Workshop H How Changes to U.S. EPAs Guideline on Air Quality Models - - PDF document

Workshop H

How Changes to U.S. EPA’s Guideline on Air Quality Models Could Affect Permit Modeling in Ohio, Kentucky, and Indiana

Tuesday, March 21, 2017 11:15 a.m. to 12:30 p.m.

Biographical Information George J. Schewe, CCM, QEP, Principal Consultant Trinity Consultants, 1717 Dixie Hwy. S. Ste. 900, Covington, KY 41011 859-341-8100 FAX: 859-341-1021 gschewe@trinityconsultants.com

• Mr. Schewe is a Certified Consulting Meteorologist as well as a Qualified Environmental Professional who

has over 40 years of dispersion modeling and air quality management experience in Kentucky, Indiana, and Ohio. He has prepared permit applications, interfaced with state agencies, prepared overall air quality impact assessments as well as regulatory review requirements, prepared additional impacts analyses, and modeled both criteria and toxic chemical releases to assess potential air impacts. He has contributed to a wide variety of environmental assessment studies including Prevention of Significant Deterioration, non-attainment area net emission modeling, state and federal air toxics analyses and risk assessments, RACT and BACT assessments, and State Implementation Plan (SIP) preparation. He has used modeling approaches for emergency as well as routine releases of air contaminants. He has prepared modeling studies covering plantwide point-source emissions as well as plantwide fugitives from roadways, materials handling, waste and scrap areas or other process related fugitive emissions. While with the U.S. EPA, he performed dispersion modeling in support of emission standards development and helped develop and improve industrial source dispersion models. He has conducted numerous workshops, seminars, and technical classes over the past 25 years for the U.S. EPA - Air Pollution Training Institute, Ohio EPA, and the Dayton Regional Air Pollution Control (RAPCA). Christopher P. Beekman, Environmental Specialist II Ohio EPA, Division of Air Pollution Control, 50 West Town Street, Columbus, OH 43215 (614) 644-3597 Fax: (614) 644-3681 christopher.beekman@epa.ohio.gov

• Mr. Beekman works in the State Implementation Section of the Ohio EPA, Division of Air Pollution
• Control. His primary duties include dispersion modeling in support of air quality permits and State

Implementation Plans, as well as the statistical analyses of various air quality issues in the State of Ohio. He serves as the primary contact for the NOx Budget Trading Program, Cross State Air Pollution Rule, and the Mercury and Air Toxics Standards. Chris has been with the Ohio EPA for five years. Prior to working for the Ohio EPA, Chris served as a Chemistry lecturer for The Ohio State University. He has his Bachelor of Science in Chemistry and Environmental Science from Muskingum University, and his Doctoral degree in Environmental Science from The Ohio State University. David J. Long, P.E, Environmental Engineer / Principal in the Air Quality Services Section of Environmental Services, American Electric Power Service Corporation 1 Riverside Plaza, Columbus, OH 43215 614-716-1245 Fax: 614-716-2255 djlong@aep.com

• Mr. Long has over 35 years of experience in various aspects of environmental management and

compliance in the utility industry. He is currently responsible for supporting air quality compliance and permitting activities at several company facilities in the states of Indiana, Michigan, and Illinois, as well being the technical lead in the areas of air quality modeling and ambient monitoring in support of AEP System facilities across the eleven state American Electric Power System. Mr. Long currently serves as Chair of the Atmospheric Processes Division of the Air and Waste Management Association and is active

• n several utility industry committees in the area of ambient air quality and air quality modeling. Mr. Long

holds a Bachelor of Science Degree in Mechanical Engineering from the West Virginia University Institute

• f Technology and a Master of Science Degree in Environmental Studies from the West Virginia College
• f Graduate Studies, now a part of Marshall University. He is a registered Professional Engineer in the

states of West Virginia, Kentucky, Ohio, and Indiana, and a member of the Air and Waste Management Association, and American Society of Mechanical Engineers.

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Workshop H - How Changes to EPA’s Guideline

• n Air Quality Models Could Affect Permit

Modeling in Ohio, Kentucky, and Indiana

David J. Long AEP , Environmental Engineer - Principal George J. Schewe, CCM, QEP Trinity, Principal Meteorologist/Consultant Christopher Beekman Ohio EPA, Specialist III

March 21, 2017 – Cincinnati Convention Center

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Presenters

George Schewe Trinity David Long AEP Chris Beekman Ohio EPA

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Agenda for Workshop H

˃ George – overview of changes ˃ Discussion Break ˃ Chris – Change effects in Ohio ˃ Discussion break ˃ David Long – industry observations and

concerns with the changes

˃ Roundtable discussion of Guideline

changes implications for permitting

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Changes to the Guideline on Air Quality Models – Appendix W to 40 CFR Part 51 George Schewe

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What is the Guideline?

A document that directs how acceptable regulatory air quality modeling should be performed.

Industry and control agencies have long expressed a need for consistency in the application of air quality models for regulatory purposes. In the 1977 Clean Air Act (CAA), Congress mandated such consistency and encouraged the standardization of model applications. The Guideline on Air Quality Models (hereafter, Guideline) was first published in April 1978 to satisfy these requirements by specifying models and providing guidance for their use.

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Changes to the Guideline on Air Quality Models – Appendix W to 40 CFR Part 51

˃ Signed off December

20, 2016

˃ Published in Federal

Register January 17, 2017

˃ Overview of the

Guideline

˃ How these changes

can affect modeling

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But An Executive Order Put the Brakes on Effective Date!

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Why do we need a guideline?

For consistency in regulatory activity

U.S. – Clean Air Act

1970 CAA, 1977 CAAA, 1990 CAAA

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What is the Guideline on Air Quality Models?

˃ 40 CFR Part 51 Appendix W or the Guideline provides

direction to EPA, states, tribes, and industry on how to conduct air dispersion modeling

˃ Outlines requirements and recommendations for:

 SIP revisions,  NSR/PSD permitting, and  Other regulatory modeling

˃ Appendix W is a legally binding regulation

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Guideline on Air Quality Models – Summary of 2017 FR Version

˃ Some changes streamline modeling process 



Tier 3 NO2 as recommended default



Incorporation of Buoyant Line Plume into AERMOD



Modified ADJ_U* available in AERMET



De minimis thresholds for secondary pollutants (MERPs) ˃ Some changes could slow the process 



Codified requirements for Model Clearinghouse



Removal of recommended model for LRT – drops CALPUFF



Drops CALINE3



Lack of prescriptive guidance or models for secondary pollutant modeling



Some meteorological options not in final version (LowWind)

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What’s in the Guideline?

˃

Guideline provides preferred models

˃

Guideline provides other recommended techniques

˃

Guideline provides guidance for their use in estimating ambient concentrations of air pollutants

˃

Guideline provides models for PSD

˃

Guideline provides enhancements to AERMOD

˃

Guideline provides tiered demonstration approach for secondary chemical formation of ozone and PM2.5

˃

Guideline provides change of preferred status and model removal

˃

Guideline provides updated and reorganized information to streamline compliance assessment process

˃

Effective date was February 15, 2017 but has moved by Executive Order to March 21, 2017

˃

One year transition period for regulatory processes to January 17, 2018

˃

Three year period for modeling for transportation conformity purposes to January 17, 2020

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Background and Preamble

˃ 21 pages of background information, pp 5182-5203 ˃ Does this action apply to me? ˃ Summary of 10th & 11th Modeling Conferences ˃ Public Comments on proposed changes ˃ Summary of AERMOD updates ˃ Status of AERSCREEN ˃ Status of CALINE3 Models ˃ Single source ozone and PM2.5 impacts ˃ Status of CALPUFF ˃ Role of Clearinghouse ˃ Updates to cumulative impact modeling ˃ Updates on meteorology use in regulatory modeling ˃ Summary of editorial changes

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The Guideline

32 pages of jam-packed information - pp 5203- 5235

1.

Intro

2.

Overview of model Use

3.

Preferred and Alternative AQ models

4.

Models for CO, Pb, SO2, NO2, PM2.5, and PM10

5.

Models for Ozone and Secondarily Formed PM

6.

Modeling for AQRVs and other Gov’ Programs

7.

General Modeling considerations

8.

Model Input Data

9.

Regulatory Application of Models

• 10. References

А

Summary of preferred models

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Section 1- Introduction

˃

Models are provided for SIPs, NSR/PSD, conformity analysis, and

• ther AQ assessments

˃

Only applicable to criteria pollutants

˃

Techniques and databases that EPA accepts

˃

Not a compendium of modeling

˃

Rather a “common measure” of acceptable technical analysis

˃

Monitoring inadequate

˃

New or modified source impacts only through modeling

˃

Monitoring is complementary to modeling

˃

No one model that can do it all

˃

Need for individuals with broad range of experience and knowledge in AQ

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Section 1- Introduction (cont)

˃

Best model is always sought

˃

Model consistency always sought which ensures AQ agencies, public have common basis

˃

Guideline provides that consistency

˃

Guideline makes recommendations

˃

Alternate models welcome but must be vetted for use

˃

Clarifications are sometimes required

˃

Done through workshops, conferences

˃

New findings always evaluated and welcome

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Sections 2-3

˃ Section 2: Overview of Model Use

 Revision provides a good guide map to clear

confusion and use consistent definitions of terms:

♦ screening technique ♦ screening model ♦ refined model

˃ Section 3: Preferred & Alternative Air Quality

Models

 Preferred models: Conditions for Appendix A models  Alternative models: Conditions and their approval  Role of Model Clearinghouse

♦ Section 3 provides the “rules of the game”

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Identifying Modeling Approaches: Section 4

˃ Section 4: Models for “inert pollutants“

 AERSCREEN as screening model (now

codified)

 AERMOD Modeling System as preferred

model (no change)

 Remove CALINE3 - AERMOD replaces CALINE3  Remove BLP and integrate into AERMOD  Multi-tiered approaches for NO2  CALPUFF removed as preferred for LRT

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Section 4 Comments on Model Accuracy in 2016-2017 Version of Guidelines

> Section 4.1.e ‐ The “irreducible” uncertainty associated with Gaussian plume models may be responsible for variation in concentrations of as much as +/‐ 50 percent. “Reducible” uncertainties can be on a similar scale.  > Section 4.1.e – Composite errors in highest estimated concentrations of 10 to 40 percent are found to be

• typical. However, estimates of concentrations paired in

time and space with observed concentrations are less

• certain. 

> Section 4.1.e – Such uncertainties do not indicate that an estimated concentration does not occur, only that the precise time and locations are in doubt. 

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Identifying Other Modeling Approaches: Section 5

˃ Section 5: Models for O3 & Secondary

PM2.5

 Sierra Club petition was the key driver  No preferred model or technique yet

♦ Goal was to offer flexibility

 Recommends two-tiered approach with

detailed guidance

♦ MERPS (Modeling Emission Rate for Precursors)

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Section 5 – Changes

˃ Entire Section 5 dedicated to secondarily formed

pollutants – Ozone and PM2.5

˃ A multi-tiered approach for single source permit

assessment

˃ Additional rulemaking/guidance required for the

approach (MERPs guidance to be discussed)

˃ Emphasis on use of chemical transport models

• nly for the less-anticipated situations

˃ S

ection focuses on importance of protocol and consulting with the reviewing authority

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Identifying Other Modeling Approaches: Section 6

˃ Section 6: Modeling for AQRVs & Other

Gov’t Programs

 No critical changes to Section 6 except that

all references to CALPUFF are removed

 AQRVs – visibility, deposition  BOEM & FAA mentioned along with model

needs

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Section 7 – General Modeling

 More streamlined than previous Guideline  Recommendations for dispersion modeling  Expanded discussion of dispersion coefficients  “Complex winds” but no CALPUFF  Deposition  GEP & plume rise  Mobile sources – very contentious in the DOT

community

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Section 8 – Model Inputs, the EPA’s “How To Manual”

8.0 Model Input Data 8.1 Modeling Domain 8.2 Source Data 8.3 Background Concentrations 8.4 Meteorology Data

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Section 8.1 Domain

˃ Specific requirements

for NAAQS or PSD increment assessments, a radius extending

 to most distant point

that is significant

 to 50 km  whichever is less!!

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Section 8.2 Source Data

˃ New language how to characterize direct

and precursor emissions for SIP demos

˃ Revised nearby source guidance – big change

 Nearby sources in Tables 8-1 and 8-2 will be

based on “actual” emissions rather than allowable

 Based on most recent 2 years at nominal

• perations

˃ Revised mobile source emission guidance

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Section 8.3 Background

˃ Discerning what

monitoring data exists

˃ Isolated versus multi-

source situations

˃ Nearby source

contributions versus background

˃ Use of monitor data to

represent other sources in modeling

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Section 8.4 Meteorology Data

˃ Introduction of prognostic meteorology data

as an option when no representative NWS data exists and it is infeasible to collect site-specific data

 Reviewing authority (typically EPA Regional

• ffice) can approve use.

˃ Introduce AERMINUTE processor into

Appendix W

˃ LowWind3 options was not included as

regulatory default in final rule

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Section 9 – Regulatory Applications More “How To Manual”

9.0 Regulatory Application

9.1 Discussion 9.2 Recommendations Protocols, design values, NAAQS, PSD increments, compliance demos

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Section 10 – References Appendix A – Preferred Models

• AERMOD
• CTDMPLUS
• Offshore and Coastal Dispersion Model
• And that is all!! No more!

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How Will Guideline Changes Affect Modeling in Ohio? Chris Beekman

Appendix W, MERPs, and AERMOD

Christopher P. Beekman Ohio EPA Division of Air Pollution Control

Revised Appendix W

• Appendix W to 40 CFR Part 51
• Proposed 7/14/2015, finalized 1/17/2017
• AERMOD 16216r incorporates changes in final

rule

• Changes to modeling and methodology

include:

» Low wind performance » Language on SILs and off‐site sources » Thorough accounting of secondary pollutants » New NOx  NO2 accounting methods

Low Wind Performance Improvement

• ADJ_U* is now a regulatory default option
• More accurate under some conditions

– OEPA has observed and quantified improved performance, or no change – Sources near to Lake Erie demonstrate mixed results

• OEPA will process met data, 2010‐2014, with

ADJ_U*

– Met data without ADJ_U* will be available by request

• LOWWIND options remain in Beta stage

10 20 30 40 50 60 10 20 30 40 50 60 Modeled Concentration (ppb) Monitor Concentration (ppb)

2013 Model vs. Monitor Comparison

No AdjU* ADJ_U* ADJ_U* and LW3

1:1 2:1 1:2 Monitor 99th Percentile 29 ppb

Tall‐stack source, highly refined hourly emissions, rural hilly terrain. Monitor 4 km distant.

10 20 30 40 50 60 70 10 20 30 40 50 60 70 Modeled Concentration (ppb) Monitor Concentration (ppb)

3‐year Design Value Model vs. Monitor Comparison

No ADJ_U* ADJ_U*

1:1 2:1 1:2 Monitor 3‐year Design Value 30.3 ppb

Tall‐stack sources, highly refined hourly emissions, rural hilly terrain. Monitor 13 km distant.

Low Wind Performance Summary

• The ADJ_U* option is not a “magic bullet”
• Only has an effect in limited circumstances
• LOWWIND options are promising, but still in beta

– Hurdle to use any LOWWIND options is very high

• OEPA now has 2 sophisticated monitoring networks

to further evaluate LOWWIND options in the future

– Cardinal Power Plant (Buckeye Power/AEP) – Gavin/Kyger (OVEC)

SIL Language in Appendix W

• Use of SILs is now a “recommendation”

instead of a requirement

• Approval of the use of SILs is left to the

permitting authority (OEPA)

• This makes any project utilizing SILs open to

third party challenges

NEW OLD

NOx/NO2 Conversion: 3 Tiers

• Tier 1: Assume NOx =

NO2

• Tier 2: ARM2
• Old ARM: 0.8 for 1‐hour,

0.75 for annual

• ARM2:
• Tier 3: PVMRM or OLM
• *At present, U.S. EPA R5 is

requesting project information (ozone data, in‐stack ratios, etc.), informal process (2/9/17)

All Tiers are now DEFAULT!*

Single‐Source Photochemical Modeling

• Appendix W solidifies that some sources will require

photochemical modeling for secondary PM2.5 and O3

• Prior to this, applicants could utilize existing data to

conduct semi‐quantitative analyses of formation

• U.S. EPA contemplates a 2‐Tier approach to PM2.5 and

O3 formation analyses

• OEPA has repeatedly stated that single‐source

photochemical modeling is not appropriate

2‐Tier Approach

Use Technically Credible Existing Information to Demonstrate Secondary Impacts are Insignificant Photochemical Transport Modeling

MERPs as a Tier 1 Tool

• Modeled Emissions Rates for Precursors
• U.S. EPA work product based on

photochemical modeling (Draft Guidance)

• MERPs describe a level of precursor emissions

that are not expected to cause a significant change in secondary O3 or PM2.5

Most conservative MERPs by region

MERPs Example: 1000 MW NGCC

• 100

Ozone : NOx + VOC PM : NOx + SO2

MERPs Example: 1000 MW NGCC

240.5 170 101.4 1,159 100 Ozone:

= 150%

• Result > 100%
• Potential for CTM
• Still may avoid
• Requires additional info

• If the first‐pass test fails, Draft Guidance has options
• Demonstrate equivalence to modeled source
• 4 hypothetical sources located in Ohio
• Possible to use linear relationship of impacts/emissions?

Precursor Area Emissions (TPY) Height State County Max Impact (ppb) NOx EUS 500 H OH Tuscarawas 1.35 NOx EUS 1000 H OH Tuscarawas 2.44 NOx EUS 3000 H OH Tuscarawas 4.99 NOx EUS 500 L OH Tuscarawas 1.36 VOC EUS 500 H OH Tuscarawas 0.17 VOC EUS 1000 H OH Tuscarawas 0.37 VOC EUS 3000 H OH Tuscarawas 1.15 VPC EUS 500 L OH Tuscarawas 0.18

MERPs Test #2

• Assume new facility is equivalent to:

– 500 TPY NOx and 500 TPY VOC source – Has a tall (H) Stack – 8‐hour O3 SIL = 1.0 ppb

• Evaluate precursors separately:

1.0

. =

VOC 1.0

. =

370 TPY 2,941 TPY

MERPs Test #2

• New facility:

– 240.5 TPY NOx – 101.4 TPY VOC

• From EPA Modeling

– 370 TPY NOx – 2,941 TPY VOC

• New facility is 65% of NOx and 3% of VOC
• Based on this demo, new source is not expected to

cause significant secondary O3 impacts

Conclusions

• Revised Appendix W helps in certain areas
• Possibility of photochemical modeling
• Will require updates to EG69
• Leg‐work to avoid photochemical modeling
• OEPA has not explored developing MERPs
• OEPA expects to continue acceptance of SILs

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What Changes May Affect Industrial Applications? David Long

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General Issues

˃ Several significant changes in the Guideline impacting

permit modeling



Strengthened protocol requirements



Drops CALPUFF as an Appendix A Model



Making all lagrangian type models Appendix B Models requiring case by case approval, except for certain specified applications



Single Source Analysis requirements for Ozone and PM2.5

˃ Adds the use of prognostic meteorologic modeling data

as a source of meteorologic data to drive models such as AERMOD



The use of prognostic data must be approved by the appropriate reviewing authority for acceptability prior to its use

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General Issues

˃ Incomplete modeling procedures laid out

 Single source Ozone and PM2.5 Modeling

Guidance is unclear as to which tools should be used

 Screening emission rate (MERP) guidance is

• ut, but leaves a number of questions

 Class I Modeling is going to be much more

contentious if over 50 km from the source

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Impacts on Permit Modeling

˃ Approved AERMOD options which may serve to reduce

model conservativeness

˃ Background development as described in the guideline

may be more conservative than past practice and removing that conservatism promises to be more difficult

˃ Time to complete permit modeling is likely to be greater



Protocols involving alternative approaches will require more interaction with both the permitting agency and USEPA prior to work beginning



Model comparison studies may be necessary during protocol development to support the model or technique proposed in the protocol



Approval process for single source ozone and PM2.5 modeling protocols will be more time consuming and the modeling has the potential to be very costly

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Impacts on Permit Modeling

˃

Modeling will potentially be less consistent instead of more consistent



Each modeling exercise has the potential to become a case-by-case modeling study quite different from those done for other similar sources



This lack of consistency will lead to greater opportunity for challenges by third parties

˃

More time consuming to conduct modeling and increased risk of challenge due to each study being more site specific and USEPA’s use of language terming various items “professional judgment to be accomplished jointly by the applicant and the appropriate reviewing authority.”



More work to prepare protocol, defend options, and usher through review

♦

Possible intervention by third parties in protocol development process?



Significantly greater cost and time required for modeling should ozone and PM2.5 modeling be required



Increased risk of modeling being challenged in permit proceeding or independently by third parties

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Impacts on Permit Modeling

˃ All of these items will serve to increase the cost

to the permittee to have the modeling performed as part of the permitting process.

˃ As it is now, getting a PSD/NSR permit is a long

complex process. Making it longer and more complex is not in the best interests of the agencies or the regulated community

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Long Range Class I Modeling

˃

EPA removed CALPUFF as the preferred model for long range Class I Modeling assessments

˃

CALPUFF as well as other Lagrangian models can be used a screening technique for addressing PSD increment beyond 50 km from a new or modifying source

˃

NO LRT assessment for NAAQS beyond 50 km will be necessary for inert pollutants

˃

USEPA seems to favor full chemical transport models for deposition and visibility impacts that are analyzed in Class I areas



The current guidance from the Federal Land Managers via the FLAG Guidance, seems to favor CALPUFF



Based on the language of the Appendix W Revisions, this would become a protocol issue that would require consultation between the source, permitting agency, USEPA, and the appropriate FLM

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Modeling for Class I PSD Increments beyond 50 km

˃ EPA recommends a screening approach in situation where

LRT assessment may be necessary for PSD increment analysis

˃ Step 1 – Determine significance of ambient impact at or

about 50 km for new/modifying source using AERMOD

˃ Step 2 – Determine appropriate screening approach using

CALPUFF (or other Lagrangian Model) to determine the significant impact at Class I area

˃ In the anticipated rare cases where a cumulative source

analysis is required beyond 50 km – use section 3.2.2 (e) to

• btain an alternate model approval

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What it means to industry?

˃ Class I area analysis will be complicated as use of CALPUFF is

• nly approved for screening

˃ Consultation and approval from EPA regional office will be

required even for the screening methodology

˃ Cumulative analysis in Class I areas beyond 50 km will need

additional resources and time as it will have to go through alternate model approval process

˃ The previously approved CALPUFF version will be used for

BART determinations despite the limitations and lack of evaluation

˃ NEPA AQRV analyses may become more difficult, time

consuming, and costly until new guidance is developed by the FLMs

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Tall Stack Applications Near Small Urban Areas

60

˃ AERMOD overpredicted tall

stack impacts near small urban areas

˃ Caused by artificial limits on

plume rise in urban boundary layer

˃ Perhaps should use rural ˃ AERMOD v16216r

formulation change to reduce this overprediction

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Summary of Model Guidance Changes Impacts on Permitting

˃ Permit applications requiring modeling are going

to have deeper protocols

˃ Should see an opportunity for industry-state

cooperation as we pool statewide resources to meet the new modeling challenges

˃ May be more pass-throughs by state agencies of

decision-making on model options to Federal EPA

˃ Could be longer delays in approval ˃ Modeling could cost more

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Questions?

George J. Schewe, CCM, QEP gschewe@trinityconsultants.com Chris Beekman christopher.beekman@epa.ohio.gov David Long, P .E. djlong@aep.com