Waste

Waste and wastes are unwanted or unusable materials. Waste is any substance which is discarded after primary use, or it is worthless, defective and of no use.

The term is often subjective (because waste to one person is not necessarily waste to another) and sometimes objectively inaccurate (for example, to send scrap metals to a landfill is to inaccurately classify them as waste, because they are recyclable). Examples include municipal solid waste (household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others.

Definitions

United Nations Environment Program

According to the Basel Convention,

United Nations Statistics Division, Glossary of Environment Statistics

European Union

Under the Waste Framework Directive, the European Union defines waste as "an object the holder discards, intends to discard or is required to discard."

Types

There are many waste types defined by modern systems of waste management, notably including:

Municipal solid waste

Municipal solid waste (MSW), commonly known as trash or garbage in the United States and as refuse or rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public. "Garbage" can also refer specifically to food waste, as in a garbage disposal; the two are sometimes collected separately.

Composition

The composition of municipal solid waste varies greatly from municipality to municipality (country to country) and changes significantly with time. In municipalities (countries) which have a well developed waste recycling system, the waste stream consists mainly of intractable wastes such as plastic film, and unrecyclable packaging materials. At the start of the 20th century, the majority of domestic waste (53%) in the UK consisted of coal ash from open fires. In developed municipalities (countries) without significant recycling activity it predominantly includes food wastes, market wastes, yard wastes, plastic containers and product packaging materials, and other miscellaneous solid wastes from residential, commercial, institutional, and industrial sources. Most definitions of municipal solid waste do not include industrial wastes, agricultural wastes, medical waste, radioactive waste or sewage sludge. Waste collection is performed by the municipality within a given area. The term residual waste relates to waste left from household sources containing materials that have not been separated out or sent for reprocessing. Waste can be classified in several ways but the following list represents a typical classification:

Monster truck

A monster truck is a vehicle that is typically styled after pickup truck bodies, modified or purposely built with extremely large wheels and suspension. They are used for competition and popular sports entertainment and in some cases they are featured alongside motocross races, mud bogging, tractor pulls and car-eating robots.

A monster truck show sometimes involves the truck crushing smaller vehicles beneath its huge tires. These trucks can run up and over most man-made barriers, so they are equipped with remote shut-off switches, called the Remote Ignition Interruptor (RII), to help prevent an accident if the driver loses control at any time. At some events, only one truck is on the course at a time, while most feature two drivers racing each other on symmetrical tracks, with the losing driver eliminated in single-elimination tournament fashion.

In recent years, many monster truck competitions have ended with a "freestyle" event. Somewhat akin to dressage with giant trucks, drivers are free to select their own course around the track and its obstacles. Drivers will often try "donuts", wheelstands and jumps during this segment. Additional items for the drivers to crush, usually including a motor home, are frequently placed on the track specifically for the freestyle event. Other obstacles sometimes placed on the track include school buses and small airplanes.