Fugitive Emission Study Management

Client Name
Hayden, Arizona, USA


SLR was tasked to perform a year-long fugitive emissions study of the Asarco copper smelter located in Hayden, Arizona after the company was given a consent decree from the United States Environmental Protection Agency (EPA). The smelter operations included a 27,400 ton/day concentrator and a 720,000 ton/year copper smelter. The Hayden smelter produces almost half a billion pounds of copper anodes annually.

SLR was selected and approved by the EPA as the third-party contractor to conduct the study.


SLR performed the study to quantify fugitive emissions from the main smelter complex that included the entire process from concentrate dryers to anode casting areas, focusing on the smelting flash furnace, converter aisle and anode furnace buildings. Pollutants and parameters monitored at many locations included SO2, PM, optical density/opacity, exit velocity and temperatures, and certain metal hazardous air pollutants. The project team, which included consultants across multiple departments and states completed the study in 2021.


Both Asarco and the EPA were provided copies of the study once completed. Asarco has invested $180M in upgrades to enable environmental compliance and the capturing of fugitive emissions, ensuring safe operation of the Hayden smelter through 2040 and beyond.