EPA reverses "once-in-always-in" MACT Policy

On January 25 EPA issued a Policy reversing its May 1995 memorandum, “Potential to Emit for MACT Standards – Guidance on Timing Issues” by John Seitz, Director, Office of Air Quality Planning and Standards (the “Seitz Memo”).  The Seitz Memo established EPA’s policy that requiring any facility that was a major source of hazardous air pollutants (HAP) on the first compliance date of an applicable MACT standard to permanently comply with that MACT standard.  It was commonly called EPA’s “once-in-always-in” MACT policy.

The January 25, 2018 memo authored by William L. Wehrum, reverses that policy.  Thus, facilities that are subject to a major source MACT standard may now take enforceable limits below major source thresholds and be removed from major source status.  The “major source” threshold for hazardous air pollutants is 10 tpy or more of any single HAP or 25 tpy or more of any combination of HAP. 

This new policy provides an incentive for a facility to add controls to remove the facility from the major source category and MACT applicability.  A copy is available here.

In light of this new policy, we recommend reviewing your facilities’ current MACT status to determine if the facilities still meet major source thresholds or if there is a benefit to adding controls and enforceable limits to reduce emissions below major source thresholds.