In response to an industry petition, the EPA has amended provisions in its October 2009 final national emissions standards for hazardous air pollutants (NESHAP) for chemical manufacturing facilities at nonmajor or area sources (CMAS).  Following receipt of the petition and the EPA decision to reconsider the rulemaking, the Agency issued several stays on the effective date of the NESHAP.  The final amendments lift those stays,

Perhaps the main revision reduces the number of affected CMAS that were required to obtain Title V permits under the 2009 action.  Other amendments affect overlapping NESHAPs, the manner in which leak inspections must be conducted, the requirement to place lids on containers that contain HAP metals, the requirement to conduct inspections when equipment is in HAP service, and how compliance is triggered by the applicability of the family of materials concept. 

Major changes

With issuance of the final amendments, affected CMAS must be in compliance with the NESHAP by March 21, 2013.

Major changes include:

• Title V.  Under the 2009 action, sources that installed an air pollution control device on any chemical manufacturing process unit (CMPU) after 1990 were required to obtain a Title V permit.  In the current action, Title V permitting is required only when a federally enforceable control device is installed on at least one affected CMPU, that is, a CMPU that maintains the source’s emissions at area source levels.
• Overlapping standards.  The revised final rule requires that facilities comply with the more stringent requirements when there are overlapping provisions in the CMAS rule and any other NESHAP. Sources are required to determine which of the overlapping requirements are more stringent.
• Inspections.  The 2009 rule required “direct and proximal (thorough)” leak inspections.  Petitioners were concerned that regulatory agencies could have interpreted “proximal” to require facility staff to get closer to regulated equipment than was either possible or safe.  The revision allows that inspectors can use detection methods incorporating sight, sound, or smell.
• Lids.  Several revisions adjust the requirement to keep lids on process vessels in metal HAP service.  Specifically, a lid is not required (1) after a process vessel is emptied to the extent possible and (2) when the vessel contains metal HAP in certain solutions (e.g., ingot, paste, or slurry form) that the source determines are not sources of particulate emissions of metal HAP. 
• Inspections during HAP service.  Petitioners noted that the original requirement that leak inspections be conducted only when the affected equipment was in HAP service severely limited the available time to conduct inspections.  The EPA agreed that this was too restrictive.  Accordingly, the revisions allow inspections when the equipment is in volatile organic compound (VOC) service. 
• Family of materials.  The original CMAS required compliance if a source emitted one of 15 HAPs as well as a family of materials that are similar products.  Petitioners said that under the concept, facilities that used none of the 15 HAPs could be required to comply.  In the amendments, the EPA clarifies that the family of materials concept applies only to those products whose production involves emissions of specifically listed HAPs.

Also, in line with judicial instructions and consistent with other recent EPA rules, the final CMAS action adds an affirmative defense to civil penalties for violations of emissions standards that are caused by malfunctions.  In addition, the rule includes about 30 technical corrections to the 2009 CMAS.

The final CMAS amendments were published in the December 21, 2012, FR.