6
Monitoring and Analytical Issues

OVERVIEW OF CLOSURE STRATEGY

Depending on the particular site, the planning for closure of the chemical agent disposal facilities that are the subject of this report is designed to achieve Resource Conservation and Recovery Act (RCRA) clean closure according to either industrial or residential standards (Bechtel Aberdeen, 2007; EG&G, 2009b). Facility closure is complete when these conditions are met: all waste management units have been decontaminated, dismantled, and demolished; all ancillary buildings are dispositioned per contractual agreements; and the regulatory authority agrees that closure performance standards have been achieved. The facility closure process includes management of surplus buildings and equipment and waste generated during processing operations.

During closure operations, the concern with respect to potential agent exposure primarily deals with occluded spaces. These are confined volumes within a system, structure, or component that were exposed, or potentially exposed, to liquid agent and therefore have the potential to contain some quantity of agent-contaminated liquid (Bechtel, 2006; Herbert, 2010; Battelle Memorial Institute, 2010; Parsons, 2009).1 Although in most instances the quantity of agent that may be encountered in such spaces is likely to be small, it takes only a small amount of agent to generate an exposure incident. Therefore, accurate measurement of residual agent is a critical activity in the closure processes.

The challenges posed for closure of chemical agent disposal facilities relate to the measurement of agent quantities that remain in waste media, structures, and equipment. Sampling and analysis of many of these materials is difficult and may not be suited to conventional approaches used for measuring agent contamination. Examples include concrete, polymeric materials, and other waste solids, as well as metal equipment parts. In all of these, small amounts of agent can be retained in occluded spaces or sorbed onto porous materials. Moreover, the agent will not be uniformly distributed, which means that using a reasonable sampling plan structured on a strictly statistical basis may be prone to underrepresentation of the extent of contamination. In view of the extreme toxicity of agents and certain degradation products, there may be significant consequences from misidentifying or underestimating contamination. These conditions carry the additional consequence of high costs and delays derived from the need to collect and analyze many samples.

A potentially sensitive and protective means of identifying residual agent in materials and equipment during closure is the unventilated monitoring testing (UMT) (Herbert, 2009).2,3 This is a variation on the headspace monitoring approach traditionally used by

1

Battelle, “Occluded Space Training,” presentation to UMCDF, March 3, 2010, provided to the committee by Raj Malhotra, Deputy, Risk Management Directorate, CMA, via email to Nancy Schulte, study director, May 3, 2010.

2

Carla Heck, Project Manager, URS, “Programmatic Closure Document Development and Status of Closure Planning,” presentation to the committee, January 26, 2010.

3

Richard Sisson, Senior Research Scientist, Battelle, “Closure Tips and Tricks,” presentation to UMCDF, provided to the commit



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6 monitoring and analytical issues overvieW oF closure sTraTegy incident. Therefore, accurate measurement of residual agent is a critical activity in the closure processes. Depending on the particular site, the planning for The challenges posed for closure of chemical agent closure of the chemical agent disposal facilities that disposal facilities relate to the measurement of agent are the subject of this report is designed to achieve quantities that remain in waste media, structures, and Resource Conservation and Recovery Act (RCRA) equipment. Sampling and analysis of many of these clean closure according to either industrial or resi- materials is difficult and may not be suited to conven- dential standards (Bechtel Aberdeen, 2007; EG&G, tional approaches used for measuring agent contamina- 2009b). Facility closure is complete when these con- tion. Examples include concrete, polymeric materials, ditions are met: all waste management units have and other waste solids, as well as metal equipment parts. been decontaminated, dismantled, and demolished; all In all of these, small amounts of agent can be retained ancillary buildings are dispositioned per contractual in occluded spaces or sorbed onto porous materials. agreements; and the regulatory authority agrees that Moreover, the agent will not be uniformly distributed, closure performance standards have been achieved. which means that using a reasonable sampling plan The facility closure process includes management of structured on a strictly statistical basis may be prone surplus buildings and equipment and waste generated to underrepresentation of the extent of contamination. during processing operations. In view of the extreme toxicity of agents and certain During closure operations, the concern with respect degradation products, there may be significant con- t o potential agent exposure primarily deals with sequences from misidentifying or underestimating occluded spaces. These are confined volumes within a contamination. These conditions carry the additional system, structure, or component that were exposed, or consequence of high costs and delays derived from the potentially exposed, to liquid agent and therefore have need to collect and analyze many samples. the potential to contain some quantity of agent-contam- A potentially sensitive and protective means of inated liquid (Bechtel, 2006; Herbert, 2010; Battelle identifying residual agent in materials and equipment Memorial Institute, 2010; Parsons, 2009).1 Although during closure is the unventilated monitoring testing in most instances the quantity of agent that may be (UMT) (Herbert, 2009).2,3 This is a variation on the encountered in such spaces is likely to be small, it takes headspace monitoring approach traditionally used by only a small amount of agent to generate an exposure 2 Carla Heck, Project Manager, URS, “Programmatic Closure 1 Battelle,“Occluded Space Training,” presentation to UMCDF, Document Development and Status of Closure Planning,” presenta- March 3, 2010, provided to the committee by Raj Malhotra, Deputy, tion to the committee, January 26, 2010. 3 Richard Sisson, Senior Research Scientist, Battelle, “Closure Risk Management Directorate, CMA, via email to Nancy Schulte, study director, May 3, 2010. Tips and Tricks,” presentation to UMCDF, provided to the commit- 

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0 REVIEW OF CLOSURE PLANS FOR THE BASELINE INCINERATION CHEMICAL AGENT DISPOSAL FACILITIES Properties of agents significant to the Army for clearing material that was suspected to closure situations be agent contaminated.4 What is measured by UMT is the agent in the atmosphere associated with the loca- The chemical and physical properties of chemical tion being evaluated, which requires that that agent be agents affect their toxicity and their detectability. In present in the gas phase. UMT involves enclosing the the context of closure, agent volatility and hydrolysis room or object to be sampled with a plastic barrier that behavior are the two most significant properties. While prevents diffusion and allows concentrations to build all three of the agents processed at the baseline chemi- to the point where the agent can be readily detected cal agent disposal facilities are considered semivolatile by current near-real-time monitoring equipment. The liquids, the nerve agent GB has a markedly higher vapor method is designed to protect against airborne expo- pressure (2.9 mm Hg at 25oC), consistent with faster sures to agent, but due to the vapor pressure of the rates of volatilization (Reutter, 1999). In addition, GB agents and the sensitivity of the analyses, it is also has the greatest ability to diffuse through porous or per- used to infer the presence or absence of liquid agent. meable materials, and hence it is less likely to survive UMT, in sampling headspace, can be used for evaluat- for long periods of time on surfaces or in near-surface ing contamination in many different types of wastes environments. Mustard is relatively nonvolatile, with a and media. It does not require the time-consuming vapor pressure of 0.11 mm Hg at 25°C. The nerve agent collection of solid samples and the extractive analyses Vx has an even lower vapor pressure (only 0.0007 mm thereof, which are also subject to uncertainties arising Hg at 25°C) (Reutter, 1999).7 In situations in which from nonuniform contamination distribution, a feature mustard or Vx fills cracks or diffuses into permeable inherent to closure situations. UMT has been success- materials, volatilization may be inhibited, but subse- fully applied in the closure of both the Aberdeen and the quent disturbances of the system could expose intact Newport facilities (Battelle Memorial Institute, 2010; agent. This could produce a potential for exposure from Parsons, 2009).5,6 volatilization, or more likely from direct dermal con- Chemical or physical phenomena that limit the vola- tact. Migration or volatilization of mustard or Vx from tilization of the agent are a potential limitation of the porous or permeable surfaces may not occur. UMT approach, and occluded spaces are a particular Chemical agent residues may also become depleted concern in this regard. Any agent occupying occluded by chemical degradation processes that are principally spaces (for example, agent trapped in small cracks hydrolysis reactions and that result in significant or sorbed into porous materials) may not volatilize agent detoxification (with a salient exception of Vx sufficiently for headspace measurements. Occluded as described below). Since the majority of hydrolysis spaces can prevent (a) contact of the agent with a reactions produce degradation products having low decontamination solution; (b) volatilization of agent; toxicity, further discussion is not provided here; addi- and (c) subsequent detection using UMT. tional details can be found in Appendix C. However, In this chapter, the strengths and weaknesses of both Vx hydrolysis via P-O bond cleavage is not in this conventional analyses and UMT for monitoring equip- category: this reaction produces S-(N,N-diisopropyl- ment and spaces undergoing closure are considered, aminoethyl) methylphosphonothioic acid (known as with a primary focus on identifying approaches that EA-2192 in the Army vernacular), which is a com- maximize the utility and effectiveness of UMT during pound that retains much of the neurotoxicity of intact closure. Utilization of physical sampling followed by Vx. Hence, the possible presence of this compound extractive analysis is also briefly discussed. is an ongoing source of concern (yang et al., 1990; Munro et al., 1999).8 However, concerns related to EA-2192 are reasonably mitigated by the following tee by Raj Malhotra, Deputy, Risk Management Directorate, CMA, considerations: via email to Nancy Schulte, study director, May 3, 2010. 4 Headspace is the gaseous atmosphere associated with an object normally confined by an enclosure or container. 5 Brian O’Donnell, Chief, PMCSE Secondary Waste and Closure 7 In the context of this report, bis-(2-chloroethyl) sulfide, or sulfur Team, CMA, “CMA Programmatic Closure,” presentation to the committee, January 27, 2010. mustard, is referred to as H, HD (distilled mustard), or HT (distilled 6 Jerry Spillane, Closure Engineer, NECDF, “NECDF Closure mustard mixed with bis-(2-(2-chloroethylthio)ethyl) ether). 8 The state of Utah requires measurement of EA-2192 to ensure Lessons Learned,” presentation to the committee, October 20, 2009. detoxification to closure standards (see Chapter 5).

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 MONITORING AND ANALYTICAL ISSUES • EA-2192 has extremely low volatility and there- is designed primarily to document the history fore poses virtually no inhalation hazard. of chemical agent contamination in assessing • EA-2192 does not diffuse through the skin barrier whether the component or area in question may (as does Vx). have come in contact with agent and, if so, in • Hydrolysis of EA-2192 proceeds fairly rapidly, what form. This phase is used to guide where and with a rate constant on the order of that of the how occluded space surveys should be conducted, parent compound (0.1 day–1) (Kaaijk and Frijlink, and it may have value for correlating historical 1977; Verweij and Boter, 1976).9 exposure events with residual agent when retro- spectively compared with the results of UMT. The rate of Vx degradation is expected to be fast (on 2. Identification and elimination of occluded spaces. the order of 0.1 day–1), which suggests that residual agent This includes conducting an occluded space sur- concentrations are likely to be low10 unless protected in vey, which is designed to identify locations where an occluded environment. The degradation rates of G agent liquid or vapor may have accumulated, in agents will be even faster than those of Vx. order to ensure that effective decontamination takes place. 3. Applying decontamination methods. This includes residual ageNT measuremeNT iN closure the preparation of an occluded space decontami- Closure operations at chemical agent disposal facili- nation plan and identification of the appropriate ties are to be conducted in a manner that is intended to methods to be used for decontamination. These eliminate the potential for exposure to agent and haz- methods will be dependent on the agent and the ardous by-products. Each facility will have to comply equipment or material to be decontaminated. with closure standards for waste, residues, and media Procedures to document decontamination are that may be different depending on individual state also defined, as are the future uses planned for regulations. the equipment and the appropriateness of the Closure operations are conducted in a series of steps, decontamination criteria employed. This step also the explicit definition of which can vary somewhat encompasses decontamination of equipment and depending on the site and the individual area under- areas. going closure. However, all closure operations have 4. Removal of equipment or leave in place. Equip- common activities, which in general include (Herbert, ment removal requires dismantling and decon- 2009; Battelle Memorial Institute, 2010):11,12 tamination of the equipment. These activities, as well as the decontamination of areas, are guided 1. Identification of all areas of historical contamina- by the planning done in the previous phases with tion (URS, 2009; EG&G, 2009a).13 This phase a goal of achieving maximum efficacy and with a focus on areas identified in the occluded space surveys. 9 Rate studies of degradation of EA-2192 are few, and rates will 5. Verification of equipment decontamination. This certainly vary depending on the specific temperature, moisture pres- ent, and the surface with which the compound is in contact. may include wipe testing, extractive analysis, 10 See Appendix C for citations from the Livermore National or vapor monitoring. Because many pieces of Laboratory group, which indicate that rates of 0.1 day–1 can be equipment are not appropriately characterized by expected for Vx, as well as Groenewold (2010). wipe testing or extractive analysis, this normally 11 Brian O’Donnell, Chief, PMCSE Secondary Waste and Closure involves tented headspace monitoring of the Team, CMA, “CMA Programmatic Closure,” presentation to the equipment to ensure that airborne concentrations committee, January 27, 2010. 12 Richard Sisson, Senior Research Scientist, Battelle, “Closure are less than 1 VSL (<1 vapor screening level), Tips and Tricks,” presentation to UMCDF, provided to the commit- indicating that any residual contamination is tee by Raj Malhotra, Deputy, Risk Management Directorate, CMA, minimal.14 via email to Nancy Schulte, study director, May 3, 2010. 13 Teleconference with Brian O’Donnell, Chief, Secondary Waste, Closure Compliance and Assessments, CMA; Amy Dean, Envi- 14A ronmental Engineer, Project Manager for Elimination of Chemical vapor screening level (VSL) is an internal control limit used Weapons, CMA; Jeffrey Kiley, Chief, Quality Assurance Office, to clear materials for off-site shipment based on agent concentra- Risk Management Directorate, CMA; and the committee; May 4, tion in the atmosphere surrounding the materials. The VSL for 2010. each agent is set to the short-term exposure limit (STEL)—the

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 REVIEW OF CLOSURE PLANS FOR THE BASELINE INCINERATION CHEMICAL AGENT DISPOSAL FACILITIES 6. Monitoring to demonstrate adherence to appro- effort may be required to develop and achieve regula- priate closure performance standards. Physical tory approval of modifications. sampling followed by extractive analyses may be employed, but unventilated area monitoring sampling Followed by extractive analysis is primarily used as a more sensitive indicator of residual contamination. Closure requires that waste, residues, media, build- 7. Demolition. Destruction of the physical plant ings, and equipment be decontaminated to concen- structure, including components found within it, trations below the applicable closure performance is conducted upon successful completion of all standards appropriate for subsequent facility disman- previous steps. tling and disposal. Similarly, soil at the site must be demonstrated to be below required closure performance Throughout this process, measurements of residual standards. Analysis of solid samples from these envi- agent levels constitute a critical activity. Specific objec- ronments has traditionally been based upon extractive tives of residual agent monitoring are as follows: analysis of materials to ensure adherence to closure standards. Extractive analysis has been used both to • Protecting the workforce during disassembly and show that concentrations are below RCRA limits and demolition; to establish that decontamination is effective (Bechtel • Supporting accurate decision making with regard Aberdeen, 2007; EG&G, 2009b).15 to disposition of secondary wastes, residues, and The appropriate closure standards that may be media; applied at various facilities may differ, but in general, • Ensuring that contaminant levels at the site are at the standards should recognize that closure will result or below clearance levels; and in waste disposal or recycling of material and equip- • Protecting the general public. ment. This suggests that the most relevant standards are for occupational exposures. But specific closure The analytical approaches used to demonstrate adher- standards will be determined on a state-specific basis. ence to the standards related to the above objectives fall At the Umatilla Chemical Agent Disposal Facility into two categories: either sampling and extractive (UMCDF) there is a regulatory requirement that all analysis or vapor space monitoring, which is achieved materials sent off-site, such as construction debris, through tented headspace monitoring (for individual must be cleared using sampling and extractive analysis. pieces of equipment) or unventilated area monitor- The same is true of the soil sampling to be carried out ing. Procedural details employed for the sampling and to certify that the site meets closure requirements. The extractive analyses can vary substantially depending sampling and extractive analysis of concrete debris on the agent, the degradation product, or the matrix presents particular issues due to the difficulty of collect- being examined. Similarly, temporal variations in the ing and analyzing representative samples. Thus, unven- headspace and unventilated area monitoring procedures tilated air monitoring may be a more reliable means are employed to cover different sampling volumes that to identify the presence of residual agent. There also are related to the size of the equipment or room to be appears to be a difference of opinion between the EPA monitored. The analytical methods employed, and and the Oregon Department of Environmental Qual- their variants, must satisfy required method quality ity (ODEQ) as to the proper procedure for analyzing control specifications, including accuracy, precision, concrete debris.16 UMCDF has ODEQ’s approval for a and detection and quantitation limits for all matrices. method that includes pH adjustment before extraction, Differences in the material and equipment matrices while the EPA method does not allow for pH adjust- may cause deviations in method performance; these ment. If the EPA method is to be adopted it will require are discussed in more detail below. Analytical method modification may be needed to achieve state-specific closure standards; in these cases, significant time and 15 C AMDS/TOCDF Closure Team, URS, “CAMDS/TOCDF Closure Status Implementing Programmatic Closure Approach,” presentation to the committee, January 27, 2010. 16 P ersonal communication between Mike Daniels, closure concentration to which workers can be exposed continuously for a short period—established by the Centers for Disease Control and manager, UMCDF, and Peter Lederman, committee chair, June Prevention (Federal Register, 2003a, 2003b). 16, 2010.

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 MONITORING AND ANALYTICAL ISSUES an estimated year to carry out laboratory validation and ing (i.e., tenting of the equipment) and monitoring the ODEQ acceptance. This type of challenge can become vapor concentration of agent after a fixed period of time a major impediment to meeting schedules. dependent upon the tented volume (i.e., 15 minutes for a tented volume equal to or less than 0.8 m3, 45 minutes Although sampling and extractive analysis is avail- for a tented volume between 0.8 and 20 m3, and 4 hours able as a means to define the status of agent decontami- for a tented volume in excess of 20 m3). The vapor nation for closure and to guide the disposition of waste, residues, media, equipment, and buildings potentially concentration within the sealed volume at the end of the contaminated with agent, the problems of representa- hold time must be less than the vapor screening level. tive sampling, accuracy, time requirements, and cost The VSL for each agent is set at the short-term expo- of extractive analysis remain. Due to the difficulty of sure limit—the concentration to which workers can be measuring concentrations in porous solids, particu- exposed continuously for a short period—established larly construction debris and equipment, the Army has by the Centers for Disease Control and Prevention chosen to pursue alternative measurement approaches, (Federal Register, 2003a, 2003b). The use of a standard namely, headspace monitoring of individual pieces of 1 VSL in a sealed environment ensures that concen- of equipment and unventilated area monitoring for trations much less than 1 VSL would be observed in a buildings and large areas. As noted previously, these ventilated environment. are collectively referred to as unventilated monitoring In buildings or large areas, the area is first subjected testing (UMT); they are discussed below. States may to ventilated monitoring over a period of 12 hours to nevertheless require sampling and extractive analyses ensure that the VSL is not exceeded before initiating the in some cases, such as for clearing wastes for trans- more severe unventilated test. The area is then sealed portation off-site to a treatment, storage, and disposal to the extent possible and the unventilated monitor- facility. ing begun. At CAMDS, for example, the unventilated monitoring must show that the concentration does not exceed 1 VSL during any 4-hour period. If time-aver- unventilated vapor monitoring: an alternative aged sampling is used, this means that an average of approach 0.5 VSL will not be exceeded in any 4-hour period (i.e., The Army has developed alternatives to sampling assuming a linear rate of increase during the 4 hours). and extractive analysis. These alternatives use unven- Sampling over multiple periods may be needed to docu- tilated monitoring of the vapor space around equipment ment conformance to closure standards (e.g., 36 hours and areas, which reduces the effects of heterogeneity for CAMDS as per procedure PRP-CAM-002), but the and matrix interferences. Briefly, UMT involves seal- standard remains 1 VSL in any 4-hour period. ing off the equipment or area to be tested; ensuring The UMT is focused on airborne pathways of expo- that the temperature within the sealed volume is 70oF sure and is used to compare potential worker exposure or above; and then monitoring the vapor space within to worker population limits (WPLs) and potential the sealed volume. If volatilized agent is present, public exposure to general population limits (GPLs). this approach allows its concentration to build up by That is, the agent release rate that might lead to 1 VSL increasing volatilization and preventing diffusion to within the unventilated monitoring area is such that other parts of the atmosphere. The performance of the WPL would not be exceeded in a ventilated area and UMT will be dependent upon maintaining the speci- GPL would not be exceeded outside the work area. As fied temperature, which will require actively heating with the VSL/STEL, the WPL and the GPL are set by the areas using space heaters and careful temperature the Centers for Disease Control and Prevention (Fed- monitoring, particularly during the colder months. The eral Register, 2003a, 2003b). The airborne pathway is result is that concentrations measured in the UMT are the primary path of exposure to residual agent since much higher than in a comparable ventilated test, and the demolition strategy is designed to eliminate contact for this reason, UMT would be conservatively protec- exposure to agent in liquid or solid phases (i.e., areas tive of the workforce. of potential contamination are subjected to decon- The unventilated vapor monitoring is applied to tamination) and since the facility destruction is done both individual pieces of equipment and to buildings mechanically. Airborne sampling also can be a sensitive and areas. When applied to individual pieces of equip- indicator of the presence of agent, but only as long as ment, the approach involves sealing with plastic sheet- occluded spaces are properly identified and eliminated

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 REVIEW OF CLOSURE PLANS FOR THE BASELINE INCINERATION CHEMICAL AGENT DISPOSAL FACILITIES even though the precise location of the contamination configuration. If vented monitoring meets the <1 VSL is unknown. Measurement of airborne agent in the criterion, a final unventilated area monitoring is per- headspace can reduce analytical complexity because formed. Measured UMT concentrations <1 VSL will it effectively samples the entire environment being ensure that exposure concentrations are greater than sampled, and it avoids problems with low extraction WPL in the working area and greater than GPL out- efficiency and high chemical background and interfer- side the working area. The previously described seven ence that can accompany an extractive analysis. To steps of the approach are designed to ensure that mass date, UMT has been approved for use at CAMDS by demolition of areas and equipment is limited to only the state of Utah. those materials that have been decontaminated of agent The UMT approach maximizes the concentrations of or have been otherwise cleared. The approach ensures agent in the sampled headspace by allowing the con- that workers are not exposed to vapors in excess of the centration to build up in the absence of air exchange, WPL and the general population to vapors in excess of thus making measurements of vaporized agent concen- the GPL, but it does not directly address direct contact trations easier. This approach thus takes advantage of exposures. The effectiveness of the monitoring proce- the stringent precision and accuracy capabilities of the dures to support this alternative testing protocol will be agent air monitors.17,18 The measured values provide an discussed in the next section. estimate of agent release rate, which can then be used to estimate maximum airborne exposure in a ventilated assessmeNT oF moNiToriNg Procedures configuration. The approach is attractive because it does not require extensive analysis (i.e., sample collection The overall monitoring procedure involves ventilated and extraction). UMT is easy to apply in the field and workplace monitoring (near-real-time measurements); is relatively rapid, and therefore can be implemented occluded space identification and decontamination as with relatively minimal effort. The waste acceptance needed; and, finally, UMT. criteria are straightforward data quality objectives (in particular, detection limits to <1 VSL and avoidance of assessment of Workplace monitoring, ventilated false negatives).19 environment configuration The acceptably protective airborne limits of expo- sure to agents for workers (the WPLs) and for the Near-real-time monitoring (i.e., having a response general public (the GPLs) are shown in Table 6-1, time of approximately 3 to 15 minutes) is used in together with the corresponding vapor screening level areas where the presence of agent is possible (NRC, (VSL-STEL) used to evaluate airborne exposures in 2005b). Miniature Chemical Agent Monitoring Sys- UMT measurements. tems (MINICAMS) are used at the Tooele Chemical The UMT is designed to ensure that monitored items Agent Disposal Facility (TOCDF) for this purpose, or areas will successfully meet WPL and GPL levels in while automatic continuous air monitoring systems (ACAMS) units are used at CAMDS.20 The same types a ventilated configuration when the tented or unventi- lated concentration is maintained below 1 VSL. In the of instruments are used at the other baseline disposal event of agent measurement above the VSL, the area facilities. Confirmation monitoring is used to validate is decontaminated (or decontaminated again), and air- or invalidate a positive result from another monitor- borne concentrations are again measured in a ventilated ing system, such as MINICAMS and ACAMS, and is accomplished with the depot area air monitoring systems (DAAMS), which employs variable sampling 17 Richard Sisson, Senior Research Scientist, Battelle, “Closure times. The DAAMS backs up the MINICAMS and Tips and Tricks,” presentation to UMCDF, provided to the commit- ACAMS and reduces false positives.21 These systems tee by Raj Malhotra, Deputy, Risk Management Directorate, CMA, via email to Nancy Schulte, study director, May 3, 2010. 18 C AMDS/TOCDF Closure Team, URS, “CAMDS/TOCDF 20 Thaddeus Ryba, Site Project Manager, TOCDF, “TOCDF In - Closure Status Implementing Programmatic Closure Approach,” presentation to the committee, January 27, 2010. troduction (DEMIL-101),” presentation to the committee, January 19 Richard Sisson, Senior Research Scientist, Battelle, “Closure 26, 2010. 21 Thaddeus Ryba, Site Project Manager, TOCDF, “TOCDF In - Tips and Tricks,” presentation to UMCDF, provided to the commit- tee by Raj Malhotra, Deputy, Risk Management Directorate, CMA, troduction (DEMIL-101),” presentation to the committee, January via email to Nancy Schulte, study director, May 3, 2010. 26, 2010.

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 MONITORING AND ANALYTICAL ISSUES TABLE 6-1 Airborne Exposure Limits for GB, Vx, and H, and Ratios of Worker Protection Limit and General Population Limit to Vapor Screening Level VSL (mg/m3) WPL (mg/m3) GPL (mg/m3) Agent WPL/VSL GPL/VSL GB 0.0001 0.00003 0.3 0.000001 0.01 Vx 0.00001 0.000001 0.1 0.0000006 0.06 H 0.003 0.0004 0.13 0.00002 0.0067 NOTE: The ratio of WPL to VSL and the ratio of GPL to VSL provide an indication of the magnitude of the respective WPL and GPL as a fraction of VSL. SOURCE: NRC, 2005a; Battelle Memorial Institute, 2010; Washington Demilitarization Company, 2010. comprise the continuous emissions monitoring systems Piping could represent an occluded space if capped, or (CEMS) for the sites. merely by slow diffusion rates from an interior run to Workplace monitoring measures actual exposures an opening to the ambient atmosphere (NRC, 2005a, during operations and closure activities and should be pp. 16-26). Occluded spaces can potentially trap liquid used to confirm that acceptable closure standards have agent, prevent contact with a decontamination solu- been met. It does not provide pre-demolition standards tion, and prevent agent vaporization, and hence prevent for decontamination, however, nor does it predict the detection during unventilated monitoring. Some com- potential for exposure during closure and dismantling mon examples of occluded spaces include internal cavi- activities. It is toward the latter goal that occluded ties of pumps and other equipment, cavities or cracks space surveys and unventilated monitoring tests are in concrete, internal sections of closed pipes and other directed. systems, flat parallel surfaces in close proximity to each other, pipe and tank supports, and caulking seals around equipment supports and concrete joints. assessment of occluded space identification for Occluded spaces can be present in clean and screened decontamination material (<1 VSL); this includes decontaminated rooms The occluded space survey is a key step in the within facilities and materials such as waste, residues, unventilated monitoring test and the ultimate clearance media, or decontaminated equipment removed for dis- of the site. As such, it is important that it be carried out posal. Of particular concern are items and areas that very carefully and uniformly at all sites. were potentially contacted by high concentrations of As previously indicated, occluded spaces are con- agent, either in liquid form or in vapor form at concen- fined volumes within a system, structure, or component trations above the immediately dangerous to life and health (IDLH) levels.23 Past exposure to high vapor that were exposed, or potentially exposed, to liquid agent, and thus have the potential to contain small concentrations does not necessarily lead to significant quantities of agent or agent-contaminated liquid (Bat- liquid entrapment, but using an IDLH vapor concentra- telle Memorial Institute, 2010; Herbert, 2010; Parsons, tion as an indicator of a need for special decontamina- 2009; Washington Demilitarization Company, 2010). tion procedures is conservative (protective). An example is found at the former Newport Chemical Occluded space teams (OSTs) have the responsibility Depot (Indiana) facility for the production of the nerve for identifying occluded spaces and are the key to find- agent Vx, in piping that was not knowingly exposed ing agent that might not be identified by other means. to agent but in fact had residual agent contamination.22 That is, extractive testing may not involve testing of the specific space containing the occluded liquid; likewise, vapor testing is more likely to detect the presence of 22Vx degradation products were found in a 0.5-inch nitrogen line occluded agent, but even that may not be successful if at NECDF in February 2004. The nitrogen had been used to purge the agent is completely contained or tightly sorbed into tanks and reactors, for transferring liquids using pressure, and in the material. Accordingly, identification of occluded the munitions filling process. Contamination of nitrogen systems is not uncommon in the petrochemical industry. It can occur if the supply pressure of the nitrogen system is not designed to be greater 23 IDLH values are 0.1, 0.003, and 0.7 mg/m3 for GB, Vx, and than the maximum system pressure or if the nitrogen supply failed during the operation of the process. HD, respectively (NRC, 2005a).

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 REVIEW OF CLOSURE PLANS FOR THE BASELINE INCINERATION CHEMICAL AGENT DISPOSAL FACILITIES Finding 6-1. The occluded space survey is a key com- spaces requires significant expertise and thoroughness that are achieved in the form of a multidisciplinary ponent of the overall monitoring strategy for closure, team trained for this extremely important purpose (Bat- and it requires occluded space survey teams with a high telle, 2010; Herbert, 2010).24 level of expertise and significant training for proper The Army utilizes contractor experts for training execution. the OSTs because of the diversity of possible occluded Recommendation 6-1. Occluded space survey proto- spaces. However, training expertise is concentrated in a relatively small number of individuals. Ideally, it would col should be standardized across the entire enterprise, be desirable to draw upon the skills and experience of and training should be strengthened, standardized as broad a cross section of occluded space expert train- across the program, and continually updated. ers as possible. Expertise should be solicited from those Finding 6-2. The expertise for occluded space survey who have participated in various closure activities and from various organizations within a site, and such per- training is concentrated in a few individuals within the sonnel should be tapped to provide OST training. This overall closure activity. would ensure that occluded space surveys would ben- Recommendation 6-2. Occluded space survey training efit from information exchanged with other locations and would include formal transference of occluded should be diversified to include multiple experts to pro- space survey experiences through regular meetings vide redundancy commensurate with the importance of focused on discussing common challenges. To ensure this activity. that the results of the OSTs are shared, they should be Finding 6-3. It is possible to fail to identify occluded made part of the lessons learned program and reported as lessons learned. spaces during the survey process, but a second survey Because of the complexity of the occluded space can provide a more comprehensive identification. survey activity, and because it is possible for potential Recommendation 6-3a. A second occluded space occluded spaces to be missed in the survey process, a second occluded space survey is carried out at the survey should be conducted by an occluded space direction of management.25 The committee believes team independent of the team that conducted the initial that at a minimum, a second survey is necessary. Based survey as a means of providing a higher level of confi- on a comparison of the first two surveys, management dence that all occluded spaces have been identified. may in its judgment decide to do a third survey. Recommendation 6-3b. A third occluded space survey In an occluded space survey, the OST conducts a preliminary occluded space inspection and generates should be considered based on a comparison of the first an occluded space task list. The occluded spaces thus and second surveys. identified are opened, decontaminated, and wedged open or supported to eliminate the occluded space assessment of unventilated monitoring Testing potential. The OST then performs a physical survey by walk through. If any additional occluded spaces are Upon completion of decontamination of equipment identified at this stage, they are then decontaminated and small areas, buildings and larger areas are subjected prior to final unventilated monitoring. first to ventilated and then to unventilated monitoring as described earlier. If the headspace concentrations are measured at <1 VSL in the UMT, further decontamina- 24 Teleconference with Brian O’Donnell, Chief, Secondary tion is not required, and the area can be made available Waste, Closure Compliance and Assessments, CMA; Amy Dean, for demolition. The unventilated environment does not Environmental Engineer, Project Manager for Elimination of represent the conditions that demolition workers would Chemical Weapons, CMA; Jeffrey Kiley, Chief Quality Assurance encounter, but nonetheless, it enables measurement at Office, Risk Management Directorate, CMA; and the committee; May 4, 2010. lower levels and thus provides a more conservative 25Teleconference with Brian O’Donnell, Chief, Secondary Waste, evaluation of a potentially exposed environment. The Closure Compliance and Assessments, CMA; Amy Dean, Envi- product of the UMT measurement is actually a rate at ronmental Engineer, Project Manager for Elimination of Chemical which vapor source is emitted, which is calculated by Weapons, CMA; Jeffrey Kiley, Chief, Quality Assurance Office, Risk dividing the measured concentration by the time during Management Directorate, CMA; and the committee; May 4, 2010.

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 MONITORING AND ANALYTICAL ISSUES waste or industrial recycling facilities where WPLs which the sample was collected. The rate is converted (the focus of the UMT) will be protective and where to an unventilated-environment concentration by divid- there is no potential for dermal contact. In addition, the ing the rate by the rate of air exchange in the fully ven- UMT may have potential for clearing other types of tilated configuration. It should be noted that extractive materials produced during closure—including waste, sampling requires defining a statistically valid sampling residues, and media (e.g., soil)—as being below levels protocol, and this can be very difficult to achieve in a of concern for agent contamination. By employing this heterogeneous environment. The approach assumes test for waste, residues, and media as well, expensive that the concentration versus time profile generated in and time-consuming direct sampling and extraction and the UMT is linear. In actuality, the time plot usually analysis could be avoided, and the committee believes produces a logarithmic profile, which results from the that overall closure schedules could be expedited while depletion of the source or reduction in the release rate still protecting human health and the environment. as the system approaches equilibrium. A grab sample The Army may benefit from an evaluation of whether after a relatively short time will provide the initial slope or not UMT is protective of human health and the environ- and overestimate the average emission rate. Thus, UMT ment when applied to a broader ensemble of waste, resi- measured concentrations will tend to provide conserva- tively high emission rates for agents.26,27 dues, and media (e.g., porous matrices). Finally, the results of the UMT measurements may be particularly valuable The UMT is appropriately designed to protect the when correlated with agent spill or release histories. Care- worker and general populations against exposure ful comparisons of UMT results with past exposures may via airborne pathways. The data resulting from this enable conclusions regarding agent persistence, occluded approach can be used to verify that workers are not space surveying, and UMT efficacies. exposed to vapor concentrations in excess of the WPL It is highly probable that this approach will be pro- and that the general population is not exposed to vapor tective of the workforce against airborne exposure. It concentrations in excess of the GPL. However, the should be noted that the series of protocols that cul- approach does not evaluate the presence of agent in minate in the UMT provide only information on the occluded spaces that were not properly identified and absence or presence of agent. They are, as has been from which agent does not partition into the vapor stated, aimed at protecting workers. The protocols do phase at sufficient rates to exceed the VSL during the not provide any information about the presence of such testing hold times. Since these residual quantities will other hazardous materials as semi-volatiles or heavy be small, risks due to inhalation exposure will likely be metals (e.g., mercury (Hg) or arsenic (As)), which negligible. In local instances, however, some dermal could affect the options for disposing of materials that contact risk may arise during demolition. This should could be contaminated with such materials. be mitigated by the fact that there will be no human contact with the demolition waste, as all handling will Finding 6-4. Unventilated monitoring testing—con- be done mechanically. ducted in sequence with site exposure and spill his- While the Army is applying its UMT for clearance tories, ventilated monitoring, and occluded space of equipment and structures, there may be additional surveys—is appropriately designed to ensure protec- applications for this test. First, the committee believes tion of workers and the general population from agent that because the UMT is being used to clear buildings, exposure via airborne pathways. It is the final “critical the resulting debris from building demolition does not step” in clearing a site for mass demolition. need to be subject to additional agent testing, either vapor screening or direct analysis. This assumes that Recommendation 6-4a. The Army should ensure the ultimate disposition of all materials is in industrial both that the unventilated monitoring testing (UMT) protocol is uniform throughout the enterprise and that the information gained by the UMT sequence is aggres- 26 Richard Sisson, Senior Research Scientist, Battelle, “Closure Tips and Tricks,” presentation to UMCDF, provided to the commit- sively communicated to subsequent closure sites. tee by Raj Malhotra, Deputy, Risk Management Directorate, CMA, via email to Nancy Schulte, study director, May 3, 2010. Recommendation 6-4b. Locations of prior exposures 27 C AMDS/TOCDF Closure Team, URS, “CAMDS/TOCDF and spills should be compared with the results of the Closure Status Implementing Programmatic Closure Approach,” unventilated monitoring testing (UMT) measurements. presentation to the committee, January 27, 2010.

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 REVIEW OF CLOSURE PLANS FOR THE BASELINE INCINERATION CHEMICAL AGENT DISPOSAL FACILITIES Correlation (or not) of past exposure events with method is protective of human health and the environ- UMT release rates could provide valuable insight into ment for waste, residues, and media. residual contamination, effectiveness of occluded space Finding 6-8. Some analytical method modifications surveys, and UMT efficacy. may be needed to achieve state-specific closure and disposition standards, and in such cases, significant Finding 6-5. The unventilated monitoring testing time and effort may be required for these modifications sequence does not protect against dermal contact aris- and for achieving regulatory approval. ing from waste contaminated with small quantities of agent that could be sequestered in occluded spaces. Recommendation 6-8. Where method modification is Worker protection against this risk is reliant on the needed, the Army should begin the modification and occluded space surveys and on the all-mechanical approval process as early as possible. In all cases, the handling of the demolition wastes. Army should present its method modifications plans, including acceptance criteria, to the regulatory author- Recommendation 6-5. Worker training should rein- ity before method modification begins to gain prelimi- force the use of proper protective measures against nary approval. In addition, where method modifications dermal contact even where vapor space monitoring at individual baseline facilities appear to be similar, the shows no inhalation risk. Army should coordinate its method modification activi- ties among the sites to avoid duplication of efforts. Finding 6-6. The monitoring program is appropriately focused on agent. Agent hydrolysis products are non- toxic or have low toxicity, with the salient exception of reFereNces EA-2192 (see discussion earlier in this chapter), which Battelle Memorial Institute. 2010. Occluded Space Survey Plan Revision does not have probable exposure routes and hence does A. Columbus, Ohio: Battelle Memorial Institute. not pose a significant risk. Other waste components Bechtel. 2006. Attachment VII. DWO18941 Occluded Space Survey. Gun- powder, MD: Bechtel. (e.g., Hg and As) may affect ultimate disposal of waste Bechtel Aberdeen. 2007. 24719-100-30L-B93H-00009—Revision 0 Aber- materials and debris, but these can be managed within deen Chemical Agent Neutralization Facility RCRA Closure Certifica - existing waste disposal rules. tion Report. APG Edgewood Area, MD: Bechtel Aberdeen. EG&G Defense Materials, Inc. 2009a. CAMDS Due Diligence Review Contamination History Review. Stockton, Utah: EG&G Defense Ma- Recommendation 6-6. The Army should ensure that terials, Inc. procedures are in place to adequately analyze for other EG&G Defense Materials, Inc. 2009b. Chemical Agent Munitions Disposal waste components that may affect ultimate disposal of System (CAMDS) Closure Verification Sampling and Analysis Plan (Draft). Stockton, Utah: EG&G Defense Materials, Inc. waste materials and debris. Federal Register. 2003a. Final Recommendations for Protecting Human Health from Potential Adverse Effects of Exposure to Agents GA Finding 6-7. The unventilated monitoring testing can (tabun), GB (sarin), and Vx. Federal Register 68(196): 58348-58351. Federal Register. 2003b. Proposed Airborne Exposure Limits for Chemi - potentially be used for screening many different types of cal Warfare Agents H, HD, and HT (sulfur mustard). Federal Register closure waste, residues, and media as being below levels 68(140): 43356-43357. of concern for the agents. Additional evaluations may Groenewold, G. 2010. Degradation Kinetics of Vx. Main Group Chemistry. In press. demonstrate that vapor screening will meet regulatory Herbert, J. 2010. PRP-CAM-004—Occluded Space Process. Stockton, approval in states in which it will be used to characterize Utah: URS, EG&G Division. debris for disposal, and they may determine whether the Herbert, J. 2009. Unventilated Monitoring Prerequisites and Conduct to method is protective against dermal exposure. Support Closure. Stockton, Utah: URS, EG&G Division. Kaaijk, J., and C. Frijlink. 1977. Degradation of S-2-di-isopropylaminoethyl O-ethyl methylphosphonothioate in Soil. Sulphur-Containing Products. Recommendation 6-7. The Army should consider Pesticide Science 8(5): 510-514. conducting additional evaluations for two reasons: to Munro, N., S. S. Talmage, G. D. Griffin, L. C. Waters, A. P. Watson, J. F. King and V. Hauschild. 1999. Environ. Health Perspect. 107:933-974. demonstrate that vapor screening will meet regulatory NRC (National Research Council). 2005a. Impact of Revised Airborne Ex- approval in all states in which it will be used to charac- posure Limits on Non-Stockpile Chemical Materiel Program Activities. terize debris for disposal, and to determine whether the Washington, D.C.: The National Academies Press.

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 MONITORING AND ANALYTICAL ISSUES NRC. 2005b. Monitoring at Chemical Agent Disposal Facilities. Washing- Verweij, A., and H. Boter. 1976. Degradation of S-2-Di-isopropylamino - ton, D.C.: The National Academies Press. ethyl O-ethyl Methylphosphonothioate in Soil: Phosphorus-Containing Parsons. 2009. Final Clearance Report to Support Termination of Engineering Products. Pesticide Science 7(4): 355-362. Controls and Mass Demolition of the UB. Indianapolis, IN: Parsons. Washington Demilitarization Company. 2010. PB-PL-110 Facility Closure Reutter, S. 1999. Hazards of Chemical Weapons Release during War: New Plan (Draft). White Hall, AR: Washington Demilitarization Company. Perspectives. Environmental Health Perspectives 107(12): 985-990. yang, y.-C., L. Szafraniec, W. Beaudry, and D. Rohrbaugh. 1990. Oxidative URS. 2009. CAMDS Chemical Test Facility (CTF) Building C-7071 Detoxification of Phosphonothiolates. Journal of the American Chemi- Decommissioning Work Package (DWP). Stockton, Utah: EG&G cal Society 112(18): 6621-6627. Division.

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