Environmental Lexicon Part III: More on Air

I have been mired in PAL permitting work for one of my clients. I can see the benefit of the permit, but at times it just seems the path to the final product is too long and convoluted to traverse safely and efficiently. This is a fairly new permitting realm in the EPA world. In fact there are currently no permits of this kind in Ohio, which complicates matters.

So, I thought today I would share what I'm learned about the Plantwide Applicability Limit, or PAL permit option. We talked about the NAAQS last time and the PAL is a direct result of the existence of the NAAQS. Below are some related definitions.

New Source Review or NSR is a pre-construction permit program for significant new or modified source of air emissions at major stationary sources. The basic idea is to ensure that any new or modified air emission source construction does not adversely impact the air quality (specifically NAAQS) in a non-attainment area. NSR permitting is a notoriously long and arduous process, taking up to and sometimes over a year to complete. It is also not uncommon, under project aggregation, to inadvertently miss the need for NSR permitting, particularly if you are sometimes major and sometimes not (I'll discuss this a bit more below).

Prevention of Significant Deterioration or PSD is kind of the counterpart to NSR but for sources located in an attainment area. The requirements are not as strict, but the general intent is similar to NSR. I mention this just because even in NAAQS attainment areas there are requirements that must be met regarding maintenance of air quality. So just because you're in an attainment area doesn't mean you are home free.

Major Stationary Source is a source, or group of sources that has a 'potential to emit' (see definition below) a regulated pollutant in excess of the major stationary source threshold. In an attainment area, unless the source is one of a group of 26 industries for which the threshold is set at 100 TPY, the threshold is 250 TPY. In a non-attainment area, the threshold is 100 TPY, regardless of industry. Note that a source that is major for VOC (volatile organic compounds) is considered major for ozone.

Potential to Emit or PTE is the maximum emission of pollutants from an emission unit or stationary source usually based on 365 days per year, 24 hours per day operation, UNLESS there are federally enforceable limits that place legally-binding operational limits on the unit/source. Developing the PTE calculations for a new/modified source is the first step that must be taken in order to determine the applicability of the various air permitting requirements. Often voluntary restrictions can be written into a permit to install (they must be in the federally-enforceable portion of the permit) to avoid major source issues, if they are operationally feasible.

That brings us, in a round-about way to the PAL or Plantwide Applicability Limit. Plant-wide limits are not a new concept. When Title V permits were born, along with them came a plant-wide limit that would allow a source that was a major facility based on PTE to take voluntary, federally-enforceable limits to reduce allowable emission below the major-source threshold, allowing the facility to be a synthetic minor, thus avoiding Title V permitting. (Side note - 'major' in Title V has a different definition then 'major' in NSR/PSD).

The PAL is a similar idea, only instead of avoiding Title V permitting, with a PAL the facility is avoiding NSR pre-construction permitting issues. Another neat thing about the PAL is that it can provide some flexibility, depending on how the permit terms and conditions are written. For a facility which is looking at possible expansions that are likely to be over the 'significant' level for a regulated pollutant, but is also working on improving their existing processes to reduce emissions of the regulated pollutant, the PAL can offer a nice unbrella under which to make changes without triggering NSR.

I am still reading and learning about the PAL, and permit flexibility. It's a huge issue, especially given the economic pressures that industry is facing. The ability to make changes rapidly in response to business opportunities is something that my clients are always interested in. It is worthwhile to review your permit structure and take advantage of whatever flexibility you can get written into the permits themselves.

Any tips for building flexibility into air permits? Just curious what others are doing or have seen done.