Ohio EPA Issues Revised Air Permit Guidance

Environmental Update

Date: October 02, 2013

On August 30, 2013, Ohio EPA issued revised guidance regarding the determination of Best Available Technology (BAT) for new and modified air permits issued on or after October 1, 2013. See, Ohio EPA, http://www.epa.state.oh.us/dapc/sb265.aspx (last visited October 1, 2013). BAT is a case-by-case determination (recommended by an applicant and reviewed and approved by Ohio EPA) of an emission limit and/or control technique that represents the maximum emission control achievable by that source under the circumstances. Ohio law requires that all non-exempt1 air sources utilize BAT to obtain an air permit. Ohio EPA’s recent guidance represents a revised approach for determining BAT that supersedes Ohio EPA’s December 10, 2009 BAT Requirements for Permit Applications Filed on or After August 3, 2009, although it remains an informal policy imposing case-by-case determinations until Ohio EPA promulgates its delayed rule-based approach as required under Senate Bill 265 (2006).

Ohio EPA initially proposed revisions to the BAT program on May 1, 2013 through proposed revisions to the 2009 guidance and amendments to the Ohio Administrative Code concerning BAT (OAC 3745-31-05). Following a comment period, however, Ohio EPA published only the revised August 30, 2013 guidance, and OAC 3745-31-05 remains unchanged. Thus, for the moment, owners of non-exempt new or modified air sources applying for a PTI or PTIO on or after October 1, 2013, must follow this new guidance until Ohio EPA issues a final BAT rule.

The revised guidance does not affect BAT determinations for sources of “Hazardous Air Pollutants” subject to Maximum Achievable Control Technology (MACT) rules, Best Available Control Technology (BACT) or Lowest Achievable Emission Rate (LAER) requirements under the major source new source review permit programs, or Reasonably Available Control Technology (RACT) standards. For sources subject to these standards, BAT for the applicable criteria pollutant is equivalent to the most stringent of the applicable standards (except that in some cases a more stringent case-by-case BAT standard could apply in lieu of the applicable RACT standard).

The revised guidance, however, does alter Ohio EPA’s case-by-case BAT determination for two BAT options available under SB 265. Specifically, SB 265 requires that BAT be expressed (for sources not subject to the above standards) in only one of the following ways as appropriate for the applicable source or category:

  • Work practices
  • Source design characteristics or design efficiency of applicable air contaminant control devices
  • Raw material specifications or throughput limitations averaged over a 12-month rolling period
  • Monthly allowable emissions averaged over a 12-month rolling period

Each of these options was generally addressed in the 2009 guidance, but the revised guidance alters when work practices and source design characteristics or design efficiency are the appropriate approach for control.

With respect to the work practices BAT option, the revised guidance no longer focuses on opacity limits to verify the effectiveness of control measures. Instead, the guidance recommends implementing appropriate control measures (e.g., work practices such as watering to control roadway dust emissions at a regular frequency) rather than imposing opacity or emission limits. In the roadway example, the opacity or emission limit approach (as previously required) can still be used where preferred by the applicant, but it is no longer Ohio EPA’s primary approach.

The recent guidance also revises BAT requirements under the “source design characteristics” or “design efficiency” approach. Under the revised guidance, no emission limits will be established for BAT using this approach; the 2009 guidance required setting short-term emission limits that must be met at all times. BAT now may be the source design characteristic if provided from the manufacturer of the equipment (i.e., design specifications for certain pollutants), or even a description of installed equipment that reduces emissions. BAT also can be a design efficiency where a control device has a designated percent control efficiency. Importantly, this type of BAT carries no ongoing compliance obligation (i.e., testing, monitoring, etc.) other than initial confirmation that the design specifications are met and ongoing maintenance of equipment.

The revised guidance also allows BAT based on raw material specifications, throughput limitations or monthly allowable emissions averaged over a 12-month rolling period. These approaches to BAT remain largely unchanged and frequently have been used by Ohio EPA in the past to support synthetic minor permit limits. Under these BAT approaches, no short-term BAT limits will be imposed.

This is an important development for owners and operators of air sources that must apply for a PTI (Title V sources) or PTIO (non-major sources) on or after October 1, 2013. Under the revised guidance, applicants will continue to recommend BAT in their permit applications, but should now consider the above factors in their case-by-case determinations. These changes to the BAT program may reduce the setting of specific emissions limits and ongoing monitoring requirements under qualifying circumstances.


For more information, please contact:

Devin A. Barry

Wray Blattner

Andrew L. Kolesar

or any member of Thompson Hine’s Environmental practice group.


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1Exempt sources include sources exempt under OAC 3745-31-03; sources that have a potential to emit (considering pollution controls) less than 10 tons per year of an air contaminant or an air contaminant precursor; and de minimis sources, generally less than 10 lbs./day, under OAC 3745-15-05.