Draft Summary of the Science and Technical

Support Work Group Meeting

May 29, 1996

Omni Hotel

Durham, North Carolina

The Science and Technical Support Work Group held its second face-to-face meeting on Wednesday, May 29, 1996 at the Omni Hotel in Durham, North Carolina. A summary of the meeting and a list of attendees follows.

Work Group Members in Attendance:

Name	Affiliation

Tom Helms	EPA

Harvey Jeffries	University of North Carolina

Diana Andrews	Kentucky

John Cabaniss	AIAM

Kirit Chaudhari	Virginia

Ellis Cowling	North Carolina State University

Jay Hudson	Santee Cooper

Dave McNeill	Utah

Tom Moore	WESTAR

S.T. Rao	New York

Mark Scruggs	National Park Service

Dan Weiss	Cinergy Corporation

Steve Ziman	Chevron Corporation

Work Group Members Not In Attendance:

Bruce Hill	Appalachian Mountain Club

Richard Paul	AAMA

Rich Poirot	Vermont

Manop Vanichchagorn	Louisiana

David Chock	Ford Motor Company

Jeff West	NARSTO

Non-Work Group Members In Attendance:

Jo Ellen Cawlfield and J.R. Arnold, University of North Carolina; Shawn Kendall, Phelps-Dodge Corp.; John Langstaff, ICF; Pradeep Saxena, EPRI; Robert Judge, EPA/Region I; Tom Diggs, EPA/Region VI; W.A. McClenney, EPA/ORD; Robin Dennis, Ken Schere, Basil Dimitriades, and Frank Binkowski, EPA/NERL; Terrence Fitzsimmons, EPA/AQTAG; William Wilson, EPA/NCEA; Jim Berry EPA/ESD; Tom Walton, EPA/ISEG; Bill Kuykendal, Neil Frank, and Rich Scheffe, EPA/EFIG; Charlene Spells EPA/IPSG; David Sanders and David Stonefield, EPA/OPSG.

Summary of the Meeting

The Science and Technical Support Work Group (STSWG) meeting began with a discussion of the Conceptual Model. Harvey Jeffries noted some of the problems with the creation of the document. The Work Group then discussed the role of the Science and Technical Support Work Group in the FACA process and the role of science in general in making environmental policy. The Work Group addressed questions that were posed by the National and Regional Strategies (NRS) and Base Programs and Policies (BPAP) Work Groups regarding issues such as monitoring and substitution.

Several presentations were made to the Work Group including: a presentation on transport by Robin Dennis; an update on the National and Regional Strategies Work Group given by Don Theiler; and an update on the BPAP Work Group given by Jerry Golden. In addition, Doug Grano participated in a discussion on the substitution of NOx for VOCs in nonattainment areas.

During this meeting, Work Group members expressed their concern over the lack of communication with the other Federal Advisory Committee Act (FACA) Subcommittee Work Groups. Subsequently, coordination with the other Work Groups was identified as a key issue. The Work Group co-chairs committed themselves to bringing this issue before the Coordination Committee of the FACA Subcommittee.

Work Group Issues/Products

Conceptual Model

Harvey Jeffries led a discussion on the development of the conceptual model. He said that the original concept for the model came from Steve Ziman. This design was later modified by Harvey Jeffries. Mr. Jeffries identified the following problems with the creation of the conceptual model:

(1)	Outline - Mr. Jeffries noted that he is unhappy with certain sections of the outline. He added that those parts will be discussed later in the afternoon.

(2)	Writing Assignments- Work Group members are writing sections 2 and 3 without seeing the precursor pieces of the document. He added that it is difficult to do this without seeing the entire document first.

Regarding the need for the Work Group and the role of science in policy making, the following were identified:

The role of the Science and Technical Support Work Group is to explain, predict, and confirm results in support of the NAAQS revisions.

The role of the scientist in the regulatory process is to explain the world in terms of the current state of science. In order for the scientist to make sure that his/her explanation of the "world" is accurate, the scientist must make a prediction and then he/she must validate this prediction. The scientist will then publish the findings. These findings will form the scientific basis for regulatory actions.

It was noted that the Work Group is not concerned with policy; however, it was added that it is not a foreign concept for science to be influenced by policy and financial decisions. Science has always been tainted by social goals and agendas; from the very beginning. Thus, the "world" must be explained and the problem solved.

Harvey Jeffries added that he did not like the term "sound science" because it promoted the idea that there is "unsound science." He explained that the models are not always accurate but that they give us an answer which we can evaluate and use to describe the state of some future world. He stated that policy cannot be based on today's information because the world will not be the same 20 years from now. The models must apply current processes to the future state and then you must evaluate the results. Mr. Jeffries said that "sound science" is thus a referral to our comfort level with our ability to predict this future state.

In addition, this Work Group must support the other Work Groups involved in the FACA process. It was noted that some of the Work Group members have misunderstood the purpose of the Conceptual Model. The purpose of the document is not to educate people involved in the FACA process. The model is to allow "us" to have enough information from which to reach a consensus on the issues and uncertainties associated with particulate matter (PM), ozone (O3 ) and regional haze (RH).

It was noted that the handouts from the first FACA meeting held on September 26, 1995 have a good deal of the data necessary to provide the information on the current state of the environment. Thus, we have at least a start in producing the Conceptual Model.

The following is Harvey Jeffries understanding of the Conceptual Model:

(1)	Describe the environmental state and the processes which change the environmental state; and,

(2)	Provide a description of the processes. Some of these processes are positive, some are negative [e.g. horizontal transport, vertical transport, emissions, deposition (wet and dry), chemical production, chemical loss, and phase change].

Mr. Jeffries commented that the following questions must be addressed: how do we use these things to evaluate the state of the future environment; how much do we know about the world? If we cannot explain the current environmental state (e.g. the current state), then we cannot expect to realistically project the future environmental state.

It was noted that using the present day observations you cannot realistically address transport and its impacts on ozone, PM and regional haze. Also, given only concentration measurements, it is impossible to explain their origins. It was added that it is not sufficient only to understand the current environmental state, you must understand process magnitudes and their relative importance. The measurements by themselves cannot get us to a prediction of the future environmental state.

Tom Moore mentioned the importance of having sufficient observational data even though it may not solve all the issues at hand. He added that observational data is important. Harvey Jeffries indicated that it is definitely a confirmation of the processes - but cannot be considered a "forecast" for the future. Steve Ziman disagreed with Mr. Jeffries statement. Mr. Jeffries responded that if we cannot explain an observation, then we cannot verify anything. It is impossible to verify a model's forecast. All models are simpler than the world which they were designed to represent. Because a model exhibits low bias in a "base case" test does not mean that it will forecast correctly for changed inputs. The real world forms the upper bound on the state of the science. The laboratory is the lower bound. The model is the bridge between these two pieces of knowledge.

Mr. Jeffries asked how do we make progress? Policy makers are going to make decisions, regardless of the science. Thus, the question for the scientist becomes, how do we play in their game? Some do choose to simply not play in the game. How do we do this, given that our science is incomplete, the observations lacking and the models not perfect? Mr. Jeffries noted the following model vindication statement:

The model is as well-formulated as any model I know and it uses inputs and assumptions more likely than any other set, and therefore, until additional information becomes available that will change the model's formulation or the inputs, it makes sense to act as if this model's forecasts are accurate.

Comments:

Steve Ziman questioned the rigidity of policy versus science.

Robin Dennis questioned the use of the term "accurate" in the above statement. He added that we should simply say that it is the best that we have now - it is not perfect, but it is the best that we have.

In response to a comment from Tom Moore, Mr. Jeffries noted that you must document your qualifiers and produce documentation to support them. He added that this is just beginning in the chemistry. It is rarely, if ever, seen in air quality simulations. Air quality personnel are not accustomed to providing this type of documentation. He continued that in general, sufficient time is not allowed to fully develop and support the individual arguments which go into these model/modeling documents.

Questions Raised from the other Work Groups:

Question 1:

How can models be used with monitoring to establish the boundaries of the areas that are not meeting NAAQS?

Comments:

What do we define as monitoring? (Ziman)

Hell will freeze over before anyone puts out additional monitors.(Andrews)

Do we have upper air data? Do we have enough surface monitors? The answer is no and it will not be happening in the future.(Ziman)

We have to remove disincentives for installing new monitors.(Helms)

The following is a suggested process for removing disincentives for monitoring:

Steve Ziman suggested that for ozone you could call certain monitors research monitors. These monitors cannot be used for compliance. An alternative is that you could weight your monitoring data, leaning more toward monitors in heavily populated regions.

Kirit Chaudhari noted that the States need money to put out additional monitors - either from EPA or State agencies.

Tom Moore stated that airshed considerations are important. What operates in one airshed may not happen the same in another region.

Harvey Jeffries added that he cannot imagine using only a model to designate nonattainment areas. If you are going to penalize someone, you had better use more than a model to do so. He asked if we can use models in terms of secondary pollutants and their designations?

Question 2:

How can models be used to locate where monitors should be located?

Comments from the Work Group:

Harvey Jeffries asked that if given a monitor shows air quality violations, can we draw suitable regions around these monitors for determining attainment/nonattainment areas?

Question 3:

How reliable are models to determine the areas where controls are needed versus the areas where the NAAQS is exceeded?

Comments from the Work Group:

Steve Ziman noted that we need more meteorology. We simply do not have enough of these types of data to put together the background picture for meteorology/climatology.

Harvey Jeffries agreed noting that the meteorology has gotten short-changed in recent years. Jay Rosenthal has provided some information, but it does need a great deal work to be completed. Robin Dennis has also been asked to make a 10-15 minute presentation on what he is doing in the Chesapeake Bay region.

Tom Moore stated that he must be missing something. He added that we know very little about fine particulates. He asked if there is anyway the models can be used to help locate the monitors? Are we simply trying to get the meteorology and the emissions right, and then we can use the models to site the monitors?

Harvey Jeffries responded that you have to make a valid argument for the use of the models. Then you have to evaluate if it makes sense to follow the intended approach.

Tom Moore noted that the NAAQS as a driving mechanism is confusing, because they generally apply to areas of dense population.

Harvey Jeffries commented that the BPAP Work Group has indicated "weak" support for population-based monitoring.

Steve Ziman added that the decision process should be based on spatial and temporal distributions of the pollutants.

Neil Frank responded that we do not have a fine particle monitoring network. The philosophy behind the new fine particle network, would be to have a network that is slanted more towards population. They would be designed to collect the most complete information, where the people are being affected. However, more recent ideas are being addressed which are population- weighted numbers, to represent a more population-based metric. This is all taking place outside of the FACA arena. These discussions are not going to directly influence the metric determination process. The decision would be based on the staff paper.

Tom Moore suggested that Question 2 is basically a non-issue for PM.

Neil Frank (EPA) responded that we need to know what the metric would be for the new standard. He added that EPA will then come-up with a new process for using modeling and monitoring results to do this.

Ken Schere noted that weighting is good, but, you must thoroughly understand the metric which is being used. There could be tremendous uncertainties associated with such a process.

Harvey Jeffries asked if this would not motivate additional monitoring?

Steve Ziman responded that is why 40 CFR 58 must be the driving force in this.

Diana Andrews stated that 40 CFR 58 is too general. She added that it simply says that you must put out 2 monitors.

Rich Scheffe added that the population weighting idea is a more tractable target - more so than chasing a peak. He noted that one, its a way of optimizing the controls - not Atlanta versus New York. Second, it is a measure of quantifying rate of progress by evaluating the changes in exposure.

Mark Scruggs commented that most of the discussion is dealing with primary emissions. He added that secondary emissions could be quite different. Mr. Scruggs noted that if you think PM is difficult, think about the regional haze problem.

Frank Binkowski (EPA) noted that people do not live in rural areas - they travel to them. Thus, he added that transportation must be factored into the problems.

Kirit Chaudhari commented that with regards to transport, why should I apply controls when the problem is coming from outside my area.

Harvey Jeffries stated that Robin Dennis' presentation will address transport.

Range of Influence of Pollutants, Robin Dennis (EPA)

Robin Dennis presented the findings of his studies which explore the range of influence or "lifetime" of the pollutants. This work has been accomplished using the Regional Acid Deposition Model (RADM) with an 80 km domain. The following are findings regarding nitrogen and sulfur species.

Mr. Dennis stated that the model results are based on a 10 year aggregation of meteorological data which was developed under the Acid Rain program and NAPAP. Basically, the 80 km model is used as a screening tool to look at the influence of pollutants in a given area. Mr. Dennis noted that after the 25% isopleth, the difference in the 20 km and the 80 km model runs are not appreciably different. Additionally, there is a considerable cost savings for these two models.

Mr. Dennis indicated that the results are biased "short" for ozone and nitrogen. He stated that the range of influence is extended further south than to the north. In addition he added that nitrogen dioxide (NO2) is not good guide for the range of influence for ozone. Mr. Dennis presented example model runs from the Pittsburgh area and the Atlanta domain. Both examples demonstrated that pollutants from these areas traveled long distances and had impacts in areas hundreds of miles from the source regions. Mr. Dennis stated that the major conclusion is that the distances associated with pollutant transport are extremely important. Further, the distribution can be segregated by mobile, area and point sources.

Comments/Discussion:

Ellis Cowling noted that the air quality management issue is an Eastern North American issue, very similar to what Tom Helms alluded to in the first FACA meeting. Mr. Cowling noted that the implications of this for the use of SIPS in addressing ozone nonattainment regions is substantial.

Robin Dennis commented that the meteorology is biasing things towards the east.

Harvey Jeffries asked what would it take to make these runs for the west?

Mr. Dennis responded that under the Models-3 project we are actually going to do this.

Tom Moore asked how terrain affects the model? Mr. Dennis responded that RADM uses the MM4 meteorology model, which takes into account the terrain. However, he added that this is not a complex terrain model. He stated that it takes a lot of resources and time to make these model runs, approximately 2 hours to run one episode on a C90.

Robin Dennis added that this is also important for monitoring and monitor placement. Thus, only focusing on the population centers is probably not a viable monitoring strategy.

Rich Scheffe stated that because of all the linkages in the chemistry, and the meteorology we may have more comfort than we originally thought.

Tom Moore asked what are the particle uses of this model? He also asked if the local factor is still important.

Mr. Dennis responded that he is working on this with Binkowski in terms of a regional particulate model (RPM) post-processor. He noted that the local effects are important because the first 25% falls-out relatively quickly.

Ken Schere asked that if it took 1000 hours on a C90 to do this work, what is Mr. Dennis' feeling on the error-bounds of this study? What is the confidence factor in your answers.

Mr. Dennis responded that the method does have it's uncertainties - the chemistry is the worst bias that I have encountered. But, overall, he thought the results were valid.

Steve Ziman commented that running MM4 without FDDA on an 80 km grid scares him. He added that another thing that must be dealt with is how to put this in perspective of most urban areas being hydrocarbon limited. I think these things are next steps in terms of the research.

Robin Dennis responded that the meteorology is very crucial. He indicated that he would never recommend running these models without FDDA.

AFTERNOON Session

Question 4:

How can a State use modeling to demonstrate equivalence of substitutions of one control measure for another in achieving progress toward air quality improvement?

Comments/Discussion:

None.

Question 5:

Is there a scientific meaning to a convertible currency for emissions trading?

Comments/Discussion:

Tom Helms introduced a memo written by Doug Grano addressing nitrogen oxides (NOx) substitution.

Steve Ziman asked why are we constrained by these options? He added that he did not think there was any room here for accommodation and that this was "old box" thinking.

Tom Helms responded that we must maintain the progress effort (i.e., we must move forward in a means that is scientifically equivalent). He added that we are simply trying to maintain air quality the best way possible.

Steve Ziman clarified his position by stating that the forcing function right now is the emissions reduction per annum. Mr. Ziman noted that the real issue is can you develop a strategy to improve air quality in the future, without these mandated emissions reductions. Thus, if you are asking if we want a substitution policy, that is not necessarily the case.

Tom Helms stated that the Work Group has been asked what makes a sensible point from the substitution viewpoint. The agency has done substitutions in the past and so we cannot simply say that substitution does not make sense. Mr. Helms commented that he believed what Mr. Ziman was asking for is a new metric; something other than tons.

Jeff West added that what is important is the reduction in ozone. The substitution makes sense if you run a model and reduce the ozone. He followed by asking why do we have to make this paper game assessment here for a substitution?

Ken Schere commented that the models are there for doing this type of analysis. If the changes were greater than what we are talking about, then we would be able to use them. However, he added that emission inventory changes on the order of 3-5% are really contained within the noise levels of the current models.

Harvey Jeffries stated that in North Carolina emission changes would be on the order of 1200 tons VOC from a source and a 500 ton exchange of NOx. A modeling effort was done, and showed an almost negligible change in the ozone (e.g. approx. 2 ppb). He asked if, given this information, are we interested in running models for this level of change?

Ken Schere responded that it is dangerous to look at models for making these level of changes. We need more than just a general understanding of these situations.

Steve Ziman added that if you have significant amounts of data (e.g. observations, models, etc.), then you can make an educated decision.

Harvey Jeffries note that there is no legal force to require a NOx source to reduce in the region, whereas, we do have that incentive for a VOC source.

Dan Weiss asked if the issue regarding substitution was only valid during the interim implementation period?

Tom Helms responded yes, but he thought that it could be folded over into the entire program.

Doug Grano commented that the policy is developed for nonattainment areas, post 1996, for NOx substitution.

Diana Andrews asked what happens when a State makes its trades and then someone upwind makes a change that destroys what they just did because of transport.

Ken Schere responded that when you focus on one individual, rather than on one group of sources, then your margin of error can become quite large.

Harvey Jeffries noted that the model is a single tool which is used to evaluate a substitution situation. It is not the only tool used to make a decision. Mr. Jeffries asked what should be done to achieve attainment?

Steve Ziman responded that it would depend on what defines the rate of progress. He added that he would evaluate what reductions make sense, but not restrict himself to simply NOx or VOC reductions. He said that he would want to look at ozone and make whatever changes are necessary to reduce ozone.

Robin Dennis noted that EPA is looking for guidelines. Ken warned us on the sole use of modeling to determine these situations. These are all guidelines for how the models could be used in making a substitution type adjustment.

Tom Moore noted that with regards to PM, there is clearly an interpretation of these two questions, which will drive the ultimate policy. A better approach, in terms of air quality improvements over time, might be a better way of phrasing this question.

S.T. Rao suggested that we must define the metric that we are going to be using to quantify improvements in air quality. Secondly, we must define the spatial extent - improvements both outside and inside the attainment area. Mr. Rao added that if we could define the variables that we need to address, then he thought we could address the substitution process.

JoEllen Cawlfield (UNC) reminded the Work Group that the fall back position is a ton for ton substitution. She continued that if we look at both space and time, then things could be different.

Dan Weiss added that there cannot be a ton for ton basis on this process, rather it must be centered on the ultimate reduction in ozone, PM or regional haze. He noted that substitution should also take into account the population exposure as well.

Jim Berry (EPA) commented that the CAA of 1977 told us to be in attainment by 1985, except for California which was to be in attainment by 1987. It still took another 5 years before we had another law. It will take a long time to get this thing through Congress. Thus, if there is a place for substitution here, then we need to include this if not, this needs to come out here as well.

Kirit Chaudhari asked if Question #4 was to be implemented before or after 1996?

Tom Helms responded that it would be following 1996. He added that we cannot reasonably expect this to happen. There are two camps dealing with this interim transition policy.

Steve Ziman noted that if a new standard is promulgated in the next year we could use models to go back and re-evaluate the results.

Conceptual Model (continued)

Harvey Jeffries commented that he is unhappy with the structure of the outline and that he wanted to spend some time in this session actually looking at the new material and discuss whose written what and who will need to write more. He noted that he would be gone for two weeks to South America and would be out of touch and unable to do too much.

Mr. Jeffries asked if perhaps, we should set up a phone conversation to discuss this next week. He added that he would like to get the revised document to the contractor by the end of June and produce a final document by the end of July.

Steve Ziman said that he preferred to have the document edited and then re-distributed. He added that everyone is frustrated by the lack of communication between us and the other Work Groups.

Tom Helms stated that he could probably arrange a session with the other groups. If everyone was in attendance however, it would be a meeting with 130 people.

Steve Ziman responded that this is his complaint. Science usually goes by the wayside. The problem is how do we educate them before they go by the wayside.

Tom Moore added that the argument could be made that the Science and Technical Support Work Group is not actually needed. However, he stated that we have this quasi-open process, where we could potentially be important.

Tom Helms responded that he thought this Work Group is very important. He added that the materials that the Work Group is developing are important and will be included in the Part 51 guidance. We will integrate this information at the Coordination Group level.

Ellis Cowling suggested that the Work Group review the five questions from the BPAP and National and Regional Strategies Work Groups. He asked if the questions could be reformulated in terms of the scientific questions that we have? Then, he noted that we can take this information to the other Work Groups which originally formulated them and see what we can do there.

Harvey Jeffries relayed that during a lunch conversation with Joe Paisie he indicated that their group is not this far along. He added that they think we are dealing with small, detailed issues (i.e., they appear to be dealing with the issues at the CAA level). There is "alienation" he added that he thought that this is an issue that must go before the Coordination Committee.

Ken Schere stated that he thought there is merit in going through the Conceptual Model. He added that it will prove itself in years to come; even if we cannot see it right now.

Rich Scheffe agreed with this. He added that we must review this information; we need patience. Mr. Scheffe asked where his reference document fits into this process.

Harvey Jeffries brought the need to target this document at the right audience. He stated that we need to write a document to target a different audience than we originally intended. He continued that the Work Group should identify at what level and to whom we are writing this document to. The Work Group should then make the necessary corrections in the document, as it currently exists.

It was suggested that John Bachmann is too far advanced to review this document, perhaps someone liked Tom Helms, a policy maker, would be the target audience.

Rich Scheffe added that he did not think that there is a target audience or target person for this document. Tom Helms noted that this document will be used to underwrite the Part 51 guidance. Harvey Jeffries commented that this document must cover a lot of issues. He noted that this document is not a state of science by any means, but, it is more than a one pager on any one issue.

Tom Moore commented that the other key issue is that we convey that this is what we currently know, but gaps do exist.

S.T. Rao stated that no one is paying any attention to this Work Group, they are marching forward, implementing policy without science. Tom Helms noted that he and Rich Scheffe will carry the Work Group comments back into the system internally. He reiterated that what the Work Group is doing today is important. It may not seem like it right now, but it will be considered in the long run. Rich Scheffe added that the Work Group can have a large impact on how EPA manages its Technical Programs. For example, the specification of a guideline model could actually become a FACA item. This is the technical group, and often times we lose sight of this.

Harvey Jeffries stated that there will be a gap while we wait for the contractors to do a better job at integrating and formatting what we currently have. There are those who would like to communicate to the BPAP Work Group in the interim. Thus, as the contractor re-does the document, if a small group could re-phrase these issues for the BPAP Work Group, then we could take the best advantage of this interim time.

Mr. Jeffries added that he and Tom Helms will bring a request for more communication with the other groups before the Coordination Committee. He added that what we need is a group to reformulate these questions while David and the contractors revise the document - this should be done by the middle of June; shooting for a final document by the end of July.

Steve Ziman, Tom Moore, and Ellis Cowling were selected to reformulate the questions.

Interaction with the National and Regional Strategies, Don Theiler

Modeling versus Monitoring Issue

Mr. Theiler presented a discussion addressing the modeling versus monitoring issue. He stated that if we are going to identify an area that is not meeting the standard we would do this with monitoring. However, we must remember that monitors are point measurements. Thus, the radius of influence for a given monitor must be evaluated. We could therefore use some type of "modeling" to locate additional monitors, which could then be used to further identify areas that do not meet the standard.

Mr. Theiler added that the only time modeling would be used to designate nonattainment would be under the above scenario when an area was "modeled" as nonattainment and there is no monitor there to verify this, and the entity in charge is unwilling (for whatever the reason) to place a monitor there.

Comments:

Steve Ziman commented that it appeared that the National and Regional Strategies Work Group is putting a lot of reliance on modeling.

Mr. Theiler responded that the Work Group wants to use modeling to identify the contiguous area that is not meeting the standard.

S.T. Rao added that it is not quite that simple to define such an area.

Mr. Theiler noted that their job is to evaluate where monitors should be placed so that air quality improvements can be made. It is not their job to address the level or form of the NAAQS.

Steve Ziman responded that we are trying to answer technical questions without having any idea about what the standard is going to be. How do you know if you will actually be making improvements if you do not know what the standard is?

Mr. Theiler responded that if you are making emissions reductions, you are cleaning up the environment. He added that you can also monitor the ambient air, and see whether any improvements in air quality are being made and you can use models to look at improvements. Harvey Jeffries noted that there has been a lot of sentiment for exposure-based standards. He asked if the National and Regional Strategies Work Group had discussed this.

Mr. Theiler responded that his Work Group had not discussed this. He asked if we are going to make the determination that we are going to provide more air quality protection for one who lives in an urban area as opposed to a rural area? He suggested that David Mobley and he should coordinate more with this Work Group on the issue of exposure-based monitoring.

Steve Ziman stated that the time to define the issue and the necessary time to frame the issue is always less than the regulatory time schedule. He asked how do we build into this process the necessary time to do an adequate job?

Mr. Theiler responded that he thought this timing could be accounted for in the phasing process of the implementation of the rules.

Interaction with the BPAP Work Group, Jerry Golden

Mr. Golden commented that substitution is the only issue related to the interim implementation policy. He stated that there should be no backsliding in air quality, however, controls must be cost effective and flexible. He added that the current CAA allows substitution if States can show that it will improve air quality.

Regarding the use of modeling to address substitution, Mr. Golden stated that if the analytical tool cannot show improvement, then the BPAP Work Group would recommend a ton for ton substitution of the same pollutant.

Mr. Golden noted that substitution is applicable during the interim implementation period only. He added that backsliding addresses everything that is in the current CAA. He explained that in order to determine if the required rate of progress is being met you would establish a glide slope that is imposed by the guidelines. Any substitution must meet this glide slope. If there is no noticeable improvement, then you have a "no-brainer" on your hands.

Comments:

It was noted that the 3% rule says absolutely nothing about "improvements in air quality."

Steve Ziman asked Mr. Golden what he meant by "improvement in air quality?"

Mr. Golden responded that in the region of interest, you must maintain the glide slope as established by the CAA and show no disincentive towards the improvement of air quality.

Ken Schere commented that the use of models to show a demonstration for air quality improvement for substitutions is not very well founded, because the changes would be lost in the noise of the models accuracy.

Mr. Golden defined the charter for the BPAP Work Group as one where they are starting with a basic requirement: to try and be as creative as we possibly can, and still make it work. He added that Robin Dennis' work is a clear indication of the merits of a broad-scale, regional approach. However, he stated that he is not responsible for this in Base Programs, and I cannot speak to this; but, that he would carry this back to the Work Group.

Harvey Jeffries asked if it is possible that a NOx/VOC substitution could potentially screw-up the PM/PM2.5 policy?

Don Theiler responded that this could affect the PM policy but the Work Group has not gotten that far in its considerations.

S.T. Rao commented that the concern is that we do not have the ability to adequately demonstrate the improvement in air quality Do we have the flexibility to not require modeling in the demonstration?

The meeting was adjourned at 5:00 pm.