The purpose of the CIA is to quantitatively evaluate cumulative air quality impacts due to emissions from the Project and reasonably foreseeable and known sources of emissions in the region near the Project. The identified nearby sources, modeling methods, and results of the CIA are presented in this technical memorandum.
Response to US EPA comment #524-20, "While the Draft EIS relied on [a dispersion] analysis contained in the Resolution Copper Project NEPA Air Quality Impacts Analyses, we are concerned that it may have underestimated PM10, as well as PM2.5, emissions.[...]"
Response to comment #278-5 from ADEQ, "The most recent 3 years of [air quality] monitoring data show that the concentration levels in Year 2017 were higher than previous years. However, the NEPA Air Quality Impacts Analyses does not consider the 2017 monitoring data for the background concentrations determination. Would it be a concern?"