Accounting for fugitive eimssions in determining major PSD modifications

In December of 2008 EPA issued a final rule that revised the NSR rules so that fugitives would be considered consistantly for major source and major modification determinations. Previously, all sources had to credit fugitive emissions in determining whether a change was major, but only listed sources had to include fugitives when determining major source status. With the December 2008 rule change, only listed sources had to credit fugitive emissions for both major source and major modification determinations. Unlisted sources would not have to inlclude fugitives for either type of determination.

On Sept. 30, 2009, EPA stayed the December 2008 rule change for 3 months and issued an additional 3-month stay on December 31, 2009. Then, on March 31, 2010, EPA extended the stay for an additional 18 months. As a result, at least until October 3, 2011, all sources -- listed and unlisted -- must count fugitive emissions toward determination of a major modification. Major source determination remains as it always has been (count fugitives only if you're a listed source).

Here's a link to the December 2008 fact sheet.
EPA New Source Review: Fact Sheet