Hazardous Waste Combustors: Regulatory Review ofRisk Assessment Protocols and Reports

摘要

Expertise in the RCRA permitting of hazardous waste combustors varies amongregulators and their contractors. Some are technically astute in all areas while others arewell-versed in many areas but not in all. Due to the diverse levels of expertise amongpotential readers and reviewers, facilities are well served by submitting clear andtransparent documentation in risk assessment protocols and reports. Such documentationensures that regulators, readers and reviewers understand all aspects of the risk analysis.This approach can be especially important when portions of the analysis are open tocontention or interpretation.In reviewing combustion risk documents, two areas are consistently identified whereregulators need more information than provided initially by the facility: describing theenvironmental setting and the design and operation of the hazardous waste combustionsystem; and documenting the use of site-specific parameter values and deviations fromthe methodologies recommended in regulatory risk documents. Further, many facilitiesfail to take full advantage of the uncertainty analysis, limiting the discussion to specific,isolated issues. Discussions that integrate the effect of all sources of uncertainty on theestimated risks, authored by the risk assessor(s), are needed to adequately characterize thelevel of conservatism in the risk analysis. Issues can also arise around policy decisions.It is not unusual for a regulatory agency to modify a previously recommended approach.Agency-authored risk documents may even be revised or replaced while a facility ispreparing a protocol.Frequent communication between facilities and regulators during the process can providethe foundation for performing complete and defensible risk assessments in an expeditiousmanner. For example, interaction between all interested parties at the start of the projectcan help establish expectations, develop consensus on contentious issues, and assistfacilities in clearly defining the audience and purpose of their risk assessment documents.