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REQUIREMENTS AND CONSIDERATIONS FOR CHEMICAL DEMILITARIZATION TECHNOLOGIES 88 EFFLUENT RETENTION TIME REQUIREMENTS Further reduction of the risk of potential releases of agent or air toxics to the atmosphere could be accomplished in three ways: store and test gaseous waste streams before release, use activated-carbon beds (charcoal filters) to capture organic matter contained in the gaseous effluents, and reduce gaseous effluents by conversion to solids. The baseline system does not currently store and test (storage and certification) gaseous effluents before release to the environment. To ensure that an effluent waste stream is safe for disposal requires a retention time including time required for analyses and certification plus time to shut down all inputs to the effluent stream safely if the analyses determine that the waste stream exceeds specified standards. It takes several minutes to perform normal operational analyses (up to 20 minutes if repeat analyses are required) and several hours to collect and analyze samples from the site boundary. Although more nearly real- time analyses may be possible in the future, the times cited reflect actual current baseline capability. The time required to terminate process operations and to stop the effluent stream varies depending on the operations involved. Some processes may be shut down almost instantaneously, but most will require more time. For example, any thermal process may be shut down instantaneously by shutting off the agent feed stream, rapidly removing the greatest contamination source. However, if the system design requires the feed system to be kept hot, and if doing so requires the continued feeding of an alternative (if innocuous) fuel in place of chemical agent, there will be continuing flow of material through the contaminated system, which may take tens of minutes or longer to stop production of additional contaminated waste stream. Because combustion chambers and gas cleanup systems are both potential contamination sources, the continuing gas waste stream will also require analysis before its release. Using the existing metal parts furnace to evaporate and pyrolyze agent that has been polymerized and cannot be drained from the ton containers or projectiles continues to produce contaminated wastes until all of the agent is destroyed because the system remains hot for hours. Should storage and certification be implemented, all process waste streams should be retained for at least 1 hour (preferably up to 8 hours),-to provide adequate time to certify their acceptability for uncontrolled release to the atmosphere (see Chapter 5). Charcoal beds could be used to capture any organic materials, including agent, that might be in the gaseous waste streams. These charcoal filters would in effect store such compounds. An alternative to storage and certification would be to convert the waste stream to a form easily stored for long periods of time. For example, all
