Draft Summary of the Federal Advisory Committee Act (FACA)

Science and Technical Face to Face Meeting

March 20, 1996

Radisson Plaza Hotel

Alexandria, Virginia

The Science and Technical Support Work Group of the FACA Subcommittee held its first face to face meeting on Wednesday, March 20, 1996, in Alexandria, Virginia. A list of attendees and a summary of the meeting follow.

Work Group Attendees

Name	Affiliation

Tom Helms, Co-Chair	U.S. EPA

Harvey Jeffries, Co-Chair	University of North Carolina - Chapel Hill

Steve Ziman	Chevron Corporation

Diana Andrews	Kentucky

Dave McNeill	Utah

Jay Hudson	Santee-Cooper

Mark Scruggs	DOI

Rich Poirot	Vermont

Kirit Chaudhari	Virginia

S.T. Rao	New York

Tom Moore	WESTAR

Dan Weiss	Cinergy Corporation

Work Group Members Absent

Bruce Hill	Appalachian Mountain Club

Manop Vanichchagorn	Louisiana

Richard Paul	AAMA

John Cabaniss	AIAM

Non-Work Group Attendees

Shawn Kendall, Phelps Dodge Corporation; Jeffrey West, General Public Utilities; Al Furillo,

Pennsylvania Power and Light Company; John Jansen, Southern Research Corporation; John Taunton, Exxon Corporation; Lucinda Langworthy, Hunton and Williams (Utility Air Regulatory Group); Rich Scheffe, U.S. EPA/AQMG; Bruce Polkowsky and Rich Danberg, U.S. EPA/EVPG; Robin Dunkins and Charlene Spells, U.S. EPA/IPSG; Dave Sanders, U.S. EPA/OPSG.

Summary of the Meeting

Bibliography

Harvey Jeffries suggested that the Work Group develop a bibliography and list of citations to support the scientific issues it addresses. He requested input to the bibliography from meeting attendees.

Conceptual Model

Harvey Jeffries initiated the conversation on the conceptual model by noting that it is the structure for examining what is known about the state-of-science for ozone, particulate matter, and regional haze. Jeffries has taken the model from Steve Ziman and added new areas. The model now consists of only titles and subheadings; the job today is how to flesh out this framework, concentrating on what we currently understand and deciding how to treat certain issues. Jeffries acknowledged that this task is hard to do without knowing what is on policy makers' minds.

Steve Ziman defined the conceptual model as a means to understand the physical processes of the formation of ozone, particulate matter, and regional haze. Importantly, it allows one to look at air quality, meteorology, emissions, and deposition and try to understand how they affect pollutant formation and transport. The model integrates these separate factors so that one can begin to identify gaps in understanding and develop ways to fill those gaps in the future using measurements and data analysis. The conceptual model also allows one to select an appropriate model to predict episodes, and provides the ability to evaluate that model. Finally, the conceptual model provides a level of confidence that what you are proposing will have a positive impact. Ziman noted that conceptual models are being used in both the San Joaquin Valley and Gulf of Mexico studies. The conceptual model is a scientific process, not a regulatory process and thus cannot be placed on a regulatory schedule. This issue will have to be worked out with the other Work Groups.

Comments on the conceptual model and where the gaps exist included:

Are zonal and spatial influences the same for ozone and PM?

Do we have a good conceptual understanding of what PM is? What is the state of knowledge on PM? If we don't know this, what work do we have to do to go forward?

How extensive is the database on PM? Do we have monitoring networks that are adequate to evaluate the temporal and spatial scales involved?

Particulate Matter Monitoring

Mark Scruggs noted that the National Park Service and EPA have operated a network called IMPROVE that contains information on aerosols, which will be made available to the Work Group. Bruce Polkowsky added that the IMPROVE network was initially designed for monitoring visibility. It shows the regional kinds of PM on which data exist; data on individual urban kinds of PM, especially the fine fraction, are more sparse. Steve Ziman confirmed that the state of knowledge on fine particulates is poor. He also stated that you must determine the composition on the filters in order to determine control strategies. The question was asked whether there currently is a network in place to monitor fine particles.

Miscellaneous Discussion on Conceptual Model

Harvey Jeffries noted that the conceptual model is a checklist designed to explain the basis for modifying environmental policies. It is a way to provide support to other work groups. He added that EPA is following a timeline and will have a schedule for doing something with the model.

Rich Scheffe added that the conceptual model will define areas where there are overlaps for PM and ozone, and where there are areas of disconnect. He said that the word "model" is overused and he would rather use the term conceptual "picture" because of the number of physical models that are being discussed.

Rich Danburg stated that other groups will be looking to this work group to provide support for policy decisions. Harvey Jeffries responded that we are still trying to get a handle on the science, and he is not sure whether we can answer policy questions at this point.

S.T. Rao asked what the objectives of this Work Group are. Tom Helms responded that it is this Work Group's job to anticipate what other groups will be asking and to provide answers as to whether the science can or cannot support implementation programs.

Harvey Jeffries added that while this Work Group's role is to provide support to the other work groups, we must know first what their questions are. In large part, today's meeting should help define these questions. It also is the role of this Work Group to set a research agenda, which goes back to efforts such as NARSTO and SOS, which said this is important work that can and needs to be done.

Tom Helms said that from EPA's standpoint, there are mandates and schedules and we want to work wisely to meet them. Ideally the other work groups would ask their questions and then this Work Group would respond. However, given the parallel nature of the work group process, we will need to anticipate the questions of the other groups.

Bruce Polkowsky noted that the heart of the science issue is whether we have information to move forward, especially for PM. He pointed to the National Academy of Science's study of ways to protect visibility in the national parks. Their goal was to look at the state of the science and then make a determination on whether enough information was available to proceed, at least directionally, with regulations to address regional haze.

Technical Presentations

Transport - Kirit Chaudhari

Chaudhari used two air quality models to depict ozone episodes in eastern Virginia. ROM boundary conditions were used as input to the model. The first model, UAM-IV, demonstrated that ozone episodes in eastern Virginia during July 1988 were attributable to transport south from Pennsylvania and Washington, D.C. However, some of the problem was attributable to localized problems in Richmond. The episodes also showed plumes coming from the south from power plants in North Carolina. In addition, a second model, UAM-V, was used to depict air pollution episodes during this time period. This model is operated at a grid resolution of 20 km and is a five-layer model. In UAM-V, vertical space is traded for horizontal space.

Discussion:

Harvey Jeffries stated that models are not prognostic in nature, and that it is very difficult to use them for forecasting. With respect to monitors, he said that monitoring is driven by a need to measure concentrations. This is not the kind of monitoring you need to verify model results. Jeffries said that there need to be more monitors sited to confirm the models.

Bruce Polkowsky noted that PM, unlike ozone, can be tracked much more easily. If you get the particles and species correct, the global model can be used to address ozone formation.

S.T. Rao suggested that models should be used as evaluative tools rather than as methods to predict nonattainment.

Steve Ziman added that, because of the penalty for locating monitors (i.e., the information must be turned in to the regulatory agency if NAAQS are violated), States are less likely to locate monitors to confirm model predictions.

Tom Helms stated that EPA is rethinking the policy on requiring all violations, even from research monitors, to be reported. He cited Smith Mountain in Virginia as an example of one location where a research monitor was placed and a NAAQS violation occurred. The state was required to report the violation and Smith Mountain, a rural area with no industrial sources, was designated nonattainment.

Harvey Jeffries stated that monitors are necessary for control strategies and that monitoring data rather than modeling data should be used to designate nonattainment areas.

Regional Haze Issues - Tom Moore

Moore presented a historical perspective on PM-10 and a discussion of PM-fine and regional haze. Historically, there have been problems with siting PM-10 monitors. First, the composition of PM-10 is difficult to characterize. Second, PM-10 monitors were placed initially where the old TSP monitors were with seemingly little thought given as to who needed to use the PM-10 data and for what purpose. We now have an opportunity to deal with the siting criteria for PM-10 monitors. Moore noted several lessons learned:

In designing networks, we need to determine what we are trying to characterize. If health effects are the primary concern, we should consider design in terms of density and exposure, not in terms of the number of people in a geographic region.

We need to evaluate field performance and provide siting guidance for monitors to ensure uniformity and equity in determining what areas are in nonattainment.

We currently cannot have an emissions inventory with any degree of confidence. When the goal is to meet the standard, the strategy selected often does not have anything to do with getting the most effective inventory for the money spent. We need to help decision makers define a tool to make better decisions on emissions inventories.

Moore noted that things are supposed to get better with PM-2.5. This improvement will be attributable to sharp cutpoints that will sort source categories much more cleanly. There will be little if any geologic material. Also, emission reductions of PM-2.5 will result in improved health and visibility. However, Moore also noted that there are some limiting factors in defining a PM health standard when using filter mass as the indicator. These factors may include meteorology and collection procedures for samples (e.g., how an operator might interfere with samples quality). In addition, there are tradeoffs between how much is spent on monitoring and modeling. In areas other than the West, states may not be familiar with fine particle monitoring.

Moore stressed the linkages between PM-2.5 and visibility protection. PM-2.5 is the predominant cause of visibility impairment in Class I areas. It is likely that EPA's approach to developing regional haze rules will be Section 169(b) of the Clean Air Act, not the secondary standard under NAAQS. He added that he does not know how this approach will affect other programs such as PSD. To protect Class I area visibility, we will have to look at all sources, including urban population centers, industrial sources, and emissions from prescribed burning. One likely result for Class I area protection is that existing attainment areas will have to address the impact their emissions may have on Class I areas.

For the Work Group, Moore said that these issues point to the need to integrate monitoring work and emissions work for PM NAAQS and urban and regional haze. It will need to be flexible; a "one size fits all" regional approach will not work. Moore also encouraged EPA to consider changing its monitoring policy.

Additional issues Moore raised included needs to:

Collect ammonium nitrate data

Help the Base Program and Policies Work Group deal with its design data concept

Develop siting criteria

Address urban monitoring requirements

Integrate NAAQS and regional haze monitoring network designs

Evaluate representativeness of models

Gather more information on chemical mechanisms for integrating PM, ozone, and regional haze

Determine what tools we need to make public policy and air pollution control decisions: decide what we know now and what we need to know.

OTAG Issues - S.T. Rao

Rao identified some problems with the current program and the way nonattainment designations are made:

Designations are based on the fourth highest ozone concentration.

Prescriptive controls are based on the classification of a nonattainment area.

Ozone transport is not adequately defined in terms of spatial extent.

Rao also identified issues related to grid-based modeling for attainment demonstrations:

The models are usually based on episodes of high ozone concentrations, not on baseline concentrations.

There is a focus on urban rather than regional conditions; however, ozone is a regional problem, not a local one.

Modeling applications are pass/fail.

The final control strategy should produce concentrations of ozone less than or equal to 120 ppb at each grid cell in modeling domain. This approach is not an extreme value approach and serves to reduce baseline ozone concentrations, not peak ozone values.

Rao discussed the variability of ozone, noting that a measured ozone time series indicates that there are cyclical variations in ozone production, which include short-term, long-term, and seasonal variations. The various components of ozone time series data can be delineated and analyzed separately to elucidate seasonal, interannual and episodic variations in ozone concentrations.

Regional Haze - Rich Poirot

Poirot said there is a pre-existing bias that transport is important to air quality in Vermont. To gain a better understanding of the role of transport, the state of Vermont ran the Hy-Split model developed by NOAA in a backward mode to develop a trajectory. The trajectory analysis showed the following:

Over the seven years of analysis, air pollution masses affecting regional haze tended to originate from outside of Vermont and were transported into the state.

Plots showed large numbers of areas that were south of the White Mountain site in Vermont where the winds originated. These were the grids where the measured ozone values were high.

Receptor modeling techniques showed that coal combustion, industrial, and mobile sources affect regional haze in Vermont.

Ozone and PM10 Issues - Richard Scheffe

Scheffe discussed issues associated with ozone, PM-10, and fine particles. He noted that videos of PM-10 and ozone episodes in the eastern United States show the commonality of the pollutants in spatial terms. Some of these commonalities include the interdependence of the OH radical in fine particle and ozone formation; and the strong influence of water on fine particle formation, which affects PM and visibility.

Scheffe also noted that the next generation of EPA models, Models 3, will be taking the place of the current models. Models 3 will take into account the commonality of ozone and PM, and thus provide a singular modeling framework for dealing with these issues.

Fine Particulates and Haze - Glen Cass

Cass began his presentation by discussing the impact of fine particles on visibility. Studies have shown that on a smoggy day when the concentration of fine particles is much greater than on a clear day, haze is much greater. The concentration of course particles seems to have little effect on haze.

The direct measurement of organic and other secondary fine particles is difficult. However, dilution samplers circumvent measurement problems by simulating atmospheric conditions. The profiles of primary particle emissions show that only vehicular emissions are comprised of fine particles (PM-2.5). The main sources of fine particulates are combustion sources. Fugitive dust is a reduced component of fine particulates.

Cass discussed some of the models that relate particulate matter emissions to air quality, including transport/chemical reaction models and tracer models. Predictions based on transport/chemical reaction models and observed aerosol content have been shown to be somewhat different.

Cass continued his discussion by stating that we have an understanding of what causes regional haze in Los Angeles (i.e., fine particles). It is not certain whether the cause of haze in Los Angeles is the same cause of haze in other parts of the United States. There is a model that is in the research phase that hopefully will be able to identify sources of haze. This model will analyze many years worth of data for a cost of $150,000. The trajectories used for this model are for 48 hours and could be used for a regional study in the eastern United States.

Visibility - Bruce Polkowsky

Polkowsky made a video presentation depicting the differences in uniform regional haze and plume blight. He introduced the concept of "deciviews" as an alternative indicator of visibility. The deciview scale is linear and is in many respects easier to understand than other metrics, such as visual range or light extinction. A change of one deciview represents a 10 percent change in the extinction coefficient. The deciview scale is applicable regardless of baseline visibility conditions.

Polkowsky described the monitoring system that currently is run by the National Park Service to measure fine particles and visibility. Fine particle measurements are made using a four channel particle measurement system; visibility measurements are made primarily with nephelometers. There are 40 official monitoring sites and approximately 40 unofficial sites. Seasonal trends show a significant deterioration of visibility in the summer months in the eastern United States. This trend may be attributable to ammonium sulfate, which has very high concentrations in this region during the summer.

Joint Meeting Between the National and Regional Strategies Work Group and the Science and Technical Support Work Group

Summary of the Meeting

Harvey Jeffries began this session by asking the National and Regional Strategies Work Group to identify three key issues that they would like to have addressed by the Science and Technical Support Work Group. David Mobley responded for the National and Regional Strategies Work Group with the following questions:

To what extent is the fine particulate matter problem a regional vs. local problem? If it is a regional problem, what is the size of a region and how do you define a region?

Can you provide us with information regarding precursors for PM, ozone, and regional haze? Can you provide us with qualitative answers regarding the commonality of these precursors.

How sensitive are monitoring vs. modeling data to control strategy reductions?

Harvey Jeffries responded that the size of regions will be a combination of science and policy concerns.

Other topics addressed included:

Providing qualitative indicators for PM and ozone

Determining quantitative indicators that exist for PM and ozone

Determining what tools exist and what level of confidence we have in them

Seeking regulatory certainty for both the regulatory and regulated community, i.e., how can plans be made if rules are expected to change? Will there be a series of mid-course reviews?

Evening Session

Designations

The evening session began with a discussion of nonattainment designations. Tom Helms asked if there were sufficient data to support a fine particulate program. Charlene Spells noted that a regulatory monitoring method blueprint, developed by Neil Frank, was sent to CASAC for review.

Harvey Jeffries asked how you trade resources where PM mass vs. composition need to be addressed along with a number of monitoring sites.

Tom Moore noted that if we go to a fine particulate standard of PM-2.5 and it is mass-based as it exists now, western States would resist this since they know how difficult it is to comply with mass-based standards.

Harvey Jeffries then asked whether we would use a phased approach to designate nonattainment areas for PM-2.5. Neil Frank responded that to designate nonattainment areas would require analysis of three years of data collected at NAM sites. This activity would not require compositional analysis but archival review of filters at these sites, allowing for later analysis.

Tom Moore suggested that one can get locked into a timeline for attainment that will kick in after the nonattainment designation, putting pressure on developing a control strategy that may not be feasible.

Harvey Jeffries noted that EPA should take into account a cost benefit analysis for siting monitors. This would ensure getting the most information from the limited dollars currently available.

Steve Ziman asked if there are monitors that can provide an adequate measurement of fine particulate background concentrations.

Rich Scheffe noted that RADM modeling results clearly indicate a regional sulfate problem in the east. Scheffe said that transport of different species over distances does occur but other factors, such as meteorology and relative humidity, also affect concentrations.

Neil Frank suggested that we could easily deal with compiling a species profile by co-locating a PM-2.5 monitor with ozone precursor monitor from the PAMS network.

Richard Scheffe suggested that existing monitoring networks (e.g., CASNET) should be reformatted and used to compliment the urban monitors suggested by Neil Frank.

Harvey Jeffries stated that a preliminary network for measuring PM-2.5 could be in place by 1998 but that monitoring data would not be available until 1999. Jeffries noted that the Science and Technical Support Work Group would like to produce the primary points of the conceptual model, which would be supported by a large body of literature. He said that he could take a first stab at this. Rich Scheffe requested that Jeffries put together the framework and then ask for input on filling in the gaps.

Tom Helms requested that everybody provide input of some kind based on their areas of expertise and understanding to facilitate the work for Jeffries.

Harvey Jeffries identified two remaining issues: emissions data and timelines for these products. These issues will be addressed at later meetings.