tiated as permit compliance limits. The concentration of mustard that remains on the carbon filters had not been measured at the time this report was prepared.
General Recommendation 4. Carbon that has been exposed to agent should be sent off-site under one of the following arrangements:
Use of waste control limits (WCL) or permit compliance concentrations (PCC). If the agent concentrations on the exposed carbon are below the waste control limits or the permit compliance concentrations, the carbon can be shipped off-site for proper disposal at a waste treatment facility licensed to receive and treat this waste under existing regulations. For this arrangement it will be necessary to develop and validate analytical methods that accurately measure agent concentration for both GB and mustard. The methods must be capable of analyzing the agents on carbon that has been exposed to all three agents and that will have both the agents and their respective degradation products from hydrolysis adsorbed on the carbon.
Use of a transportation risk assessment. By using the precedent negotiated at Aberdeen Chemical Agent Disposal Facility, if the mass of the agent on the carbon in a drum is less than specified by the Chemical Materials Agency transportation risk assessment (see Table 7-1) but >1 VSL, the drum can be transported to a treatment, storage, and disposal facility. Each chemical agent disposal facility will have to negotiate with the appropriate regulatory authorities to ensure proper permit conditions to ship exposed carbon off-site based on the transportation risk assessment and the validated analytical methods.
Adding caustic solution to the drums. If the addition of caustic (NaOH) decontamination solution to a drum of exposed carbon wets the carbon, the caustic will hydrolyze the agents remaining on the exposed carbon to below the WCL or PCC. The drum containing the decontaminated carbon and decontamination solution can then be shipped off-site. The method of applying the decontamination solution must be negotiated and approved by the facility’s regulatory authority. Analysis for agent on the carbon should not be necessary with this arrangement.
General Finding 5. Environmental Protection Agency Method 3571 appears to have provided an improved method detection limit for extractive analysis of VX on the Bank 1 carbon sample from the Anniston Chemical Agent Disposal Facility, but it must still be validated. Neither Environmental Protection Agency Method 3571 for HD nor modified Method 3571 for GB, which appears to minimize re-formation of GB during extraction and analysis, had been validated at the time this report was being prepared.
General Recommendation 5. Both the original Environmental Protection Agency Method 3571 and the modified Method 3571 must be validated for use on carbon exposed to all three agents (GB, VX, and mustard) since the chemical agent disposal facilities expect to operate without changing out the heating, ventilation, and air conditioning filter units before closure.