It sometimes seems that certain parts of the federal hazardous waste regulations were written with no awareness of what other parts say, and as a result, requirements may appear contradictory.  One example recently addressed by  EPA’s Materials Recovery and Waste Management Division concerns dilution of F003 waste, which is listed solely for the characteristic of ignitabilty, and the land disposal restrictions (LDRs).  Essentially, the F003 waste can be diluted to remove the ignitability characteristic. 

In this case, the waste is no longer considered a hazardous waste.  However, if the waste exhibits the ignitability characteristic at the point of generation, it is still subject to the LDRs at 40 CFR 268 even if dilution renders it not a hazardous waste.  

Bear in mind here that the EPA uses the phrase “not a hazardous waste,” not nonhazardous waste.  The first phrase indicates that the waste does not meet the definition of a characteristic hazardous waste.  In contrast, the second phrase would suggest that there is no hazard associated with the waste, a suggestion the Agency does not make.  This may explain why the LDRs still apply to de-characterized wastes.

Spent solvents

F003 wastes comprise spent nonhalogenated solvents, including xylene, acetone, ethyl acetate, ethyl benzene, ethyl ether, methyl isobutyl ketone, n-butyl alcohol, cyclohexanone, and methanol.   The category also includes:

• All spent solvent mixtures/blends containing, before use, only the above spent non-halogenated solvents;
• All spent solvent mixtures/blends containing, before use, one or more of the above nonhalogenated solvents and a total of 10 percent or more (by volume) of one or more of those solvents listed in F001, F002, F004, and F005; and
• Still bottoms from the recovery of these spent solvents and spent solvent mixtures.

Dilution with water

In the example, the generator dilutes the F003 waste with water to render it not a hazardous waste—i.e., not ignitable.  The EPA notes first that 40 CFR 261.3(g)(3) states that any hazardous waste that is listed solely because it exhibits one or more of the characteristics of ignitability, corrosivity, or reactivity is not a hazardous waste if it no longer exhibits any characteristic.  If a waste is not a hazardous waste, it is not subject to the hazardous waste regulations pertaining, for example, to accumulation, storage, and manifesting.  The EPA adds that water or any other diluent may be added to the F003 waste to render it not a hazardous waste for the hazardous waste characteristic.  

LDRs

However, dilution does not provide an exemption from the LDRs.  Two points are relevant.

• First, the LDRs apply to the F003 waste at the point of generation.  If the waste is hazardous at the point of generation, no amount of dilution will exempt it from the LDRs. 
• Second, under the LDRs, dilution cannot be used as a substitute for adequate treatment to achieve compliance, to circumvent the effective date of a prohibition, to otherwise avoid a prohibition, or to circumvent an LDR.  

The LDR treatment standards are listed at 40 CFR 268.40 as constituent concentrations that differ for wastewaters and nonwastewaters.  In the case of F003, the required concentration standards apply to 30 constituents of concern.  The concentration standards for these constituents can be met by various deactivation technologies, but no specific treatment technology is required.  For other hazardous wastes, specific treatment technologies are required, often in addition to requirements to meet concentration standards.  For F003, the wastewater standards are considerably more stringent than the nonwastewater standards.  A facility may not dilute or perform partial treatment of a hazardous waste to switch applicability from a nonwastewater to a wastewater, or vice versa.

State authority

The EPA emphasizes that authorized RCRA states were not required to adopt the 261.3(g)(3) exclusion or any other exclusion under 261.3(g).  In addition, states were not required to adopt the May 16, 2001, revisions to the mixture and derived-from rules that included the 261.3(g) exclusions, since such revisions are less stringent than the existing federal RCRA regulations.  In a state that has not adopted 261.3(g), the F003 waste continues to be regulated as a hazardous waste (e.g., subject to requirements for storage and manifesting) even if it does not exhibit any characteristic of hazardous waste at the point of generation. 

EPA’s letter discussing dilution of F003 and the LDRs