Solid and Hazardous Waste
Core concepts
Solid and hazardous waste questions hinge on RCRA: Subtitle C hazardous waste and Subtitle D municipal solid waste. Memorize the four hazardous-waste characteristics-ignitability, corrosivity, reactivity, toxicity-and listed wastes (F, K, P, U). Generator status depends on monthly mass: very small (<1,000 kg/month), small (1,000–6,000), and large (>6,000), with special acute-waste rules. Know manifests, land-disposal restrictions, universal waste, used oil, and the mixture/derived-from/contained-in rules. Landfill design involves liners, leachate collection, caps, gas collection, and closure/post-closure care; treatment includes incineration, stabilization/solidification, composting, and recycling. CERCLA and TSCA may intersect but are separate authorities. Closure requirements, financial assurance, and waste minimization also appear. Household hazardous waste is excluded, but VSQG status brings reduced-not zero-requirements. TCLP determines the toxicity characteristic for metals and organics. Landfill gas is roughly half methane and half carbon dioxide.
Worked example
A facility generates 500 kg/month of non-acute hazardous waste and 2 kg/month of acute hazardous waste. The acute waste makes it a large-quantity generator (LQG), because >1 kg/month of acute hazardous waste triggers LQG status even though total mass is low. Trap: classify by the most stringent stream, not by total mass alone.
Rule of thumb
1,000 kg/month is about 2,200 lb/month. Compare each waste stream to its threshold and remember that accumulation-time limits differ by generator category.