Solid Waste Management

As humans have organized society toward greater productivity and prosperity, solid wastes have increased due to ever-higher levels of consumption of goods and services. Solid waste is typically an unwanted by-product from many of our daily activities, easily generated and often difficult to eliminate. Waste is best defined as material from a process that is discarded or unusable. It may occur as a liquid waste, gaseous waste, biodegradable waste, or solid waste. Some wastes are considered a pollutant, disrupting natural ecosystems, while others like biodegradable waste are more in balance with the system or process from which they are created. For this article's purpose, solid waste is commonly referred to as household trash or garbage, discarded or abandoned, including the often-used interchangeable term municipal solid waste (MSW). Several strategies exist to manage MSW, including landfilling, recycling/reusing, incineration, and source reduction.

Prior to the modern industrial age, human populations were much smaller and, hence, their solid waste outputs were a fraction of what they are today. Solid waste in ancient times consisted primarily of ash from fires, animal carcasses, and discarded tools. It was not until people gathered in ever-larger groups that solid waste became a concern. The first recorded landfill site was created around 3000 B.C.E. in the Cretan capital of Knossos. Waste was placed in large holes in the ground and covered with dirt. In response to the [Page 445]black plague of the mid-14th century, Britain employed “rakers” to collect refuse on the street, place it in carts, and remove it from the population centers. These two events mark the most widely adopted strategy of solid waste management to this day—collection of waste for removal and disposal in a landfill.

Modern solid waste management in the United States consists mainly of disposing of waste directly on land, incinerating it, or placing it in a sanitary landfill. The sanitary landfill process is currently the most widely used method to manage MSW. The waste industry employs over 360,000 with annual revenues of approximately $43 billion.

Modern solid waste management in the United States consists mainly of disposing of waste directly on land, incinerating it, or placing it in a sanitary landfill. The landfill option is currently the most widely used.