On March 21, 2014, representatives from the Coronado National Forest met with representatives of Caterpillar, Inc. at the Tinaja Hills testing facility in Green Valley, Arizona. Caterpillar is the manufacturer of much of the mobile mine equipment to be purchased by Rosemont Copper, and the purpose of the meeting was to discuss timing and phasing of more stringent emission requirements (specifically, Tier 4 engines).
SWCA Environmental Consultants. 2015a. Clarification of Air Emission Factor Revisions. Memorandum to file from Chris Garrett, SWCA Environmental Consultants. Tucson, Arizona: SWCA Environmental Consultants. March 4.