Frequent Questions About Land Disposal Restrictions for Hazardous Waste

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Are underlying hazardous constituents as defined in Section 268.2(i) considered "contaminants subject to treatment" for debris contaminated with characteristic hazardous waste?

Underlying hazardous constituents are "contaminants subject to treatment" and must be identified and addressed under the debris standards for debris contaminated with characteristic hazardous waste. Therefore, if the debris contains underlying hazardous constituents at concentrations above those given in Section 268.48, the treatment method applied to the debris must effectively treat for those constituents. The underlying hazardous constituents must also be identified in a generator's LDR notification under Section 268.7 (see item 7 of the Generator Paperwork Requirements Table in Section 268.7(a)(4)).

Can debris which exhibits a characteristic of hazardous waste, and is then treated using an immobilization technology, be sent to a Subtitle D landfill?

Immobilized hazardous debris which still exhibits characteristics cannot be sent to a Subtitle D landfill. Characteristic debris that has been treated using an immobilization technology and no longer exhibits a characteristic of hazardous waste may be disposed in a nonhazardous waste landfill (Memo, Shapiro to Deitchman; June 23, 1994). On the other hand, debris contaminated with a listed hazardous waste and treated using an immobilization technology must always be managed in a Subtitle C landfill unless the owner and operator gets a site-specific determination from the EPA Regional Administrator (Section 268.45(c)).

What is the maximum concentration of hazardous waste contaminants that may be present in or on debris in order for a generator to take advantage of the land disposal restrictions (LDR) alternative debris standards?

There is no maximum contaminant level that hazardous waste debris must meet to be eligible for the LDR alternative debris standards. In order to take advantage of the alternative debris standards, the hazardous waste must meet the definition of debris. Debris means a solid material exceeding a sixty mm particle size that is intended for disposal and that is a manufactured object, plant or animal matter, or natural geologic material. The following materials are not debris: any material for which a specific treatment standard is provided in 40 CFR Subpart D, Part 268, namely lead acid batteries, cadmium batteries, and radioactive lead solids; process residuals such as smelter slag and residues from the treatment of waste, wastewater, sludge, or air emission residues; and intact containers of hazardous waste that are not ruptured and that retain at least seventy-five percent of their original volume. A mixture of debris that has not been treated to the standards provided in Section 268.45 and other material is subject to regulation as debris if the mixture is comprised primarily of debris, by volume, based on visual inspection (Section 268.2(g)). In addition, when performing the alternative debris standards, a hazardous waste must meet the contaminant restrictions, performance and/or design and operating standards, and treatment technology (Section 268.45, Table 1). 

The following guidance documents provide additional information on the LDR alternative debris standards: 

Memo, Fields and Herman to Regions; October 14, 1998 (RCRA Online 14291) 
Memo, Cotsworth to Sharp; October 3, 1997 (RCRA Online 14241) 
Memo, Shapiro to Humphrey; October 6, 1994 (RCRA Online 13705) 
Memo, Shapiro to Deitchman; June 23, 1994 (RCRA Online 13681) 
Memo, Shapiro to Dolce; March 1, 1994 (RCRA Online 11815) 
Memo, Weddle to Colamarino; November 18, 1993 (RCRA Online 13640) 
Memo, Lowrance to Rankin; November 5, 1992 (RCRA Online 13575) 

In addition, it is important to note that most states are authorized to implement the federal regulations. We recommend that you contact your state's implementing agency to determine if your state has additional requirements. See EPA Regional offices and state environmental agencies to locate the appropriate agency.

In the land disposal restrictions (LDR) regulations at 40 CFR 268.45, Table 1, footnote 3, EPA defines "clean debris surface", part of which is "limited to no more than 5 percent of each square inch of surface area". How is the 5 percent surface area defined?

A "clean debris surface'' is a surface that, when viewed without magnification, is free of all visible contaminated soil and hazardous waste, except that residual staining caused by soil and waste consisting of light shadows, slight streaks, or minor discolorations. EPA allows minor residual staining caused by soil and waste as, well as soil and waste itself, to remain in cracks, crevices and pits up to 5 percent of each square inch in surface area. The 5 percent surface area criterion is applied to each square inch of the debris surface that has been contaminated with hazardous waste. The area covered by large stains cannot be averaged against large unstained areas. Only 5 percent of the area within any square inch can contain a residual stain (57 FR 37194, 37230, footnote 31; August 18, 1992).

EPA considers this a reasonable and practical method to ensure that the toxic contaminants are not allowed to remain at levels that could pose a hazard to human health and the environment absent Subtitle C regulation, and should remove contaminants so that threats posed by disposal of the debris are minimized. EPA notes that staining such as rust stains on concrete adjacent to steel reinforcing bars is not indicative of the potential presence of hazardous waste and need not be removed nor considered in determining compliance with the maximum 5 percent surface area limit on residual staining.

Do the regulations allow dilution of an ignitable or characteristic waste to remove the characteristic?

No generator, transporter, handler, or owner or operator of a TSDF shall dilute a hazardous waste as a substitute for adequate treatment.

However, dilution of wastes that are hazardous only because they exhibit a characteristic and are subsequently discharged under the Clean Water Act or Safe Drinking Water Act (e.g., Class I underground injection well) is not impermissible, unless a treatment method other than deactivation (DEACT) is specified.

In all cases, the Agency has determined that for non-toxic hazardous characteristic wastes, it should not matter how the characteristic property is removed so long as it is removed.  Thus, dilution is an acceptable treatment method for such wastes.

Any solid waste is not a hazardous waste if it does not exhibit any of the characteristics of hazardous waste identified in 40 CFR Part 261 Subpart C.  However, wastes that exhibit a characteristic at the point of generation may still be subject to the LDR requirements in Part 268, even if they no longer exhibit a characteristic at the point of land disposal.

Characteristic wastes that are exempt from the dilution prohibition and which are managed and disposed of on-site, are not subject to the full Section 268.7 requirements for waste analysis and record keeping.

References:  40 CFR Section 268.3(a)
40 CFR Section 268.3(b); 55 FR 22520, 22532, June 1, 1990
40 CFR Section 261.3(d)
Monthly Call Center Report Question, October 2002 (RCRA Online 14638)
66 FR 27266, 27269, May 16, 2001
The Hazardous Waste Identification Process.
40 CFR Section 268.7(a)(7)

If a prohibited waste is both listed under 40 CFR Part 261, Subpart D, and exhibits a characteristic under Part 261, Subpart C, does the waste need to meet the Part 268 land disposal restrictions (LDR) treatment standards for both the listing and characteristic?

Where a prohibited waste is both listed under Part 261, Subpart D, and exhibits a characteristic under Part 261, Subpart C, the treatment standard for the waste code listed in Part 261, Subpart D will operate in lieu of the standard for the waste code under Part 261, Subpart C, provided that the treatment standard for the listed waste includes a treatment standard for the constituent that causes the waste to exhibit the characteristic. Otherwise, the waste must meet the treatment standards for all applicable listed and characteristic waste codes (Section 268.9(b)).

Are the Land Disposal Restriction (LDR) treatment standards based on grab sampling or composite sampling?

Compliance with LDR treatment standards is based on grab sampling for D004-D011 wastewaters and for all nonwastewaters (Section 268.40(b)). In addition, compliance with treatment standards for underlying hazardous constituents is measured by an analysis of grab samples, unless otherwise noted in Section 268.48. A grab sample is a one-time sample taken from any part of the waste. Using grab sampling to measure compliance with the treatment standards ensures conformity with LDR program goals such that all of the hazardous waste to be land disposed is treated to minimize the threats to human health and the environment (62 FR 26041, 26047; May 12, 1997). EPA established treatment standards for prohibited wastes based on grab sampling because it makes treatment standards easier to enforce. In addition, grab samples normally reflect maximum process variability, and thus reasonably characterize the range of treatment system performance (54 FR 26594, 26605; June 23, 1989). By contrast, composite sampling, which is a combination of samples collected at various locations or times for a given waste, may result in only an average portion of the waste being treated (62 FR 26041, 26047; May 12, 1997).

Is a waste mixture (in this case, a mixture of a Bevill waste and a characteristic hazardous waste F003) subject to the land disposal restrictions (LDR) requirements in Part 268? If so, what underlying hazardous constituents (UHCs) are subject to treatment?

The resultant waste mixture is subject to the requirements in Part 268 even though it is no longer hazardous at the point of land disposal. A mixture of a Bevill waste and a characteristic hazardous waste (or a waste listed solely because it exhibits a hazardous characteristic) is considered hazardous if it exhibits a characteristic of the non-excluded waste, but not if it exhibits a characteristic imparted to it by the Bevill waste (Sections 261.3(a)(2)(i) and 261.3(a)(2)(iii)). However, even if the F003 waste is rendered nonhazardous when mixed with the Bevill waste, the waste still remains subject to LDR requirements because LDR attaches to the F003 waste at the point of generation. The waste mixture must be treated for any characteristic(s) and UHCs attributed to the non-excluded portion. The waste mixture does not have to be treated for any UHCs uniquely contributed by the Bevill portion. Thus, Bevill status of one waste cannot be used to immunize requirements applicable to prohibited wastes. In addition, the facility must comply with applicable LDR notification and certification requirements in Section 268.7. The act of mixing a hazardous waste with a Bevill-exempt waste to render it nonhazardous meets the definition of treatment in Section 260.10. As a result, the act of mixing a hazardous waste with a Bevill waste or other solid waste may require a Subtitle C permit (63 FR 28556, 28595-97; May 26, 1998). Furthermore, such mixing may be a form of impermissible dilution.

Does a decharacterized waste have to meet the land disposal restrictions?

Any solid waste is not a hazardous waste if it does not exhibit any of the characteristics of hazardous waste identified in 40 CFR part 261 Subpart C.  However, wastes that exhibit a characteristic at the point of generation may still be subject to the LDR requirements in Part 268, even if they no longer exhibit a characteristic at the point of disposal.

References:  40 CFR Section 261.3(d)
Monthly Call Center Report Question, October 2002 (RCRA Online 14638)
66 FR 27266, 27269, May 16, 2001

What land disposal restriction (LDR) notification and certification requirements apply to Subtitle D facilities that treat decharacterized wastes?

Subtitle D facilities that treat decharacterized waste for underlying hazardous constituents (UHCs) are not subject to LDR notification and certification requirements. The initial generator of the hazardous waste is required to place a one-time notification and certification in the facilities files and send copies to the EPA region and authorized state (40 CFR 268.9(d)). However, the generator is not required to notify the Subtitle D facility of the constituents subject to treatment. Accordingly, Subtitle D treaters (i.e., treaters of wastes which are no longer hazardous but which require treatment to satisfy LDR treatment standards) are not currently required to verify compliance with treatment standards or to provide further notification of constituents in the waste or certification of treatment (58 FR 48092, 48135; September 14, 1993). EPA decided against imposing notification requirements on Subtitle D facilities that decharacterize waste because the parties involved have substantial incentives (such as CERCLA liability) to exchange and verify compliance with treatment standards for UHCs independent of federal notification requirements. EPA reserves the right to revisit this issue if it becomes aware that substantial amounts of decharacterized wastes are sent to nonhazardous facilities for treatment of UHCs, or that there is a paperwork loophole not addressed by existing arrangements between generators and treatment facilities (59 FR 47980, 48016; September 19, 1994). See also Treatment Standards for Hazardous Wastes Subject to Land Disposal Restrictions.

What is the standard for macroencapsulation for the treatment required for disposal of radioactive lead solids?

Radioactive lead solids that are wastes and that exhibit the toxicity characteristic for lead (D008) must comply with the land disposal restrictions (LDR) treatment standard for the Radioactive Lead Solids Subcategory, which is a type of macroencapsulation that is abbreviated as MACRO (40 CFR 268.42 Table 1).  EPA established MACRO as a required method of treatment only for the Radioactive Lead Solids Subcategory for D008 wastes, and does not require the use of MACRO for other subcategories or for hazardous debris.

D008 lead-containing waste must be treated and properly disposed because the waste is not reusable or recyclable due to its radioactive nature.  Radioactive lead solids (RLS) include, but are not limited to, all forms of lead shielding and other elemental forms of lead.  These radioactive lead solids do not include treatment residuals such as hydroxide sludges, other waste treatment residuals, or incinerator ashes that can undergo conventional pozzolanic stabilization, nor do they include organo-lead materials that can be incinerated and stabilized as ash.  This D008 waste subcategory consists of  nonwastewaters only.

RLS is often commingled with debris and non-debris wastes, but RLS waste materials are not "debris" by regulatory definition under Section 268.2(g).  Therefore, commingled RLS with debris requires the use of the MACRO technology standard if the waste cannot be readily or safely separated into its individual components for separate immobilization methods of treatment (i.e., as hazardous debris and RLS).

The MACRO technology standard also specifically does not include any material that would be classified as a tank or container according to 40 CFR 260.10 (40 CFR 268.42, Table 1).  Compliance with the MACRO technology standard requirement is achieved with the application of surface coating materials using polymeric organics (e.g., resins and plastics) to completely encapsulate the waste to substantially reduce surface exposure to potential leaching media.  Low-Density Polyethylene (LDPE) is a polymeric organic used to meet the MACRO standard.

On the other hand, hazardous debris can be treated by several technologies, including macroencapsulation, and has a similar but separate standard under 40 CFR 268.45.  The definition of macroencapsulation in Table 1 of 40 CFR 268.45 for hazardous debris differs in two ways from the definition of the MACRO technology standard specified for the Radioactive Lead Solid Subcategory.  First, it does not specifically prohibit the use of containers.  Second, it has a performance standard, stating that:"Encapsulating material must completely encapsulate debris and be resistant to degradation by the debris and its contaminants and materials into which it may come into contact after placement (leachate, other waste, microbes)."  This separate definition of macroencapsulation allows container-based macroencapsulation technologies to be used to comply with the LDR technology standard for mixed waste debris.

As a result of the differing definitions, mixed waste debris composed of co-generated radioactive lead solids and hazardous debris must either be managed entirely as D008 Radioactive Lead Solids Subcategory wastes, which requires treatment using the MACRO methods as defined in 40 CFR 268.42 Table 1, or be separated into its component parts by ordinary means so that the RLS component and the hazardous debris component can be treated separately.

The following memoranda also provide clarification on the macroencapsulation of lead:

Memo, Cotsworth to Lawrence; August 9, 2001 (RCRA Online 14554)
Monthly Call Center Report Question; April 1997 (RCRA Online 14091)
Memo, Kinch to Igli; September 19, 1995 (RCRA Online 13762)
Memo, Lowrance to Guida; July 30, 1990 (RCRA Online 13393)

What waste analysis procedures must a generator follow if they are treating their hazardous waste to comply with the land disposal restrictions (LDR)?

The general requirements for generators treating in tanks, containers, and/or containment buildings to meet land disposal restrictions (LDR) treatment standards are included in 40 CFR Section 268.7(a)(5).  These requirements must be documented in a Waste Analysis Plan (WAP), and are designed to ensure that the generator has sufficient knowledge of their wastes to manage them properly, including identifying: 

• Parameters to be analyzed
• Sampling methods
• Testing and analytical methods
• Frequency for re-evaluating wastes; or frequency of spot checks.

The generator must obtain a detailed chemical and physical analysis of a representative sample of any waste that they generate, treat, store, or dispose.  The WAP must contain all information necessary to treat the waste in accordance with the LDR requirements.  It must be kept on-site and made available to inspectors when requested.

When wastes treated on-site are shipped off-site for disposal, the generator must comply with the notification and certification requirements of Section 267.8(a)(3) (for wastes which meet their treatment standards prior to shipment offsite).  This notice must accompany the first shipment of waste to the disposal facility and be retained in the generator's files.

Detailed guidance regarding WAP development is available in the following document: 

Waste Analysis at Facilities that Treat, Store, or Dispose of Hazardous Waste: A Guidance Manual

What are the land disposal restrictions (LDR) alternative soil treatment standards?

Pursuant to the LDR alternative soil treatment standards in Section 268.49(c)(1), there are two approaches to achieving compliance. Either:

  • hazardous constituents must be reduced by at least 90 percent through treatment so that no more than 10 percent of their initial concentration remains, or
  • hazardous constituents must not exceed ten times the universal treatment standards (10 x UTS) in Section 268.48. 

In addition to the treatment standards in Section 268.49(c)(1), prior to land disposal, a generator or treatment, storage, or disposal facility must treat soils that exhibit the characteristic of ignitability, corrosivity, or reactivity to eliminate these characteristics (Section 268.49(c)(2)).

EPA defines a hazardous constituent as a regulated constituent specified in the treatment standards in Section 268.40 or an underlying hazardous constituent (UHC) as defined in Section 268.2(i), which means any constituent that is listed in the UTS Table at Section 268.48, except for fluoride, selenium, sulfides, vanadium.

Additional guidance on the LDR alternative soil treatment standards for hazardous waste is available in the following documents:  

Guidance on Demonstrating Compliance with the Land Disposal Restrictions  
Alternative Soil Treatment Standards: Final; July 2002
Monthly Call Center Report Question; August 2002 (RCRA Online 14628)
Monthly Call Center Report Question; April 2000 (RCRA Online 14445)
Monthly Call Center Report Question; October 1999 (RCRA Online 14409)

Under the alternative treatment standards for hazardous soils subject to land disposal restrictions, what constituents are subject to treatment?

Section 268.49(d) defines constituents subject to treatment as any constituents listed in Section 268.48 (i.e., the UTS table) that are reasonably expected to be present in any given volume of contaminated soil, except fluoride, selenium, sulfides, vanadium, and zinc, and that are present at concentrations greater than 10 times UTS. Generators of contaminated soil are not required to monitor soil for the entire list of underlying hazardous constituents (UHCs) to determine the constituents subject to treatment. Instead, EPA allows generators of contaminated soil to reasonably apply knowledge of the contaminants that are likely to be present in the soil and use that knowledge to select appropriate UHCs, or classes of constituents, for monitoring (63 FR 28556, 28609; May 26, 1998). For soils containing a listed waste, using the alternative soil treatment standards may encompass constituents subject to treatment that do not require treatment under the Section 268.40 waste code specific standard. The treatment standards for listed waste in Section 268.40 do not require identification or treatment of UHCs. However, under the alternative soil treatment standards, facilities must identify and treat all UHCs reasonably expected to be present in both characteristic and listed soil. Finally, the alternative soil treatment standards are not automatically available in all states. Before using the alternative soil standards, facilities should check with their implementing agency to verify which treatment options are available for contaminated soil in their state. Facilities operating in states that have adopted the alternative soil treatment standards have the option of treating hazardous soils in accordance with the original waste code specific standards in Section 268.40 or the alternative Section 268.49 soil standards.

If an owner or operator treats D018 soil that is regulated under 40 CFR Parts 264/265 Subpart CC to meet the alternative soil treatment standards in Section 268.49, can this soil be managed in units that do not have Subpart CC controls?

Tanks, containers, and surface impoundments storing soils that contain hazardous waste and that meet the alternative soil treatment standards in Section 268.49 for organic constituents are subject to the Subpart CC air emissions standards. Units storing hazardous soils are eligible for the LDR exemption from Subpart CC only when the VOCs meet the numerical concentrations specified in Section 268.40 or when the soil has been treated by a treatment technology established in Section 268.42(a) for the organic hazardous constituents in the soil. Wastes treated to a standard, such as the alternative soil treatment standards, which does not fully remove VOCs to the extent contemplated in creating the Subpart CC exemption remain subject to Subpart CC rules (62 FR 64636, 64645; December 8, 1997). Although the LDR exemption would not apply in this case, these soils may qualify for other exemptions from Subpart CC controls, such as the remediation waste exemption in Sections 264/265.1080(b)(5).

What notification requirements apply to a generator of soil that does not meet the treatment standard at the original point of generation? Are the requirements different if the soil meets the treatment standard at the original point of generation?

A generator of contaminated soil that does not meet the applicable treatment standard at the original point of generation is subject to the notification requirements of 40 CFR 268.7(a)(2). An authorized representative must sign the certification statement in Section 268.7(a)(2)(i), which states that the soil requires treatment and identifies whether the soil contains listed waste and/or exhibits a characteristic of hazardous waste. The notification must include all of the elements in column 268.7(a)(2) of the Generator Paperwork Requirements Table in Section 268.7(a)(4). A generator of contaminated soil that meets the applicable treatment standard at the original point of generation is subject to the notification requirements of Section 268.7(a)(3)(ii). An authorized representative must sign the certification statement in the Generator Paperwork Requirements Table in Section 268.7(a)(4), column Section 268.7(a)(3), which states that the soil meets the applicable treatment standard. The generator must also include information about whether the soil contains listed waste and/or still exhibits a characteristic of hazardous waste. This information is required because soil that meets the applicable treatment standard can still exhibit a characteristic or contain listed waste (63 FR 28556, 28620; May 26, 1998). In both cases, the generator must send a one-time written notice containing the above information to each treatment or storage facility receiving the soil and place a copy of the notice in the facility's files. Subsequent notification is required only if the waste or the facility receiving the waste changes.

Are residues from treatment of listed wastes that result in new treatability groups considered a new point of generation?

Because of the derived-from rule, the waste will be hazardous in any case and will normally carry the waste code of the listed waste. Thus, treatment residues derived from the treatment of a listed hazardous waste are considered to be that listed waste (Section 261.3(c)(2)). Consequently, all of the wastes generated during the course of treating a listed hazardous waste would be prohibited from land disposal unless they satisfy the treatment standard for that particular waste (53 FR 31147; August 17, 1988). Residues that are in a new treatability group must meet the LDR treatment standards appropriate for that particular treatability group (54 FR 48383; November 22, 1989). For example, a F001 wastewater is combusted, producing treatment residues that meet the definition of nonwastewater. 

Under the derived-from rule, these residues are still considered F001 and are considered as a new point of generation for LDR purposes.  The new treatability group residue must be treated to meet the F001 treatment standard (for the new treatability group) prior to land disposal.  Furthermore, if there is a residue from the original treatability group, it would not be a new point of generation; however, it must be treated to meet the F001 LDR treatment standards for the original treatability group, if the residue will be land disposed.   This guarantees that residues are treated to a treatment level or with a technology appropriate for the form of the waste.

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Last updated on December 15, 2023