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Calpuff Modeling Of Copper Smelter Emissions
Primary Issue Addressed: Modeling
Secondary Issues Addressed: Aerial Deposition of Contaminants
Project Site: Anaconda Smelter
Collaborating Entities: Montana Tech
Cost Share: None
Project Description
The main objective of this study is to use the advanced features of the CALPUFF air diffusion modeling system to investigate and predict aerial impact in southwest Montana from the previously active Anaconda copper smelter and to identify terrain sites (or locations) that may warrant further investigation/characterization and, ultimately, remediation.
Until recently, models were not available to handle plume diffusion amid complicated terrain features such as the mountains in southwest Montana, and most of the models were not very accurate over long distances. CALPUFF, however, is a state-of-the-science model capable of predicting air pollution impact from many types of industrial sources. The model simulates plume transport and plume diffusion on scales ranging from tens of meters to hundreds of kilometers, and it addresses effects from complex terrain in addition to time-varying and space-varying meteorological conditions. CALPUFF was recently adopted as the U.S. Environmental Protection Agency’s “preferred technique of assessing long range transport of pollutants and their impacts on Federal Class I areas” (Federal Register 2003). The goal of this project is to use the advanced features of the CALPUFF modeling system to investigate and/or predict the transport of airborne constituents from the Anaconda Smelter and to identify locations that may warrant further investigation, and possible remediation. This phase of the project will focus primarily on arsenic transport.
Status
All modeling has been completed, and work has begun on the final report, which is expected to be completed in FY05. Preliminary analysis of the model results shows arsenic deposition on the mountains east of Anaconda and the smelter. CALPUFF modeling indicates that concentrations increase with elevation. That is, deposition is higher on ridges and hilltops. Contour lines of arsenic concentrations predicted by the model have been plotted in terms of milligrams per square meter (mg/m2) along with existing soil data. A more in-depth evaluation and detailed quantitative analysis of the data will be provided in the final report.