ALL4’s: Is That Your Final Answer?

The “Is That Your Final Answer” question has been around for a year now and we would

like to get your feedback on this feature. So send us an email about what you think. We will collect all comments received from now until the end of the year and randomly select one commenter to receive a special gift. Thanks for playing along with us, and our best to everyone for a great new year.

Last Month’s Answer and Winner:

The answers to November’s “Is That Your Final Answer” question came fast and furious as a record number of respondents vied to the penultimate qualifier for the $500

American Express gift card. As the dust settled, Ann Modro Borowski of J&J correctly deducted that an emergency generator is that often overlooked item that requires consideration from an air permitting perspective. Congratulations to Ann and all of the others who supplied an answer.

Question: 

We had a very spirited debate recently regarding the need to use a double space or single

space after a period. The argument for a single space was bolstered by the fact that most fonts are proportional fonts, which means that characters are different width

s depending on the space available. The double space is a remnant of old-school typewriter mono-spaced fonts where every character takes up the same amount of space regardless of the space available.   The double space proponents held the day, especially after showing the pitfall of the proportional font spacing contained in the Section 114 U.S. EPA Information Collection Request (ICR) shown below. What is the pitfall?

Answer: 

Please e-mail your answer to final.answer@all4inc.com.  Include in the e-mail your name,

answer, and address (to receive your prize).

Mass Confusion: Are Greenhouse Gases for PSD Permitting Treated the Same Way as Other Regulated PSD Pollutants?

Can a facility be a classified as a major stationary source for greenhouse gas (GHG) emissions only, and if so, do all modifications at the facility need to be evaluated for Prevention of Significant Deterioration (PSD) applicability for all New Source Review (NSR) regulated pollutants?  Since we are now well into implementation of the GHG Tailoring Rule, one would expect that there should be a simple answer for such basic questions – right?  ALL4’s John Slade set out to provide a “plain English” explanation but, as is typical with anything related to NSR applicability, nothing is simple.  Undaunted, John provides his explanation below.

But before getting into these questions that surely perplex you, it is important to review some of the new and unique terms we must use when discussing this topic.

•  Tailoring Rule refers to the Prevention of Significant Deterioration (PSD) and Title V Greenhouse Gas (GHG) Tailoring Rule published at 75 FR 31514 (June 3, 2010), which sets the timing and thresholds for addressing GHG emissions from stationary sources under the Clean Air Act (CAA) permitting programs.

• GHG means the sum of the following six well-mixed gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (NO2), sulfur hexafluoride (SF6), hydrofluorocarbons (HFC), and perfluorocarbons (PFCs).  For PSD applicability purposes, GHG is calculated in two (2) different ways (i.e., on a mass basis and expressed as a carbon dioxide equivalent (CO2e)).
• GHG on a mass basis is calculated by summing the mass amount of emissions of the six well-mixed gases.
• GHG expressed as CO2e is calculated by summing the resultant values from multiplying the mass amount of each of the six well-mixed gases by each gas’s associated global warming potential.
• Global warming potential (GWP) is a measure of how much a given mass of each gas is estimated to contribute to global warming.  It is a relative scale which compares the gas in question to CO2.
• Potential to emit (PTE) means maximum potential to emit a pollutant.
• “Subject to regulation” means that below a certain threshold, a pollutant is simply not regulated and you can forget about it (sort of).  For all NSR regulated pollutants other than GHGs, that level is zero.  For GHGs, a stationary source is not subject to regulation unless the GHGs equal or exceed 100,000 tpy CO2e.  For a modification, GHGs are not subject to regulation unless the emissions increase equals or exceeds 75,000 tpy CO2e.
• An “anyway source” is a stationary source that is major for a non-GHG pollutant (e.g., it is major for one or more criteria pollutants).
• A “GHG-only source” is a stationary source whose CO2e emissions are greater than 100,000 tpy and GHG mass emissions are greater than 100/250 tpy on a mass basis.   All other NSR regulated pollutants have a PTE less than the major stationary source thresholds.

Prior to the Tailoring Rule, the first question you would ask in a PSD applicability determination is whether or not the source was major for any PSD regulated pollutant.  Now (post-Tailoring Rule) you have to ask two questions:  (1) what pollutants emitted by the facility are subject to regulation; and (2)

Prior to the Tailoring Rule, the first question you would ask in a PSD applicability determination is whether or not the source was major for any NSR regulated pollutant.  Now (post-Tailoring Rule) you have to ask two questions:  (1) what pollutants emitted by the facility are subject to regulation; and (2) is the source a major source for any NSR pollutants subject to regulation.  For the non-GHG pollutants it’s easy, since any emissions over zero are subject to regulation.  For GHGs, it’s not so simple.  Emissions from the source must be greater than 100,000 tpy CO2e to be subject to regulation (first question) and greater than 100/250 tpy on a mass basis (second question) in order to be a major source for GHGs.  For modifications, the two questions are similar:  (1) will the project result in emissions increases from any pollutants subject to regulation; and (2) will the emissions increases of pollutants subject to regulation equal or exceed the significant emission rates (SERs).  For non-GHG pollutants any increase in emissions is subject to regulation and we are all familiar with the SERs in 40 CFR §52.21.  For GHGs, an emissions increase is not subject to regulation unless the increase in emissions equals or exceeds 75,000 CO2e and the mass emissions increase is greater than zero.

A confusing situation regarding the applicability of PSD occurs when a facility makes a modification at a GHG-only source.  The confusion relates to the applicability (or non-applicability) of PSD to non-GHG regulated NSR pollutants.  As you know (or used to know), a source only has to be a major stationary source for one PSD pollutant in order to trigger the requirement to review a modification for all PSD pollutants at their SERs.  However, for a GHG-only source, the emissions increase is subject to regulation only if the emissions increase results in an increase of GHGs greater than or equal to 75,000 CO2e.  So at a GHG-only source, a modification can result in emissions increases of, for instance, criteria pollutants above their SERs, and not trigger PSD if the increase in GHGs is less than 75,000 tpy CO2e.

Let’s try some examples:

Each scenario and the associated air permitting implications are discussed below.

What is the Status of Your Emission Inventory?

The U.S. Environmental Protection Agency (U.S. EPA) uses emission inventories from facilities that are readily available to support key policy and regulatory decisions that directly affect the regulated community.  When looking for emissions data, U.S. EPA may use the information available in the National Emissions Inventory (NEI), Toxic Release Inventories (TRI), or other annual emission reporting mechanisms.  U.S. EPA will most likely assume that the reported emissions data is correct and “ready to go” for various purposes including conducting air dispersion modeling studies.  It is important to understand that this means that U.S. EPA is compiling data from multiple data sources, making assumptions about your facility’s data, and pulling the trigger on evaluations that can impact current and future regulations, designation of attainment status, and even public perception of your facility.

Remember the USA Today Article published in December 2008 that addressed air toxics emissions that were alleged to be impacting schools?  The facilities that were scrutinized with regard to air toxics risks around those schools were provided in a searchable database listed by school.  How many parents checked their kid’s school out?  Was your facility noted?  It was clear after some analysis that the data used in the study was not always representative of actual facility emissions.  Why?  Because the data that U.S. EPA used may have been incomplete or incorrect.  Some of the data may have been incorrectly reported and in some instances mistakes may have occurred while entering information into databases. In other instances U.S. EPA appears to have made assumptions where the data was incomplete that drastically affected the evaluation.

U.S. EPA is also required under Section 112 of the Clean Air Act (CAA) to evaluate Residual Risk for the Section    112(d) Maximum Achievable Control Technology (MACT) Standards.  Some industries, such as the pulp and paper industry, are very familiar with this process.  For example, U.S. EPA’s initial Residual Risk evaluations determined that a number of pulp and paper mills had emissions that could result in unacceptable public health risks.  Upon further review initiated by the industry, it was discovered that much of the emissions data that were used were incorrect or outdated.  In addition to the incorrect emissions data it was also discovered that the stack characteristics and other information used in the analysis were also not always representative.  In some instances where exhaust point information was not available U.S. EPA used default values for stack characteristics. This is a very important distinction because stack configuration and discharge data can directly impact modeled ambient impacts.  For example, if U.S. EPA did not have specific discharge data,  they inserted “”default”” generic stack data for many point sources that are more reflective of a fugitive emission source (e.g., using a 1 foot stack height for paper machine vents) resulting in poor dispersion.  Addressing such issues can drastically alter the Residual Risk evaluation results and significantly change the outcome.

What Can You Do?

After responding to Information Collection Requests (ICRs) issued by U.S. EPA for multiple industry sectors, it became evident to the ALL4 staff involved in this work that many facility emission inventories are not as complete as they could be or are based on outdated information.  Why wait to update your emission inventory until you receive a Section 114 CAA request from U.S. EPA, or until a potential expansion project requires that emissions be estimated as part of an air permitting evaluation?  Make no mistake; completing an emission inventory at a complex industrial facility is a labor-intensive undertaking.  However, the completion of a site-wide emission inventory can be efficiently managed in distinct steps that can be completed over a several year time frame.  For those facilities that submit annual emission fee statements to state or local regulatory agencies based on actual emissions, you might begin by spending a little extra time during each reporting period to not only improve the data, but to also improve the recurring inventory process.

What Are Emission Inventories?

Emission inventories represent the air emissions from a facility over a period of time.  The emission inventory can be based on data collected from emission test programs, continuous emission monitoring systems (CEMS), mass balance calculations, and/or published emission factors.  Typically, operational parameters such as operating time or production rates are used to calculate emissions of particular pollutants on a mass basis.  A complete emission inventory will include multiple pollutant categories, not just regulated New Source Review (NSR) pollutants such as sulfur dioxide (SO₂), nitrogen oxides (NO_X), and particulate matter (PM). Hazardous Air Pollutants (HAPs) and Greenhouse Gases (GHGs) should also be included in your facility’s emission inventory.  All emissions units with the potential for air emissions should be considered in the inventory.  Emissions units that are sometimes overlooked may include units that are not listed, units that are grouped, or units deemed as insignificant activities in your current Title V permit.  For additional information on emission inventories, see ALL4’s November 2010 4 The Record article.

When Should Emission Inventories Be Updated?

It is recommended that the emission factors based on emission test programs be revised upon completion of subsequent emission test programs, or any time that a modification to the source occurred that deems the results of a past emission test program no longer applicable.  Emissions based on CEMS and mass balance measured should be updated based on the actual measured emissions or measured material usage.  Published emission factors from trade organizations or from U.S. EPA should be reviewed at least annually to ensure that the emission factors are current and that new emission factors for new pollutants have not been added.  The selection of an appropriate published emission factor based on source type and the understanding of the emission factors used can be critical to properly estimating emissions.  Particular attention should be paid to emission factors, specifically for HAPs, which may result in the double reporting of emissions for certain speciated compounds.  Understanding the emission factors associated with particulate matter is also critical with respect to filterable and condensable particulate matter.  Remember that U.S. EPA is developing a more dynamic system for emission factor determination called the Electronic Reporting Tool (ERT) that is based on electronic submittal of emission test data, which means that more frequent updates to emission factors are likely.

How Are Emission Inventories Used?

An emission inventory could be used for annual emission fees statements, Toxic Release Inventories (TRI), Prevention of Significant Deterioration (PSD) and other air permitting evaluations, post-PSD recordkeeping demonstrations, National Emissions Inventory (NEI) dataset updates, residual risk assessments, air dispersion modeling for National Ambient Air Quality Standards (NAAQS) compliance, and/or compliance with state air toxics programs and responses to specific requests from U.S. EPA. Sometimes emission inventories are used by U.S. EPA for regulatory evaluations (sometimes without direct knowledge by the facility).  More often than not during any potential facility modifications requiring a PSD analysis, a substantial effort is often required to calculate past or baseline emissions.  In fact, many times past emission reports and annual emission fee statements must be reconciled to account for discrepancies due to incorrect or outdated emission factors.  The use of the best available and most up-to-date data for compiling your emission inventory should be a high priority for any facility environmental manager.

How Are Emission Inventories Compiled?

In the end, once all of the most accurate throughput data and emission factors are identified, an emission inventory is all about data management.  Whether it is a spreadsheet-based system or based on third party software, the emission inventory must be transparent.  The source of all emission factors must be well documented with the source of the information and the revision date (including revision history).  In addition to documenting the source of the emission factors, several other keys to a successful emission inventory database should be noted.  The emission inventory database must be easy to use.  All of your emission factors should be in one place to expedite review and future revisions.  All of your production data used for the emission calculations (preferably on a monthly basis for purposes of a potential PSD analysis) should be located in one place to expedite data entry.

What Else Can You Do?

Correctly identifying not only what and how much is emitted of a particular pollutant is not the end of the process.  Where the emissions come from and how they are emitted is just as crucial if the data is to be used in subsequent analyses.  Identifying the proper coordinates for each emission point location and the associated stack characteristics (e.g., stack heights and diameters, exit velocities, exit temperatures, etc.) for potential air dispersion modeling studies and residual risk assessments can be critical.

A little emission inventory hygiene today can save a lot of last minute activity later.  It can put your mind at ease knowing that you can feel confident that the emission inventory for your facility is complete and correct.

Oil and Gas System Greenhouse Gas Reporting—Where Do You Stand?

U.S. EPA’s Mandatory Reporting of Greenhouse Gases Rule, codified at 40 CFR Part 98 (the GHG Reporting Rule), requires certain facilities to report annual emissions of greenhouse gases (GHG) including, as applicable, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFC), perfluorochemicals (PFC), and other fluorinated gases. Facilities that are subject to the GHG Reporting Rule must comply with many complicated provisions which include, but are not limited to, requirements for data monitoring, quality assurance, recordkeeping, required specific emissions calculation methodologies, and reporting content.

Subpart W of the GHG Reporting Rule covering Petroleum and Natural Gas Systems was published at 75 Fed. Reg. 74458 on November 30, 2010, and became effective on December 30, 2010.  This new rule has an expansive reach requiring companies in the oil and gas industry that exceed certain GHG emission thresholds to monitor and annually report GHG emissions to U.S. EPA.  Oil and gas facilities that are subject to Subpart W must report their 2011 GHG emissions to U.S. EPA by March 31, 2012, and then annually thereafter. Even though the reporting date in 2012 may seem to be a long way off, there are actions that the oil and gas industry needs to be taking now to comply with their obligations under the GHG Reporting Rule.

Who must report under Subpart W?

Subpart W requires facility level reporting of GHG emissions from the following source categories within the petroleum and natural gas industry if their total GHG emissions in a calendar year exceed 25,000 metric tons of CO2 equivalent (mtCO2e):

• Offshore petroleum and natural gas production.
• Onshore petroleum and natural gas production.
• Onshore natural gas processing plants.
• Onshore natural gas transmission compression.
• Underground natural gas storage.
• Liquid natural gas (LNG) storage and import/export.
• Natural gas distribution.

The key factor that makes Subpart W applicability so expansive is how it defines a “facility.”  Instead of using a traditional approach to define a facility as the physical boundaries of contiguous or adjacent property, under the definition in Subpart W an onshore facility includes collectively all emission sources on well pads, or associated with well pads, that are under common ownership or control and are located in a single hydrocarbon basin as defined by the American Association of Petroleum Geologists (AAPG).  With this definition, a single facility for Subpart W reporting could consist of the collection of over a thousand individual wells!  For natural gas distribution, a facility