Mercury Work Group
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APPENDIX C

DISPOSAL OF MERCURY WASTES

1.0 OVERVIEW

Although efforts have been made to reflect current regulatory requirements in this Appendix, the applicable regulations are periodically revised and updated. Therefore, the following discussions are for general information only. Anyone managing hazardous waste should definitely refer to the latest regulations. Assistance in interpreting and implementing the regulations can be obtained from a facility environmental compliance officer, hazardous waste contractors, environmental laboratories, environmental lawyers, and environmental engineering consulting firms. Some of these resources also offer seminars on complying with hazardous waste regulations.

This section presents a general review of regulations affecting the management of wastes containing mercury. Such wastes can be generated during mercury source identification and reduction and infrastructure cleaning efforts. Source reduction efforts can often generate unused (or discarded) elemental mercury, mercury-containing reagents/products, and process wastes containing mercury that must be segregated from sewer disposal. Infrastructure cleaning activities can generate mercury-containing wastes and bacterial biomass from sink traps, waste piping, solids settling tanks, and limestone chip tanks (used in passive pH neutralization systems).

1.1 Regulatory Programs Controlling Mercury Wastes
At least three regulatory programs apply to elemental mercury and mercury-containing wastes in the liquid or solid phase: Environmental Protection Agency (EPA) and Massachusetts Department of Environmental Protection (MA-DEP) hazardous waste regulations^1,2 and MWRA sewer use regulations.³ The MA-DEP regulations are similar to the EPA Hazardous Waste Management Regulations. However, there are several significant differences such as differing definitions of generator status and the added MA-DEP regulations on waste oil and polychlorinated biphenyls (PCBs) equal to or greater than 50 mg/L (or parts per million - ppm). Discussions in this Appendix are based on the MA-DEP Hazardous Waste Regulations.

1.1.1 Hazardous Waste Mercury Limits
A mercury-containing waste stream would be regulated as a hazardous waste by both the EPA and the MA-DEP if an extract of a representative sample of the waste stream exhibits a mercury concentration of 0.2 mg/L (ppm) or greater when laboratory-tested using the Toxicity Characteristic Leaching Profile (TCLP).⁴ Such a waste stream would be called a characteristic hazardous waste or, more specifically, a Toxicity Characteristic (TC) hazardous waste. For a liquid waste stream, the fluid itself is the extract, and the TCLP becomes essentially a "total" analysis. For a waste stream with a free liquid component, each phase is tested separately, and a weighted average concentration is determined based on the ratio of the solid and liquid phases in the sample.

A TC hazardous waste for mercury is given the hazardous waste code D009 - Mercury. By definition, elemental mercury would fail TCLP testing. In addition, unused (discarded) elemental mercury would be a listed hazardous waste with the hazardous waste code U151 (see Section 2.0 below for further information).

Alternatively, if the TCLP extract of a representative sample of the waste exhibits a concentration of less than 0.2 mg/L (ppm) mercury, the waste is considered a non-hazardous waste (if mercury is the only contaminant of concern). Wastes determined to be non-hazardous are exempt from most sections of the EPA and MA-DEP hazardous waste regulations. Mixtures of non-hazardous waste and hazardous waste containing mercury are also hazardous wastes.

1.1.2 MWRA Sewer Use Limits for Mercury
The MWRA has a stringent limit for total mercury that applies for discharge of Industrial Waste to sewers, i.e., prohibition. However, the MWRA currently enforces its mercury discharge prohibition for permitted wastewater discharges at a concentration level of 1.0 µg/L (ppb). For comparison, the 0.2 mg/L (ppm) TCLP limit for RCRA wastes is equivalent to 200 µg/L (ppb), i.e., 200 times the MWRA enforcement limit.

1.2 Hazardous Waste Determination
Under EPA and MA-DEP hazardous waste regulations, a waste generator may use either "knowledge" or "testing" to find whether a waste or discarded reagent/product would be a listed or characteristic hazardous waste. This process is sometimes also called "identifying," "classifying," or "characterizing" a waste.

Knowledge of the waste can include the determination of mercury content from Material Safety Data Sheets (MSDS) for raw materials and from analytical testing results of others (e.g., the MWRA/MASCO Mercury Products Database). However, using knowledge for classifying a waste as hazardous is usually appropriate if the waste has a contaminant concentration equal to or greater than 1.0 percent.⁵ Products that contain mercury at levels equal to or greater than 1.0 percent would most likely fail TCLP testing, so it is appropriate to assume such wastes would be classified as hazardous wastes.

It is much more difficult to try to use Acknowledge to find whether a waste stream with a lower mercury concentration is a hazardous waste or a non-hazardous waste. Extreme care should be taken when determining that a waste stream is not a hazardous waste without the benefit of running a TCLP test on a representative sample. TCLP testing is considered an accurate method of waste characterization.

Although analytical testing is the preferred method for determining if a waste stream is or is not a hazardous waste, complete analytical testing can be costly if the generator has no knowledge of the waste. The lack of knowledge means that several different analytical tests (e.g., volatiles, semi-volatiles, ARCRA 8" metals, and even pesticides) would be required to ensure that all potential waste constituents have been evaluated. Therefore, most waste generators use a combination of knowledge and testing to find whether a given waste stream is or is not hazardous. Knowledge of the waste enables a waste generator to eliminate analytical testing for constituents known not to be present.

For waste streams that are mixtures of different wastes, the generator would use knowledge and testing of each waste component for the determination. Of course, if hazardous waste constituents are known or found by testing to be present above TC limits, the appropriate waste codes would be applied when shipping and disposing of the waste.

EPA and MA-DEP hazardous waste regulations require that all facilities that transport, receive, store, treat, or ultimately dispose of hazardous wastes have a permit for such operations. Such facilities are known as licensed Treatment, Storage and Disposal Facilities (TSDF). A TSDF would typically require a waste generator to furnish a certified "profile" of each waste stream before the TSDF will accept it for treatment or disposal. The waste profile characterizes the waste based on the generator's knowledge and waste analytical testing. It is very important that each waste shipment under an established profile have all the same characteristics as initially submitted to and approved by the TSDF.

For example, if an originally approved hazardous waste profile was for Alow mercury (see Section 2.3 below for definition) and the waste was treated by addition of a bleach solution to remove a biohazard (many TSDFs do not accept biohazardous wastes), a new waste profile could be required.⁶ In this case, because bleach is known to often contain mercury, an "off-spec" waste stream could be shipped to a TSDF. Additional steps then would have to be taken (including dealing with manifest discrepancies if new waste codes have to be added), and "off-spec" charges could be incurred.

1.3 Waste Disposal Options
After the waste stream has been analyzed and a determination made regarding its status as a hazardous waste, the following are some of the waste management methods that can be considered:

• If the waste is a characteristic hazardous waste with code D009-Mercury, solely because of its mercury content (i.e., greater than 200 µg/L), ship to a licensed TSDF following applicable EPA, MA-DEP, and U.S. Department of Transportation (DOT) regulations.

• If the waste is not a hazardous waste but is an industrial wastewater with a mercury content greater than 1.0 µg/L (ppb) and other constituents may or may not meet the MWRA Sewer Use Regulations (360 CMR 10.021-10.024), treat the waste stream in a pretreatment system before discharge to the MWRA sewer system according to an MWRA Sewer Use Discharge Permit and applicable federal pretreatment regulations.

• If the waste is not a hazardous waste but is an industrial wastewater with a mercury content less than 1.0 µg/L (ppb) and all other constituents meet the MWRA Sewer Use Regulations, discharge to the MWRA sewer system according to an MWRA Sewer Use Discharge Permit and applicable federal pretreatment regulations.

For example, waste piping infrastructure cleaning (e.g., trap cleaning/replacement and power washing of waste piping) typically can produce wastewaters with mercury concentrations in the 1.0 to 200 µg/L (ppb) range or more. Mercury levels in sink trap water have at times been found in the low mg/L (ppm) range (i.e., greater than 1,000 µg/L (ppb)). Thus, infrastructure cleaning operations will likely involve collection of wastewater and mercury-laden biomass for off-site disposal because the waste streams may violate the MWRA mercury prohibition for sewer discharge and may be hazardous wastes. Refer to Appendix B and Sections 1.3.1 and 1.3.2 below for further information on these issues.

1.3.1 Offsite Disposal as Hazardous Waste
Before shipping mercury-containing hazardous waste to a TSDF for ultimate disposal, the waste generator has responsibility for preparing a manifest and Land Disposal Restriction (LDR) notifications (discussed in Section 2.3 below). In addition, the waste generator must make sure that U.S. Department of Transportation (DOT) regulations (49 CFR beginning at Part 171) are following including proper placarding of the vehicle transporting the waste. Requirements of the U.S. DOT regulations, such as training of personnel involved in shipment of hazardous waste, are beyond the scope of this Appendix.

Requirements of federal and state hazardous waste regulations regarding the handling and temporary onsite storage of hazardous wastes are also beyond the scope of this Appendix.

1.3.2 Offsite Disposal as Non-hazardous Waste
If an extract of a representative wastewater sample is TCLP tested and the results show a mercury concentration of less than 0.2 mg/L (ppm) (or 200 µg/L (ppb)), the waste would not be a hazardous waste for mercury. However, if the total mercury concentration is 1.0 mg/L (ppb) or greater, the waste would violate the MWRA sewer discharge mercury prohibition and must either be pretreated for mercury before sewer discharge or collected and sent offsite for disposal.

Before a facility installs and operates a tank to collect, hold, and discharge industrial wastewater for offsite disposal, one of the MA-DEP regional offices may require the facility to obtain an industrial wastewater holding tank permit known as BWP IW 29.^{7, 8} Typically, this MA-DEP permit is granted to facilities generating industrial wastewater in areas that are not sewered. The permitting requirements are intended to reduce overland transport of industrial wastewater from sewered areas and to prevent a facility from avoiding the discharge limits of a local POTW by hauling its wastewater to another POTW that may have less stringent discharge limits.

To obtain the MA-DEP industrial wastewater holding tank permit, a facility might have to submit the following as determined by the appropriate MA-DEP regional office:

• A two-page permit application form.

• Based upon analyses of the wastewater, documentation that a primary licensed disposal site will accept the wastewater.

• Based upon analyses of the wastewater, documentation that an alternate (backup) licensed disposal site will accept the wastewater.

• Documentation of a pending contract with a licensed waste hauler (with a minimum duration of one year).

• Four copies of an engineering report prepared by a Massachusetts Registered Professional Engineer (MRPE) having knowledge and experience in industrial wastewater.

• Four copies of design plans and specifications prepared and sealed by the MRPE. Required design elements include a wastewater holding tank size of at least five times the average daily wastewater flow. In addition, the holding tank must have level instruments with visual and audible alarms at 75 percent capacity.

Note: The above required design elements for the holding tank are good conservative design guidelines for any proposed industrial wastewater holding tank.

• If applicable, post-installation certification by the MRPE that an in-ground holding tank was installed according to approved plans.

• Local Board of Health (BOH) approval may be required. For all in-ground holding tanks, the BOH approval would be required.

Before a non-hazardous waste is transported to a licensed waste disposal facility, the waste will require preapproval similar to that used for "profiling" a hazardous waste. The profiling typically would include generator knowledge and both total and TCLP analytical test results.

The application fee for the MA-DEP BWP IW 29 Permit is set at $350. There are no subsequent annual fees. The permit remains valid if the system served by the holding tank remained unchanged or until the MA-DEP revokes or modifies the permit. If the facility fails to maintain the holding tank properly or prevent overflows, the permit can be revoked.

Facilities that intend to collect their industrial wastewater in holding tanks for offsite disposal should remain alert to any new proposed MA-DEP regulations on this matter. For reference, the MA-DEP Web-site is: http://www.magnet.state.ma.us/dep

In addition, MA-DEP Hazardous Waste Regulations (310 CMR 30.000) allow for non-hazardous wastes to be shipped under a hazardous waste manifest using the MA-DEP waste code MA99. This approach is recommended for offsite disposal of industrial wastewater because the manifest will provide documentation of waste transport to the ultimate disposal facility.

1.3.3 Discharge to the MWRA Sewer System
The MWRA Sewer Use Regulations (360 CMR 10.000) is the primary information source about MWRA Sewer Use Discharge Permits. The general rule is that, unless specifically exempted by the Regulations, facilities will require a MWRA Permit if they: 1) discharge Industrial Waste⁹ to the MWRA Sewer System, 2) are subject to a federal Categorical Pretreatment Standard, 3) are septage haulers that discharge to the MWRA Sewer System, 4) temporarily discharge construction site dewatering drainage, or 4) are municipalities in the MWRA Sewer District.

To obtain a MWRA Sewer Use Discharge Permit, a facility must submit a Sewer Use Discharge Permit Application to the Toxic Reduction and Control Department of the MWRA. In the Application, the facility would provide:

• General information such as name, address, and responsible officials
• Product or service information
• Facility operational characteristics
• Facility water usage
• Sewer connection information
• Wastewater discharge flow characteristics
• Wastewater pretreatment processes (if any)
• Anticipated future wastewater changes
• Other waste stream quantities (such as waste oils, sludges, or hazardous wastes)
• Chemical characteristics of the wastewater discharge.

The MWRA may issue a Sewer Use Discharge Permit to a facility with a validity period generally from two to five years depending upon the applicable Category and Significant Industrial User (SIU) Classification as determined for each discharge. The Category and SIU Classification establish the value of an annual permitting charge that varies from $100 (with an initial extra charge of $50 for the first year) for Category G1 Permits to as much as $1,430 for Category 1 - SIU Permits and Category 12 Permits. There is no annual permitting charge for the General Permit for Low Flow and Low Pollutant Dischargers that carries a charge of $150 once every five years.

In addition, the Category, SIU Classification, and a Monitoring Point Score establish the value of an annual monitoring charge that varies from zero for Category G1 Permits (and for other permits in special cases) to as much as $5,550 for discharges classified as SIUs with a High Monitoring Point Score. For definitions and further information on MWRA Categories, SIU Classifications, and Monitoring Point Scores, refer to the MWRA Sewer Use Regulations 360 CMR 10.101-10.104.

If a facility determines that its wastewater contains mercury below 1.0 µg/L (ppb) and that all other pollutant concentrations are below the respective MWRA discharge limits, the wastewater can be discharged to the MWRA Sewer System after submitting a MWRA Sewer Use Discharge Permit Application and receiving the Permit. However, if the wastewater exceeds 1.0 µg/L (ppb) mercury at any time after aggressive source reduction (including purchasing and inventory controls) and source segregation (including training and supervision of individual daily waste disposal practices), the facility should study its available options to decide the most cost-effective approach to disposal of the wastewater.

Possible options could include pretreatment and sewer discharge, installation of a wastewater holding tank for offsite disposal of some or all of the wastewater according to requirements of the MA-DEP (as outlined above in Section 1.3.2), or even installation of an atmospheric thermal evaporator system. For certain low annual emissions rates of hazardous and miscellaneous air pollutants, the MA-DEP would not require a facility to hold an air emissions permit¹⁰ for an evaporator system. However, the MA-DEP is opposed to the use of evaporators on mercury-bearing wastewater streams. Refer to Appendix H for a copy of a recent letter written by MA-DEP in response to a letter sent on behalf of MASCO regarding this issue. The original letter to MA-DEP is also included in the Appendix.

An economic analysis of these options, performed by an experienced engineer, can provide insight into the most cost-effective method of wastewater disposal. The wastewater flow and characteristics and many other permitting and site-specific factors will uniquely affect the results of the economic analysis.

2.1 Background on Hazardous Waste Regulations
The first federal hazardous waste legislation enacted by Congress was the Resource Conservation and Recovery Act (RCRA) of 1976. This Act required the Federal Environmental Protection Agency (EPA) to develop hazardous waste regulations. The resulting regulations are found in Title 40 of the Code of Federal Regulations (CFR) Parts 260-268. Parts 271 - 272 allow responsibility for operation of the EPA hazardous waste programs to be transferred to state environmental protection agencies after certain conditions have been met. Massachusetts is an EPA "authorized state" for the purposes of administering and enforcing the EPA's hazardous waste program. The Massachusetts hazardous waste legislation is found in the Massachusetts General Laws, Chapter 21C. The corresponding regulations are in Chapter 30 of the Code of Massachusetts Regulations Section 310 (310 CMR 30.00).

The Massachusetts hazardous waste regulations are similar to the federal hazardous waste regulations, but they may lag behind as described below. However, it should be noted there are sometimes differences in the way EPA and MA-DEP interpret their regulations. It is entirely possible to get differing opinions from different regulatory compliance officials from the same agency and branch on certain topics. (It is generally advisable to comply with the most restrictive interpretation). One reason that Massachusetts elected to administer its own hazardous waste disposal program was so it could regulate several additional waste streams as hazardous (e.g., waste oil and PCBs greater than 50 mg/L or parts per million - ppm).

The RCRA legislation was updated in 1984 by the Hazardous and Solid Waste Amendments (HSWA) in which Congress specified that land disposal of hazardous waste is prohibited unless the waste meets treatment standards established by EPA. HSWA required that treatment standards must substantially diminish the toxicity or mobility of hazardous waste, so that short and long term threats to human health and the environment are minimized. The treatment standards are part of the Land Disposal Restriction (LDR) requirements at 40 CFR Part 268. In developing the treatment standards, EPA sought to make the standards as uniform as possible. The results are the Universal Treatment Standards (UTS) whereby the EPA has, wherever possible, developed the same numerical limit for a hazardous constituent in all of the hazardous wastes where the constituent may be present.

Before HSWA, authorized states had one year or more to adopt new EPA hazardous waste regulations as they were promulgated. During the interim period in which state hazardous waste regulations were being updated to reflect the new federal requirements, the regulated community had to comply with the current state hazardous waste regulations. However, regulations based on HSWA go into effect immediately. A generator must comply with the HSWA regulations and the state hazardous waste regulations in all EPA authorized states.

Except for HSWA, complying with MA-DEP hazardous waste regulations will usually ensure compliance with RCRA hazardous waste regulations as well. However, the LDR regulations have changed several times and are presently in Phase IV of implementation. Once a waste is determined to be hazardous, the waste generator is required to use the LDR regulations to find what disposal alternatives are acceptable and to prepare the LDR certifications for the TSDF receiving the wastes.

Although efforts have been made to reflect current regulatory requirements in this Appendix, the applicable regulations are periodically revised and updated. Anyone managing hazardous waste should refer to the latest regulations. Assistance in interpreting and implementing the regulations can be obtained from a facility environmental compliance officer, hazardous waste contractors, environmental laboratories, environmental lawyers, and environmental engineering consulting firms. Some of these resources also offer seminars on complying with hazardous waste regulations.

2.2 Determining Whether a Waste Is Hazardous
A generator of hazardous waste must "identify", "classify", or "characterize" each hazardous waste stream. Both EPA and MA-DEP regulations require the generator of a waste use "knowledge" of the process generating the waste or "testing" of the waste to find whether it is hazardous within the meaning of the regulations. Earlier in this Appendix, the manner by which a waste containing only mercury was determined to be a hazardous waste was discussed. The following discussion will be helpful when dealing with mixed waste streams that have multiple hazardous waste constituents and, thus, potentially multiple hazardous waste codes.

The federal regulation 40 CFR 261.3 provides a definition of Ahazardous waste" and Subpart B provides "Criteria for Identifying the Characteristics of Hazardous Waste and for Listing Hazardous Waste.  The corresponding MA-DEP regulation at 310 CMR 30.100 also provides for the "Identification and Listing of Hazardous Wastes.  More specifically, 310 CMR 30.102 provides the following "Methods of Identification of Hazardous Wastes.

The following four-step decision tree can be used to find whether a given waste stream is a hazardous waste within the meaning of the EPA/MA-DEP hazardous waste regulations (note, however, that the MA-DEP definitions are given):

Wastes designated as listed wastes by MA-DEP include:

1. Wastes determined to be hazardous wastes by MA-DEP on a case-by-case basis (MA00).
2. Waste oil (MA01).
3. PCBs at 50 mg/L (ppm) or greater (MA02).
4. Class A regulated recyclable material being manifested (MA97).
5. Off-spec fuel oil being manifested (MA98).
6. Non-hazardous waste being manifested (MA99).

Note that, except for the above added state-listed wastes, MA-DEP uses all of the federal hazardous waste codes.

Note that 310 CMR 30.121 requires that "a representative (emphasis added) sample of the waste shall be analyzed using the tests specified in 310 CMR 30.152 - 155." Representative sampling methods are defined in 310 CMR 30.151. It is important to note that the EPA believes that grab sampling would best produce representative samples and thus requires grab sampling for hazardous waste determinations.

Since obtaining a representative waste sample is a critical element in determining whether a waste is a characteristic hazardous waste, it is suggested that guidance be obtained from a hazardous waste disposal company and an environmental testing laboratory. Also, guidance is presented in Appendix D on good sampling techniques (e.g., how to avoid contaminating sample containers with mercury from powdered gloves).

The four characteristics of hazardous waste are specified as:

1. Ignitability

Definition: 40 CFR 261. 21 and 310 CMR 30.122
Testing method: 310 CMR 30.152
EPA/MA-DEP waste code "D001"
Liquid: Flash point <60 ^oC (<140 ^oF)
Non-liquid: Spontaneously combustible, etc. (see 310 CMR 30.122(b))
Compressed gas: Concentration, flame length, etc. (see 310 CMR 30.152(c))
Oxidizer:

2. Corrosivity

Definition: 40 CFR 261.22 and 310 CMR 30.123
Testing: 310 CMR 30.153
EPA/MA-DEP waste code "D002"
Aqueous: pH < 2 or pH > 12.5
Liquid: Corrodes SAE 1020 steel at a rate given in 310 CMR 30.123.

(Interestingly, there is no corresponding definition for a solid waste, e.g., sodium hydroxide).

3. Reactivity

Definition: 40 CFR 261.23 and 310 CMR 30.124
Testing: 310 CMR 30.154
EPA/MA-DEP waste code "D003"
Unstable and readily undergoes violent changes
Reacts violently with water
Cyanide- or sulfide-bearing
Explosive
Other (see 310 CMR 30.124(1))

4. Toxicity

Definition: 40 CFR 261.24 and 310 CMR 30.125B
Testing: 310 CMR 30.155B
EPA/MA-DEP waste codes "D004 - D043"

Wastes having the hazardous characteristic of toxicity are those that leach specified constituents greater than specific limits when laboratory tested using the Toxicity Characteristic Leaching Profile (TCLP) method. The wastes are then called Toxicity Characteristic (TC) wastes. The purpose of the TCLP test is to simulate conditions in a landfill where hazardous constituents in a waste could leach out over time. The associated waste codes include certain heavy metals and organics (selected pesticides and solvents).

If mercury is present in an extract of a representative waste sample in a TCLP concentration of 0.2 mg/L (ppm) or greater, the waste is considered a TC hazardous waste for mercury and must carry a "D009" waste code. The following are all equivalents to 0.2 mg/L: 0.2 parts per million (ppm), 200 micrograms per liter (µg/L), or 200 parts per billion (ppb). Note that if "total" analytical test results for mercury are available for a liquid sample and are less than the TCLP limit of 0.2 mg/L (ppm), TCLP testing need not be run. If a TCLP-derived result for a waste that is a solid exceeds 0.2 mg/L (ppm), a total mercury analysis will need to be run to find the applicable treatment standard under the LDR regulations.

For a waste sample that is a solid, be careful to not compare a total analytical test result reported in units of mg/Kg to a TCLP Maximum Concentration limit. The TCLP Maximum Concentration Limit is given in units of mg/L (ppm) because the TCLP test is performed on an extract of the solid sample. Only the total analytical result for a liquid sample (reported in mg/L (ppm)) can be compared directly to the TCLP Maximum Concentration limit.

Testing of wastes to find whether they are hazardous wastes and, if so, the applicable treatment technology (see Section 2.3 below) usually makes economic sense only for consistent processes that generate waste streams in sufficient quantity as to be collected in "bulk" quantities for disposal. Small quantities of mercury-bearing reagents can often be classified using "knowledge" rather than testing and then can be placed into mercury-specific "lab pack" containers.

What happens when the waste is not a hazardous waste for mercury because it is not a listed waste and because mercury is present, but at concentrations less than TCLP? The answer depends in part on the TSDF to which the waste is going. Each TSDF will have its own unique set of state and local regulatory compliance limits besides federal limits, depending on its state and local political subdivision. As discussed in Section 1.3.2 above, the MA-DEP prefers that a facility dispose of non-hazardous wastewater to a sewerage system whenever access to the system is available. Currently, MA-DEP does not prohibit the disposal of non-hazardous mercury-containing wastewater (of greater than 1.0 µg/L (ppb)) at a TSDF but may require that a facility obtain a permit for such disposal. The best approach may be to deal with the ultimate disposal facility through your hazardous waste disposal contractor.

In summary for hazardous wastes, it is possible to have a waste stream that is:

• A listed hazardous waste but is not a characteristic hazardous waste.
• A characteristic hazardous waste but is not a listed hazardous waste.
• A listed hazardous waste that is also a characteristic hazardous waste.

2.3 Land Disposal Restriction (LDR) Regulations
It is now appropriate to address the federal LDR Regulations (40 CFR Part 268) or, in other words, how a hazardous waste may be disposed. The purpose of this section is develop a general awareness of the LDR Regulations. The information presented in this section is a very brief summary intended only as an introduction to LDR requirements. A generator of hazardous waste should learn the regulations by referring to the latest versions before making any shipment of hazardous wastes. In addition, specific guidance should be sought from the resources discussed in Section 2.1 above.

It is important to note that a generator of hazardous waste is responsible for correct classification of the hazardous waste and for preparation of hazardous waste manifests and LDR certifications. Therefore, while a generator may use hazardous waste disposal contractors to help prepare the needed documents, the generator must have enough knowledge of the regulations to be able to verify the contractor's work.

Because of the Hazardous and Solid Waste Amendments (HSWA) of 1984, hazardous wastes cannot be ultimately land disposed unless they either:

• Meet treatment standards, or are
• Treated to meet standards.

The LDR treatment standards are expressed either as a numerical concentration limit of a hazardous constituent in the waste, or a specific treatment technology. Concentration-based limits may be expressed as total or TCLP.

Theoretically, a waste could be treated before it leaves the facility. However, many facilities do not have a RCRA Part-B permit that would allow them to perform on-site treatment of hazardous wastes, so instead they must have a licensed TSDF treat the waste for them. One purpose of the LDR Regulations is to ensure that the TSDF is properly notified of waste shipments being sent by a generator. Then the waste can be ultimately land-disposed if the TSDF first treats the waste to meet the applicable standards or if the waste meets treatment standards without actual treatment.

The operative word is ultimately. For example, the EPA has disallowed the incineration of inorganic metal-bearing wastes, because incineration is deemed to constitute a form of "impermissible dilution." This is because the metals are not treated (i.e., "destroyed, removed, or immobilized") during the incineration process. In fact, incineration actually concentrates metals in the incinerator ash that is ultimately land disposed. Therefore, the incinerator facility has to TCLP test its ash regularly, and determine whether the ash must be stabilized before disposal in a chemical secure landfill. Similarly, metals such as mercury may have to be recovered from wastewater treatment facilities (e.g., in sludge) before the treated waste can be disposed of on land.

The following process must be performed for each waste stream:¹¹

A. Identify (classify or characterize) each wastestream.

Determine each Federal hazardous waste code for characteristic and listed wastes that applies to the waste. (Note that state waste codes do not affect the federal LDR regulations). For mercury, we will consider two cases: D009 and U151.

B. Determine if the waste is a wastewater (WW) or non-wastewater (NWW).

In general, a wastewater must contain less than 1.0 percent Total Organic Carbon (TOC) and less than 1.0 percent Total Suspended Solids (TSS). Otherwise, it is a non-wastewater. TOC is the percent by weight of the carbon content in the waste. TSS is the percent by weight of the filterable solids in the waste. (There is an exception: < 1% TOC or 1% solvent constituent for F001 - F005 solvent waste mixtures).

C. Determine applicable treatment standard.

This is accomplished by referring to the Treatment Standards in the "Consolidated Table" in Section 268.40. Use the Treatment Standard for listed waste number. Use also the Characteristic Treatment Standard if a constituent causes the waste to be a characteristic waste unless the Listed Treatment Standard applies to the constituent causing the characteristic waste property. Because Treatment Standards can be expressed as either total or TCLP concentrations, it is very important to be sure of the type of test (i.e., total versus TCLP) and units when comparing laboratory data with Treatment Standards.

Characteristic wastes cannot be land disposed until the characteristic is removed and any underlying hazardous constituents (UHCs) are below universal treatment standards (UTS). UHCs are any constituents in 40 CFR 268.48 that are reasonably expected to be present at levels above the UTS at the point of generation of the characteristic waste.

The following categories are listed for D009 involving no radioactive materials or radioactive mercury (which is beyond the scope of this discussion):

1. High Mercury-Organic Subcategory. "Non-wastewaters...containing greater than or equal to 260 mg/kg total (emphasis added) mercury that also contain organics and are not incinerator residues." The specified treatment technology code is "IMERC" (incineration) or "RMERC" (recovery or reclamation of mercury, e.g., "roast and retort").

2. High Mercury-Inorganic Subcategory. "Non-wastewaters...containing greater than or equal to 260 mg/kg total (emphasis added) mercury that are inorganic..." The specified treatment technology code is "RMERC."

3. Low Mercury Subcategory. "Non-wastewaters...(that) contain less than 260 mg/kg total mercury." The specified Treatment Standard is 0.20 mg/L (ppm) TCLP (emphasis added).

4. D009 - All others. For this subcategory of TC mercury wastewater, the specified Treatment Standard is 0.15 mg/L (ppm) total (emphasis added) mercury which is the same as the UTS for mercury wastewaters (Mercury - All Others). The Treatment Standard for TC mercury nonwastewaters in this subcategory is 0.025 mg/L TCLP (emphasis added). This is a strict standard.

The following categories apply to U151 listed wastes:

1. "U151 (mercury) non-wastewaters that contain greater than or equal to 260 mg/kg total (emphasis added) mercury." The specified treatment technology is "RMERC."

2. "U151 (mercury) non-wastewaters that contain less than 260 mg/kg total (emphasis added) mercury and are not residues from RMERC." The specified treatment standard is 0.025 mg/L (ppm) TCLP. This is a strict standard.

3. "All U151 (mercury) wastewaters." The specified treatment standard is 0.15 mg/L (ppm) total (emphasis added) mercury.

F. Prepare LDR Notification/Certifications (there is no required format but there is required certification language) to the TSDF stating that: The waste does or does not meet treatment standards, the EPA waste code(s), underlying hazardous waste constituents for F001 - F005, F039, D001, D002, and D012 - D043, WW or NWW, subcategory (if applicable), and manifest number. Note that LDRs must be prepared for excluded, recycled and treated wastes also. Refer to the Generator Paperwork Requirement Table at 40 CFR 268.7.

G. Attach each LDR notifications/certification to the applicable uniform hazardous waste manifest. Note that the LDR notification/certification is only a one-time notification, rather than with each shipment of a particular hazardous waste. No new notification would be required unless there were a change in the waste, process, or receiving facility. The one-time notification would apply to shipments of all restricted hazardous wastes, and so would include lab packs.

The EPA requires LDRs to be retained for a minimum of three years from the date the waste was last sent off-site for treatment and disposal. Massachusetts also requires hazardous waste manifests be retained for three years. Regardless, consideration should be given to retaining all documentation relating to hazardous waste activities indefinitely because of perpetual liability concerns (the RCRA "cradle to grave" concept).

Two final LDR considerations should be addressed. At the end of Section 2.2 on TCLP testing, it was noted that small containers of waste reagents are often packaged as "lab packs." Although there is a less burdensome alternative for lab packs than the full LDR procedure, it is not possible to use this alternative for mercury-containing hazardous wastes because D009 and U151 waste codes are prohibited from being included in organic lab packs by reason of the issue of concentrating metals in incinerator ash as discussed above. Therefore, the full LDR requirements apply to lab pack quantity shipments of D009 and U151 wastes.

However, the federal LDR regulations have a de minimis exemption. A generator that is generating less than 100 Kg (about 220 pounds) per month of non-acute hazardous waste or less than 1 Kg (about 2.2 pounds) per month of acute hazardous waste is not required to comply with the federal LDR regulations.

For all hazardous waste determinations, shipping manifests, LDR treatment standard determinations, and LDR Notifications/Certifications, it is important to repeat the recommendation that a generator of hazardous waste learn the regulations by referring to the latest versions before making any shipment of hazardous wastes. In addition, specific guidance should be sought from the resources discussed in Section 2.1 above.

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