4 The record articles

U.S. EPA Revises “Once In, Always In” Policy for MACT Sources

Posted: January 26th, 2018

Authors: Colin M. 

The U.S. EPA has withdrawn the “once in, always in” policy associated with changing the status of a facility from a major source of hazardous air pollutants (HAP) to an area source of HAP to avoid the applicability of major source maximum achievable control technology (MACT) standards for a given source category.  MACT standards are included in the National Emissions Standards for Hazardous Air Pollutant (NESHAP) rules at 40 CFR Part 63.   NESHAPs are established for both major sources and area sources of HAP in a variety of source categories.  A major source of HAP is a facility with a potential to emit (PTE) of greater than 25 tons per year (tpy) of all HAP or 10 tpy of a single HAP.  The distinction between being a major source or minor source is significant in many industries since area sources are not always subject to costly NESHAP obligations or are subject to less stringent obligations.  The “once in, always in” policy was originally articulated in a May 16, 1995 memorandum referred to as the “Seitz Memo.”  The change in policy was finalized in a January 25, 2018 memo authored by EPA Assistant Administrator William Wehrum. It is the second policy memo within the past several weeks aimed at reducing the regulatory burden on industry.

The “once in, always in” policy presented in the Seitz Memo stated that facilities had the ability to switch their categorization as a major source of HAP to an area source of HAP until the “first compliance date of the standard.”  This policy meant that if a facility was categorized as a major source of HAP upon the compliance date of the applicable NESHAP standard, they would have no ability thereafter to reduce their emissions and be subsequently categorized as an area source of HAP.  A previously categorized major facility that had reduced HAP emissions to negligible amounts would still have needed to comply with major source NESHAP obligations.  The current U.S. EPA administration has now reversed the policy, allowing facilities to accept federally enforceable HAP emissions limits to avoid major source obligations at any time.  The January 25, 2018 memo makes it clear that the current administration believes that the CAA imposes no temporal limitation for a source to restrict HAP emissions below major source thresholds and no statutory authority exists to enforce a once in, always in policy, as stated:

“…EPA has now determined that a major source which takes an enforceable limit on its PTE and takes measures to bring HAP emissions below the applicable threshold becomes an area source, no matter when the source may choose to take measures to limit its PTE. That source, now having area source status, will not be subject thereafter to those requirements applicable to the source as a major source under CAA 112, including, in particular, major source MACT standards – so long as the source’s PTE remains below the applicable HAP emission thresholds.” 

The EPA previously attempted to revise the “once in, always in” policy in 2003 and 2007.  The 2007 proposal was in the form of a proposed regulatory revision.  Based on the January 25, 2018 memo, the EPA is again planning to propose regulatory revisions to codify the policy change.  ALL4 anticipates that the proposed regulatory language will be very similar to the regulatory language that was proposed in 2007 as 40 CFR §63.1(c)(6) (see page 80 of the linked 2007 proposal).  As with any proposed regulatory revision, there is a good chance the regulatory language will be litigated.  Also note that certain states may opt to retain the 1995 “once in, always in” policy in the interim.

As described in ALL4’s Lookahead Article, ALL4 expects that U.S. EPA will focus on areas where policy changes and guidance can be used to achieve its regulatory reform goals.  The reversal of the “once in, always in” policy is such an example.  We will continue to monitor the timing and pace of these changes as they lead to other possible areas of reform such as National Ambient Air Quality Standard (NAAQS) procedures, Title V permitting, and New Source Review (NSR).  Feel free to contact me with questions at cmccall@all4inc.com or 908.328.9429.


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