7.9.1: Types of Trash/Municipal Waste

Garbage is categorized as municipal solid waste (MSW), special waste, or hazardous waste according to specific characteristics. MSW includes nearly all household trash: paper, plastic, glass, aluminum, food scraps, textiles (old clothing etc.), yard trimmings, and wood (Frumkin, 2016). But this trash generated by homes, businesses and schools actually accounts for only about 2-5% of the total amount of waste products produced in the U.S. (Seabert et al., 2021). Special waste accounts for almost anything that isn’t the typical household waste but also doesn’t fall into the hazardous waste category. This includes:

• Medical waste: medical devices, syringes, sharps, blood-soaked bandages, gloves, gowns - anything that comes in contact with blood or bodily fluids. This must be disposed of separately to general MSW in order to protect workers from contracting infectious diseases. Typically this waste is incinerated before being disposed of along with MSW (Frumkin, 2016).
• Construction debris: any building materials (other than asbestos), such as drywall, wood, metal, tile, cement etc. are typically disposed of at special construction waste sites or along with MSW. Asbestos has to be carefully removed and disposed of in order to prevent inhalation which can cause cancers and other lung diseases such as mesothelioma (EPA, 2013a).
• Mining waste: which can be liquids or fine, ground up rocks called “tailings”, which can contain heavy metals and byproducts from mining such as sulfuric acid or cyanide. If mining waste storage dams break they can wreak havoc and cause damage to the local environment, or release toxic substances into rivers and lakes (Tailings, 2017).
• Agricultural waste: solid animal waste or runoff from farms may include pesticides, pathogens, or antibiotics (which may encourage antibiotic resistant microbes) (Frumkin, 2016). Growing and processing grains, legumes, fruit and vegetable products also generates plant waste, which could be useful for biofuels or compost (Sadh et al., 2018).
• Radioactive waste: may include the nuclear fuel and waste products or clothing and protective gear that has come in contact with it. While the U.S. struggles to find a permanent solution for disposing of nuclear waste (high-level radioactive waste), the less dangerous, low-level reactive waste is typically disposed of in special landfills (Frumkin, 2016).
• Sewage sludge: is typically separated from wastewater as part of the treatment process, and chemically treated to remove pathogens. These solids are either put in landfills or used in agriculture as fertilizer (Frumkin, 2016).
• eWaste (electronic waste): includes computers, phones, printers, televisions, gaming devices, or anything with electronic components that are non working or obsolete. These may still contain valuable materials that can be extracted and recycled, but if disposed of improperly can leach heavy metals into the environment (Seabert et al., 2021).

The best solution for waste is simply not to make it in the first place. For example, offices can convert to modern technology and use electronic communications and documents (such as email and electronic signatures) to reduce paper waste production. Food production companies can utilize less plastic packaging. Companies that ship products can combine shipments and reduce unnecessary paper and cardboard use. Reducing the production of waste would be the best option, followed by recycling or recovering “waste” to be reused for other purposes. For example, old tires can be broken down into crumb rubber and used to make playground equipment, truck bed liners, and other products that benefit from the elasticity of the rubber (Frumkin, 2016). Some waste can be used to generate energy through combustion, or the conversion of food waste into compost or animal feed. If nothing more can be used from the waste or if it is too hazardous to keep around, then treatment and proper disposal are the only other options (EPA, 2018). See Fig. \(\PageIndex{1}\ below for a diagram of the waste management hierarchy.

Figure \(\PageIndex{1}\): Waste Management Hierarchy. Adapted from https://www.epa.gov/trinationalanalysis/waste-management.