7
Disposal of Carbon from Chemical Agent Disposal Facilities

The preceding chapters of this report have indicated the sources, amounts, and properties of activated carbon; described how it is actually used and managed at chemical agent disposal facilities and other industrial operations; and discussed the chemical fate of the agents on the carbon. This chapter addresses disposal options for all of the used carbon (exposed and unexposed) from chemical agent disposal facilities, including methods that have been used or proposed by both closed and operating chemical agent disposal facilities. It also assesses the type of scientific support required for the disposal facilities to obtain regulatory approvals.

The central theme of this report is that the used activated carbon from chemical agent disposal facilities can be assigned to one of two categories: (1) carbon that has been exposed to chemical agent(s) in the course of its utilization (“exposed carbon”) and (2) carbon that has not been so exposed (“unexposed carbon”). Analyses performed on samples of exposed carbon have confirmed that contamination with agents decreases over time because the agents react with the moisture adsorbed on the carbon and form degradation products via hydrolysis. However, the analytical evidence suggests that a small, parts-per-billion level of agent may always remain on the carbon after normally expected storage times following removal from service and storage.

PAST EXPERIENCE WITH DISPOSAL OF USED ACTIVATED CARBON

The first integrated chemical agent disposal facility was the Johnston Atoll Chemical Agent Disposal System (JACADS), which used incineration technology and completed 10 years of disposal operations in 2000. In 2005, the Aberdeen Chemical Agent Disposal Facility (ABCDF), which used neutralization technology to destroy agent, was the first integrated disposal facility in the continental United States to complete agent disposal operations. JACADS and ABCDF have already disposed of their entire inventory of used carbon by incineration, the former on-site and the latter off-site. The Newport Chemical Agent Disposal Facility (NECDF), another facility that used neutralization, completed agent disposal operations in 2008. It had a regulatory permit allowing shipment of all of its exposed carbon as a listed secondary waste to a qualified treatment, storage, and disposal facility (TSDF) for incineration. NECDF was in the process of shipping its exposed carbon off-site as this report was being prepared. It has also shipped approximately 220,000 lb unexposed carbon to Calgon Carbon Corporation for reactivation and resale. The determination that this carbon had not been exposed to agent was based on generator knowledge. Further details of these disposal activities and their relevance to future carbon disposal at other facilities are provided below.

Incineration of Used Carbon at JACADS

The closure plan for JACADS required that all used carbon be incinerated on-site. This was accomplished by a process known as carbon micronization. The used carbon was first pulverized to a fine powder in a carbon micronization system (CMS) and then blown into the deactivation furnace system, where it was incinerated.



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7 Disposal of Carbon from Chemical Agent Disposal Facilities The preceding chapters of this report have indi- System (JACADS), which used incineration technol- cated the sources, amounts, and properties of activated ogy and completed 10 years of disposal operations in carbon; described how it is actually used and man- 2000. In 2005, the Aberdeen Chemical Agent Disposal aged at chemical agent disposal facilities and other Facility (ABCDF), which used neutralization technol- industrial operations; and discussed the chemical fate ogy to destroy agent, was the first integrated disposal of the agents on the carbon. This chapter addresses facility in the continental United States to complete disposal options for all of the used carbon (exposed agent disposal operations. JACADS and ABCDF have and unexposed) from chemical agent disposal facilities, already disposed of their entire inventory of used car- including methods that have been used or proposed bon by incineration, the former on-site and the latter by both closed and operating chemical agent disposal off-site. The Newport Chemical Agent Disposal Facil- facilities. It also assesses the type of scientific support ity (NECDF), another facility that used neutralization, required for the disposal facilities to obtain regulatory completed agent disposal operations in 2008. It had approvals. a regulatory permit allowing shipment of all of its The central theme of this report is that the used exposed carbon as a listed secondary waste to a quali- activated carbon from chemical agent disposal facili- fied treatment, storage, and disposal facility (TSDF) for ties can be assigned to one of two categories: (1) incineration. NECDF was in the process of shipping carbon that has been exposed to chemical agent(s) in its exposed carbon off-site as this report was being the course of its utilization (“exposed carbon”) and prepared. It has also shipped approximately 220,000 lb (2) carbon that has not been so exposed (“unexposed unexposed carbon to Calgon Carbon Corporation for carbon”). Analyses performed on samples of exposed reactivation and resale. The determination that this carbon have confirmed that contamination with agents carbon had not been exposed to agent was based on decreases over time because the agents react with the generator knowledge. Further details of these disposal moisture adsorbed on the carbon and form degrada- activities and their relevance to future carbon disposal tion products via hydrolysis. �owever, the analytical at other facilities are provided below. evidence suggests that a small, parts-per-billion level of agent may always remain on the carbon after normally Incineration of Used Carbon at JACADS expected storage times following removal from service and storage. The closure plan for JACADS required that all used carbon be incinerated on-site. This was accomplished by a process known as carbon micronization. The used PAST EXPERIENCE WITH DISPOSAL carbon was first pulverized to a fine powder in a carbon OF USED ACTIVATED CARBON micronization system (CMS) and then blown into the The first integrated chemical agent disposal facil- deactivation furnace system, where it was incinerated. ity was the Johnston Atoll Chemical Agent Disposal 

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 DISPOSAL OF CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES Disposal of Used Carbon at ABCDF The experience was summarized as follows (NRC, 2007, p. 60): At ABCDF, after their removal from service, the The micronization process proved difficult to operate, and used carbon filters were double bagged in polyethyl- throughputs were much lower than expected. In addition, ene. The vapor space in the bag was then sampled for while being transported in pipes from the micronizer to the agent. Bags with >1 vapor screening level (�SL)1 agent deactivation furnace system, the resulting powder could levels of mustard agent �D were placed in 95-gallon under some circumstances become an explosive mixture. polyethylene drums and shipped by truck to the �eolia Fortunately, no explosive event happened at JACADS, but the possibility is real and must be considered. A prudent Environmental Services Facility in Port Arthur, Texas, course now would be for the Chemical Materials Agency to where the used carbon was incinerated without open- immediately pursue alternative disposal options for treating ing the drums. There were 482 drums with >1 �SL spent activated carbon resulting from current operations as contamination. well as for the large amounts of spent activated carbon that The remaining filter trays from the heating, ventila- will [be] generated during closure operations. tion, and air conditioning (��AC) Banks 2 through 6 were placed in bags and shipped without drumming On p. 45 the same report stated that “depending on since they had agent levels <1 �SL. The total weight the organic contaminants adsorbed, spent carbon may of carbon filters with <1 �SL contamination was be classified as hazardous or nonhazardous.” In this 94,720 lb. context, “spent carbon” is a more generalized term Since the polyethylene drums and bagged filters than “exposed carbon” because it refers to activated were not to be opened before being fed to a rotary carbon that has been exposed either to agent or to other kiln and incinerated at the �eolia facility, the metal airborne contaminants. filter frames became part of the kiln discharge solid The JACADS experience demonstrated that acti- residue. Kiln flue gases were processed through the vated carbon exposed to agent can be incinerated. As �eolia facility’s gas scrubbing system. Carbon at well as oxidizing the carbon, this process destroys ABCDF was contaminated only with mustard agent any agent that may be present. �owever, use of the �D, with the worst-case loading of �D estimated to micronization process to prepare the carbon for incin- be 16 weight percent, the �D saturation level.2 The eration created an explosion hazard associated with waste was transported based on a transportation risk the handling of the finely divided carbon. The carbon assessment (TRA). dust also created operational problems that extended JACADS’ operating time and necessitated additional Finding 7-2. The use of a transportation risk assess- maintenance. Also, CMS processing required many ment provides a methodology to assist the permitting demilitarization protective ensemble (DPE) entries by regulatory authority in making a determination of personnel to conduct maintenance operations. At times, whether the proposed method of shipment is safe. CMS maintenance operations accounted for 85 percent of DPE entries, which increased the risk to personnel Recommendation 7-2. T he Chemical Materials and created additional secondary waste for disposal. Agency should explore with the appropriate regulatory Used DPE suits were a major source of secondary waste. This had a direct impact on closure decontami- nation operations and schedule. 1�apor screening levels (�SLs) and short-term limits (STLs) are names for equivalent measurements (specified in RCRA operating Finding 7-1. The micronization of carbon before it is permits) for control limits used to help plan for waste transport and incinerated in the deactivation furnace system is a haz- disposal. They also supplement short-term exposure limits (STELs) ardous operation with operational problems and a lot for protecting workers’ health during plant operations as waste is generated and moved to storage areas within the plant. �SL/STL of maintenance. Fine pulverized carbon is susceptible concentrations vary by agent and are the same values as STELs to dust explosions. except that �SL is measured in air sampled for about 5 minutes instead of 15 minutes for STELs. For GB, �X, and �D, 1 �SL is Recommendation 7-1. If a chemical agent disposal equivalent to 0.0001 mg/m3, 0.00001 mg/m3, and 0.003 mg/m3, facility must dispose of any carbon on-site, microni- respectively. 2Brian O’Donnell, Chief, Secondary Waste and Closure Team, zation should not be used to prepare the carbon for CMA, “CMA carbon management,” Presentation to the committee, incineration. June 4, 2008.

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 DISPOSAL OF ACTIVATED CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES authorities the use of a transportation risk assessment obtained permission from the Army Material Com- as a method of permitting the transportation of exposed mand to allow Calgon to sell the reactivated carbon carbon for off-site disposal. on the open market for nonfood use. Calgon assumes any liability. Disposal of Used Carbon at NECDF Finding 7-3. Used carbon that qualifies as unexposed The NECDF permit had no requirement for sam- to agent based on generator knowledge can be reacti- pling or analyzing the used carbon before its shipment vated at a commercial carbon activation facility if it to an off-site TSDF. NECDF managed the carbon, meets the reactivation contractor’s requirements for which had been exposed to the nerve agent �X, as a physical condition and chemical contamination. designated hazardous waste and shipped it off-site to Recommendation 7-3. T he Chemical Materials �eolia for incineration using this permit. Bank 1 carbon from the NECDF ��AC filter units was analyzed by Agency should consider the reactivation and sale of the extractive method and found to contain less than unexposed used carbon on the open market provided 95 ppb of �X. The Bank 2 carbon would have even that the Army’s liability terminates with transfer of the less contamination. Based on generator knowledge, carbon to the reactivation contractor. carbon from Banks 3 through 6 had not been exposed to agent. On-site Disposal of Exposed Carbon at Operating Approximately 70,000 lb of carbon that had been Disposal Facilities exposed to �X was shipped to �eolia during closure of NECDF. A TRA had been prepared in July 2008 for the Treatment in the Metal Parts Furnace shipment of �X-exposed carbon to �eolia. All of the documentation to meet National Environmental Policy At the Anniston, Pine Bluff, and Umatilla Chemi- Act requirements for the shipments was completed, and cal Agent Disposal Facilities (ANCDF, PBCDF, and the Indiana Department of Environmental Management UMCDF respectively), operating permits allow thermal treatment of exposed carbon (1000°F for at least 15 and the Centers for Disease Control were informed of the planned shipments. The TRA was based on con- minutes) in the metal parts furnace (MPF). �owever, centrations determined for Bank 1 ��AC filter trays while this is an accepted decontamination procedure (the most heavily contaminated trays).3 As of August used for steel munition bodies and certain other sec- 2008, NECDF had 792 polyethylene drums containing ondary wastes, it results in smoldering carbon. At pres- carbon filters in bags ready for shipment. In September ent, only the small amounts of carbon from the filter 2008, all drums containing exposed carbon filters had units of the agent collection system (ACS) vent line been shipped to the �eolia facility for incineration.4 and M-40 protective mask canisters are treated in the NECDF has already shipped approximately 220,000 lb MPF. These filter trays are placed in waste incineration of used unexposed carbon from Banks 3 through 6 of containers that are fed to the MPF. Since the carbon the ��AC filter units to Calgon Carbon Corporation would not be completely oxidized at the end of normal for reactivation. Generator knowledge confirmed that thermal treatment, processing times were established this carbon had not been exposed to �X. The used for achieving complete oxidation of carbon during the (unexposed) carbon from Banks 3 through 6 also met UMCDF ACS Filter Processing Evaluation—namely, Calgon’s acceptance criteria for physical condition and 90 minutes in Zone 1 of the MPF, 90 minutes in Zone 2, and 1,260 minutes in Zone 3, for a total of 24 hours.5 amount of other contaminants. The reactivated carbon was stored at Calgon pending a decision for its final The material exiting the MPF is agent-free metal and disposition. The Chemical Materials Agency (CMA) ash. The amount of used carbon that can be processed in the MPF in this manner is limited by overall facility scheduling because the primary function of the MPF 3Brian O’Donnell, Chief, Secondary Waste and Closure Team, CMA, “NECDF carbon shipment decision,” Presentation to the committee, July 24, 2008. 4Timothy Garrett, Site Project Manager, ANCDF, “CMA’s efforts 5Robie Jackson, Waste Management Manager, ANCDF, and on carbon management disposal,” Presentation to the Committee Tracy Smith, Trial Burn Manager, ANCDF, “The use of carbon at on Chemical Demilitarization, September 17, 2008. ANCDF,” Presentation to the committee, June 5, 2008.

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 DISPOSAL OF CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES is to thermally treat the casings and other metal parts allow disposal of the treated carbon from the autoclave from munition disassembly. in a permitted hazardous waste landfill. Some additional heavily exposed carbon filters could The operating principles for the autoclave are simi- be processed in the MPF without adversely impacting lar to those incorporated into the metal parts treater the throughput rate for treating munition casings and that will be used in the Blue Grass Chemical Agent the like during operations or during plant closure, but Destruction Pilot Plant. The metal parts treater will processing all the Bank 1 and Bank 2 filter units of the use a steam atmosphere, but the temperature will be above 1000°F for more than 15 minutes to achieve an ��AC filter units in the MPF would seriously delay the overall operating schedules of the disposal facilities. agent-free condition. Finding 7-4. On-site thermal treatment in the metal Finding 7-5. Autoclaving may be a satisfactory method parts furnace has been demonstrated to be a satisfac- of decontaminating exposed carbon, but its efficacy has tory method for disposing of exposed carbon and is not been demonstrated and the treated carbon may still being used at some chemical agent disposal facilities. contain agent in low concentrations. �owever, the residence time must be sufficient to fully Recommendation 7-5a. The use of dedicated auto- oxidize the carbon or prevent smoldering. The solid metallic filter trays and ash that remain afterward can claves should be considered as an alternative means be disposed of with other thermally decontaminated for treating large amounts of exposed used carbon to secondary waste. ready it for off-site shipment to a permitted hazardous waste disposal facility. Recommendation 7-4. Although carbon can be suc- Recommendation 7-5b. T he Chemical Materials cessfully treated in the metal parts furnace, on-site disposal treatment of exposed carbon in the metal parts A gency should review the planned sampling and furnace should be limited to small quantities of exposed analysis procedures for carbon that will be treated in the carbon—from, for example, agent collection system fil- autoclave. This would ensure that they are appropriate ter units and M-40 protective mask canisters—because for achieving the postautoclave processing condition the time required to completely oxidize all of the of the carbon and that they can reliably measure agent exposed carbon generated at a chemical agent disposal concentrations at levels required by the permit for off- facility would seriously extend the disposal operations site shipment to a hazardous waste disposal facility. schedule of the metal parts furnace and closure of the disposal facility as a whole. CURRENT CMA CARBON MANAGEMENT STRATEGY Treatment in Autoclaves The CMA has proposed a carbon management The Tooele Chemical Agent Disposal Facility strategy that uses on-site disposal of highly contami- (TOCDF) is planning to treat agent-exposed carbon in nated carbon in ACS vent filter trays and M-40 gas an autoclave at 305°F. The autoclave will use a high- mask canisters. The strategy also states that all other pressure steam atmosphere to reduce agent concentra- exposed and unexposed carbon will be disposed of at tions on the carbon to levels suitable for shipment off- a qualified TSDF, either by incineration or in a landfill. site to a permitted hazardous waste landfill. The steam The feasibility of off-site disposal is decided by using also prevents the carbon from smoldering. Offgas from approved sampling methods to determine the amount the autoclave will pass through an offgas treatment of agent contamination that is present on the carbon in system to ensure that agent released during autoclave each polyethylene shipping drum and comparing that treatment will be destroyed before offgas is released amount to the amount allowed by a bounding TRA. to the atmosphere. The optimum autoclave operating A bounding TRA has been prepared and approved by conditions will be determined by demonstration testing. the CMA for use on all agent-contaminated secondary Results of any such testing were unavailable at the time waste shipments, including used carbon, having agent concentrations of >1 �SL. The committee did not this report was being prepared because the details of the autoclave process had not been completely developed. assess the basis used for the bounding TRA since it was TOCDF has requested that its permit be modified to reviewed in prior National Research Council studies on

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 DISPOSAL OF ACTIVATED CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES secondary waste disposal and regulatory requirements TABLE 7-1 Agent Mass Limits per Drum for Off-site Shipment of Secondary Waste (NRC, 2007, 2008). An addendum for carbon shipment is under development. Maximum Anticipated Actual Maximum Agent Concentration of Concentration of As noted earlier, CMA used a TRA to obtain state Mass per Druma Agent on Carbonb Agent on Exposed approval for the shipment of �D-exposed carbon from Allowable to Meet per Drum to Meet Carbon per Drum ABCDF and �X-exposed carbon from NECDF to the Agent GPL of 1 AEGL (g) 1 AEGL (ppb) (ppb) �eolia facility in Port Arthur, Texas. Use of a bound- 130c GB 0.008 400 ing TRA for carbon at other sites is expected to require 17c �X 0.29 13,000 acceptance by the state regulators for those sites and for 80d �D 6.5 290,000 each of the states through which the materials are pro- aApplies to both 55-gallon and 95-gallon drums. Amounts based on analyses for residual agent on decontaminated secondary waste. GPL, posed to be moved. �owever, the committee considers general population limit. the use of a TRA to be an appropriate approach. bAssumes 48 lb of carbon per 95-gallon drum. The bounding TRA specifies the maximum mass cBased on analysis of Bank 1 carbon at ANCDF. of a specific agent that may be held in a shipping dBased on NECDF carbon. container, the number of containers per shipment, SOURCE: Adapted from Michael McNaughton, Southwest Research Institute “Analytical procedures for GB/�X carbon,” Presentation to the and the total number of shipments in a given time. committee, July 23, 2008; Brian O’Donnell, Chief, Secondary Waste, These values are set to limit general population risk to Closure Compliance and Assessments, CMA, “Transportation risk assess - 1 acute exposure guideline level (AEGL).6 Table 7-1 ment,” Presentation to the committee, July 24, 2008; site visit to Southwest summarizes the limits of agent mass per drum deter- Research Institute, January 14-15, 2009. mined by CMA using this approach. The maximum concentration allowed on the exposed carbon can be calculated by accounting for the expected mass of at greater than 20 ppb could be transported off-site if carbon per drum (~50 lb). The values are given in the the TRA is approved by state regulators and procedures third column of Table 7-1. The last column provides the are implemented to satisfy the risk assessment values. anticipated actual concentration on the carbon based on These values are a function of accidental release sce- analyses that have already been performed at ANCDF narios assumed in the assessment and the frequency and NECDF. Clearly, the nerve agent GB presents the established for such release scenarios. highest risk for off-site transportation to a TSDF. GB The application of the CMA’s bounding TRA will necessitate sampling and analysis. Currently, CMA is working on an analytical method to clear exposed 6Acute exposure guideline levels (AEGLs) are a hazard commu- carbon for off-site shipment. There are at least two nication measure developed by the National Advisory Committee challenges to implementing this methodology: to Establish Acute Exposure Guideline Levels for �azardous Sub- stances. The committee developed detailed guidelines for devising • Sampling. CMA must validate a sampling tech- uniform, meaningful emergency response standards for the general nique to ensure that samples of exposed carbon public. The guidelines define three tiers of AEGLs as follows: are representative of the carbon in the shipping • AEGL-. The airborne concentration of a substance above container. This includes representative sampling which it is predicted that the general population, including susceptible individuals, could experience notable discomfort, within a filter unit, selection of the filter tray(s) irritation, or certain asymptomatic nonsensory effects. �ow- within a bank, and, for carbon previously placed ever, the effects are not disabling and are transient and revers- in polyethylene drums, the selection of drums ible upon cessation of exposure. within a lot. • AEGL-. The airborne concentration of a substance above • Analysis. CMA must show that the extractive which it is predicted that the general population, including analysis procedure accurately measures the con- susceptible individuals, could experience irreversible or other serious, long-lasting adverse health effects or an impaired centration of agent on the exposed carbon at the ability to escape. parts-per-billion level. The method must be accept- • AEGL-. The airborne concentration of a substance above able to the state regulators. which it is predicted that the general population, including susceptible individuals, could experience life-threatening All exposed carbon is contained in steel filter trays health effects or death. consisting of two layers of carbon, each held between The guidelines for each level consider five exposure periods: 10 metal screens (see Figures 2-3 and 2-4). Each layer minutes, 30 minutes, 1 hour, 4 hours, and 8 hours (NRC, 2001).

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 DISPOSAL OF CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES is approximately 2 inches thick. Upon removal from approval for off-site shipment to a qualified treatment, service, these filter trays are double bagged in plastic storage, and disposal facility. and placed in a polyethylene drum, one tray per drum. Recommendation 7-7. A transportation risk assess- The drums are then moved to a safe storage location awaiting final disposition either on-site or off-site. ment and a suitable sampling and analysis protocol for Sampling for agent on the carbon in filter trays all exposed carbon other than that from the agent col- requires that the sampling personnel don DPE suits and lection system filter units and the M-40 mask canisters open the drums in a Level A area.7 The double-bagged should be used to allow the carbon to be sent off-site filter tray must be pulled from the drum and removed for disposal. This approach could expedite closure and from the plastic bags. The workers in DPE suits must minimize the number of operations required by workers then cut open the metal screen on one side of a carbon in demilitarization protective ensemble suits, thereby layer to obtain representative samples. The sharp edges reducing worker risk and adhering to the facility clo- that result from cutting the screen to access exposed sure schedule. carbon for sampling pose a threat to the integrity of the DPE suits worn by workers. ALTERNATIVE METHODS FOR DISPOSAL OF CARBON Finding 7-6. The sampling of used carbon in filter trays involves a number of steps that increase the risk This section describes alternative methods for treat- that workers in demilitarization protective ensemble ing and disposing of exposed and unexposed carbon. suits will be exposed to agent. Use of Decontamination Solution for Off-site Recommendation 7-6a. A protocol that uses statisti- Disposal of Exposed Carbon cal sampling methods to minimize the number of filter trays to be sampled and analyzed should be developed The committee believes that adding caustic NaO� to ensure that the samples obtained are representative decontamination solution to drums containing exposed and accurately satisfy the criteria of the transportation carbon offers an attractive method for safely shipping risk for off-site shipment of exposed carbon while this material to a TSDF. Other agent-contaminated also minimizing the risk of personnel being exposed waste has been treated with caustic solution to decon- to agent. taminate it before bagging and drumming for ship- ment to a qualified TSDF from ABCDF, ANCDF, Recommendation 7-6b. To minimize the risk of sam- and NECDF (NRC, 2007). The committee believes pling personnel exposure to agent, sampling methods this method could also be used for off-site disposal of should be developed that minimize the number of poly- exposed carbon. �owever, there has been little experi- ethylene drums that must be opened while accurately ence with using caustic decontamination solution on determining agent concentrations on stored carbon. exposed carbon. A protocol and a procedure would have to be Finding 7-7. The Chemical Materials Agency car- established to determine how much decontamination bon management strategy includes treatment of all solution should be added and how to ensure adequate of the agent collection system filter unit carbon and wetting of carbon surfaces to achieve decontamina- carbon from the M-40 protective mask canisters on- tion to levels safe for shipment. While experimental site because treatment of the small quantities involved data indicate that a p� of 7 completely hydrolyzes GB will not disrupt or delay overall facility operations or in solution, decontamination solution having a p� of closure. The exposed carbon from the agent collection 10 or more could compensate for any effect that the system filters is highly contaminated with agent, mak- carbon may have on the reaction. One approach might ing off-site treatment and disposal undesirable. For all be as follows: Inject sufficient decontamination solu- other carbon, the CMA’s strategy is to seek regulatory tion into the double bags to cover and fully wet all of the carbon. The decontamination solution should be in direct contact with the carbon inside the bags. For the filters that have not yet been removed from the banks, 7A Level A area is one expected to be contaminated with agent addition of caustic solution directly into the bags would and under engineering controls.

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 DISPOSAL OF ACTIVATED CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES be a simple additional step in the bagging and storage policies would not allow it to accept for reactivation operation. carbon that contains mercury or other chemical species This approach could eliminate the requirement in concentrations exceeding the company’s acceptance for sampling and analysis to determine the mass of criteria. Calgon will accept exposed carbon for reacti- agent on the carbon and the risk of any agent being vation provided that (1) agent concentrations are below released during transportation. �owever, because it current detection limits, (2) unexposed filter trays are also increases the weight of the drums and reduces the separated from exposed filter trays, and (3) unexposed heat content of the carbon, it would result in higher filter trays are accompanied by a letter stating there is transportation and incineration costs. no detectable agent present based on either generator knowledge or test results and identifying the filter trays Finding 7-8. The committee believes that decon- that were tested. These constraints preclude reactiva- tamination solution could be applied to carbon that tion of carbon with detectable levels of agent (see has been exposed to agent to enable shipment off-site Chapter 4). Other carbon reactivation companies have to a treatment, storage, and disposal facility based on similar criteria for agent and other chemical species. the precedent that other secondary waste, porous and While unexposed carbon from NECDF has been nonporous, exposed to agent has been decontaminated reactivated, experience reveals some remaining chal- by this procedure and shipped to a qualified treatment, lenges for exposed carbon even if the agent has been storage, and disposal facility. completely degraded. First, the carbon must be shown to be free of agent prior to reactivation because these Recommendation 7-8. T he Chemical Materials units are not currently permitted for processing carbon Agency should investigate adding decontamination that contains detectable levels of agent. Second, there solution to drums of carbon exposed to agent as a is no body of evidence on the fate of the decomposi- means to allow the carbon to be transported to a quali- tion products that remain on the carbon, although the fied treatment, storage, and disposal facility for final reactivation process, carried out at approximately 850°C, will destroy them. The Army also does not disposal. A protocol should be formulated for specify- ing the amount of decontamination solution to be added want to retain liability for the reactivated carbon after to the carbon. This would include determining whether it arrives at the vendor. The reactivation facility must the carbon must be fully immersed in the decontamina- assume liability for any issues resulting from reuse of tion solution or only wetted by it, and whether using the reactivated carbon. caustic solution with a p� at or above 10 will guarantee Finding 7-9. Reactivation of unexposed carbon from that the GB concentration is below the waste control limit. Such a method could eliminate the need to mea- chemical agent disposal facilities has been demon- sure agent contamination on carbon before shipping it strated by the experience at the Newport Chemical off-site. Agent Disposal Facility. The reactivation of exposed carbon may require some level of sampling and analysis that may not be cost-effective. Reactivation of Unexposed Carbon Recommendation 7-9. T he Chemical Materials Sending carbon to a vendor for reactivation, blend- ing it with other sources of carbon, and reselling it Agency should consider reactivation and resale as an offers a disposal alternative, possibly reducing disposal option for the disposal of unexposed carbon. �owever, costs. As indicated in Chapter 2, approximately 80 it should evaluate the costs and liabilities associated percent of all of the used carbon that will be generated with reactivation and compare them with those for at the four incineration facilities will never have been other disposal options. exposed to agent. As noted previously, Calgon Carbon Corporation GENERAL FINDINGS AND RECOMMENDATIONS has reactivated 220,000 lb of unexposed carbon from NECDF. This carbon was considered agent-free based The committee concludes this report with the fol- on generator knowledge and is being resold on the lowing general findings and recommendations, which open market by the vendor. Calgon representatives told summarize the specific findings and recommendations committee members that the company’s permits and set forth throughout this report.

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 DISPOSAL OF CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES General Finding 1. About 80 percent of all the used General Finding 4. Nerve agents GB and �X and activated carbon that has been or will be generated at mustard agent �D have been shown to degrade on the chemical agent disposal facilities operating under activated carbon to their usual hydrolysis products by the Chemical Materials Agency has never been exposed reacting with the moisture adsorbed on the carbon. This to agent and can be treated as ordinary hazardous waste. occurs both while the carbon is in use and after, during This includes the carbon from Banks 3 to 6 of the heat- storage. Of the known analytical results, the concen- ing, ventilation, and air conditioning filter units and the trations of �X that remain on carbon samples from bulk carbon from the filter beds of the pollution abate- heating, ventilation, and air conditioning Bank 1 at the ment system filtration system. Anniston Chemical Agent Disposal Facility appear to be below the waste control limits of 20 parts per billion. General Recommendation 1. All unexposed carbon �owever, the remaining concentration of GB appears (as determined by generator knowledge) should be dis- to be about 130 parts per billion, well above the waste posed of off-site as a hazardous waste without further control limit of 20 parts per billion. Thus, the carbon chemical analysis for agent or sent for reactivation if that has been exposed to GB cannot be sent off-site a contractor will accept it and assume ownership and based on the waste control limits. The concentration of liability. The choice of disposal method and treatment, �D that remains on carbon filters had not been mea- storage, and disposal facility will be dictated by what- sured at the time this report was prepared. ever other contaminants are present on the carbon. General Recommendation 4. Carbon that has been General Finding 2. Unless there is an unexpected exposed to agent should be sent off-site under one of upset resulting in contamination with agent, all of the the following arrangements: sulfur-impregnated carbon that is to be used in the pol- lution abatement system filtration systems will not have • Use of waste control limits or permit compliance been exposed to agent. Thus, based on generator knowl- concentrations. If the agent concentrations on the edge, the carbon can be sent off-site without further exposed carbon are below the waste control limits analysis for chemical agents. This carbon can be treated or the permit compliance concentrations, the car- as a hazardous waste contaminated with mercury. bon can be shipped off-site for proper disposal at a waste treatment facility licensed to receive and General Recommendation 2. A ll of the sulfur- treat this waste under existing regulations. For impregnated carbon used in the pollution abatement this arrangement it will be necessary to develop system filtration systems and not involved in an unex- and validate analytical methods that accurately pected upset condition at a chemical agent disposal measure agent concentration for both GB and facility should be sent off-site. This carbon should be �D. The methods must be capable of analyzing treated as a hazardous waste that is contaminated with the agents on carbon that has been exposed to all mercury. three agents and that will have both the agents and their respective degradation products from General Finding 3. Treatment of all of the exposed hydrolysis adsorbed on the carbon. carbon on-site in the metal parts furnace would seri- • Use of a transportation risk assessment. If the ously delay the closure of the currently operating mass of the agent on the carbon in a drum is less Chemical Materials Agency chemical agent disposal than specified by the Chemical Materials Agency facilities. transportation risk assessment (see Table 7-1), the drum can be transported to a treatment, stor- General Recommendation 3. Only the carbon filter age, and disposal facility. The transportation trays from the agent collection system tank vent lines risk assessment requires determining the mass and the canisters from the M-40 protective masks of each agent on the carbon by a validated ana- should be treated on-site in the metal parts furnace lytical method. In addition, each chemical agent when the metal parts furnace is not performing its pri- disposal facility will have to negotiate with the mary function of treating metal parts or other wastes. appropriate regulatory authorities and apply for a permit change to ship exposed carbon off-site

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0 DISPOSAL OF ACTIVATED CARBON FROM CHEMICAL AGENT DISPOSAL FACILITIES based on the transportation risk assessment and 3571 for �D nor modified Method 3571 for GB, which the validated analytical methods. appears to minimize re-formation of GB during extrac- • Adding caustic solution to the drums. If the addi- tion and analysis, had been validated at the time this tion of caustic (NaO�) decontamination solution report was being prepared. to a drum of exposed carbon completely wets General Recommendation 5. Both the original Envi- the carbon, the caustic will hydrolyze the agents remaining on the exposed carbon to below the ronmental Protection Agency Method 3571 and the waste control limit (WCL) or permit compliance modified Method 3571 must be validated for use on car- concentration (PCC). The drum containing the bon exposed to all three agents (GB, �X, and mustard) d econtaminated carbon and decontamination since the chemical agent disposal facilities expect to solution can then be shipped off-site. The method operate without changing out the heating, ventilation, of applying the decontamination solution must be and air conditioning filter units before closure. negotiated and approved by the facility’s regula- tory authority. Analysis for agent on the carbon REFERENCES should not be necessary with this arrangement. NRC (National Research Council). 2001. Standing Operating Procedures for Developing Acute Exposure Guideline Levels for �azardous Chemicals. General Finding 5. Environmental Protection Agency Washington, D.C.: National Academy Press. Method 3571 appears to have provided an improved NRC. 2007. Review of Chemical Agent Secondary Waste Disposal and method detection limit for extractive analysis of �X on Regulatory Requirements. Washington, D.C.: The National Academies Press. the Bank 1 carbon sample from the Anniston Chemical NRC. 2008. Review of Secondary Waste Disposal Planning for the Blue Agent Disposal Facility, but it must still be validated. Grass and Pueblo Chemical Agent Destruction Pilot Plants. Washington, Neither Environmental Protection Agency Method D.C.: The National Academies Press.