Appendix W Revision: The New Era of Air Quality Modeling – Introduction

(UPDATE 1/26/17): In accordance with the White House executive directive as expressed through a memorandum on January 20, 2017, EPA has temporarily delayed the effective date of the Revised 40 CFR 51, Appendix W until March 21, 2017.

(ORIGINAL: 1/17/17): The long awaited revisions to the 40 CFR Part 51, Appendix W (also known as the Guideline on Air Quality Models referred to as Guideline hereafter) were finally published in Federal Register (FR) on January 17, 2017.  The final Guideline, which was signed by U.S. EPA Administrator Gina McCarthy on December 20, 2016, will become effective on February 16, 2017 for all of the covered regulatory applications with the exception of transportation conformity.  The respective reviewing authorities such as state, local, and regional permitting authorities will have until January 17, 2018 to integrate the Guideline in the regulatory process.  However, if you have already submitted a protocol for air quality modeling analysis, the approval of the protocol will be at the discretion of the appropriate reviewing authority.  As for the transportation conformity purposes, the final Guideline will set a 3-year transition period ending on January 17, 2020.

This revision to the Guideline comes more than a decade after the previous update and sets the stage for the new era in the world of air dispersion modeling.  In this new era, that the focus will be on improving the modeling techniques and incorporating the new science to address the secondary chemical formation of fine particles and ozone pollution.  The new Guideline also comes with a revised version of U.S. EPA’s AERMOD modeling system v16216.  One of the two primary objectives of the Guideline revisions was to address technical concerns within the AERMOD modeling system to generally improve model performance.  The second primary objective was to finalize the modeling techniques to address secondary chemical formation of fine particle (PM2.5) and ozone (O3) pollution from direct, single source emissions of sulfur dioxide (SO2), oxides of nitrogen (NOX) and volatile organic compounds (VOCs).  In addition to the Guideline revisions, the final rule will also include guidance on single source modeling, Model Emission Rates for Precursors (MERP) guidance, and guidance on use of Model and Mesoscale Model Interface Program (MMIF) for use of prognostic meteorological data in the AERMOD modeling system.  All of these revisions could impact the obligations that facilities must meet for upcoming Prevention of Significant Deterioration (PSD) permitting projects.

In order to help you navigate through all parts of this complex regulation, the ALL4 modeling team is publishing a blog series entitled “Appendix W Revision: The New Era of Air Quality Modeling”.  The first two blogs of this series are already published and available for you.  Brief information on the blog series is as follows:

  • The first blog by Maggie Greene on the revisions to the AERMOD Modeling System provides a brief summary of key updates to model codes including incorporation of ADJ_U*, Buoyant Line and Point Source (BLP) model, bug fixes, incorporation of horizontal and capped stacks, and AERSCREEN.
  • The second blog published by Amanda Essner focuses on the NO2 Modeling Updates and the impact of these changes on your upcoming air quality modeling projects.
  • The future blogs in this series will include:
    • Introduction to MMIF;
    • Review of Single Source Secondary Formation Modeling Guidance;
    • SO2 SIP Attainment Demonstration; and
    • Long Range Transportation Modeling Updates.
    • In addition to these blogs, you can also read Meghan Barber’s blog on introduction to the MERP Guidance.

The new era in air quality modeling is going to be exciting and adventurous.  But at the same time, this new era will have its own set of challenges.  The ALL4 modeling team is here to help you navigate through these challenges.  For all your modeling needs, feel free to give us a call or reach out to any of the ALL4 modeling team members.

What-If Island

This blog is about making a distinction and then doing something about it. At ALL4, we embrace a coaching management philosophy and we believe that by facilitating conversations that prompt self-discovery great things happen.   

What do you think about on your way home from work?  If I’m not careful, I get hijacked and taken to the horrible, scary, dreary What-If Island. I’m sure you can relate.

Don’t get me wrong, I have no one to blame for these hijacks except myself, well, my thoughts to be specific.  A hijacking occurs when you lose track of time and perspective and you end up in a bad place. Most of the time, you don’t even know you’re going.  Then, all of sudden, you’re on What-If Island.  At ALL4, we also like to refer to this as, Creating a Story.  It starts with one little thought (it often happens on my drive home from work).  “What if I messed up that calculation?” or “My client is probably tired of hearing from me” and then it snowballs into a whole lot of worries, woes and What-Ifs (sounds like lions, tigers and bears!).  That’s when you arrive on What-If Island. The sun never shines, and it’s cold and lonely…except for the big monsters that chase you – although they never catch you.  The shadows of monsters are your What-Ifs that are dark.  When I’m hijacked, it’s no good for anyone.  I arrive home stressed…and act like something that rhymes with lurk

Am I increasing your blood pressure?  Don’t worry (no pun intended).  You probably started going to What-If Island when you were a kid…yet you didn’t turn into a permanent castaway (hopefully).  My point to all of this hijacking and island hoopla is to share the escape route to your worries, woes and What-Ifs …and there’s only two steps.  

First: Give your worry a name and frame it, e.g. “What-If Island”, “Creating a Story”. Next time you hear it, from yourself, a colleague, a friend, or even your kid… call it out.  Give it a name…what’s that cliché?  Awareness is the first step.  Here’s how a What-If sounds at work:  (George) “Did we win that proposal yet?” (Me) “No, they never called, they probably (insert What-If here).”  I could pick from a laundry list of What-Ifs such as “they probably thought the cost was too high” or “perhaps they went with our competition”.  But the thing about worries and What-Ifs is that they are not the facts.  Too many times we considered a proposal “lost” only to get the purchase order the next day… with a note that says, “Sorry for the delay, I was visiting my cousin Elma in North Dakota.”  How many times have you had the same type of experience?  Although the names may change, the story remains the same.  My friend Mark Twain always said, “Worrying is like paying a debt you don’t owe.”  When you’re aware of and frame your worries, you quickly realize how much time you spend on What-If Island…the only place where fiction lives.

Second: We all know that worries, woes and What-Ifs can mess up your head, not to mention your health.  It’s ironic that what you need to do is the same thing that got you there, think.  Once you frame it, light it up.  Bear with me because this is where I go competitive.  Frame it – then game on.  What’s the worst thing that could happen?  Yeah, go there.  Turn that light on – find those monsters under your bed and on What-If Island.  When you face that monster square in the nose, you know what happens?? You realize that whatever it is, isn’t that bad…and you can handle it. If you’d rather go with the analogy of Creating a Story, acknowledge that great imagination of yours, and then pivot to the facts.

Case in point.  What-If Island is a well-known destination in my household.  I was putting my daughter to bed last night (the timing of this blog was impeccable) and she was worrying about her first lacrosse practice, ever. “What if I’m not good?  What if the coach doesn’t like me?” I just looked at her.  “Wait.  No. I’m on the island Mom.  You know what…there’s nothing here but sunshine.  I’m going to kick some butt, bring it…”   Score.

2017 Air Quality Look Ahead

Changes in the Wind | John Egan

For over 40 years I’ve been involved in the business of environmental regulation, and more specifically air pollution control.  From my early days as a field enforcement officer in Pennsylvania’s hard coal region in the mid-‘70s, to serving as air permitting chief in the state’s busiest regional office, to working for a large multinational environmental consulting firm, and finally to starting my own firm with my partners almost 15 years ago; I’ve learned lots of lessons, earned some scars, seen unbelievable changes and accomplishments for our country, and been blessed many times over.  I’ve seen administrations come and go and have watched the pendulum of regulatory oversight swing back and forth. All the while things continued to drastically improve from an air quality perspective.

One of the best things about aging is the advantage it gives you on putting things in perspective.  So I feel the need to share some thoughts about how things may, or may not change in the coming months with respect to what we do, “we” being all of us working in the environmental regulatory field, for the government or directly or indirectly for the regulated community.  Since these are my own thoughts and I’m not clairvoyant, I could be way off-base and if I am, I promise to be the first to admit it.  On the other hand, that age perspective thing may actually have some relevance.

Immediately after the election and amongst all that emotion I heard some amazing predictions regarding what was going to happen when the new administration took over.  I have no doubt that the incoming administration will alter the course of many government directives that will influence all of us including taxes, health insurance, and the economy to name of few. But specifically from an air quality regulatory perspective, I heard several curious “tidbits” worth sharing including:

  • Coal is coming back and greenhouse gases will no longer be a concern or be regulated.
  • The EPA will be eliminated.
  • Regulated facilities will be able to do whatever they want in terms of facility changes by just reaching out to their politicians.
  • All of us working in this field will no longer be needed and will need to pursue new careers.

This is all very entertaining, much like the election itself, but not much of it appears grounded in reality.  Don’t get me wrong, I cut my teeth learning about coal firing and I firmly believe there is a place for coal with the right technologies.  But having lived in this business through 8 Presidents now, I continue to be amazed at the checks and balances that are built into our government. You have to remember that:

  • Regulatory agencies and the associated regulations that impact the regulated community are a direct result of the Clean Air Act (CAA) which is a federal law.
  • Federal laws cannot be changed or eliminated without a formal process and, as we know, federal process typically means years; and even after years there may be no progress thanks to litigation.
  • The underlying basis for the CAA is protecting public health and welfare and, as a result, rolling back health-based standards and associated rules will be a monumental task that will likely be met by unprecedented public opposition.

What I think may actually happen:

  • EPA funding, manpower, and influence will almost certainly be impacted and likely will result in reduced EPA oversight and more independent action by state agencies.
  • Industry will view these changes as an opportunity to expand and grow, without the burdensome level of red tape, second guessing, and time delays that typically are associated with EPA for many permitting actions.
  • Non-governmental organizations (NGOs) will be empowered and fundraising efforts will increase significantly, resulting in their greater participation in the regulatory process, permitting events, and litigation.
  • EPA policy and guidance which have driven decisions beyond the text of the law and regulations and have impacted many real projects will likely reverse course.  In other words, if a project complies with regulatory requirements there will be much less chance of delays over policy interpretations regarding what the rule states.
  • The National Ambient Air Quality Standards (NAAQS), which are the backbone of the CAA, will not likely be relaxed.
  • The number of new air quality regulations will likely be limited and those that are proposed would be expected to be manageable by the regulated entities (i.e., effectively implemented with less burdensome associated process).

Based on our experiences in recent years supporting our clients and negotiating with EPA on real projects, those in power in the agency have been pushing an agenda that in some cases went beyond the scope of the rules that they are charged by us to implement and enforce, with no real accountability.  The positions taken by EPA on major project regulatory decisions and on the interpretation of their regulations left us, as experts, in a position where we could often not provide clear direction to our clients and that is an untenable situation.  The “trickle down” influence by EPA over state and local regulatory agencies was all too obvious when those individuals felt powerless to make their own decisions over concerns about how EPA would react.

Earlier I mentioned that in my 42 years in the environmental world I’ve seen the pendulum swing back and forth as we shifted from Republican administration to Democrat and back again.  I have never seen the pendulum swing so far in one direction as I’ve witnessed under the outgoing administration and while I don’t necessarily support a number of the incoming administration’s agenda items, the mere fact that the power wielded by EPA will need to become more grounded and accountable is a welcome situation.  Also, understand that change can result in surprises.  The CAA amendments of 1990, now 26 years old, were implemented by a conservative republican administration and those changes resulted in the Title V permitting program, Part 63 NESHAP regulations, and other sweeping air quality regulatory changes that still influence much of what we do today.

So stay tuned, pay attention, and keep connected.  And above all, understand that when big changes occur there is often the opportunity to influence the change.  Part of ALL4’s vision statement that we wrote over a decade ago includes the terms “shaping environmental responsibility” so expect to see us actively involved in the process and we’ll keep you informed as we go.

 

Next Generation Compliance and Continuous Monitoring Data – Here to Stay | Colin McCall

In 2016 U.S. EPA (particularly the compliance and enforcement branch) placed a great deal of emphasis on Next Generation (Next Gen) compliance.  Next Gen compliance is an enforcement philosophy that focuses on increased electronic reporting, ambient monitoring, and providing direct public access to a wide range of facility air quality information.  The involvement of the public in the enforcement process appears to be a response in part to the increasing regulatory complexity that needs to be addressed by state agencies combined with decreased staff levels in enforcement at those agencies.  In concept, the general public could serve as another arm of air enforcement.  Next Gen compliance consists of five components:

  1. Regulation and Permit Design:  Taking the opportunity to introduce Next Gen concepts such as ambient monitoring and public access to monitoring data into new Federal regulations (e.g. Refinery MACT benzene fence line monitoring).
  2. Advanced monitoring:  Evaluating more affordable and user-friendly ambient monitoring techniques that can be employed by stakeholders outside of regulatory agencies (e.g., remote sensing of VOC emissions).
  3. Electronic Reporting:  Use of the electronic reporting tool (ERT) for submittal of facility compliance and emissions information for Federal regulations, including expanded reporting of continuous emissions monitoring (CEMS) data.
  4. Transparency:  An overarching theme of NextGen compliance related to public access to data.
  5. Innovative Enforcement:  efforts to automate enforcement where possible as described by the phrase “data analytics and targeting” on U.S. EPA’s website.

The current (and soon departing) U.S. EPA administration’s enforcement arm emphasized Next Gen compliance principles wherever possible.  It remains to be seen how the incoming administration views these concepts.  The best guess is that the focus on NextGen principles related to regulation and permit design, advanced monitoring, and innovative enforcement will be de-emphasized from a Federal perspective.  We do expect, however, that electronic reporting under ERT and U.S. EPA’s Compliance and Emissions Reporting Data Interface (CEDRI) to continue and grow.  With the emphasis remaining on electronic reporting, CEMS data, in particular, will be taken on continued importance.  For even the most sophisticated environment programs, CEMS reporting remains one of the final frontiers of areas that can still be improved and evaluated to stand up to an agency and public scrutiny.  We are recommending a full understanding of CEMS data collection, validation, averaging, and reporting for the following reasons:

  1. Electronic reporting is a concept that is here to stay from the standpoint of efficiency and the public’s expectation that regulatory agencies are being as efficient and comprehensive as possible in monitoring their regulated entities.  Electronic reporting means wider access to your CEMS data.
  2. Third-party environmental groups will consider themselves the “last line of defense” for regulatory enforcement once the new U.S. EPA administration begins.  Funding to these organizations has already increased since the election, and CEMS data is an area that is ripe for them to pursue when targeting stationary sources.

We will get a better sense for NextGen compliance and its future once the new administration begins to implement its own enforcement priorities.

Boiler MACT Remand and Planning for January 31, 2017 | Lindsey Kroos | Ashley Howard

Back in August, I wrote a blog about the United States Court of Appeals for the District of Columbia Circuit (Court) decision related to Major Source Boiler MACT, Area Source Boiler MACT, and CISWI rules1.  As mentioned in my blog, these are three related rules for boilers, process heaters, and incinerators.  My follow-up blog in September explained more details regarding the Court’s decision and the potential impact on the regulated community.  In recent months there have been three primary petitions to the Court regarding the decision.

The petitions are as follows:

  1. U.S. Environmental Protection Agency (EPA) has requested that the Court convert the vacatur to a remand without vacatur.  As of November 16, 2016, environmental groups have also asked the Court to remand instead of vacate the standards.  These groups argue that it is more beneficial to the environment to keep the existing limits in place while they are being revised, rather than vacate them.  EPA also argues that a remand will minimize the uncertainty of the ruling on the regulated community.
  2. Environmental groups argue against the Court’s decision to uphold EPA’s use of the Upper Prediction Limit (UPL) as an average.  EPA used the UPL to calculate the Boiler MACT standards, but environmental groups argue that the UPL is an upper limit and should not have been used.  Instead, they argue that average emissions should be used, which would make the standards more stringent.
  3. A utility argued against the Court’s decision to uphold the requirement for emissions limits to apply during periods of malfunction, startup, and shutdown.  Utilities argue that malfunctions are unavoidable and the rule should permit waivers for situations of startup, shutdown, and malfunction.

On December 23, 2016, the Court granted EPA’s petition that “the numeric MACT standards set in the Major Boilers Rule for new and existing sources in each of the eighteen subcategories be remanded without vacatur for the agency to conduct further proceedings.” However, no timeline was established for EPA to act on the remand, other than the expectation to “complete this rulemaking promptly.” The other petitions were denied.

While we continue to wait for a final resolution, our advice to the regulated community is to continue to plan for January 31, 2017.  This date is important for two reasons:

  1. January 31, 2017 is the first reporting deadline for sources that complied by January 31, 2016.
  2. January 31, 2017 is the compliance date for sources that were granted a one-year extension.  Stack tests demonstrating compliance must be complete by July 29, 2017 and site-specific plans must be in place 60 days beforehand.

For more information regarding specific reporting requirements, refer to Kayla Turney’s blog post.  If you’re unsure about your obligations for the January 31, 2017 deadline, reach out to us.  We’re happy to support you with these requirements.

1MACT = Maximum Achievable Control Technology; CISWI = Commercial and Industrial Solid Waste Incineration

New Era in Air Quality Modeling:  Appendix W Revision | ALL4 Staff and Dan Dix

After a long wait, the anticipated revisions to the 40 CFR Part 51, Appendix W (also known as the Guideline on Air Quality Models) was signed by U.S. EPA administrator Gina McCarthy on December 20, 2016.  The rule which was published in the FR on January 16, 2017 and contains enhancements to air quality modeling procedures that will benefit regulated stakeholders.  One of the two primary goals of the Appendix W revisions is to address technical concerns within U.S. EPA’s AERMOD modeling system to generally improve model performance.  The second primary objective is finalizing air quality modeling techniques to address the secondary chemical formation of fine particle (PM2.5) and ozone (O3) pollution from direct, single source emissions of sulfur dioxide (SO2), oxides of nitrogen (NOX) for PM2.5, and volatile organic compounds (VOCs) and NOX for O3 formation.  In addition to the Appendix W revisions, the final rule also includes guidance on single source modeling, Model Emission Rates for Precursors (MERP) guidance, and guidance on the use of Model and Mesoscale Model Interface Program (MMIF) for use of prognostic meteorological data in AERMOD modeling system.  With the release of this new guidance, 2017 is all set to become an exciting breakout year for air quality modeling.  ALL4 is all over the new guidance documents and will be releasing a series of blogs to help you navigate this new era of air quality modeling.

2015 Ozone NAAQS Implementation | ALL4 Staff and Dan Dix

On November 2, 2016, the U.S. EPA proposed an implementation of the 2015 National Ambient Air Quality Standard (NAAQS) for O3 (2015 ozone NAAQS) with requirements that would apply to states with nonattainment areas and States in the ozone transport region (OTR).  The proposed rule, which was subsequently published in the FR on November 17, 2016, largely resembles the implementation rule promulgated for the 2008 O3 NAAQS and establishes the framework for U.S. EPA, state, tribes, and local air quality agencies for planning to achieve the 2015 O3 standards.  The three key features of the proposed rule which might impact you are nonattainment area classifications, updates to the nonattainment NSR offset requirements, and guidance to revoke the 2008 O3 NAAQS.  The finalization of this rule is anticipated to impact the nonattainment New Source Review (NSR) air permitting process by the inclusion of the evaluation of the inter-precursor trading ratio (IPT).  ALL4 is currently evaluating the IPT guidance document and will publish a blog to provide additional information that will help stakeholders understand and plan for air permitting in areas with O3 nonattainment designations.

Key Regulatory Developments for the Oil & Gas Industry | ALL4 Staff

Last year’s Look Ahead article forecast a busy regulatory year for the oil and gas industry.  If you have been on the receiving end of all of the subsequent regulatory activity or have been following our blog and newsletter articles, you may rightly feel that “busy” was an understatement.  In this article, we summarize some of the recent and key regulatory actions impacting the oil and gas industry and discuss some of the issues to keep in mind as you plan for 2017.

  • Back in March 2016, U.S. EPA announced that it intended to issue an Information Collection Request (ICR) to the oil and gas industry as part of a concerted push for increased methane regulations for this industry.  The final ICR was issued on November 10, 2016 as discussed in our November 16, 2016 blog.  U.S. EPA expected to issue all 114 ICR letters by the end of 2016 and we have heard from a number of clients that have since received the requests.  Companies that receive the ICRs will need to respond by early 2017 (within 60 days of receiving the operator survey or within 180 days of receiving the detailed facility survey).  Information collected through ICRs is typically used in the development of new regulations.  Whether that will be the case for this ICR is something we will continue to monitor.
  • The NSPS Subpart OOOOa regulations became effective on August 2, 2016 and will continue to be a significant regulatory force in 2017 for new or modified facilities that trigger these requirements.  In addition, initial fugitive emissions monitoring activities and the first annual compliance report for facilities already subject to Subpart OOOOa will be due in 2017 (on June 3 and October 31, respectively).
  • In addition to U.S. EPA’s ability to regulate emissions from new and modified oil and gas facilities under Subpart OOOO and Subpart OOOOa, the control technique guidelines (CTGs) finalized on October 20, 2016 will result in increased regulation of existing oil and gas sources in ozone non-attainment areas.  Although the CTGs are technically voluntary, states seeking approval of their State Implementation Plans (SIPs) from U.S. EPA will need to demonstrate that their proposed control measures are at least as stringent as those specified in the CTGs.  With the 2015 revision to the ozone National Ambient Air Quality Standards (NAAQS) and as states submit SIP regulations to U.S. EPA for approval, the CTGs are expected to play an increasingly significant role in 2017.
  • With regards to the U.S. EPA Mandatory GHG Reporting Rule and as discussed in ALL4’s October 24, 2016 blog, the calendar year 2016 GHG reports due at the end of March 2017 will be the first reports required to include GHG emissions from the new Onshore Petroleum and Natural Gas Gathering and Boosting and Onshore Natural Gas Transmission Pipeline segments added to Subpart W of the rule on October 22, 2015.  In addition, starting January 1, 2017, facilities will no longer be able to use the Best Available Monitoring Methods (BAMM) provisions of the rule to estimate emissions and, instead, will need to follow all rule requirements for the new segments.  Finally, 2017 will also bring new requirements related to leak surveys and emissions reporting for facilities subject to Subpart W and NSPS OOOOa (see our December 12, 2016 blog for more on this topic).
  • In 2016, we saw Pennsylvania and California continuing the trend set by Colorado back in 2014 by proposing state regulations to reduce methane emissions from the oil and gas industry.  Pennsylvania recently published draft general permits for natural gas production, processing, and compression facilities, which are discussed in ALL4’s December 20, 2016 blog.  California’s GHG emissions standards for oil and gas facilities were proposed in June 2016 and are discussed in our June 27, 2016 blog.  Although not final, companies with oil and gas operations in these two states should continue to follow the development of these regulations closely as they plan for 2017.

If you would like to discuss these or other regulatory issues impacting your oil and gas operations, please contact Roy Rakiewicz at (610) 933-5246 x127, rrakiewicz@all4inc.com.

U.S. EPA’s Collection of Information from Stakeholders | Dan Holland

Information collection requests are the Federal government’s notice of its intent to collect information from stakeholders.  Beginning with the first Paperwork Reduction Act (PRA) of 1980 and highlighted by the PRA of 1995, Federal agencies including U.S. EPA are required to justify and explain instances when information is going to be collected.  U.S. EPA and other Federal agencies are required to submit the ICR to the Office of Management and Budget (OMB) for review and approval.  The process for developing the ICR is a multi-step process and typically includes at least three notices in the Federal Register.  Most U.S. EPA ICRs that appear in the Federal Register (FR) are for a renewal of data collection for an existing regulation.  In situations involving regulations, the ICR renewals are required every three (3) years.  Other ICRs are a one-time focused request for information that U.S. EPA will subsequently use as part of rulemaking or other assessment of existing regulation (e.g., residual risk under the National Emission Standards for Hazardous Air Pollutants regulations – NESHAP).  Regardless of the type of ICR that is issued, tracking ICRs in the FR that may be relevant for your particular operations could really be worth your time and effort, especially when the ICR is requesting that you submit information.  For 2017, no slow down in the issuance of ICRs is anticipated.  Stationary sources of Lime Manufacturing, Stationary Combustion Turbines, Asphalt Processing and Asphalt Roofing Manufacturing, and several other source categories are expected to experience focused ICR activity in 2017; however, until the dust associated with U.S. EPA’s administration change settles, who actually receives an ICR in 2017 or beyond is uncertain.

For more information about any of the topics above, please reach out to the authors or contact us at info@all4inc.com.

Appendix W Revision: The New Era of Air Quality Modeling – NO2 Modeling Updates

(UPDATE 1/26/17): In accordance with the White House executive directive as expressed through a memorandum on January 20, 2017, EPA has temporarily delayed the effective date of the Revised 40 CFR 51, Appendix W until March 21, 2017.

(ORIGINAL: 1/17/17): Air dispersion modeling of nitrogen oxides (NOX) emissions and I have a love-hate relationship.  As a meteorologist, I love the process of implementing air quality modeling studies, but I hate giving bad news to clients about elevated concentrations.  Luckily, the updated 40 CFR Part 51 Appendix W (Guideline on Air Quality Models) Final Rule has shifted my feelings more towards love, due to some of the improvements made by U.S. EPA in this rulemaking, and I am looking forward to my next air quality modeling project where I have to demonstrate compliance with the nitrogen dioxide (NO2) National Ambient Air Quality Standards (NAAQS)!

Improvements, you say?

On December 20, 2016, the long awaited Appendix W Final Rule was signed, which revised the Guideline on Air Quality Models.  With it, came a great deal of updates, some impacting NO2 air quality modeling.  In July 2015, Dan Dix published a 4 The Record article detailing the proposed changes to Appendix W overall. He followed this up in August 2015, with a blog that discussed the details of 1-hour NO2 air quality modeling.  Now that U.S. EPA has finalized the rule, let’s take a look at what’s new and improved for NO2 air quality modeling using AERMOD…

Regulatory Options

AERMOD currently has several regulatory and non-regulatory options for air quality modeling of NO2 that use atmospheric chemistry to predict more realistic modeled concentrations.  These options require additional user inputs and initial data to set up and run AERMOD.  Historically, the use of non-regulatory options in AERMOD reclassified AERMOD as an “alternative model”; and therefore, required U.S. EPA Regional Office approval prior to use.  The Appendix W Final Rule has made several of these options regulatory default options in AERMOD, thus no longer requiring Regional U.S. EPA approval prior to use.

The Ambient Ratio Method 2 (ARM2) has been added as a regulatory tier 2 option.  The Minimum Ambient Ratio (MAR) is set at a default of 0.5, which will, in some instances, still overstate modeled concentrations.  Justification and approval by the appropriate reviewing authority to use a lower or alternative MAR is still required.  The ARM2 essentially multiples the modeled concentrations by a NO2/ NOX ratio [developed from U.S. EPA’s Air Quality System (AQS) data] to provide an improved prediction of NO2 concentrations.

The Ozone Limiting Method (OLM) and Plume Volume Molar Ratio Method (PVMRM) have been added as regulatory tier 3 options.  PVMRM has also been replaced with PVMRM2 (although still referred to as “PVMRM” in AERMOD).  PVMRM2 includes 3 major modifications to PVMRM: adjusts the formulation during stable conditions to avoid over predictions, assesses impacts of plume width far from the centerline, and addresses the treatment of penetrated plumes.  The OLM and PVMRM2 options use ozone data to reflect the conversion process of nitric oxide (NO) to NO2 and will improve the accuracy of modeled NO2 concentrations.

1-Hour NO2 Modeling Updates

Modeling for compliance with the 1-hour NAAQS has been tricky regarding NO2.  Maybe the most impactful update to Appendix W is that for cumulative air quality modeling analyses (i.e., when you are evaluating  your facility plus local sources), local sources can be modeled at average actual emissions based on the most recent 2-years of normal source operation.  This use of actual emissions rates for local sources is HUGE.  Compiling local source data is a long and painful process in some States, so being able to use more readily available data, such as annual emissions statements, permit limits, and operating information is a big plus.  In addition, we can now evaluate actual reported emissions for local sources, which should represent lower emissions rates and thus reduce the impact of local sources when modeling for NAAQS compliance.

So, Let’s Get Modeling!

If in the past, the effort of conducting NO2 air quality modeling was too high of a hurdle for your project due to the need to obtain U.S. EPA Regional approval of alternate air quality modeling procedures, the updates to Appendix W will be important to you.  However, the use of these options for NO2 air quality modeling still require experienced and knowledgeable staff to apply the options in a supportable and appropriate manner.  That’s where ALL4 comes in.  Our experience implementing NO2 air quality modeling options goes back to the release of AERMOD.  Give me a call (610-933-5246×129) or reach out to Dan Dix (ddix@all4inc.com, 610-933-5246×118), or the rest of ALL4’s air quality modeling team if you have any questions and want to know more.  And, stay tuned for more blogs about the Appendix W Final Rule updates, and how they could impact your projects.

Appendix W Revision: The New Era of Air Quality Modeling – AERMOD Modeling System Updates

(UPDATE 1/26/17): In accordance with the White House executive directive as expressed through a memorandum on January 20, 2017, EPA has temporarily delayed the effective date of the Revised 40 CFR 51, Appendix W until March 21, 2017.

(ORIGINAL: 1/17/17): I have to say, I personally was prettyyyy excited for 2017 to finally get here [and according to the internet (which is obviously never wrong), I wasn’t the only one].  Likewise, the air quality modeling team here at ALL4 has been anxiously awaiting the final revisions to 40 CFR Part 51, Appendix W (Guideline on Air Quality Models) (Guideline or Appendix W).  On December 20, 2016, U.S. EPA Administrator Gina McCarthy granted our holiday wish by signing the final rule!

For those of you entrenched in the air quality modeling world (read: fellow nerds), the Appendix W revisions have been on your radar for a while now.  You may have read Dan Dix’s article about the proposed revisions back in July 2015.  But for those who can’t be entrenched in the air quality modeling world, here is the main take away: these Appendix W revisions offer relief to regulated entities and will help you when you are required to demonstrate compliance with air quality standards.

In this blog, I’ll provide an overview of the revisions that affect AERMOD, U.S. EPA’s preferred air quality dispersion modeling system (but stay tuned… we will be publishing a series of articles in the coming weeks covering all of the impactful updates!).

Two primary goals of the Appendix W revisions were to address technical concerns within the AERMOD (American Meteorological Society/Environmental Protection Agency Regulatory Model) modeling system, and to generally improve model performance.  To accomplish this goal, U.S. EPA made the following key updates:

  1. Incorporated ADJ_U* as a regulatory option in AERMOD’s meteorological data preprocessor (AERMET).  ADJ_U* works by (yup, you guessed it) adjusting U* (the surface friction velocity) and addresses issues with AERMOD over-prediction of concentrations under stable, low wind speed conditions.  It is not uncommon for an emissions source to have its highest concentrations predicted to occur during periods of low wind speed and stable atmospheric conditions.  Previously, ADJ_U* was an alternative option (i.e., beta) that required U.S. EPA Regional Office approval; now ADJ_U* can be used without U.S. EPA Regional Office approval. Thus with ADJ_U* becoming a regulatory option, an emissions source may have more flexibility when addressing air quality concentration levels for air permitting projects.  The only caveat is that that use of site specific turbulence measurements (i.e., sigma W and sigma q) can’t be utilized with ADJ_U* because of documented issues with under predicted concentrations.
  2. Integrated the Buoyant Line and Point Source (BLP) model into AERMOD.  BLP was designed to handle unique modeling scenarios where plume rise and downwash effects from stationary line sources are important.  In this update, BLP was removed from 40 CFR Part 51, Appendix A as a preferred model and integrated directly into AERMOD for use.  This enhancement will help those sources with emissions that exhaust from roof monitors/vents/cupolas.
  3. Made modifications to address over-prediction for scenarios where tall stacks are located near small urban areas. This change was made within the model itself, so no user input is required as long as the correct version of AERMOD (i.e., v16216r) is used.  It should be noted that, while AERMOD v16216r is currently available for download on U.S. EPA’s Support Center for Regulatory Atmospheric Modeling (SCRAM) website, the official effective date of the final rule will be 30 days after publication in the Federal Register, which was published on January 17, 2017.  Until that time, use of the new version of the model should be discussed with the appropriate reviewing authority.
  4. Updated the nitrogen dioxide (NO2) Tier 2 and Tier 3 screening techniques within AERMOD.  Previously, the Guideline outlined a 3-tiered approach for assessing nitrogen oxides (NOX) sources that addressed the co-emissions of NO2 and nitrogen oxide (NO).  With the Appendix W revisions, the Ambient Ratio Method (ARM) Tier 2 option was replaced with the ARM2 option.  The ARM2 option utilizes a NO2/NOX ratio based on an evaluation of measured NO2/NOX ratios from U.S. EPA’s Air Quality System (AQS) data.  Furthermore, the Ozone Limiting Method (OLM) and updated Plume Volume Molar Ratio Method (PVMRM) were incorporated as default options in AERMOD.  This means that these options will no longer be treated as an alternative model requiring U.S. EPA regional office approval.  All emissions sources of NOX stand to benefit from availability of these air quality modeling options as regulatory options.  See Amanda’s blog for more details on NOX air quality modeling.
  5. Updated the AERMOD formulation to address plume rise for horizontal and capped stacks.  This included updating the POINTHOR and POINTCAP options from beta to default options.  The POINTHOR and POINTCAP include adjustments to account for the Plume Rise Model Enhancements (PRIME) algorithm, which accounts for entrainment of plume mass into the cavity recirculation region, for sources subject to building downwash.  Capped stacks are frequently found at smaller (i.e., non-major) emissions sources that seldom have to address air quality modeling issues.  However, as U.S. EPA tightens the National Ambient Air Quality Standards (NAAQS), some state agencies require these non-major sources to assess air quality impacts.  This AERMOD formulation change will help small and large emission sources address their capped and horizontal stacks in a more realistic manner than was available with previous versions of AERMOD.
  6. Incorporated AERSCREEN (a screening version of AERMOD) as the recommended screening model for all types of terrain and applications, replacing SCREEN3. 

Also, a notable change that U.S. EPA did not incorporate into the Appendix W revisions is the addition of LOWWIND3 as a regulatory option in AERMOD.  This, like ADJ_U*, is a model option to address issues with over-predication of concentrations under low wind speed conditions.  Although U.S. EPA had proposed this change, they determined that additional study and evaluation is still warranted for this option at this time.

This overview is not a comprehensive list of all of the AERMOD modeling system change resulting from the Appendix W revisions (for a complete summary see this model change bulletin).  If you’d like more detail about the changes within AERMOD including which pollutant(s) and source type(s) would be affected and how your facility may benefit from the changes, ALL4’s air quality modeling staff has extensive experience with the implementation of AERMOD, AERMOD regulatory and non-regulatory options, and applying AERMOD for the best possible outcome for air quality modeling demonstrations.  Do not hesitate to reach out to me at mgreene@all4inc.com or 678-460-0324 x213!  The rest of ALL4’s modeling team is here to help, too.

Major Source Boiler MACT Report Due January 31, 2017

So it’s time to complete your first Boiler MACT compliance report. What exactly does that mean?  It means that’s just one more thing for you to do in January! (Hint: we can help, contact me.)  The report must be submitted via U.S. EPA’s Compliance and Emissions Data Reporting Interface (CEDRI) located on U.S. EPA Central Data Exchange (CDX) platform.  CEDRI is a web-based application used for the electronic reporting of various reports required by both Standards of Performance for New Stationary Sources (NSPS) and National Emission Standards for Hazardous Air Pollutants (NESHAPs), codified at 40 CFR Parts 60 and 63, respectively.  If you have not previously used CEDRI, you will need to make sure that you allow enough time to register.  U.S. EPA has provided a number of helpful tools to assist facilities with registering with CEDRI for the first time, including this video.

CEDRI learning curve aside, you will need to gather some data from the reporting period.  Whether you are submitting the compliance report under 40 CFR §§63.7550(c)(1), (2), (3), or (4) (more on these later), you’ll need to gather information on the source relating to emissions/operating limitations, operating time, and records of tune-ups and/or fuel analyses.  In addition, you may also need to gather information relating to deviations from limitations, malfunctions of the source, control device, or continuous monitoring system (CMS), and information relating to startup and shutdown periods.  Several examples of specific pieces of information required (depending on applicability) include:

  • Type(s) and amount(s) of fuel used during the reporting period
  • CMS downtime and reasons for downtime
  • Corrective action performed on malfunctioning equipment
  • Date, time, and description of each deviation
  • Date and time of each startup/shutdown event and fuels fired during those times

Information such as fuel use, CMS downtime, and malfunctions must be submitted in a specific format, and U.S. EPA has developed Excel templates for this information to facilitate the reporting process.  Other types of information, such as tune-up records, and startup/shutdown details, do not have a prescribed format.  Once complete, the compliance report must be signed and submitted by a responsible official.

As promised, let’s discuss those four reporting provisions.  One or more out of four total possible reports must be submitted depending on your compliance method as follows:

  • §63.7550(c)(1) – Tune-Ups
  • §63.7550(c)(2) – Fuel Analysis
  • §63.7550(c)(3) – Performance Testing
  • §63.7550(c)(4) – Continuous Monitoring Systems

Each citation specifies what type of information is required for each report.

January is already a busy reporting month, so don’t wait to start compiling your data and developing your reports.  Contact me at kturney@all4inc.com or 610.933.5246 x143 or Lindsey Kroos at lkroos@all4inc.com or 610.933.5246 x122 to discuss your compliance methods and reporting obligations in more detail.

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