Doe Run made significant efforts to reduce lead emissions from the smelter, but in 2008 the federal Environmental Protection Agency issued new National Ambient Air Quality Standards for lead that were 10 times tighter than the previous standard. Given the new lead air quality standard, Doe Run made the decision to close the Herculaneum smelter.
At this time, it’s unclear if Doe Run or another company will open a new lead smelter in the United States that can meet the more stringent lead air quality standards by using more modern smelting methods. What is clear is that after the Herculaneum smelter closes its doors in December, entirely domestic manufacture of conventional ammunition, from raw ore to finished cartridge, will be impossible.