This column covers three more EPA-related topics from the American Foundry Society’s (AFS) August 2008 meeting.

Foundry MACT: Modifications to the 2004 MACT standard for ferrous foundries (40 CFR Part 63, Subpart EEEEE) were published in February 2008. Among these are new opacity limits (20%) for fugitive emissions from buildings with foundry processes, new leak-detection requirements for baghouses and a change in the method of determining “total metal HAP,” including a new manner of counting non-detects and the identification of 11 metals that comprise the HAP total: antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel and selenium.

Attendees were advised of the January 2009 deadline to report their 2008 metal melt production to the EPA as the basis for initial size classification. Under the new MACT rule, existing iron and steel foundries with annual metal melt production of 20,000 tons or less are considered “small area source foundries” and those with greater than 20,000 tons are considered “large area source foundries,” with different rules applied to each class.

EPA also completed several new standards for ancillary metal fabrication processes in 2008. These include “Area Source Iron & Steel Foundry MACT,” “Area Source Surface Coating,” “Area Source Plating & Polishing” and “Area Source Metal Fabrication and Finishing.”

Magnesium Production: The International Magnesium Association has entered into a voluntary agreement with the EPA to eliminate the use of sulfur hexafluoride (SF6) – a potent GHG – from magnesium production and casting operations by 2010. Some U.S. manufacturers have proposed SF6 capture and recycling as an alternate option for reducing these emissions.

Lead NAAQS: AFS staff reported that the National Ambient Air Quality Standard (NAAQS) for lead (Pb) is likely to be revised downward from 1.5 μg/m3 to approximately 0.2 μg/m3. Also proposed are an increase in sampling frequency from a 1-in-6 format (one 24-hour sample taken every six days) to a 1-in-3 format and a decrease in averaging time from one calendar quarter to one month. Public commenting on the proposed rulemaking ended recently, with final rulemaking expected by Oct. 15, 2008. This change could impact facilities with Pb air emissions that are currently in compliance with applicable regulations but might be at risk for exceeding the new ambient threshold at the facility’s fenceline under the new rules.