Draft Summary of the Federal Advisory Committee Act (FACA)

Science and Technical Support Work Group Face-to-Face Meeting

July 22, 1996

Sheraton - Washington Hotel

Washington, DC

The Science and Technical Support Work Group (STSWG) of the FACA Subcommittee held the second Face-to-Face meeting on Monday, July 22, 1996 at the Sheraton-Washington Hotel in Washington, DC. A list of participants and a summary of the meeting follows.

Work Group Participants

Name	Affiliation

Tom Helms, Co-Chair	U.S. EPA/OAQPS/OPSG

Harvey Jeffries, Co-Chair	UNC-Chapel Hill

Diana Andrews	Kentucky

Kirit Chaudhari	Virginia

Tom Moore	WESTAR

S.T. Rao	New York

Dave McNeill	Utah

Jeffrey West	NARSTO-NE

John M. Cabaniss, Jr.	AIAM

David Chock	Ford Motor Company

Steve Ziman	Chevron Corporation

Dan Weiss	Cinergy Corporation

Mark Scruggs	DOI/NPS

Leon Outlaw (for Jay Hudson)	Santee Cooper

Jay Rosenthal	U.S. Navy

Ellis B. Cowling	NCSU

Rich Poirot	Vermont

Work Group Members Not Participating:

Manop Vanichchagorn	Louisiana

Bruce Hill	Appalachian Mountain Club

Non-Work Group Member Participants:

Pradeep Saxena, Electric Power Research Institute; Mike Teague, Hunton and Williams; Bob Judge, EPA/Region 1; John Chamberlin, EPA/OPPE; Rich Scheffe, EPA/EMAD; Bill Kuykendal, EPA/EFIG; Joe Paisie, Tom Rosendahl and Charlene Spells, EPA/IPSG; David Cole, Bill Johnson, David Sanders and Dave Stonefield, EPA/OPSG.

Meeting Summary

Tom Helms opened the meeting by thanking the Work Group members for taking the time to travel to Washington, DC for the two-day meeting. He stated that the Group would begin to finish-off several items during the course of the two days. He reminded the Work Group that it probably seemed as if we were not making a lot of progress; however, after today's meeting and tomorrow's meeting with the National and Regional Strategies Work Group (NRSWG), we will start to finish some things, and make progress toward our goal. Mr. Helms moved from his opening remarks directly into an introduction of the Science and Technical Support Work Group (STSWG) participants present at today's meeting.

Following the introduction of Harvey Jeffries, STSWG Co-Chair, Mr. Helms asked Mr. Jeffries to comment on today's agenda. Mr. Jeffries asked that the Group discuss a couple of pre-agenda issues: (1) The Conceptual Model Document; and (2) Rich Scheffe's ANPR Document. Mr. Jeffries suggested that immediately following these two brief topics, the Work Group move directly into a discussion of the Issue Papers.

Tom Helms stated that with regard to the Conceptual Model Document, the Work Group members have a set of maps which were compiled by Warren Freas (EPA/OAQPS). Mr. Helms indicated that he believed that these maps would address the current state of the environment better than the previous maps. Each of these maps is based on 15 years of data, and will be used as a substitute for some of the current maps in the document.

Mr. Helms stated that Rich Scheffe's ANPR document was scheduled to go out last week. However, Mr. Scheffe received some late, last minute comments from several Work Group members, which prohibited getting the document distributed. Mr. Helms stated that most of the issues that the Work Group will be dealing with today, could have been better dealt with, if the policy personnel had read the ANPR document prior to stating the policy. Mr. Helms urged the Work Group to reach closure/consensus on the ANPR document during the course of today's meeting, so that it could be distributed to the full FACA Subcommittee prior to next week's FACA meeting in Washington, DC.

Steve Ziman voiced concern that the cutoff for comments was close of business this past Tuesday. He stated that the comment period was over, and that the document should be distributed as is. Tom Helms acknowledged Mr. Ziman's remark, but indicated that Dan Weiss had distributed comments to both himself and Rich Scheffe. Some serious concerns were raised regarding the current version of the ANPR document. Therefore, Mr. Helms said that he held off distributing the document until the Work Group had the opportunity to discuss these concerns during today's meeting.

Mr. Ziman reiterated that we need to get this document into the Subcommittee members' hands by this Wednesday. He stated that getting it into their hands next Tuesday is of no value. He indicated that the Subcommittee members must receive the document and have the opportunity to review it prior to next Tuesday's full Subcommittee meeting. Harvey Jeffries echoed Mr. Ziman's comments. However, Mr. Jeffries cautioned the Work Group members that this did not necessarily have to be the final version of the document. He stated the important issue here was to get something containing science into the hands of the Subcommittee members, prior to next week's meeting. He stated that if necessary, the document could be reworked later and then redistributed.

Steve Ziman suggested that we have Rich Scheffe send the most recent version of the ANPR document to the Work Group either by facsimile or electronically. Mr. Ziman stated that the Work Group needed to get the most recent version of this document so that we could bring this issue to closure today. Harvey Jeffries agreed, and Rich Scheffe (via telephone) agreed to get the most recent version of the document (including Dan Weiss' comments) to Mike Teague's office by mid morning. Thus, Harvey Jeffries instructed the Work Group members that the STSWG would reach closure on the ANPR document immediately following the lunch break.

Tom Helms indicated that Warren Freas would call in around 11:00 a.m. to review the maps. In light of this, he suggested that Harvey Jeffries move to the discussion of the individual Issue Papers. Mr. Jeffries conveyed that he would allocate 10 minutes per paper, and that he would discontinue the discussion after 15 minutes.

WORK GROUP MEMBER PRESENTATIONS

Tom Moore - WESTAR

Tom Moore presented information regarding the current status of particulate matter nonattainment in the United States. This information indicated that most of the current PM nonattainment areas are in the western United States. Mr. Moore's maps indicated that some states use very large spatial boundaries to denote nonattainment areas (e.g. Utah, Montana and California), while others (e.g. Oregon and Arizona) use rather small, well-defined geographic regions to describe nonattainment areas. He indicated that wood smoke is very important in Washington and Oregon. To a lesser extent, it is also important in Montana, Arizona and California. Other fugitive sources of importance include agricultural dust and construction. He concluded by stating that the focus has been on, what are the primary coarse particles; not the secondary aerosols.

Diana Andrews said that she recently reviewed an EPA article, which stated that the Agency was not going to consider wind-blown dust as a cause for nonattainment. Ms. Andrews asked the Work Group members if this was a correct assumption. Tom Moore stated that there was going to be a natural events policy, which deals with wind-blown dust, volcanos and wild fires. Joe Paisie acknowledged that this concept does reflect a change in the Agency's current policy. Steve Ziman also commented that in the western United States most of your secondary particle events are wintertime events.

Tom Moore displayed a map showing the spatial coverage of PM-10 monitors in the west. The map depicted 198 counties (from a total of 560), which have sufficient monitoring (e.g. by the Federal Register method) data to define nonattainment. Thus, he concluded that there needed to be a good deal more monitoring data collected. Next, Mr. Moore moved to a discussion of Prescribed Burning and the potential impacts on PM-2.5 emissions. Mr. Moore's data was taken from the 1995 prescribed fire database. He noted that the heaviest hitters were Idaho, New Mexico and Arizona, which individually account for approximately 25,000 tons per year. He concluded stating if the National Park Service (NPS) could set the policy, then California would lead the western states in prescribed burning by 2040 by producing approximately 101,000 tons annually.

Tom Moore also displayed a map showing the 50-km grid inventory for the Grand Canyon Visibility Transport Commission (GCVTC). This map indicated that most of the burning currently takes place in the Northern Sierra, with very little in southern California. However, in 2040, it is projected that the majority of the burning will take place in the Los Angeles region, and the northwest portions of the state. Currently, very little burning goes on in Utah. However, by 2040, the Park Service envisions a substantial increase in the prescribed burning emissions for this region.

Harvey Jeffries questioned the coordination mechanism within the Forest Service and the EPA for prescribed burning. Tom Moore responded that the Forest Service has to burn these areas for forest/ecosystem management; however, he quickly added that there is little or no coordination between the National Park Service/United States Forest Service and the EPA. In concluding this presentation, Tom Helms asked Tom Moore to identify three things that the Work Group members should take away from this presentation. Tom Moore stated the following key objectives: (1) There are new source categories that need to be investigated; (2) Coverage is pretty poor for existing PM-10 monitoring data (only approximately one third of counties included); and, (3) Lack of information on PM-fines, because most of the attention has been focused on the coarse size fraction. Steve Ziman added that a concern of his was that time of occurrence for peak PM-fine episodes was substantially different than for PM-10.

Discussion on Rich Scheffe's ANPR Document:

At this point in the meeting, Rich Scheffe joined via telephone from Research Triangle Park, NC. Harvey Jeffries summarized the earlier discussions on the ANPR document, and stated that the Work Group was trying to reach consensus on this document today. Rich indicated that he had received a fax from Dan Weiss and that he was working on incorporating the comments into the document. Dan Weiss explained to the Work Group that he had submitted a revised version that had both textual and structural changes. The majority of the changes were needed to emphasize the local scale, and to de-emphasize the regional approach. Mr. Weiss acknowledged that in the July 12 version, Mr. Scheffe was attempting to work toward this goal; however, Mr. Weiss indicated that there were still a couple of sentences/words that need to be changed to more

accurately reflect his comments on the importance of local area control issues versus the regional approach.

Harvey Jeffries indicated that he initially had problems with Mr. Weiss' comments. Mr Jeffries indicated that he had interpreted Mr. Weiss to say that "it appeared that we should just continue as is; the current programs are working and thus we do not need to change anything". Mr. Jeffries stated that after hearing Mr. Weiss' clarification on these issues, he was okay with allowing the changes to stand. Steve Ziman reminded Mr. Jeffries that the interpretation of Mr. Weiss' comments were based solely on how you define success. Mr. Ziman stated that we have made some progress in recent years as evidenced by the reductions in the number of violations recorded in the peak concentration monitoring effort.

Harvey Jeffries responded that he believed that the local response issue, for the most part, had been unsuccessful. He stated that it was not possible to reach your goal with local programs; nor was it possible to do it solely with regional programs. Rather, what is required here is a combination of both scales for the common goal of improved air quality management. Following the above discussion, the Work Group decided to amend the document with Dan Weiss' comments, to allow for an increased emphasis on the importance of local controls, and their relative success in the recent past.

Mark Scruggs - DOI/NPS:

Mark Scruggs presented some maps, which he indicated were provided to generate some information to guide our compatriots in the other Work Groups, which may have only been treated briefly in the ANPR. Mr. Scruggs indicated that these files were available as CGM files to any member of the STSWG that was interested.

PM2.5 - Annual Average (1988-1994)

(1)	Tremendous differences in the east and west (almost a factor of 4-5 in the averages themselves); the Washington, DC area is the highest; with the exception of San Gregoria State Park, which is in southeastern California.

Steve Ziman questioned the availability of seasonal averages, because of the seasonality of PM- fines. Mark Scruggs responded that these maps had been generated; however, he did not have them with him, except for the seasonal nitrate map. Mr. Scruggs described the make-up of these particles as being 50-75% secondarily formed particles. As an example, he stated that ammonium sulfate in the eastern U.S. accounts for approximately 60% of the sulfate deposition. However, in the western U.S., the percentages are on the order of 25-30%. Mr. Scruggs stated the estimates were made from reconstructed mass, and that the importance of seasonality and episodicity was evident throughout the data set.

In summary, Mr. Scruggs provided these three points:

(1)	The data must be speciated to get reasonable results;

(2)	Successful implementation of control strategies is seasonally dependent; and,

(3)	Successful implementation of control strategies is geographically dependent.

Rich Poirot - Vermont:

Rich Poirot presented some Case Study-based research which highlighted similarities between PM and ozone levels in the east, and similarities/differences in these pollutants between the eastern and western U.S. On August 22, 1992, high levels of ozone and PM were observed in the midwestern U.S. These plumes later moved into the northeastern U.S. He stated that while there are spatial similarities, there are notable differences between the eastern and the western U.S.

Mr. Poirot also presented a movie describing the deviations from the average for a trajectory reaching Bennignton, VT at 3 am, 9 am, 3 pm and 9 pm. The trajectory calculations were made using the Nested Grid Model (NGM) wind fields. He stated that the mean ozone value is calculated daily at the monitoring. The results are based on a 7-year record, over which the mean ozone value is approximately 40-50 ppb. S.T. Rao suggested that under this approach, the mean value is changing with time. He suggested that the research would be more beneficial if a long- term mean were calculated and what was displayed was simply the deviation of that day's ozone concentration from the long-term mean. Mr. Poirot summarized by stating the research presented indicates that focusing on individual urban centers is a flawed approach to solving the overall air quality management issue.

David Chock - Ford Motor Company:

David Chock began his presentation by requesting that the Work Group members review a recent paper in the Journal of the Air and Waste Management Association, which was written by Lefohn and Altschuller. He indicated that this research was very relevant to the discussions this Work Group was engaged in. Secondly, he cautioned the Work Group on the acceptance of Robin Dennis' Regional Acid Deposition Model (RADM) modeling work. Mr. Chock stated that he had a great deal of respect for Mr. Dennis and his work; however, he was concerned about the use of the RADM model. He stated that his concern was based on the RADM's use of the Smolarkewitz advection scheme, which is very sensitive to grid size selection and the known fact that the Carbon Bond-IV chemical mechanism was not "hot enough".

Harvey Jeffries stated that Mr. Chock's latter issue was not important, because Mr. Dennis is using the RADM solver and not the standard CB-IV module. Mr. Jeffries also stated that it is the conversion of NOx to NOy which is running too rapidly, and that this assumption is based solely on comparing model predictions with aircraft data. David Chock questioned how the SAPRC90 mechanism would compare with the CB-IV mechanism. Mr. Jeffries responded that the SAPRC90 mechanism was even hotter than the CB-IV solver; however, he did say that there has not been a really good comparison of the two chemical mechanisms (e.g. CB-IV and SAPRC90). Mr. Chock concluded by stating that we should be careful in our deliberations on the use of these types of data.

Tom Helms - U.S. EPA:

Tom Helms indicated that Warren Freas (U.S. EPA) had joined the meeting via phone to discuss some maps, which had been prepared for evaluation and use by the STSWG. Warren Freas described the data contained in the maps and tables for the Work Group as follows:

Tables:

County-level data

Peak site in the county

Units are ppm

Column 1:	Design value for the current one-hour standard.

Column 2:	Alternate standard

Column 3	One-exceedance 8-hour standard (e.g. fourth highest)

Column 4:	Eight-hour 3 exceedance standard

Column 5	Five exceedance 8-hour standard

Column 6:	Average Second Max (second highest day in 1993, 1994 and 1995)

Column 7:	Average Fifth Max

Mr. Freas cautioned the Work Group members that these data only represent counties which have currently available monitoring data. S.T. Rao questioned the methodology behind computing the 8-hour average. Mr. Freas explained the calculation as follows: The 8-hour average is a daily maximum, eight hour average. Each value was computed by calculating a running eight-hour average throughout the day. Upon completion of 24 hours of data, the highest 8-hour average is chosen. Mr. Rao also questioned the issue of missing data in these averages, and Mr. Freas responded that if there was less than 75% of the data available for the year, then the data was considered missing and no value was calculated. Mr. Freas further quantified his results, stating that the analyses were restricted to the six month ozone season. This procedure allowed for approximately 600 monitors to be included in the analysis. Mr. Freas also reminded the Work Group members that the values contained in the tables were for the monitor which had the highest value for that particular standard (e.g. 8-hour, 3 exceedances, etc.) and that each value in a row could actually represent a different monitoring location.

Maps:

Warren Freas indicated that the table discussed above was the basis for the maps which we would be discussing now. Mr. Freas indicated that all of the options had initially been overlaid on a single base map. However, after photocopying and faxing was done, the options became non-distinguishable. Therefore, the approach was taken to prepare individual maps for each proposed monitoring option.

Map #1: 1-hour, 3-exceedances

Map #1 presents the number of counties which would not meet the current standard for the period 1993-1995. This approach is similar to the work of Lefohn and Altshuller.

Maps #2-4

Maps 2-4 presented three different levels for the average second maximum option. These maps indicated counties which would not meet the second average maximum value for the 0.07, 0.08 and 0.09 ppm levels, respectively. As expected, the number of counties drops off substantially as the standard is increased from 0.07 ppm to 009 ppm.

Maps #5-7

Maps 5-7 presented three different levels for the average fifth high maximum exceedance form of the standard. These maps displayed similar trends to Maps 2-4.

Harvey Jeffries - Summary of Morning Discussions:

Harvey Jeffries warned the Work Group that it is one thing to look at maps and spatial type distributions; however, the truth would lie in the actual numbers. He stated the 1993-1995 data is a little bit higher, but not substantially higher than the previous 3-year cycle. However, if we choose a 1-hour 0.07 exceedance form of the standard, no matter what the scenario, the number of nonattainment counties is going to increase substantially. The current standard being discussed (e.g. 0.08 5th highest max), would represent an approximate doubling of the number of nonattainment counties.

S.T. Rao stated that if you look at the current standard, between 1991-1993 and 1993-1995, you see some improvement in the number of nonattainment areas. However, if you look at the 0.08 standard, you see an increase in the number of nonattainment areas. Thus, an exceedance based standard is very difficult to implement and monitor progress. Mr. Jeffries agreed, stating that there are a number of places which move into and out of nonattainment over a 15-year period. He indicated that there are an incredible number of locations which have this problem. Mr. Jeffries attributed this result to the inter-annual meteorological variations, which are not properly accounted for in the current ozone analyses. Mr. Jeffries stated that some places may meet the 1-hour standard, but not meet the 8-hour standard, and thus, the "in and out of nonattainment" issue will be a problem with whatever type of standard is chosen.

S.T. Rao added that anytime you use an exceedance-type metric for your standard, you are dealing with a highly unstable metric. David Chock voiced his agreement stating that for 1988, the number of counties in violation of the standard was approximately 50%. However, based on the 3-year fifth high and second high max exceedance standards, you see an overall increase in the total number of counties in nonattainment. Steve Ziman remarked that what we should be trying to do is to reduce the underlying concentrations, and not so much the peak.

In closing the morning session, Ellis Cowling reminded the Work Group members of their charge from the FACA Subcommittee. He challenged the Work Group to stand up and be heard. Mr. Cowling indicated that science must be presented before the other Work Groups of the FACA subcommittee. He concluded by expressing that science must come first, then the National and Regional Strategies must listen to our arguments, then the Base Programs Group must develop the proper policy. He challenged the Work Group members to "get the science right", and then worry about how to educate everyone else.

Tom Helms concluded the morning session by announcing that the Agency's Green Book is available on the TTN Web Site and asked the Work Group members to obtain a copy. Any comments and/or feed back should go to Barry Gilbert. The Web Site address is as follows:

TTN Web Site

http://TTNwww.rtpnc.epa.gov

The meeting was adjourned for lunch, and was scheduled to reconvene in the afternoon.

Afternoon Session

The afternoon session was dedicated to discussion of the Issue Papers before the STSWG. The first paper discussed was "Designation Issues for the New NAAQS", which was authored by Theiler and Gerritson. Tom Moore made the presentation to Work Group members. The individual slides of the presentation are presented below, with titles in bold, and sub-topics listed subsequently.

Background Viewpoint: Current Regulatory Framework - Is it Really the (An) Old Paradigm?

-	PM-10 by nature and form is highly site specific

-	Coarse fraction exclusions - variety of sources

-	Fine fraction (PM-2.5) also can be coincident and/or concurrent with PM-10 at a given site.

-	What do we think we know now about PM2.5 from the PM-10 regulatory science experience?

Technical "Fixes" Focus on Contributing PM-10 Sources - What Does That mean?

-	Share the pain?!

-	Class-specific source category regulations of the CAA - That is, stationary sources.

-	Mobile and other area sources more "problematic" - woodstove controls successful in the West.

-	"Tragedy of the Commons" - kicks in when definable, local sources are not available.

Monitoring Data Bottom Line

Air quality remains unhealthy at the monitor

-	Scale of measurement is dimensionless at the site

-	Scale is in the eye of the beholder

-	Scale does not address frequency/marginality of violations

-	Scale is related to health exposure for the secondary PM NAAQS

Ambient Monitoring Data

-	Defines the NAAQS

-	Purpose of the Monitoring Data

-	Goals of Nonattainment Sites' Data Collection

Model Performance Issues

Spatial advantages limit point-specific accuracy, for the following reasons:

-	fundamentals of "good" modeling (in order): emissions, meteorology, chemistry, dispersion and predicted (but unknowable) air quality improvement.

Need Feedback Loop

- Monitoring drives the need for accurate/precise emissions data

- Level of effort for developing emissions and meteorology drives the model(s) selected

- Model tests

Following Mr. Moore's presentation, Steve Ziman asked the rhetorical question, how do we get to where we want to go? He emphasized that we need to get away from the idea of demonstrating attainment. He stated that emissions are important, but in some instances, it does

not pay to do emissions; for example, fugitives. He concluded his remarks by stating that PM is being simplified, when it does not deserve to be simplified at all.

Harvey Jeffries stated that he felt the paper really has only two themes. He indicated that it does not tell us anything about designating attainment, rather it is simply an argument for separating the region of the violation from the region where the controls are implemented. Mr. Jeffries indicated that he had been fairly critical of a lot of the issues contained within the paper. In concluding, Mr. Jeffries noted that these flaws are fixable, most likely by the authors taking the time to review the STSWG ANPR Science Document.

Steve Ziman again voiced his concern regarding the over simplification of the issues. Mr. Ziman stated that at some point, you simply have to stop and address some very simple issues about causation. He said that you must have a set of data, which provides for a basic set of analyses from which you can draw reasonable scientific conclusions. He reminded the Work Group members that this is not a simple issue. Harvey Jeffries contested Mr. Ziman's emphasis on monitoring, declaring that monitoring data alone could not solve the issue at hand, because a measurement has no cause and effect relationship within itself at all. Mr. Ziman responded that he was not advocating solely a monitoring program, rather he was stressing the use of monitoring data and model results.

Harvey Jeffries disagreed that a comprehensive modeling, monitoring and data analysis was necessary to support the designation process. Tom Moore and Steve Ziman indicated that such a program needed to be implemented sooner or later. Steve Ziman continued with the argument about the representativeness of a given monitor. How far from a given monitor does one have to go to reduce fugitive dust concentrations? Mr. Ziman stated that in order to answer this question you need information about the source (e.g. emissions), you need to understand the meteorology (e.g. transport) and you need to understand the monitoring site. He argued that the designation process must incorporate all of these issues. Mr. Ziman concluded that it makes absolutely no sense to designate with incomplete or incorrect information.

Harvey Jeffries questioned if the lack of information was restricted to PM-fines, or was it also relevant for ozone. Steve Ziman responded that you need area-specific measurements from which to base the designations. Mr. Ziman explained that you simply cannot make effective designations without a case-specific understanding of the processes at hand. Mr. Jeffries asked the Work Group for some feedback on the actual environmental state for PM. Mr. Ziman answered that Rich Scheffe's ANPR Science Document did a fairly good job of this. Tom Moore noted that if you are writing from the perspective of the PM-10 standard in the east versus west, then the problem is not so big. However, if you are dealing with PM-fines issues, then the area of influence is much broader. Mr. Jeffries questioned whether it was conceivable to be in attainment for PM-fines and not for PM-10, or vice versa. Both Steve Ziman and Tom Moore replied that was a definite possibility. Dave McNeill indicated that this scenario happens all the time in the western U.S. Steve Ziman stated that when the western U.S.

experiences drought conditions, the PM levels are elevated, while during relatively wet years, the material tends to wash itself out, and the PM concentrations are reduced.

At this point in the discussion, Joe Paisie, mentioned that he thought the Work Group was dealing with policy and not science. Harvey Jeffries asked Tom Moore to take a shot at responding to Mr. Paisie's statement. Tom Moore then presented the following three points, which the STSWG must deal with effectively to answer the designations issue:

(1)	Do you change to a concept of an area of influence for a monitor which is in violation?;

(2)	Does your area of violation actually represent the area which is in violation?; and,

(3)	Or, do you set a boundary which is fixed in time and space by the CAA? In reality, this approach does not work effectively.

The group concluded this discussion by agreeing that more monitoring data needed to be collected, and that some incentive needs to be provided to States to collect this information. Mr. Jeffries asked Tom Moore to summarize his presentation at this time. Mr. Moore stated that he had attempted to look at the science issues from a PM standpoint. The approach presented in the Issue Paper is similar to the current EPA process for PM-10. However, when dealing with the PM-fines, the imposed deadline is causing problems with completing the scientific process. The main point of this presentation was that there are far more complicated systems of incentives which need to be addressed here to sufficiently resolve these issues.

Following Mr. Moore's presentation, S.T. Rao presented his research, which could potentially be used for determining the spatial representativeness of monitors. Mr. Rao started by asking some basic questions:

(1)	What do you want your monitor to represent?

(2)	Area of Influence - What is the concept of airshed?

In order to answer these basic questions, Mr. Rao discussed his temporal and spatial decomposition of the ozone time series data. He stated that variations in ozone data occur for several reasons: meteorology, solar influences, climatology and emissions control practices. S.T. Rao stated the last component of his decomposition was random in time, but not in space. Thus, he has aptly named this the "noise" component. Mr. Rao noted that the ozone baseline can be accurately predicted over a range of approximately 200 miles, while the spatial scale for the synoptic forcing (including emissions) is approximately 350 miles. However, Mr. Rao noted the external forcing of the ozone system was the meteorology. Mr. Rao added that what his analysis was telling us was the following:

-	The area of violation (e.g. county-wide designations);

-	The severity of the violation; and,

-	The potential sources of the violation.

Mr. Rao stated that in terms of predicting exceedances, the maximum distance that his approach would support is approximately 10 miles. He remarked that the spatial relationship must be predictable. As an example, he discussed the Pittsburgh region, which is being influenced by the Chicago, Cincinnati and Northeast ozone plumes. Mr. Rao said this was simply an extension of the interacting scales, which Rich Scheffe has outlined in the ANPR Science Document.

Mr. Rao stated there were two sides to the approach that he was presenting. The flip side of this is that the achievability of a certain standard can be analyzed/examined by this methodology. He added that we are wrestling with the concept of AOI and AOV. He noted that if we could get the policy people to accept the concept of an "airshed", then we are on the right track. Once we are at this position, then we can use the geometric mean, to determine whether a certain threshold is attainable or not. He also stated that it is relatively easy to quantify whether an area is dirty or clean, because you are looking at it on the average.

Harvey Jeffries commented that the work of S.T. Rao was fine for ozone, but raised the question about how to deal with PM. Mr. Jeffries questioned Mr. Rao if using the baseline and the associated reductions would work sufficiently for evaluating the PM standard. Mr. Rao responded that all you get is a target, with the associated error bounds. He cautioned Mr. Jeffries that we have no crystal ball to predict what emissions reductions are necessary to reach attainment. All we can do is estimate what we feel is necessary to reduce the baseline emissions.

Tom Helms reminded the Work Group members that we needed to work toward consensus on these issues, such that we could follow Ellis Cowling's request to get science involved in the FACA process. Joe Paisie indicated that a lot of what was being discussed (with respect to S.T. Rao's research) could be addressed in Phase 2, and thus was not crucial to have it worked out right now.

Joe Paisie summarized things from a policy perspective by stating that there will always be the "10-year", "100-year" and "1000-year" floods, to borrow terminology from the water engineering approach. Thus, from an air quality perspective there will always be some implicit probability value at which you are going to violate any given standard. Therefore, we should be focused on what level of violation we are willing to tolerate. Neil Frank asked if that was the 10- year flood or the 40-year flood. Steve Ziman answered we probably wanted to deal with the more realistic "1-year" flood approach. However, Harvey Jeffries said that this latter approach would prove to be too limiting for this Group's thinking.

Steve Ziman stated that he did not agree totally with all that had been said here this afternoon. He went on to state that he believed in the concept of an airshed; however, he requested more time to study the merit of the approach developed by S.T. Rao. Harvey Jeffries said that if we keep having these type open discussions, and nothing is put down on paper to go forward to the BPAP and NRS groups, then nothing has been done to scientifically support the

FACA process. Thus, Harvey urged both S.T. Rao and Steve Ziman to put something down on paper that the STSWG members could review, and then forward to the policy groups.

Too Close to Call

Joe Paisie indicated that what BPAP was looking for from the STSWG, is basically for STSWG to approve the appropriate statistical technique for determining the "too close to call" category. Also, he indicated that were policy implications for areas that will bounce in and out of attainment that remained to be quantified and dealt with.

David Chock made a presentation, which nicely followed the work presented earlier by S.T. Rao. Mr. Chock presented statistics related to the achievability of the new ozone standard by looking at day-to-day, year-to-year and site-to-site variations. Mr. Chock asked if we could not achieve the present standard, how do we expect to achieve the new standard, given that it is expected to be even more stringent? He indicated that the achievability of the new standard is a very realistic problem. Therefore, we have generated this "too close to call" category. Mr. Chock discussed his earlier proposal of using a t-test to make this determination.

Joe Paisie asked Mr. Chock if he was proposing to add a "too close to call" classification and a statistical test for verification, which he had just stated that science could not support, or would he rather ignore the "too close to call" category all together. Mr. Chock responded that it did not matter what form of the standard you choose, you will have to deal with areas bouncing in and out of attainment.

Harvey Jeffries indicated that he did not think that there was a statistical fix for this problem, unless you account for the meteorology of the fluctuations. Joe Paisie responded that you could invent whatever statistical test you want; but, it will not solve the issue. If you want to get rid of the issue, you cannot do it statistically. Mr. Paisie then asked if the STSWG was telling him that science cannot address this issue, and that the STSWG would like to do away with it?

Tom Helms argued that the proper approach would be to develop a policy that puts the individual State on a glide slope towards achieving the standard, and as long as they are making progress you leave them alone. It becomes a goal or objective for an area to strive for. Mr. Helms concluded that the only policy he could envision would be the one of a glide slope towards better air quality management. Mr. Paisie stated that he interpreted Mr. Helms response and the Work Group's discussion to mean that the STSWG preferred a policy decision as opposed to a scientific solution. He concluded that the STSWG was telling BPAP that there was no scientific basis / justification for implementing this "too close to call" category. Essentially, the "too close to call" category would be too costly to implement for the perceived benefit. Tom Helms concluded the session by stating to Mr. Paisie that the STSWG would support a glide slope policy towards an overall improvement in air quality management. The meeting was adjourned until tomorrow's joint session with the National and Regional Strategies Work Group.