Human Health and Ecological Risk Assessment for the Operation of the Explosives Waste Treatment Facility at Site 300 of the Lawrence Livermore National Laboratory, Volume 1: Report of Results

Human health and ecological risk assessments are required as part of the Resource Recovery and Conservation Act (RCRA) permit renewal process for waste treatment units. This risk assessment is prepared in support of the RCRA permit renewal for the Explosives Waste Treatment Facility at Site 300 of the Lawrence Livermore National Laboratory. The human health risk assessment is based on U.S. Environmental Protection Agency approved emissions factors and on California Environmental Protection Agency, Air Resources Board and U.S. Environmental Protection Agency risk assessment and air dispersion models. The risk assessment identifies receptors of concern and evaluates carcinogenic risk, and acute and chronic noncarcinogenic hazard. The carcinogenic risk to a 30-year resident at the maximum offsite receptor location is 0.0000006 or 0.6 in one million. The carcinogenic risk to a 25-year worker at the maximum bystander on-site receptor location is also 0.0000006 or 0.6 in one million. Any risk of less than 1 in a million is below the level of regulatory concern. The acute noncarcinogenic hazard for the 30-year resident is 0.02 and the chronic noncarcinogenic hazard is 0.01. The acute noncarcinogenic hazard for the 25-year worker is 0.3 and the chronic noncarcinogenic hazard is 0.2. The point of comparison for acute and chronic noncarcinogenic hazard is 1.0, an estimate less than 1.0 is below the level of regulatory concern. The estimates of health effects are based on health conservative assumptions and represent an upper bound of the possible exposures to the receptors. For the ecological risk assessment, four receptor species were evaluated for potential detrimental effects; none were found to be adversely affected because for each species the predicted ecological hazard quotients are always less than one. Based on these results, emissions from the operations of the Explosive Waste Treatment Facility should not be considered to be of concern for human health or ecological reasons