Subsequent to providing CALPUFF modeling data to the Coronado National Forest for the Final Environmental Impact Statement (FEIS) in support of the Rosemont Copper Project, it was requested by the Forest Service that the CALPUFF modeled visibility impacts be reported based on the 98th percentile impact interval rather than the maximum modeled impact. As a result, The CALPUFF outputs were analyzed to determine the 98th percentile impact value. This was completed by reviewing the 24-hr visibility impacts for each day of each modeled meteorological year. The days were ranked for each year and the 8th highest value was selected for each year. The highest eight high for each modeled meteorological year were then averaged. This value was reported as the 98th percentile value. The maximum modeled delta-deciview value and the days that the maximum receptor delta-deciview value exceeded 0.5 and 1.0 deciview was still reported.
JBR Environmental Consultants Inc. 2013b. CALPUFF Far-Field Analysis, Revised Impact Tables. Boise, ID: JBR Environmental Consultants Inc. March 26.