7.1 Systems of waste management  (Page 3/43)

Solid waste regulations

RCRA defines solid waste as any garbage or refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility and other discarded material, including solid, liquid, semi-solid, or contained gaseous material resulting from industrial, commercial, mining, and agricultural operations, and from community activities. In general, solid waste can be categorized as either non-hazardous waste or hazardous waste .

Non-hazardous solid waste can be trash or garbage generated from residential households, offices and other sources. Generally, these materials are classified as municipal solid waste (MSW). Alternatively, non-hazardous materials that result from the production of goods and products by various industries (e.g. coal combustion residues, mining wastes, cement kiln dust), are collectively known as industrial solid waste. The regulations pertaining to non-hazardous solid waste are contained in 40 CFR Parts 239 to 259 (known as RCRA Subtitle D regulations ).These regulations prohibit the open dumping of solid waste, mandates the development of comprehensive plans to manage MSW and non-hazardous industrial waste, and establishes criteria for MSW landfills    and other solid waste disposal facilities. Because they are classified as non-hazardous material, many components of MSW and industrial waste have potential for recycling and re-use. Significant efforts are underway by both government agencies and industry to advance these objectives.

Hazardous waste, generated by many industries and businesses (e.g. dry cleaners and auto repair shops), is constituted of materials that are dangerous or potentially harmful to human health and the environment. The regulatory framework with respect to hazardous waste, specifically hazardous waste identification, classification, generation, management, and disposal, is described in 40 CFR Parts 260 through 279 (collectively known as RCRA Subtitle C regulations ). These regulations control hazardous waste from the time they are generated until their ultimate disposal (a timeline often referred to as "cradle to grave").

According to the RCRA Subtitle C regulations, solid waste is defined as hazardous if it appears in one of the four hazardous waste classifications:

• F-List (non-specific source wastes as specified in 40 CFR 261.31), which includes wastes from common manufacturing and industrial processes, such as solvents used in cleaning and degreasing operations.
• K-list (source-specific waste as specified in 40 CFR 261.32), which includes certain wastes from specific industries such as petroleum or pesticide manufacturing.
• P-list and U-list (discarded commercial chemical products as specified in 40 CFR 261.33), which include commercial chemicals products in their unused form.

Additionally, a waste is classified as hazardous if it exhibits at least one of these four characteristics:

• Ignitability (as defined in 40 CFR 261.21), which refers to creation of fires under certain conditions; including materials that are spontaneously combustible or those that have a flash point less than 140 ⁰ F.
• Corrosivity (as defined in 40 CFR 261.22), which refers to capability to corrode metal containers; including materials with a pH less than or equal to 2 or greater than or equal to 12.5.
• Reactivity (as defined in 40 CFR 261.23), which refers to materials susceptible to unstable conditions such as explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water under normal conditions.
• Toxicity (as defined in 40 CFR 261.24), which refers to substances that can induce harmful or fatal effects when ingested or absorbed, or inhaled.