal solid waste generated in the Commonwealth is not significantly different than what is generated nationally.
  
  
• Construction and Demolition Debris (C&D) - generated from the construction, renovation and demolition of buildings, roads, bridges and other structures - is the other major component of solid waste.  C&D waste typically includes asphalt, brick, concrete, metal, wood, wallboard and plaster, and roofing and siding materials (such as wood and asphalt shingles). Wood waste can be painted or stained, unpainted or untreated, pressure-treated, or "engineered" (particle board, for example), and also can take the form of discarded pallets and crates.

There are other types of non-hazardous waste produced in our society, including include non-hazardous industrial wastes and sludges, sewage sludge, junked cars, contaminated soil, medical wastes, and dredge spoils.  While these materials can be produced in large quantities in a typical year, they are usually managed at specific facilities and not disposed of as municipal solid waste.  For example, "end of life" vehicles are crushed and shredded; the resulting steel is shipped to Asia for recycling and residual material is used for daily cover at landfills.  Because these materials are generally managed outside of the major solid waste streams, they have not been a major focus of the Massachusetts Solid Waste Master Plan.