RCRA Hazardous Waste Identification Rules
Aspect
Mixture Rule
Derived-from Rule
Contained-in Rule
Definition
If a listed RCRA hazardous waste is mixed with a solid waste, the mixture is a listed RCRA hazardous waste.
Any residue or material derived from the treatment, storage, or disposal of a listed RCRA hazardous waste remains a listed RCRA hazardous waste.
Environmental media (soil, groundwater, debris) “containing” a listed RCRA hazardous waste must be managed as a listed RCRA hazardous waste until cleaned up or approved otherwise.
Key Principle
Prevents dilution as a way to avoid regulation.
Ensures residues and byproducts remain under regulation.
Extends regulatory control to contaminated environmental media.
Applies To
Mixtures of listed wastes (F, K, P, U) with nonhazardous solid wastes; characteristic wastes only if they retain the hazardous property.
Residues such as ash, sludges, still bottoms, or other treatment byproducts of listed wastes.
Soils, groundwater, sediments, or debris contaminated with listed hazardous waste.
Characteristic Wastes
Mixtures with D-codes are hazardous only if they still exhibit the property (e.g., ignitability, corrosivity).
Not relevant to D-codes; residues hazardous only if they retain the characteristic.
Applies mainly to listed waste contamination; characteristic-only contamination regulated if characteristics are present.
Examples
– F001 solvent mixed with solid trash → entire mixture = F001.
– D002 corrosive mixed and neutralized → not hazardous if property eliminated.
– Ash from incinerating F005 remains F005.
– Sludge from treating K-listed waste remains K-listed.
– Soil contaminated with P-listed pesticide must be managed as hazardous waste.
– Groundwater pumped from beneath a waste lagoon is regulated as hazardous until treated.
Exemptions / Relief
Certain wastewater mixture exclusions (e.g., CWA discharge systems).
Residues may be delisted by petition if proven nonhazardous.
States/EPA may determine when soil/groundwater is “clean” enough to exit contained-in policy.
Regulatory Intent
Block facilities from avoiding regulation via dilution.
Maintain control over hazardous residues regardless of form.
Ensure contaminated media is remediated under protective standards.
