August 2016

Boiler MACT Vacatur and Remand: The Details Unfold

As I wrote about in my last post, the United States Court of Appeals for the District of Columbia Circuit (“D.C. Circuit Court” or “Court”) issued an opinion on July 29, 2016 regarding three related rules for boilers, process heaters, and incinerators: the Major Source Boiler MACT, Area Source Boiler MACT, and CISWI rules.1

In the action, the D.C. Circuit Court remanded several items to U.S. EPA for further explanation, and, perhaps more significantly, vacated the emissions standards for certain subcategories under Major Source Boiler MACT. In this article, I provide some more details behind the Court’s decision – what were the issues and what was decided? What does each decision mean for the regulated community? Read on to find out.

THE VACATUR

“Specifically, we vacate the MACT standards for all major boiler subcategories that would have been affected had the EPA considered all sources included in the subcategories, as explained at supra § IV.B.”

Whoa – that’s a big deal. When a rule or portion of a rule is vacated, it is no longer effective or enforceable. Other notable vacaturs include the emergency demand response provisions of the widely applicable MACT rule for reciprocating internal combustion engines (RICE), the startup, shutdown, and malfunction (SSM) exemptions in the 40 CFR Part 63 General Provisions, and of course the 2005 Boiler MACT rule which has led us to where we are today. The Court’s July 2016 decision is not entirely clear about which specific Major Source Boiler MACT subcategories are affected by the vacatur, but it appears to be those pertaining to solid fuel (i.e., coal and biomass). I have a hunch that liquid subcategories may also be affected.

Unless the decision is reversed or modified before the mandate is issued (more on that below), U.S. EPA will be required to reestablish emissions standards for the affected subcategories. Since the Court found that the current emissions standards do not account for some of the best performing units, odds are that the revised emissions standards won’t be any less stringent than they are now. What does that mean for existing or newly converted natural gas-fired sources? Not much, since the rule does not establish emissions standards for the “gas 1” subcategory. The real impacts of this decision, should it be upheld, will be for the sources with applicable emissions standards, especially those that utilize or have installed air pollution control equipment to meet the promulgated limits.

THE REMANDS

“We also remand, without vacatur, to the EPA to: (1) adequately explain how CO acts as a reasonable surrogate for non-dioxin/furan organic HAPs; (2) set emission standards for cyclonic burn barrels; (3) determine whether burn-off ovens, soil treatment units, and space heaters are CISWI units and, if so, to set standards for those types of units; (4) adequately explain the exclusion of synthetic boilers from Title V’s permitting requirements; and (5) adequately explain the choice of GACT standards over MACT standards for non-Hg metals.”

While a remand is not as immediately impactful as a vacatur, remands can result in changes to rules depending on U.S. EPA’s response and conclusions. There were five items remanded to U.S. EPA for further explanation – each remanded item, organized by the affected rule, is explained in further detail below.

Major Source Boiler MACT

CO as surrogate for non-dioxin/furan organic HAPs
Under Major Source Boiler MACT, U.S. EPA regulates carbon monoxide (CO) as a surrogate for organic hazardous air pollutants (HAPs) (except dioxin/furans) rather than regulating each of the 100+ individual organic HAPs. The Court has asked U.S. EPA to explain why this approach is appropriate, noting that U.S. EPA did not address comments during the rulemaking process claiming that there could be controls that reduce non-dioxin/furan organic HAPs but not CO, or vice versa. U.S. EPA’s justification thus far is that both CO and non-dioxin/furan organic HAPs are both a result of incomplete combustion and that emissions would be minimized through similar methods of control.

This particular remand has the potential to be especially impactful because U.S. EPA has applied this logic for other MACT standards that are currently in effect, including the widely applicable RICE MACT. However, the Court has indicated that it is highly likely that U.S. EPA will be able to sufficiently respond to the remand and adequately justify the continued use of CO as a surrogate for non-dioxin/furan HAPs.

Commercial and Industrial Solid Waste Incineration Standards

Emissions standards for cyclonic burn barrels
In its decision, the Court determined that U.S. EPA failed to establish emissions standards for cyclonic burn barrels under the CISWI rule, even though in its rulemaking, U.S. EPA clearly stated that these types of sources combust solid waste. For the record, a cyclonic burn barrel is pretty much exactly that per the rule definition: “a combustion device for waste materials that is attached to a 55 gallon, open-head drum. The device consists of a lid, which fits onto and encloses the drum, and a blower that forces combustion air into the drum in a cyclonic manner to enhance the mixing of waste material and air”. U.S. EPA argued that they chose not to regulate cyclonic burn barrels as CISWI units due to the limited amount of available data for these sources. However, the Court’s position is that U.S. EPA had the authority to collect the necessary information from owners and operators of these sources in order to establish emissions standards. Under the remand, U.S. EPA is required to now establish emissions standards for cyclonic burn barrels under the CISWI rule. This could mean an information collection request for owners and operators of these types of sources is in the near future.

CISWI status for burn-off ovens, soil treatment units, and space heaters
Similar to the cyclonic burn barrel issue above, U.S. EPA did not establish emissions standards for burn-off ovens (including foundry sand reclamation units), soil treatment units, or space heaters under the CISWI rule. However, unlike for cyclonic burn barrels, the reason U.S. EPA did not establish emissions standards is because they did not determine whether these types of sources are actually CISWI units (i.e., whether they combust solid waste). Under the remand, U.S. EPA is required to determine whether these types of sources are CISWI units, and if so, to promulgate emissions standards. Again, for the record, “space heaters” are those covered by 40 CFR Part 279 (Standards for Used Oil Generators) and pursuant to §279.23, cannot have a maximum capacity of greater than 0.5 MMBtu/hr.

Area Source Boiler MACT

Title V permitting requirements for synthetic boilers
Facilities subject to a Major Source MACT standard are automatically subject to Title V permitting requirements since, by definition, they are a major source of HAP (i.e., they emit 10 tons per year or more of a single HAP or 25 tons per year or more of combined HAP). On the other hand, MACT standards that regulate area sources of HAP (i.e., facilities that emit less than 10 tons per year of a single HAP and less than 25 tons per year of combined HAP) do not necessarily require affected facilities to operate pursuant to a Title V permit. This is because U.S. EPA believes that the Title V permitting requirements would be overly burdensome for these typically smaller facilities, and also that the sheer number of area sources operating in the country would overwhelm U.S. EPA resources. Likewise, the Area Source Boiler MACT rule does not require affected facilities to operate pursuant to a Title V permit. However, the Court has decided that U.S. EPA must specifically explain why “synthetic area sources” are excluded from the Title V operating permit requirements. Synthetic area sources are described as those that would otherwise emit HAPs at major source levels, but are physically restricted from emitting above those levels due to the installation of air pollution control equipment. The Court’s decision stems from inconsistencies in U.S. EPA’s explanation for including or excluding these sources from the Title V operating permit requirements between the 2010 proposed rule and 2011 final rule.

GACT vs. MACT for non-Hg metals
While U.S. EPA established emissions standards for mercury (Hg) from coal-fired boilers in the Area Source Boiler MACT rule, it established work practice standards for other non-Hg metals. In its decision, the Court determined that U.S. EPA must provide justification for its selection of Generally Achievable Control Technology (GACT) work practice standards rather than Maximum Achievable Control Technology (MACT) emission standards for non-Hg metal HAPs.

THE REJECTIONS

In addition to the vacatur and remands, the D.C. Circuit Court also rejected several items petitioned by industry and environmental groups. I won’t go into too much detail on these, but they are summarized below:

Rejections of Industry Petitioner Claims

Failure to account for malfunctions when setting MACT floors in the Major and Area Source Boiler MACT rules.
Failure to account for periods of startup, shutdown, and malfunction in the CISWI rule.
Use of the “pollutant-by-pollutant” approach for establishing emissions standards in the Major Source Boiler MACT and CISWI rules.
Requirement for existing sources to conduct energy assessments in the Major and Area Source Boiler MACT rules.
Presumption that failure to keep records documenting the use of non-waste fuels would cause a source to be considered a CISWI unit under the CISWI rule.
Failure to account for varying waste streams in establishing emissions standards for small remote incinerators (SRI) under the CISWI rule.
Use of CO as a surrogate for organic HAP emissions from coal-fired boilers instead of establishing work practice standards under the Major Source Boiler MACT rule.
Failure to establish a health-based emissions standard for HCl under the Major Source Boiler MACT rule.
Failure to allow facility-wide emissions averaging under the CISWI rule.

Rejections of Environmental Petitioner Claims

Use of CO as a surrogate for non-dioxin/furan organic HAPs due to breakdowns in correlations below 130 ppm under the Major Source Boiler MACT rule.
Use of the Upper Prediction Limit (UPL) to account for the amount of available data and its variability in establishing the MACT floors under the Major Source Boiler MACT and CISWI rules.
Failure to set beyond-the-floor standards for CISWI units.
Failure to delist oil- and biomass-fired subcategories and establishment of GACT standards rather than MACT standards for Hg and polycyclic organic matter (POM) from these subcategories under the Area Source Boiler MACT rule.
Selection of certain GACT standards under the Area Source Boiler MACT rule.
Establishment of a 30-day rolling average to demonstrate compliance with emissions standards under the CISWI rule.
Decision to subcategorize boilers based on the fuel the boiler is designed to burn under the Major Source Boiler MACT rule.
Classification of units that begin combusting solid waste as “existing” units under the CISWI rule.
Failure to regulate temporary boilers under the Area Source Boiler MACT rule.
Establishment of biennial tune-up requirements for small coal-fired boilers and work practice standards during startup and shutdown for large coal-fired boilers under the Area Source Boiler MACT rule.

THE IMPACTS

“It is ordered, on the court’s own motion, that the Clerk withhold issuance of the mandate herein until seven days after disposition of any timely petition for rehearing or petition for rehearing en banc.”

As has become the norm with Boiler MACT, this decision perpetuates uncertainty for the regulated community. So let’s discuss what we all really want to know – what are the immediate impacts of this decision? For the regulated community: not much…yet (other than that ongoing uncertainty). The D.C. Circuit Court’s decision was accompanied by an Order Withholding Mandate Pending Rehearing Petitions, which means that the decision is not effective until the mandate is issued. In the meantime, the parties involved have the opportunity to request a rehearing that could alter the Court’s decision. So the possibility of a final action extending over several more months is quite possible. If U.S. EPA is required to reestablish emissions standards under the vacatur, that process will most certainly take years.

Our advice to the regulated community: continue complying with the existing emissions standards. For those with extensions, continue your course of action to comply by January 31, 2017. And of course stay with us for more updates as the details continue to unfold. Contact me with questions or input at 610.933.5246 x122 or lkroos@all4inc.com.

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

2016 Chemical Data Reporting in Full Swing

In our February blog post “Brace Yourself – 2016 Chemical Data Reporting is Coming”, we talked about 2016 being a reporting year in the Toxic Substances Control Act (TSCA) Chemical Data Reporting (CDR) rule cycle. This report is due every four years and requires that manufacturers and importers of TSCA substances above certain quantity thresholds submit a report to U.S. EPA. It has been six months since our original blog post and the CDR program is now in full swing. The submission period for the 2016 reporting cycle began June 1, 2016 and we have been busy helping our clients identify reportable substances, compile the required information, and navigate changes to reporting requirements from the 2012 CDR cycle.

With the September 30 reporting deadline fast approaching, now is the time to kick CDR into full gear for your facilities. Here are some key things you should consider as you tackle the 2016 CDR:

1. Registration in CDX:
Most facilities submitted their 2012 CDR reports via a paper form. However, this is no longer an option for the 2016 reporting cycle and instead, facilities are required to report electronically via U.S. EPA’s Central Data Exchange (CDX). Making sure you are properly set up to report through CDX should be one of the first steps in the CDR process.

2. Identifying Reportable Substances:
The 2012 report for your facility is a good starting point for identifying substances that need to be reported in 2016. However, there are few things to keep in mind:

a. Changes to processes, products, and suppliers that may result in new substances that need to be reported should be thoroughly reviewed.

b. For the 2016 CDR cycle, U.S. EPA is now requiring that reportable substances be identified based on the amount manufactured or imported during any calendar year between 2012 and 2015. This is different from the 2012 CDR cycle where applicability was based only on calendar year 2011 production and import volumes.

c. Also new for the 2016 CDR is the introduction of a reduced reporting threshold of 2,500 pounds for substances “subject to certain listed TSCA actions”. This reduced threshold has the potential of adding a number of new substances to 2016 CDR reports.

3. Compiling Processing and Use Information:
Once the reportable substances are identified, processing and use information may need to be compiled for the report. Facilities should note that for the 2016 CDR, this information is now required for substances imported or manufactured in quantities of 25,000 pounds per year or more (or 2,500 pounds or more for those substances under the reduced reporting threshold). This represents a significant decrease from the 2012 CDR threshold of 100,000 pounds for reporting use information and will lead to many more substances for which use information needs to be reported.

If you have questions regarding the 2016 CDR process or need assistance to make sure your report will be submitted on time, reach out to Colin McCall at cmccall@all4inc.com or 678.460.0324 x206.

RACT 2 – T Minus 2 Months 2 Go

You have likely heard about RACT 2 at this point, but you may not have yet acted on what you’ve heard. Human nature is bent toward procrastination. We get it and that’s part of why we’re here. The proposal deadline for RACT 2 submittals is quickly approaching whether you’ve been proactive about it or not and you may need to evaluate its applicability to your Facility, develop documentation for a proposal, submit said proposal to PADEP, and potentially modify your Facility’s operating permit.

That’s a lot to accomplish in two short months.

RACT 2 proposals are due to PADEP exactly two months from today (i.e., October 24, 2016). Never heard of RACT 2? Don’t know what RACT 2 is? Not sure if it applies to your Facility’s operations or not? With an eye toward the looming deadline, here are the TOP TWO things your Facility needs to do now to comply with RACT 2:

Determine if RACT 2 is applicable to your Facility. Are you a major source of NO_X and/or VOC per 25 Pa. Code §121.1? If so, you will need to submit a RACT 2 Proposal. Not sure? ALL4 can help you determine if your Facility is a major source of NO_X and/or VOC.
Give us a call. You are quickly running out of time to submit a RACT 2 Proposal. Let ALL4 help you.

For more information regarding RACT 2, check out our RACT 2 Toolbox – a one-stop-shop for all things RACT 2. If you have any questions about developing a RACT 2 proposal, please reach out to me at (610) 933-5246, extension 135, or at cgiannascoli@all4inc.com.

Don’t Fall out of Compliance with RACT 2

Summer is practically over, fall is almost here, and Halloween costumes are already out. Although your local retail stores are prepared for October, are you?

Your facility’s RACT 2 proposal is due in nearly two months on October 24, 2016. If you followed our submittal outline and completed your RACT 2 proposal, congrats. Now you have ample time to start thinking about your Halloween costume.

Do you have a Title V Operating Permit (TVOP) and think RACT 2 doesn’t apply to your facility? Why don’t you read the rule over once more to be sure and consider including appropriate language within your TVOP to avoid any potential confusion with PADEP.

If you are beginning to feel scared of submitting your RACT 2 proposal or alternative petition prior to the looming deadline or are frightened that you may be misinterpreting something, let us know. We have completed countless RACT 2 applicability determinations, submitted numerous RACT 2 proposals, and answered some of your most FAQs.

Who’s Next?

The years really do fly by. Most of the folks I started my career with back in the early ‘70s have already retired and the remaining die-hards are certainly counting the days. Here at ALL4 we’ve been expending serious energy over the last few years with succession planning. Thanks to my partners, as we’ve grown this company we’ve worked hard to develop leadership skills in the highly talented staff we’ve been able to amass. Not everyone is quite so lucky and it puts me in mind of some counterparts who, like me, left various other callings to pursue careers as air quality consultants.

Why do I bring this up? There’s a reasonable chance that some highly regulated facilities may be facing a future where their entrenched air quality consultant might be considering life after consulting. If the incumbent has been handling much of the air quality consulting load and with limited backup, there may be a transition period with some potentially dangerous pitfalls.
Succession planning is just as important if you rely on outside help as it is in taking care of your own company planning. Documentation should exist that captures all of the important compliance needs and deadlines. The last thing anyone wants to hear is that we missed a reporting deadline because Jake retired and no one else knew about it. People planning is a critical aspect of succession planning. Who is going to be our “go-to person” when Jake retires? Think about that now, not when it’s too late and Jake’s spending time with his grandkids.

There are other aspects to succession planning aside from individual brain power. In this day and age, automated management systems should be in place to help with compliance related activities. Such systems should be designed with consideration for the folks charged with using them and with the expectation that the folks using them will also change over time. If you’re faced with a situation where your go-to person might be gone and you don’t have solid management systems in place, consider using the transition as an opportunity to develop such systems and as an opportunity to try out a new go-to consultant.

It’s not easy losing your go-to person. Odds are that over time there’s more than the work that bonds you together. If you need to think about replacing your incumbent consultant, look for someone that will take the same, or an even greater level of ownership of your air quality issues and needs. At ALL4 we instill the concept of “being your client” from the day we begin the on-boarding process with our new hires. We’d love the opportunity to be your go-to person and help you establish management systems so the next time the question arises regarding “who’s next”, you’ve already got the succession planning nailed.

D.C. Circuit Court Issues Remand and Vacatur of Certain Boiler MACT and CISWI Provisions

On July 29, 2016, the United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit Court) issued a decision regarding three rules for boilers, process heaters, and incinerators:

Major Source Boiler MACT – 40 CFR Part 63, Subpart DDDDD (National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters)
Area Source Boiler MACT – 40 CFR Part 63, Subpart JJJJJJ (National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers Area Sources)
CISWI Rules – 40 CFR Part 60, Subparts CCCC (Standards of Performance for Commercial and Industrial Solid Waste Incineration Units) and DDDD (Emissions Guidelines and Compliance Times for Commercial and Industrial Solid Waste Incineration Units)

The decision was in response to petitions submitted by the United States Sugar Corporation, American Forest & Paper Association, and American Chemical Council. In its decision, the D.C. Circuit Court remanded several items to U.S. EPA for further explanation, including their use of carbon monoxide (CO) as a surrogate for non-dioxin/furan organic hazardous air pollutants (HAPs) (more on that in a separate post). However, perhaps the most significant piece of the decision was the vacatur of emissions standards for certain subcategories under Major Source Boiler MACT, particularly for solid fuels. The D.C. Circuit Court stated that their decision to vacate the standards was based on U.S. EPA’s failure to consider all sources included in those subcategories to establish the standards.

We, as well as industry, trade organizations, regulatory agencies, and environmental groups, have been processing this court decision over the last few days. It seems that for every day of processing, the impacts of this decision, particularly the vacatur, become greater and at the same time more unclear. As we know, the only constant in life is change, and the only thing clear about this decision is that it brings more uncertainty to an already complicated set of rules.

Although we are not attorneys, a literal interpretation of the vacatur means that the CO, particulate matter (PM), hydrogen chloride (HCl), and mercury (Hg) emissions standards for certain subcategories will no longer be effective. What that means from a practical perspective for affected facilities is something else entirely. Questions are plentiful. Will new emissions standards be established? When? New standards will likely be more stringent, but by how much? Is a facility that has already demonstrated compliance obligated to continue operating according to the operating parameter limits they established? How can a facility that received a one-year extension continue pursuing controls to comply with limits that do not exist?

ALL4 is following this action closely. Stay tuned for updates and a separate post summarizing the details of the decision. In the meantime, feel free to reach out to me with questions or input at 610.933.5246 x122 or lkroos@all4inc.com.

U.S. EPA Proposes Guidance on Fine Particulate and Ozone Significant Impact Levels

UPDATE 9/7/16: The values in the tables within this article have been updated per EPA’s corrections to the draft guidance.

On August 1, 2016 U.S. EPA made available for public comment draft guidance and supporting documents recommending Significant Impact Levels (SILs) for ozone (O3) and fine particulate (PM2.5) to be used in the Prevention of Significant Deterioration (PSD) permitting program. Public comments are being accepted until September 30, 2016 at which time U.S. EPA will most likely move forward with official rulemaking. Therefore, the timeline for finalizing the O3 and PM2.5 SILs is somewhat extended and unknown at this time. However, the proposed SIL values could find their way into state policy or guidance documents in the meantime. U.S. EPA is proposing the following SILs for NAAQS and PSD increment:

What are SILs Utilized for?

SILs represent pollutant concentration levels that U.S. EPA has determine represent an insignificant level with respect to a National Ambient Air Quality Standard (NAAQS) or PSD increment. The SILs are pollutant specific and critical to the air quality modeling process for two basic reasons.

First, comparison of air quality modeled concentrations with the SILs is the initial step in the air quality modeling process. As such, a facility can limit its PSD air quality modeling obligation to a single analysis if it is possible to demonstrate project related concentration levels are below the SIL. Second, SILs are also utilized as part of the PSD air quality modeling process to determine if project related concentrations could potential cause or contribute to a violation of the National Ambient Air Quality Standards (NAAQS) or PSD increment. In this instance, the use of the SILs can be critical to a facility when project related concentrations are added to modeled concentrations from other local sources and a violation of the NAAQS or PSD increment is identified. Demonstrating that modeled project related concentrations are below the SIL represents the difference between successfully permitting the project and having to reduce emissions or add additional emissions controls.

NAAQS SILs are utilized to determine if a cumulative NAAQS air quality modeling demonstration is required and PSD increment SILs are utilized to determine if a cumulative PSD increment air quality modeling demonstration is required. If project related impacts exceed a NAAQS SIL then the applicant must undergo a cumulative NAAQS air quality modeling analysis which includes evaluating facility wide impacts, local sources, and representative background concentrations. If a project triggers a PSD SIL then project emissions and potentially facility emissions and local source emissions may need to be evaluated. PSD increment evaluations are currently split up into two classes. Class I areas are areas of special national or regional natural, scenic, recreational, or historic value such as national parks, wilderness areas, or fish and wildlife areas for which PSD regulations provide special protection and Class II areas are all other areas.
Why Is U.S. EPA Proposing O3 and PM2.5 SILs?

In July 2010, Sierra Club petitioned the U.S. EPA to designate an air dispersion model to be used to determine if PSD projects cause or contribute to violations of the O3 or PM2.5 NAAQS. This petition was granted in January 2012 by U.S. EPA and U.S. EPA subsequently proposed revisions to 40 CFR Part 51 Appendix W Guideline on Air Quality Models (Appendix W) to address O3 and PM2.5 air quality modeling in July of 2015. The proposed Appendix W revisions include criteria and steps for choosing analytical techniques or air dispersion models to estimate O3 concentrations from precursor oxides of nitrogen (NOX) and volatile organic compound (VOC) emissions and PM2.5 concentrations from direct and secondary-formed PM2.5. The August 1, 2016 proposed SILs are intended to support the Appendix W revisions. U.S. EPA had intended to finalize Appendix W revisions in July 2016; however, due to a change in the Office of Management and Budget’s (OMB) significance determination based on a congressional inquiry during U.S. EPA’s 2017 budget hearing, the finalized revisions are not expected until sometime after October 2016.

PM2.5 SILs Were Established Years Ago, Right?

Yes, PM2.5 SILs were established in 2010 in 40 CFR Part 51.166 and 52.21 of the PSD regulations. However, in January 2013, the U.S. Court of Appeals for the District of Columbia Circuit (DC Circuit) remanded the PM2.5 SILs as strict indicators of insignificant concentration levels, in other words, the SILs might not always be low enough relative to existing air quality levels for PM2.5. The court decision established a requirement to justify that air quality modeled concentrations below the SILs would not cause or contribute to a violation of the NAAQS considering existing air quality in the project location. The remanded and proposed SIL values are summarized below:

You will notice that the bolded SILs represent concentration values that are proposed to be lowered as part of the proposed SIL guidance. U.S. EPA has concluded that air quality modeled concentrations below 0.2 ug/m3 and 1.2 µg/m3 for the annual and 24-hour PM2.5 SILs, respectively, can be considered an insignificant concentration level and should be considered to not cause or contribute to a violation of the NAAQS. Therefore, no further justification is required if the proposed PM2.5 SILs are used. However, U.S. EPA is proposing that permitting authorities have the case-by-case discretion of utilizing SIL values between 0.2 µg/m3 and 0.3 µg/m3 for the annual PM2.5 NAAQS and between 1.2 µg/m3and 1.3 µg/m3 for the 24-hour NAAQS if it can be demonstrated that there is sufficient “headroom” between ambient PM2.5 concentration levels and the NAAQS to ensure impacts less than the SIL will not cause or contribute to a violation of the NAAQS. This requirement to justify the use of a SIL is no different than is currently required because of the DC Circuit Court remand.

How Will the Proposed PM2.5 SILs Affect My Facility?

This will largely be dictated by how State permitting authorities implement the case-by-case use of the range of recommended SILs. Especially for the annual PM2.5 NAAQS, it has been a strategic approach to avoid the requirement to conduct PM2.5 air quality modeling as part of the PSD permitting process either through controlling or reducing PM2.5 emissions in an effort to stay below the PSD significant emissions rate (SER). If project emissions are not below the PM2.5 SER, the next strategic approach is to remain below the PM2.5 SILs. This approach is necessary to avoid conducting cumulative NAAQS and PSD increment air quality modeling analyses. Demonstrating that a facility would not cause or contribute to a violation of the annual PM2.5 NAAQS has proven difficult with the current regulatory approach which includes many conservative components. These components include an air dispersion model designed to bias modeled concentrations high (AERMOD), relatively high background PM2.5 concentrations, a conservative approach for applying these background PM2.5 concentrations in the air quality modeling analysis, the need to factor in secondary PM2.5 concentrations, and uncertainty with PM2.5 emissions estimates for some sources.

Therefore, under the proposed regulatory framework lower SILs reduce the flexibility for a facility to avoid cumulative air quality modeling and may increase the cost to comply with air quality standards. Reduced SILs could mean capital cost to add PM2.5 controls or to make stack improvements to enhance the dispersion of PM2.5 emissions (Note: stack improvements must be considered within the framework of good engineering practice – GEP regulations). Evaluating these alternatives with air dispersion models will mean extended timelines and increased costs for developing a PSD application. In the most extreme situation, a project might be derailed because the concentration level for being insignificant (i.e., the SIL for not causing or contributing to an air quality violation) is just too low relative to the existing PM2.5 concentration levels.

Ozone SIL – What the Heck?

As mentioned above the proposed revisions to Appendix W are anticipated to include new requirements to evaluate concentrations of O3 resulting from precursor emissions (NOX and VOC) to demonstrate that a project will not cause or contribute to a violation of the O3 NAAQS. Currently assessing project related O3 concentrations are addressed as part of PSD applications on a case-by-case basis in consultation with the permitting authority. The case-by-case evaluations have varied wildly from state to state, from completely qualitative assessments to quantitative analyses utilizing a photochemical grid model such as the Comprehensive Air Quality Model with Extensions (CAMx) model. Part of the proposed Appendix W rulemaking includes a requirement to establish O3 SILs as the August 1, 2016 proposed guidance is undertaking. Additionally, U.S. EPA intends to develop rulemaking that will establish an intermediate step between the qualitative and quantitative approaches for projects with O3 precursor emissions (NOX and VOC) greater than the SERs and therefore needing to evaluate O3 concentrations with respect to the proposed SILs. This yet to be developed rulemaking will likely propose to establish Model Emissions Rates for Precursors (MERPs). A MERP would represent a level of emissions of precursors that is not expected to contribute significantly to concentrations of O3. The MERPs are expected to be greater than SERs and be a more appropriate screening threshold for evaluating their impacts as precursor pollutants to O3 formation.

O3 is not directly emitted by sources but rather created by chemical reactions of directly emitted NOX and VOC in the presence of sunlight. The chemical transformation of O3 can vary widely across the country due to different, temperature and sunlight regimes, distribution of anthropogenic and biogenic formed VOC, and topographic settings that lead to unique O3 formation to name a few. Therefore, establishing a uniform SIL and/or MERP that is representative for the entire United States would result in conservative assessments for some areas and less conservative assessments for other parts of the country. The proposed 1.0 ppb O3 SIL represents a conservative value and is only 1.4% of the new 2015 O3 NAAQS (70 ppb). Current qualitative ratio approaches for determining that project related O3 concentrations are below the propose SIL will be difficult for most sources to use. However, next generation air quality models such as CAMx, which accurately predict O3 impacts, are becoming much more accessible for consultants to utilize as federal and state permitting authorities develop a significant portion of the necessary air quality modeling inputs for CAMx. However, as with the lowering of PM2.5 SILs, the evaluation of O3 SILs will also lead to more time and cost for PSD applications.

What Can I Do Now and How Can ALL4 Help?

Public comments are being accepted until September 30, 2016 on the proposed PM2.5 and O3 SILs. Consider providing comments as the final SILs will affect your air permitting projects. ALL4 can assist by evaluating the methods utilized to develop the SILs and with the addition of our new photochemical grid modeling expert, Dr. Bhat, ALL4 can conduct CAMx modeling to evaluate the appropriateness of the proposed O3 SIL or to justify more representative O3 SIL values for your geographic area. In addition Dr. Bhat and Dan Dix will be providing a complimentary webinar on August 11th at 12pm EDT on the proposed O3 and PM2.5 SILs. In the mean time for more information on the proposed SILs and air quality modeling please contact Dan Dix or Abhishek Bhat.