United States 		Environmental Protection Agency

U.S. EPA Mixed Waste Team

Effects of RCRA LDR Regulations on Mixed Waste Management

The 1984 Hazardous and Solid Waste Amendments (HSWA) to the Resource Conservation and Recovery Act (RCRA) restrict the land disposal of hazardous wastes, including mixed waste. This overview outlines the major aspects of the land disposal restrictions (LDR) as they apply to mixed wastes.


Mixed waste is defined as a waste mixture that contains both radioactive materials subject to the Atomic Energy Act (AEA) and a hazardous waste component regulated under RCRA. The hazardous waste (i.e. the non-AEA material) can be either a listed hazardous waste in Subpart D of 40 CFR 261 or a waste that exhibits any of the hazardous waste characteristics identified in Subpart C of 40 CFR Part 261.


The 1984 HSWA amendments to RCRA prohibit the continued land disposal of untreated hazardous waste "unless the Administrator [EPA] determines that the prohibition ... is not required in order to protect human health and the environment for as long as the waste remains hazardous ... " (RCRA Section 3004(d)(1), (e)(l) and g(5)). This phrase is defined as meaning that there will be "no migration of hazardous constituents from the disposal unit . . . for as long as the waste remains hazardous."

Waste treated in accordance with treatment standards set by EPA under Section 3004(m) of RCRA are not subject to the prohibitions and may be land disposed. The statute requires EPA to set "levels or methods of treatment, if any, which substantially diminish the toxicity of the waste or substantially reduce the likelihood of migration of hazardous constituents from the waste so that short-term and long-term threats to human health and the environment are minimized". (RCRA Section 3004(m)(1).)


The LDR regulations currently apply to all hazardous waste, including mixed waste, listed or identified as of November 8, 1984 under RCRA 3001. They also apply to several hazardous wastes newly listed after November 8, 1984 for which treatment standards have been developed. EPA deferred issuing treatment standards for radioactive waste mixed with scheduled hazardous waste until the promulgation of the last scheduled LDR rule on May 8, 1990 (the so-called Third Third rule). Mixed wastes are now subject to LDR regulations.


Section 3021(b) of RCRA, as amended by the Federal Facilities Compliance Act (FFCA), requires DOE to prepare and submit to the appropriate states or the U.S. Environmental Protection Agency (EPA) Site Treatment Plans (STP) for treating mixed wastes so that they can be safely land disposed in accordance with RCRA regulations. This includes compliance with RCRA LDR restrictions. All treatment technologies that DOE intends to use or develop under the STPs must also achieve standards pursuant to the LDR requirements set forth in section 3004 of RCRA (Title 40 of the Code of Federal Regulations, Part 268, contains the applicable regulatory requirements).

DOE has completed and submitted for approval Proposed STPs for 40 sites in the United States where DOE mixed waste is currently managed or is expected to be managed during the next 5 years. Over the past 3 years, DOE developed these plans in coordination with the hazardous waste regulatory agencies of 20 states, the EPA, and other participating stakeholders. The authorized states and EPA have reviewed these plans, and most of the plans have been either approved or approved with modifications.

After each STP is approved, the authorized regulatory agency is then required to issue a RCRA order or a comparable state order requiring compliance with the approved STP.


RCRA Section 3004(m) requires EPA to "promulgate regulations specifying those levels or methods of treatment, if any, which substantially diminish the toxicity of the waste or substantially reduce the likelihood of migration of hazardous constituents from the waste ...". On January 14, 1986, EPA proposed an approach for developing treatment standards under 3()04(m) using technology-based levels determined by the performance of Best Demonstrated Available Technologies (BDAT) in conjunction with risk-based standards (screening levels). After receiving extensive comment on the proposed rule, EPA chose to promulgate only the technology-based level or BDAT approach. The U.S. Court of Appeals for the D.C. Circuit upheld EPA's technology-based approach to LDR; Hazardous Waste Treatment Council vs. EPA, 886 F. 2d (D.C. Cir. 1989).

Evaluating the performance of treatment processes for BDAT is based upon the concentration of specific constituents in treatment residuals in the land disposal environment. When establishing BDAT, EPA sets a standard for both the waste water and non-wastewater forms of a waste code. Often, EPA will set a standard for waste subgroups called "waste treat ability groups" which consist of wastes with similar physical and chemical properties. EPA then determines what the demonstrated treatment technologies are for each "treat ability group". To be considered a demonstrated treatment technology, a full-scale facility should be in operation for the waste or similar wastes. EPA then evaluates whether or not the particular demonstrated treatment technology is available.

To be considered available, a treatment technology must meet the following criteria:

  1. The process may be available for purchase or lease, if the technology is proprietary or a patented process.
  2. The technology must substantially reduce waste toxicity or substantially reduce the migration of hazardous constituents from the waste.

Once a treatment technology is determined to be demonstrated and available, EPA collects and analyzes performance data from the specific treatment. EPA then analyzes how each treatment technology substantially diminishes the toxicity of the waste or substantially reduces the likelihood of migration of hazardous constituents from the waste. Finally, EPA chooses the "best" treatment technology based on performance data (e.g., the levels to which the technologies can treat specific hazardous constituents in the waste), and sets a performance standard based on this specific technology. Where constituent specific performance data cannot be obtained or is deemed unnecessary, EPA considers specifying that a technology must be used for the waste.

It is important to note that, in some cases, the specific technologies identified as the basis for BDAT are simply those technologies which EPA used to develop the waste-specific performance standard. Any technology or combination of technologies not otherwise prohibited can be used to achieve these standards. In other words, a specific treatment technology does not have to be used unless the specific method of treatment is specified as the treatment standard.

A treatment standard can be expressed as:

  1. Concentration Levels - any treatment technology may be used, as long as hazardous constituents in the waste are treated to specific concentration levels
  2. Treatment Technologies - the standard specifies which technology must be used to treat the waste before land disposal.
  3. Deactivation - the tn treatment standard for a number of subcategories of D001-D003 wastes which specifies the removal of the characteristic of ignitability, corrosivity or reactivity. Recommended technologies that may be used to achieve deactivation are referenced in Appendix VI of Part 268.

To date, EPA has set special treatment standards for four categories of mixed waste. They include:

  1. radioactive lead solids with a BDAT treatment standard of macrocapsulation;
  2. radioactive elemental mercury with a BDAT treatment standard of amalgamation;
  3. radioactive hydraulic oil contaminated with mercury and a BDAT standard incineration and.
  4. radioactive high level wastes generated during the reprocessing of fuel rods with a BDAT standard of vitrification.

The remaining mixed wastes are subject to those promulgated treatment standards that apply to the hazardous portion of the waste unless EPA publishes specific standards for mixed waste treat ability groups in the future. (For further discussion on mixed waste treatment standards see 55 FR 22532 and 22626, June 1, 1990.)


As soon as EPA sets a treatment standard, wastes subject to that standard are automatically prohibited from land disposal, unless the wastes meet the treatment standard or are disposed in an EPA approved no-migration unit (3004(h)(1)). EPA may through rule making revise a treatment standard after the statutory date. If wastes are generated that cannot be treated to the specified treatment levels or using the specified treatment methods, the regulations allow a generator or owner/operator to submit a petition to the Administrator requesting a variance from the treatment standard. Most variances are granted through a rule making which requires publication in the Federal Register and public comment.


  • Policy on Enforcement of RCRA Section 3304(j) for Mixed Wastes

    EPA has issued a limited extension of its "Policy on Enforcement of RCRA Section 3004(j) Storage Prohibition at Facilities Generating Mixed Radioactive/Hazardous Wastes" until April 20, 1998 (61 FR 18588-18592, April 26, 1996). The extension confirms that storage of mixed waste subject to LDRs is unlawful under the section 3004(j) storage prohibition even in the absence of treatment and disposal capacity. The policy states, however, that violators who 1) are faced with an impossibility of complying with the RCRA regulations and 2) are storing their wastes in an environmentally responsible manner will be a low enforcement priority for EPA.

    The original policy was published Aug 29, 1991, and extended Apr 20, 1994 with an expiration date of Apr 20, 1996. Prior to issuing its original policy on civil enforcement of the storage prohibition, EPA determined that inadequate treatment technology and disposal capacity existed to treat or dispose of many types of mixed waste. EPA recognizes there still exists no treatment for some mixed wastes, despite significant developments in treatment technology, and reductions in mixed wastes generated since the policy was first published.

    The policy defines "commercially available treatment technology and disposal capacity" to include any facility that has either (1) a RCRA permit or interim status; (2) a research, development, and demonstration permit (40 C.F.R. 270.65); or (3) a land treatment permit (40 C.F.R. 270.63). This will help clarify that bench scale and R&D projects may provide a vehicle for some generators to have their wastes treated. The extended policy clarifies that a "low enforcement priority" applies only to wastes for which no treatment and disposal option exists and only so long as no treatment and disposal option exists. The policy states that EPA anticipates using RCRA section 3007 authorities to ensure that treatable wastes are being sent off-site for treatment and that untreatable wastes are being stored safely.

    The clarifications added ensure that generators understand the scope of coverage, including the fact that as new technologies become available, the wastes that can be treated are no longer covered by this policy. Generators with treatable waste must arrange for treatment and disposal.

  • "No Migration" Extension

    EPA will consider petitions to allow land disposal of prohibited wastes that do not meet the treatment standard, provided the petitioner demonstrates that there will be no migration of hazardous constituents from the disposal unit or injection zone for as long as the waste remains hazardous (40 CFR 268.6). At this time, petitions should be submitted to the U.S. EPA Administrator. Eventually the petitions will be handled by EPA Regional Offices or by States authorized to grant "no migration" petitions. (Note that the EPA Regions are authorized to grant "no migration" petitions for underground injection wells (Office of Drinking Water).)

  • Variances from the Treatment Standards

    EPA recognizes that some mixed waste might not be treatable by the method or to the level specified in such situations, EPA will allow petitions to be submitted requesting a variance from the treatment standard. If granted on a national basis, these variances result in the establishment of a new treatability group and new treatment standards for all wastes in the treat ability group. Variances may also be granted on a site-specific basis. Site specific variances may be granted administratively (i.e., without notice-and comment rulemaking) and have no generic application to similar wastes generated at other sites.

    Variance petitions should be sent to the U.S. EPA Administrator and the Office of Solid Waste (see 40 CFR 268.44).


    Generators must test or use their knowledge of the prohibited hazardous waste to demonstrate compliance with the LDR treatment standards or California prohibition Levels prior to land disposal (see 40 CFR 268.7). Generators who treat prohibited wastes in 90 day tanks or containers to meet treatment standards, must treat these wastes at a frequency specified in their waste analysis plan. Similarly, treatment and disposal facilities arc required to treat their wastes according to the frequency defined in the facility waste analysis plan.

    Each time a restricted waste is shipped to an off-site treatment, storage or disposal facility, notification must accompany the waste. If a waste meets a treatment standard, then certification by the generator or treatment facility is required verifying that the treatment standard has been achieved and the waste has not been impermissibly diluted. (Certain recordkeeping requirements also apply to restricted wastes that remain on-site, cease to be solid or hazardous wastes and arc not land disposed.)

    Notification and certification are not required to accompany characteristic wastes rendered nonhazardous to Subtitle D facilities. However, appropriate notification and certification for these wastes must be sent to the EPA Regional Administrator or authorized State. If the characteristic wastes rendered non-hazardous arc sent to a Subtitle C Facility, then the appropriate notification and certification must be sent to the Subtitle C facility. Note that a one-time notification and certification is allowed for small quantity generator shipments subject to tolling agreements outlined in 40 CFR 262.20(e)(2).

    Treatment in Surface Impoundment Exemption

    Treatment of wastes that are normally prohibited from land disposal is allowed in a surface impoundment or a series of surface impoundments that meet the technological requirements of 40 CFR 268.4(a)(3). After treatment, if the residues do not meet the applicable treatment standard (or statutory prohibition level if the treatment standard has not been established), then the residues must be removed for subsequent management within a year of entry into the unit and may not be managed in another surface impoundment. Also, a certification that attests that the technical requirements arc met and a modified waste analysis plan that incorporates 40 CFR 268.4 residual testing requirements must be sent to the Regional Administrator.

    Dilution as Treatment

    Under the LDRs, dilution is prohibited as treatment for both listed and characteristic wastes (see 40 CFR 268.3). However, exceptions to the prohibition were made for:

    1. Certain characteristic wastes generated and managed in waste treatment systems regulated by the Clean Water Act (See 40 CFR 268.3(b)). (Note that prohibited wastes treated by inappropriate methods are considered impermissibly diluted.)
    2. Listed and characteristic wastes that arc aggregated for legitimate treatment in centralized treatment systems. (Note that centralized treatment of incompatible waste streams is not considered legitimate treatment and is viewed as impermissible dilution.)
    3. Characteristic wastes that arc disposed into hazardous or non-hazardous Class I injection wells regulated under the Safe Drinking Water Act and do not exhibit any prohibited characteristic of hazardous waste at the point of injection.
    4. Prohibited non-toxic ignitable, reactive and corrosive wastes that are treated by dilution to meet a treatment standard


    In addition to prohibiting the land disposal of hazardous wastes, Congress also prohibited the storage of any waste which is prohibited from land disposal unless "such storage is solely for the purpose of the accumulation of such quantities of hazardous waste as are necessary to facilitate proper recovery, treatment, or disposal" [RCRA Section 3004(j)]. The intent of Congress was to ensure that long-term storage was not used as a means of avoiding a land disposal prohibition. Currently a capacity shortage exists for treatment and disposal of mixed wastes that may cause mixed waste handlers to be in violation of the storage prohibition. As a result, EPA plans to issue a policy statement regarding this matter in the fall of 1990. (For further discussion on storage issue see 55 FR 22673, June 1, 1990.)

    The implementing regulations that address the prohibitions on storage of LDR waste are found in 40 CFR 268.50. This regulation essentially restates the statutory language.

    Allowed Storage Times

    It is apparent from the language in HSWA that Congress wished to prohibit extended storage of a LDR waste in lieu of treatment. There are, however, a few instances that allow for the storage of LDR waste in tanks or containers:

    1. Continued storage of wastes first placed in storage prior to the applicable effective date of a LDR, until the wastes arc removed from storage.
    2. Placement of wastes in storage after the applicable effective date, only if the untreated Wastes arc stored solely for accumulation in the amounts necessary to facilitate proper treatment, recovery or disposal.
    3. Storage of restricted wastes that are not prohibited from land disposal because they are exempt from the land disposal restrictions by statute or EPA regulation. (see 54 FR 36968, September 6, 1989.)
    4. Specified treatment standards for the waste are met.

    EPA interprets the land disposal restrictions as applying prospectively to affected wastes. Therefore, wastes disposed of or placed in storage prior to the LDR applicable effective date arc not subject to LDR. If however wastes are removed from storage or a land disposal unit after the applicable effective date, and are subsequently placed in or on the land, then they are subject to LDR.

    The LDR implementing regulations, at 40 CFR 268.50(b), state that: "an owner/operator of a treatment, storage or disposal facility may store [LDR waste] for up to one year unless the Agency [EPA] can demonstrate that such storage was not solely for the purpose of accumulation of such quantities of hazardous waste as are necessary to facilitate proper recovery, treatment or disposal". This provision puts the burden of proof on EPA to demonstrate that storage is improper, if it takes place for less than one year, however, this should not be interpreted that an LDR waste can be stored for up to one year for any reason. This allocation of burden of proof was upheld in Hazardous Waste Treatment Council v. EPA, 886 F. 2d (D.C. Cir. 1989).

    The regulations further state in 40 CFR 268.50(c) that: "an owner/operator of a treatment, storage or disposal facility may store [prohibited waste beyond one year; however, the owner/operator bears the burden of proving that such storage was solely for the purpose of accumulation of such quantities of hazardous waste as are necessary to facilitate proper recovery, treatment, or disposal."

    The preamble to the November 7, 1986 final rule also discusses the point at which storage is considered to begin. As stated in 51 FR 40583, "to implement the storage provisions the Agency [EPA] is requiring owners/operators to comply with the same requirements for dating containers as set forth for generators under 40 CFR 262.34(a)(2)." The requirements in 40 CFR 262.34 allow a generator to store a land disposal restricted waste (as any other type of waste) in a satellite accumulation area until 55 gallons of hazardous waste or one quart of acutely hazardous waste are accumulated. Satellite areas are defined as "places where wastes are generated in the industrial process or laboratory and where those wastes must initially accumulate prior to removal to a central area" (49 Fe 49569, December 20, 1984). Therefore, the accumulation date for storage starts when the waste is moved to the central accumulation area. (Also, under the 40 CFR 262.34 requirements, a generator can store hazardous waste for up to 90 days without a permit)

    Disposal of certain restricted wastes such as those wastes listed in 40 CFR 268.1(c) is allowed by statute or regulation. For example, small-quantity generators of less than 100 kilogram of non acute hazardous waste per month or less than 1 kilogram of acute hazardous waste per month are not subject to the LDR. In addition, exempt wastes such as those with an approved case-by-case extension under 40 CFR 268.5, an approved no migration petition under Section 268.6 or a national capacity variance under Part 268 may continued to be land disposed under certain conditions and arc not subject to the storage prohibition during the period of the exemption. These wastes are not subject to the storage prohibition because the storage prohibition only applies to wastes that are prohibited from land disposal. (For further discussion see 54 FR 36968, September 6, 1989 and 55 FR 22660, June 1, 1990.)


    Like other RCRA requirements related to mixed waste, the LDRs will apply only in States where EPA administers the RCRA program (unauthorized States) or in States that have adopted mixed waste requirements as part of their authorized State programs. In other States, the LDRs will not apply to mixed waste until the State becomes authorized for mixed waste. States may implement their own disposal restrictions as a matter of State law if such actions are more stringent or broader in scope than the actions of Federal programs (RCRA section 3009 and 40 CFR 271.1(I)). In States with more stringent or broader in scope restrictions, State law would govern. For a list of States with mixed waste authorization refer to the following list.

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    Last Updated: March 4, 1998.