Response to Comment on the Resolution Copper Project DEIS: Action Item AQ9 - Surface Material Silt Content Used to Estimate Fugitive Dust Emissions
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. The dispersion analysis used the Arizona Statewide average for silt content of 3.0% in calculations for fugitive emissions from unpaved road and other sources. For unpaved roads, EPA's AP-42, Chapter 13.2.2, outlines that site-specific silt content information should be used when available, but, when they cannot be obtained, the sector-specific averages available in Table 13.2.2-1 should be used. In the absence of site-specific silt content for unpaved road emissions from the project, we recommend the sector-specific averages as the closest analogue and average silt content to use. In either case, it does not appear that modelled air quality concentrations would exceed the PM10 or PM2.5 NAAQS; however, this should be verified by the USFS. We acknowledge the revised dispersion analysis is unlikely to show the preferred alternative will cause or contribute to an increase in the severity or frequency of NAAQS violations […]
Randall, D., and M. Hampson. 2020b. Response to Comment on the Resolution Copper Project DEIS: Action Item AQ9 - Surface Material Silt Content Used to Estimate Fugitive Dust Emissions. Project No.: 262-37. Technical memorandum. Denver Colorado: Air Sciences Inc. May 18.
Email Address Created for Land Exchange Questions
The Southwestern Region Office of Lands and Minerals Management is overseeing and administering the land exchange and appraisal process which includes the 2,422-acre Oak Flat Federal Parcel. All questions about the land exchange and appraisal process should be emailed to SM.FS.email@example.com
Programmatic Agreement Info
To comply with Section 106 of the National Historic Preservation Act, the Tonto National Forest developed a Programmatic Agreement (PA) and included it in Volume 5, Appendix O of the final EIS. The PA was created in cooperation with the Advisory Council on Historic Preservation, the State Historic Preservation Office, tribes and other consulting parties. The PA contains an agreed upon process for identifying, evaluating and addressing adverse effects to historic properties associated with this undertaking.
To review Volume 5 and the PA, Download Vol 5 PDF, 27 MB.