NESHAP RULE
In 1999, EPA issued a policy where they would agree to state rules (state implementation plans) that included affirmative defense provisions for excess emissions during SSM as long as certain criteria are met. As a result of a lawsuit, in 2002 EPA proposed and finalized changes to the regulations that required a plan be developed to address periods of SSM. The Sierra Club effectively challenged the 2002 final rule and subsequent changes in court. In 2008 the exemption for excess emissions during periods of SSM was vacated by the DC Circuit Court for NESHAP affected facilities (this impacts foundries that are subject to the Iron and Steel Foundry Major Source NESHAP, Iron and Steel Foundry Area Source NESHAP and the Other Nonferrous Foundry Area Source NESHAP).