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High Level Summary of Meeting with Industry

June 1, 2012

Introduction

This summary describes ideas and thoughts expressed by industry stakeholders (IS) at the 

June 1 meeting with Environmental Protection Agency (EPA) staff regarding 

implementation of the 2010 primary 1-hour sulfur dioxide (SO2) National Ambient Air 

Quality Standard (NAAQS). While the discussion covered many topics, monitoring and 

modeling received the most attention, with the following general messages:

There was strong support for a hybrid approach which allows states flexibility to 

use monitoring or modeling to determine whether areas are meeting or not 

meeting the standard. Furthermore, a threshold should be established to prioritize 

the sources of interest. A phased monitoring approach is recommended to 

characterize air quality in areas initially designated as unclassifiable.

Only monitoring data should be used for nonattainment designations and 

characterizing air quality in unclassifiable areas. Models overpredict, while 

monitors show real data.

This summary below is organized into three broad topics consistent with the White 

Paper: monitoring, modeling, and implementation. In addition, key subtopics addressed 

are thresholds (monitoring/modeling), actual emissions (modeling), hybrid approach, 

guidance/rulemaking, and timing (implementation). A list of in-person participants is 

attached; a few additional IS representatives participated by the phone.

Limitations

Please note is a high level summary, reflecting concepts EPA heard during the meeting. It 

is not intended to be a full transcript or include all topics discussed. As EPA moves 

forward with implementation of the 2010 SO2 NAAQS, the Agency will be informed 

both by concepts contained in this summary as well as concepts not described in this 

summary. Like all of the SO2 implementation-related materials produced by EPA to date 

(e.g., the March 2011 and September 2011 guidance memoranda; the April 12, 2012 

letters to state agencies and tribal representatives; and the May 2012 White Paper) this 

summary does not constitute final or binding agency action. These materials are part of 

an overall work in progress toward developing practicable approaches to implementing 

the SO2 NAAQS that assure expeditious protection of public health. Ultimately, this 

stakeholder outreach process may lead to revised guidance or additional rulemaking. 
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Monitoring

Many IS stated support for monitoring over modeling in general because they believe that 

models over predict while monitors show real data.

Many IS stated that the next step is for EPA to issue guidance describing monitoring 

criteria for SO2. They recommend the guidance be flexible (so states can use common 

sense), clarify the number of monitors required, and consider population and 

meteorology. A few IS indicated there is also a need for monitors dedicated to tracking 

trends and to identify background concentrations.

Costs of monitoring are a key concern of the IS. One IS stated the monitoring costs were 

$50,000 per site but that operation and maintenance is not that expensive. Some IS stated 

that, compared to costs of controls, monitoring costs are dollars well spent. A few IS

noted that with network optimization and proper screening it may not be as hard as 

initially thought to deploy a sufficient network.

Who pays for monitors is also a key issue discussed. While some IS said they would be 

willing to discuss paying for new monitors, there was not a strong commitment to 

actually be willing to pay. They stated several points on this topic: EPA and other 

funding sources need to be explored; one option to consider is cost sharing; industry 

already gives the government tax dollars which the government should use to meet 

priority public health concerns; industry already pays for monitoring in many cases; and 

industry budgets also have been cut in many cases.

Many IS provided suggestions that could help optimize the SO2 monitoring network:

Relocating some monitors should be a first priority.

Recognize future controls.

Discontinue monitors showing lower levels.

Mine data already in hand.

Look at all the retired monitor data.

Use a screening model to identify sources that do not need monitors.

Shift the allocation of monitors from ozone to SO2.

Some IS felt that with proper placement, a few monitors, or even a single monitor could 

adequately characterize the air quality around a source. They noted that modeling can be 

useful in placing a monitor, but should not be the exclusive means of determining siting. 

Many IS stated there is a need for a sunset provision for monitors, the network should

change as sources change, and states should be given flexibility on implementation. Some 

IS stated that the limiting cost factor is operation and maintenance over many years. 

Some IS suggested the removal process could be supported by use of continuous 

emissions monitoring system (CEMS) data, historic data, and other pollutant monitors as 

surrogates (e.g., correlate PM and SO2 data).
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A few IS asked whether EPA is open to using data from industry-operated monitors. 

They noted that many sources already have industry-operated monitors. When these are 

considered, the burden of going to a monitoring-only approach might not be as great as 

initially thought.

Thresholds

IS made several suggestions and points regarding the concept of focusing implementation 

on sources exceeding a particular threshold:

Focus on sources over 5,000 tons per year, since it is harder for smaller facilities 

to afford monitoring; 

Establish thresholds by sector or source category;

The higher the threshold, the more likely funding will be able to be found for 

monitoring;

Consider using a population-weighted index as a factor in developing a thresholdbased approach. 

Many IS supported the threshold concept but expressed concern about implementing the 

thresholds using today’s source locations and emissions profiles, when that will be 

changing a lot over the next few years due to factors such as complying with the CrossState Air Pollution Rule and the Mercury and Air Toxics Standards, and expected source 

retirements. They stated that industry is making these regulatory decisions now even 

though compliance dates are far in the future. They suggested states should have 

flexibility in this monitoring decision to site monitors based on future emissions in order 

to avoid the unnecessary deployment of monitors in places where there will not be a 

problem in the future.

Modeling

Many IS stated that models are not a substitute for monitors. They stated it would be 

inequitable to spend hundreds of millions of dollars for controls based on modeling.

Several IS provided claims to support their position, including the following:

Current models are not representative of actual air quality, whether actual or 

allowable emissions are used.

The SO2 1-hour standard is different than any other past standard in that there is 

now no room for conservatism.

One attendee stated that in an analysis where actual hourly emissions data and onsite meteorological data were used, the results from AERMOD modeling were 3 

times the monitored ambient air quality data from the same time frame.

With higher concentrations, the difference between modeling and monitoring 

results gets larger.

Models are conservative in low wind speed and downwash cases.

Models are imperfect while monitors are the truth.
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Some IS recognized that modeling may be useful in certain situations: where states and 

sources provide technical analyses showing the modeling is accurate; where modeling 

with conservative parameters, such as potential to emit, shows attainment; and to help 

site monitors. Some IS indicated that they would be willing to help states with modeling.

Some IS stated that model refinements are needed before the AERMOD model should be

used, especially with respect to low wind speeds. They stated that revisions to Appendix 

W are needed and the next version of AERMOD needs to go through public review to 

address any unintended consequences of the revisions, especially downwash.

Some IS stated that any modeling approach must recognize that there are complex multisource areas where a monitor is a more accurate and cost-effective approach.

Some IS stated that industry ideas for model improvement have not been acted on by 

EPA. They stated that EPA’s model clearinghouse is too slow. Some IS stated they want 

more interaction with EPA and more expeditious action. They noted that Electric Power 

Research Institute model improvement activities are underway and improvements will be 

posted within one week of the June 1 meeting regarding a distance applicability study for 

steady state models and an emissions variability processor.

Some IS stated that AERMOD does not fit all cases and that EPA should allow use of 

alternative models, as is the case in SIP development. They also indicated that a less 

arduous process is needed for CALPUFF and other models.

Some IS stated EPA modeling guidance is needed to clarify issues related to the 

appropriate distance for low wind speed cases, meteorological data, background 

concentrations, and start-up emissions. Other IS stated that if on-site meteorological data 

are not available, then the results would not be realistic. Some IS stated that modeling

should not include all other sources. A few IS stated the modeling should focus on base

load units, not cycling units. They indicated concern that Canadian sources could cause 

problems.

Some IS stated that EPA should consider that the probability is low that the highest

emissions would occur at the same time as worst-case meteorology, and that a person 

would be exposed to these concentrations at the location of maximum concentration.

Some IS also stated concern over modeled impacts on an island or over water, since it is 

likely no one would be exposed at that location. 

Noting concerns about the unrepresentativeness of certain meteorological data (such as 

airport meteorological data), some IS felt that any modeling approach would need to 

include provisions for on-site meteorological data collection before modeling could be 

done. Other IS noted that the cost and timing for meteorological data collection to 

support modeling may be similar to that of simply using a monitoring-only approach.
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Actual Emissions

Some IS stated that to represent current air quality, models should use actual emissions 

and actual stack heights. They asserted that the Clean Air Act (CAA) does not prohibit 

use of actual stack heights for modeling current air quality and, thus, good engineering 

practice stack heights should not be used.

Some IS stated that modeling for planning purposes (Prevention of Significant 

Deterioration and State Implementation Plans) is not the same as modeling for 

designations. They stated that including intermittent and small sources could strain the 

modeling process; e.g., auxiliary boilers with short stacks or low capacity units (< 10%).

Some IS also noted that the likelihood of a unit operating at its permit limit for 8,760

hours per year is very low. Some IS suggested that emissions variability should be 

considered in the modeling, at least for electricity generating units with CEMS data. A

few IS also noted concern regarding start-up emissions and felt EPA should consider 

ways to simplify treatment of these sources.

Implementation

Many IS stated that designations should be made based on monitoring, not modeling. 

Most of the IS who commented stated they do not agree with the section 110(a)(1) 

concept described in the White Paper (i.e. requiring near-term modeling and controls as 

necessary for sources in unclassifiable areas) because it would require SIP action in areas

where a violation had not been identified using monitoring. Some object in principle to 

addressing unmonitored areas (or even areas with clean monitors nearby) with the same 

processes as nonattainment areas would use, even if more time were provided.

Some IS stated that areas that get designated as unclassifiable for SO2 should be treated 

in a similar manner as unclassifiable areas for other NAAQS pollutants. Some IS stated 

that areas located far from sources should be designated attainment. A few IS

recommended that future action be left to state discretion and stated this approach is 

consistent with the CAA. Other IS suggested the process could include comparing similar 

source sizes across the country.

Where a problem is observed, some IS suggested the state would, at that time, start a 

process to resolve it and felt it could be done without a nonattainment designation. One 

IS described a past case where an attainment area for particulate matter later recorded 

high readings, the state and others initiated a process and study, and emissions were 

reduced such that the problem was resolved within 18 months without a nonattainment 

designation.

A few IS commented that, if a state has a mechanism such as title V, it could work as an 

option for addressing violations, though modeling alone should not be the basis for 

identifying the violation. Other IS stated that a title V permit renewal process is not the 
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appropriate place to determine whether an area meets or does not meet the standard, nor 

to create new emission reduction requirements for sources in unclassifiable areas.

Hybrid

Some IS believe that states need the flexibility which would be allowed in the hybrid 

approach. They suggest states should decide between monitoring and modeling.

Rulemaking or Guidance

The IS stated that rulemaking with a comment period is necessary for defining 

requirements to address sources in unclassifiable areas; guidance alone would be 

inadequate.

Timing 

Many of the IS stated that EPA should not rush to adopt and implement additional 

requirements for addressing unclassifiable areas. They noted that SIPs are an iterative 

process which takes time. For unclassifiable areas, some IS suggested EPA should 

consider for the SO2 program action similar to the NO2 program, which provides 

sufficient time for a phased monitoring deployment approach.

Virtually all of the IS stated that only monitoring data should be used for nonattainment

designations. They further stated that time is needed to deploy additional monitors. 

Several recommended EPA establish a phased schedule for monitoring in unclassifiable 

areas where the Agency thinks more monitoring is needed.
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ATTENDEES FOR SO2 NAAQS IMPLEMENTATION STAKEHOLDER MEETING

June 1 - Industry Representatives

Baker Jeff Total Chemical & Refinery

Bond Alex National Mining

Caiazza Roger Environmental Energy Alliance of NY

Collins Renee Luminant Power

Coughlin Patrick Duke Energy

Cromwell T. Ted NRECA

Deason Doug Downstream and Chemical SH&E

Dupuis Lenny Dominon 

Ellis Howard EnviroPlan Consulting

Feldman Howard API

Fleischmann Laura Winston & Strawn

Garrison Mark Environmental Resources ERM

Gesser Ryan Georgia Pacific

Gossett Stephen Eastman Chemical

Greco Robert We Energies

Guerra Sergio Wenck Assoc.

Hanning Joseph U.S. Steel

Hill Jonathan Trinity Consultants

Hirsch Robert Portland Cement Association

Ipanag Sylvia Guam Power Authority

Kacenjar Allen ArcelorMittal,USA

Kaufmann Robert Koch Companies Public Sector

Knipping Eladio Electric Power Research Insitiute

Kuryla Matt Baker Botts L.L.P.

Langworthy Lucinda Hunton & Williams

Lebeis Michael DTE Energy

Lee Max Koogler & Associates

Lettrich Jeff ALCOA

Ling Michael Environmental Protection Agency

Long David American Electric Power

Lucas Kyle Black & Vech

Manousos Pete First Energy Corp. Consultant

Mastro Donna EPA Region 3

McCall Colin All4 Inc.

Morrison Angela Note: Assisting Dr. Lee

Pagano Peter American Iron and Steel Institute

Page Steve Environmental Protection Agency

Paine Robert

AECOM/American Petroleum Institute/American Iron and Steel 

Institute

Pelan Michael Lafarge North America, Inc.

Pinkerton John National Council for Air and Stream Improvement, Inc.
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Raasch Clay We Energies/Trinity Consultant

Sabangan Lorina Guam Power Authority

Scarpinuto Bill Dominion

Schewe George Trinity Consultants

Shimshock John GenOn Energy

Smith Ross PotashCorp/PCS Phosphate Co. Inc.

Smith Steve Houston Regional Monitoring

Smithson Stephen

Stephens Keith Powersouth energy Cooperative

Summerhays John EPA Region 5

Walter Justin Southern Company

Warner Brian Wolverine Power Cooperative/NRECA

Wayland Chet Environmental Protection Agency

Willoughby Patrice Oxbow Carbon

Winston Cynthia Progress Energy

Wittliff Dan GDS/Consultant for East TX Electric Coop

Zavoda Rich ArcelorMittal,USA