A SOPHISTICATED APPROACH FOR TRIAL BURN PLAN DEVELOPMENT TO SUPPORT A POST-TRIAL BURN RISK ASSESSMENT

摘要

Over the past few years, the United States Environmental Protection Agency has been increasing the use of Risk Assessments in the permitting process. With this regulatory approach, facilities throughout the United States are being faced with the challenge of integrating Risk Assessment and Trial Burn results in order to obtain a Part B Permit. Thus, the development of a Trial Burn Plan is more challenging and complicated owing to the fact that it now must support a post-trial burn Risk Assessment. A goal for the Trial Burn Plan is to yield favorable operating limits while demonstrating acceptable risks and hazards for the facility. Typically, a Trial Burn Plan includes a worst-case waste stream determination. This determination can be quite simple for one combustion unit that burns one homogeneous waste stream from one continuous process, and quite complex for several combustion units that burn an accumulated waste stream generated from several production processes. Due to the recent Risk Assessment requirements, the worst-case waste stream determination now includes risk considerations. The worst-case waste stream determination is based on a facility's production process-es, a defined universe of compounds, and risk considerations. For one facility, the risks associated with the universe of compounds was ranked based on current toxicity values and persistence in the environment. The ranked listing was developed for five different toxicity categories in order to assign an overall risk to each compound. The results were then used to determine the worst-case waste stream to be burned during the Trial Burn to generate the worst-case emissions. In addition to the worst-case waste stream determination, various Agencies have developed their own specific requirements for the Risk Assessment that must be incorporated into the target compound list for the Trial Burn Plan. The target compound list is the list of compounds that should be measured in the stack emissions from the combustion unit and it includes the chemicals of greatest concern for the Risk Assessment. The development of a target compound list requires assessing the waste stream and the available analytical methods for each chemical of concern for the Risk Assessment. The Trial Burn Plan and Quality Assurance Project Plan must include the appropriate sampling and analytical methodologies to ensure that scientifically defensible data is collected during the actual Trial Burn for use in the post-trial burn Risk Assessment. A sophisticated approach for Trial Burn Plan development to support a post-trial burn Risk Assessment was developed for Reilly Industries, Inc.'s boilers located in EPA Region V. The worst-case waste stream was deter-mined, a universe of compounds list was developed, and the compounds were ranked based on risks. A specific target compound list was developed utilizing the list of chemicals, generator knowledge, and available sampling and analytical methodologies. Both the worst-case waste stream determination and the target compound list were then integrated into the Trial Burn Plan, the Quality Assurance Project Plan, and the Risk Assessment Protocol.