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1 U.S. ENVIRONMENTAL PROTECT ION AGENCY 2 CLEAN AIR SCIENTIFIC ADVISORY COMMITTEE (CASAC) 3 OXIDES OF NITROGEN AND SUL FUR OXIDES 4 SECONDARY REVIEW PANEL 5 6 7 8 9 10 - - - 11 TRANSCRIPT OF PUBLIC MEETING 12 - - - 13 14 15 16 17 October 6, 2010 18 8:30 a.m. - 5:25 p. m. 19 20 Marriott at Research Tria ngle Park 4700 Guardian Driv e 21 Durham, North Carolina 28803 22 23 24 25

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1 CASAC SECONDARY REVIEW PANEL MEMBERS PRESENT: 2 Dr. Armistead (Ted) Russell 3 Dr. Anthony Maciorowski 4 Dr. Praveen Amar 5 Dr. Charles T. Driscoll, Jr. 6 Ms. Lauraine Chestnut 7 Dr. Dale Johnson 8 Dr. Myron Mitchell 9 Dr. Andrzej Bytnerowicz 10 Dr. H. Christopher Frey 11 Dr. Ellis B. Cowling 12 Mr. Richard L. Poirot 13 Dr. Kathleen Weathers 14 Dr. Rudolf Husar 15 Dr. Naresh Kumar 16 SCIENCE ADVISORY BOARD STAFF: 17 Dr. Angela Nugent, Designated F ederal Officer 18 ENVIRONMENTAL PROTECTION AGENCY STAF F: 19 Lydia Wegman, Esq. 20 Dr. Bryan Hubbell 21 Dr. Richard Scheffe 22 Dr. Tara Greaver 23 Karen Martin, Esq. 24 Dr. Jason Lynch 25 Mr. Randy Wade

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1 ENVIRONMENTAL PROTECTION AGENCY STAF F CONTINUED: 2 Leah Anderson, Esq. 3 Ms. Ginger Tenet 4 Mr. Travis Smith 5 Mr. Adam West 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

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1 DR. NUGENT: Good morning, everyone. It's 2 time to start our meeting. AndI am Angela Nugent, 3 the designated federal officer for the CASAC Oxides 4 of Nitrogen, Secondary NAAQS Pa nel. And this is a 5 public meeting of that panel. 6 CASAC is an independent fe deral advisory 7 committed chartered under the f ederal authority. 8 EPA policy require that the mee tings of the panel 9 be open to the public; that the y be announced in 10 the Federal Register; that ther e be opportunities 11 for public comment; that delibe rations of this 12 panel happen in open session, w here I, as the DFO, 13 am present. And I am delightedto say we've met 14 all those requirements for this panel. And we also 15 have -- have succeeded in helpi ng our members and 16 having our members help us meet the requirements of 17 the Federal Ethics in Governmen t Act. So, for the 18 record, everyone is in complian ce with that. 19 So my responsibilities her e at the meeting 20 involve taking minutes for the meeting. These 21 minutes will be available to th e public within 90 22 days, with approval of the chai r, within 90 days. 23 And assisting the panel in its deliberations today, 24 we have four oral commenters wh o were -- who have 25 time on the agenda and they'll be introduced this

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1 morning. We've had written comments provided by 2 the public that we provided to the members of the 3 panel. 4 And I'd like to proceed wi th the agenda to 5 introduce first Dr. Anthony Mac iorowski for his 6 welcoming remarks and Dr. Armis tead Russell, who 7 will carry out the agenda. 8 Before I do that, I'd just like to make a few 9 housekeeping remarks. We're onteleconference. 10 There are several people partic ipating by 11 teleconference and we're always concerned with the 12 audibility within the room and for people on the 13 teleconference. 14 So I think we have very go od teleconference 15 support here, but as the day pr ogresses, I think it 16 will be more and more important for us to remember 17 the mikes, because the mikes ar e what link us to 18 people listening on the phone, to make an effort to 19 use those mikes. And then for people who are on 20 the phone, I ask you please to put your phone on 21 mute so that we don't capture y our ambient noise in 22 the room in the hotel; and alsowhen you are 23 speaking to use a handset and n ot your 24 speakerphone. 25 So if anyone has problems with audibility on

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1 the phone, I ask them to send me an e-mail and I'll 2 be monitoring e-mails during th is teleconference 3 and we'll see what we can do toimprove your, you 4 know, your ability to hear us i n the room. 5 So with that, I'd like to turn it over to 6 Dr. Maciorowski. 7 DR. MACIOROWSKI: Thanks, Angela. I'll be 8 very brief. The CASAC, as you' re aware, it's 9 iterative. You all have met a number of times. My 10 major role is to thank you all for participating, 11 thank Dr. Russell for participa ting, and recognize 12 the work of the OEQPS and the o ther folks that are 13 in the room. So continue on. Thank you very much. 14 DR. RUSSELL: Thank you, T ony and Angela. And 15 first I'd like to welcome Angel a as being DFO of 16 this committee; and thank you, Kendall, I guess in 17 absentia for getting us here. 18 With that, also thank you very much to the 19 panel for all the work they've done in the last I 20 guess three weeks. And thanks for EPA for all the 21 work that they did to get us he re. 22 I mean, I thought the amou nt -- the amount of 23 revision done to the Policy Ass essment was quite 24 impressive and I still continue to really like the 25 direction we've been going, tho ugh I think the

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1 discussion here we'll see what more may need to be 2 accomplished to get us to where we want to be. 3 And with that, we have a w hole agenda, if you 4 look at it. And what I want todo is I'm going to 5 pretty much have to ride the cu rve through some of 6 it. Because I want to get to t he point where we 7 can have some fairly lively dis cussion on the 8 overall thoughts on the documen ts, where it stands 9 in terms of being able to advis e the administrator 10 and CASAC and this panel in ter ms of what -- what 11 would be the elements of the st andard, what we 12 might choose as level, you know , essentially, as 13 you go through the components o r elements of the 14 standard, how well informed we think we are. 15 And I think there is, just by reading the 16 individual member comments that we've gotten so 17 far, there is quite a bit of --there is a range of 18 comments that I see there. So I think we're going 19 to need some time to really dis cuss those and sort 20 of get a view of what -- where we want to go from 21 here and what sort of advice we can give EPA. 22 So that was -- if I start sort of pushing 23 onwards, don't be surprised. I want to make sure 24 that we do have time to complet e our task at hand. 25 One other thing is how man y people would be

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1 interested on the panel in goin g out to dinner as a 2 group this time? A couple of c hoices: One would 3 be barbecue and one would be ma ybe something else. 4 I realize barbecue may not be g reat for 5 vegetarians. So think about th at and at the break 6 we'll sort of take a poll and d ecide what to do 7 from there. 8 If anyone knows of a great place, you know, 9 Bullock's is one. I'm not sure if we did that with 10 this committee or maybe it was another committee. 11 It's a barbecue place, but I wa nted someplace where 12 we could go, actually, sort of relax, but also be 13 fairly quick because I think bynow you recognize 14 that I try to give everybody a significant amount 15 of writing assignments to do su ch that when we 16 reconvene tomorrow morning we'r e fairly far along 17 in our task and we can delibera te very efficiently 18 tomorrow. 19 So that is -- that is the plan. I guess the 20 next thing, just most of us kno w each other, but 21 also to make sure that the folk s on the phone know 22 who is here and just to reintro duce ourselves, I 23 thought we can go around the ta ble and again 24 introduce ourselves, where we'r e from, et cetera, 25 and end up with EPA and that wi ll be time for EPA

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1 to start off. Naresh. 2 DR. KUMAR: Naresh Kumar, EPRI. 3 DR. HUSAR: Rudolf Husar, Washington 4 University in St. Louis. 5 DR. WEATHERS: Kathleen We athers, Cary 6 Institute of Ecosystem Studies. 7 MR. POIROT: Richard Poiro t, Vermont 8 Department of Environmental Con servation. 9 DR. COWLING: Ellis Cowlin g, North Carolina 10 State University. 11 DR. FREY: Chris Frey, Nor th Carolina State. 12 DR. AMAR: Praveen Amar wi th NESCAUM. 13 DR. DRISCOLL: Charles Dri scoll, Syracuse 14 University. 15 MS. CHESTNUT: Lauri Chest nut, Stratus 16 Consulting. 17 DR. JOHNSON: Dale Johnson , University of 18 Nevada, Reno. 19 DR. MITCHELL: Myron Mitch ell, SUNY SF, 20 Syracuse. 21 DR. BYTNEROWICZ: Andrzej Bytnerowicz, U.S. 22 Forest Service, Pacific Southwe st Research Station 23 in Riverside, California. 24 DR. RUSSELL: Thanks. Andwith that, Lydia, 25 you want to take over, introduc e your gang?

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1 MS. WEGMAN: Sure. Ted, y ou didn't want to 2 check who is on the phone? 3 DR. RUSSELL: Sorry about that. Are there any 4 committee members on the phone? Who else is on the 5 phone? 6 DR. NUGENT: We weren't ex pecting any members 7 to participate by phone. 8 MS. WEGMAN: Good morning, everyone. Thank 9 you all very much for being her e and for the work 10 you did. We know we got the do cument to you a 11 little later than we had intend ed to. And we know 12 there was a lot to read in a sh ort period of time; 13 and we very much appreciate the effort that you all 14 made in reviewing it and gettin g your comments to 15 us in a timely way. Thank you very much, as 16 always, for all the work you di d. Thank you. 17 We have a great team here who has been working 18 on this and many of them will s peak to you during 19 the course of this meeting. Th e team has been led 20 by Bryan Hubble, Richard Scheff e, Tara Greaver have 21 been the main folks working on it. We've also had 22 help from our Office of Atmosph eric Program, Jason 23 Lynch is in the back, back ther e. Randy Wade, 24 Ginger Tenet, Karen Martin, Tra vis Smith is a new 25 member of our group, and Adam W est have all been

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1 working on it; and there are se veral other folks 2 here listed who are not actuall y here right now, 3 but it's been a big team and we very much 4 appreciate all the work that th ey have done. 5 Okay. Let's see, thank yo u. I wanted to just 6 remind some folks who may not b e as familiar with 7 the NAAQS process of how the NAAQS review process 8 does work. Many of you have se en this slide 9 before, probably most of you, b ut just to remind 10 you how it works and where we a re within it, we 11 started out with a kickoff meet ing and we developed 12 an Integrated Review Plan, whic h leads to the 13 Integrated Science Assessment, which you review. 14 You actually also review the In tegrated Review 15 Plan. 16 We've, of course, complete d the Integrated 17 Science Assessment. We also doRisk and Exposure 18 Assessment, which you've also r eviewed and that is 19 completed. We are now on the f ar right at the 20 Policy Assessment phase; and of course, you have 21 now reviewed our second draft P olicy Assessment. 22 The next step in moving to ward a standard, 23 this is a court-ordered schedul e that we have, is 24 for us to issue a final Policy Assessment and once 25 that final Policy Assessment is done, we will move

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1 forward. We will be briefing o ur EPA management 2 and developing a draft proposal which will go 3 through interagency review and then we will issue 4 it on the schedule I'll go thro ugh in a minute. 5 That proposal will be out for public comment. 6 And while it is not common, CAS AC is welcome to 7 provide public comment if it wi shes to on the 8 proposal. And then we will go through agency 9 briefings, interagency review a nd issue a final 10 standard. 11 So we are a major portion of the way through 12 this review now that we've revi ewed the second 13 draft Policy Assessment. And w e're going to be 14 moving on from here to the rule making phase. We 15 have very little flexibility intiming because this 16 is a court-ordered schedule. I think you are 17 already aware that we have rece ived one extension 18 from the litigant in this case in part because of 19 the comments you made earlier o n during this review 20 and we would not anticipate bei ng able to get any 21 further extensions at this poin t. 22 So I just want you to be a ware we are all on a 23 tight time line and that we are now heading toward 24 completion of the Policy Assess ment and the 25 rulemaking phase.

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1 So just to go over the sch edule and remind you 2 where we are. So, as I said, w e are in the process 3 of right around the middle here of your review of 4 the second draft Policy Assessment. We have the 5 public review meeting today andthe CASAC meeting 6 and we plan to issue the final Policy Assessment 7 document in December. So we wa nt to give ourselves 8 enough time to take your commen ts into account and 9 to respond to them, but we planto issue that 10 document in December. 11 Then between December and July, we will be 12 going through the drafting proc ess, first our 13 agency management, then draftin g the proposal, the 14 interagency review. We've got to get the proposed 15 rule out for signature by July 12th of next year. 16 We'll have a 90-day public comment period. 17 This is, obviously, a new approach to the 18 secondary standard. We want toallow adequate time 19 for public comment and then we plan to issue the 20 final rule March 20th. So it's a very short time 21 period between the proposed andfinal rule. So I 22 just want everyone to be aware of the schedule 23 we're on and how quickly we are moving forward from 24 here. 25 Then I wanted to talk for a moment about the

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1 elements of the standard. Ted mentioned them, but 2 just to remind everybody that w e do have four 3 elements to all the standards t hat we issue. This 4 is true for both the primary an d secondary 5 standards. The indicator is th e element of the 6 standard that defines the chemi cal species or 7 mixture that we measure in dete rmining whether an 8 area is meeting the standard. The averaging time 9 defines the period of time over which the indicator 10 is averaged. 11 The form defines the air quality statistic 12 that is to be compared to the l evel of the 13 standard. And the level, of co urse, is the 14 quantitative number that we off er as the maximum 15 amount of the air quality stati stic that is 16 permitted under the standard. And these four 17 elements work together. 18 And in this case, we have complexities 19 associated with each of these e lements, but they 20 all work together to determine how protective the 21 standard will be, the degree of protection we are 22 providing to the environment inthis case or the 23 public health in the case of th e primary standards. 24 And we appreciate there ar e complexities to 25 each element of the standard an d that it can be

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1 challenging to think about how to make them work 2 together to provide the degree of protection that 3 is appropriate, but it is to yo u that we look for 4 advice on how to think about th ese elements 5 together and how we can think a bout them working 6 together and determine what is a good range for the 7 administrator to consider as fa r as the degree of 8 protectiveness. 9 You do not have to give us one number or one 10 answer for each of these elemen ts. We just need 11 your advice on what the science can support as far 12 as a range of standards and a r ange for each of 13 these elements. So I don't wan t you to feel 14 pressed into giving us specific ity that you're not 15 comfortable with, but we are ve ry much looking for 16 your advice on the ranges for t hese things, to the 17 extent you can provide it to us . And overall this 18 will determine the level of pro tection the standard 19 achieves. And each of these el ements of the 20 standard will be defined by rul emaking when we go 21 forward with the standard itsel f. 22 Before I turn this over toBryan to walk 23 through the second draft overvi ew, I want to note 24 one other thing. This comes upquite frequently. 25 In setting the standard we do n ot take into

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1 account, we are not legally per mitted to take into 2 account cost or the feasibilityof meeting the 3 standard. Our job is to determ ine what standard is 4 requisite to protect public wel fare from known and 5 adverse -- adverse effect -- fr om known and adverse 6 effects, known and anticipated adverse effects, but 7 cost and feasibility to impleme nt the standard are 8 not something that we consider. It's not something 9 you should be considering eithe r. 10 So I just wanted to remindfolks of that since 11 that sometimes is lost in deali ng with the 12 complexity of a standard like t his. So, again, 13 thank you all. 14 DR. RUSSELL: Before we goon, actually, do we 15 have any questions for Lydia? 16 MS. WEGMAN: I'm going to sit here for a 17 minute while Bryan goes throughthe presentations. 18 DR. RUSSELL: In terms of any legal issue, she 19 is our resident lawyer. 20 MS. WEGMAN: I will note w e have someone from 21 our Office of General Counsel. Leah Anderson is 22 here to make sure I don't say a nything wrong and to 23 answer more difficult questions . 24 DR. RUSSELL: Are there an y questions from the 25 panel on this point? I was jus t wondering how does

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1 this work tie into the Clean Ai r Act with Title IV? 2 You know, do you just want to s ort of enlighten us 3 on that? 4 MS. WEGMAN: Sure. Title IV is the provisions 5 that address acid rain. And Ti tle IV contains very 6 specific requirements and reduc tions that are 7 needed. It sets up a, as I thi nk you're all well 8 aware, a Cap and Trade Program; and it does in 9 fact, you know, reduce SO2 and NO2 emissions and it 10 has been a quite successful pro gram. 11 This is a separate statuto ry requirement we 12 have to set a National Ambient Air Quality Standard 13 to protect public welfare and t o set a standard 14 that is requisite to protect pu blic welfare. It is 15 setting a level, an averaging t ime form, as we just 16 discussed, to protect public we lfare. 17 The Acid Rain Program has made good progress 18 certainly, but what we are find ing is that there 19 are still areas that are not infact receiving 20 protection that is requisite. And the standards 21 job is to determine what that i s. And it may mean 22 that more will need to be done in order to meet the 23 standard beyond what the acid r ain provisions 24 provide, as far as reductions i n SO2 and NO2, and 25 the Clean Air Act recognizes th at.

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1 And it's quite clear that the Acid Rain 2 Program is not meant as a subst itute for the 3 standard for the NAAQS. That, in fact, the NAAQS 4 continues to apply and even if that means going 5 beyond what the Acid Rain Progr am provides. 6 DR. RUSSELL: Any other qu estions. Lauri then 7 Praveen. 8 MS. CHESTNUT: Could you c larify the 9 difference between the primary and the secondary 10 standard in terms of what it --what it triggers? 11 I mean, I understand that the g oal is to be set or 12 the standard set without regardto the cost, but -- 13 MS. WEGMAN: Sure. So the primary standard of 14 course is the health-based stan dard and there is a 15 set of provisions. There are aset of provisions 16 within the Clean Air Act as to what has to be done 17 for both the primary and the se condary standards. 18 And basically once we set a sta ndard, it becomes 19 the obligation of the state to implement the 20 standard. 21 And I should have noted th at cost and 22 feasibility are very much able to be taken into 23 account by the states to develo p the implementation 24 plans that are needed to meet t hese standards. 25 Once we set a standard, th ere is what's called

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1 designations where areas are de termined to meet or 2 not meet the standard typicallybased on monitoring 3 programs that are in place, but sometimes modeling 4 can be used to help determine t hat. 5 Once areas are designated as attainment or 6 nonattainment there are differe nt requirements that 7 apply, but states have to devel op plans to help 8 bring areas that are not meetin g the standard into 9 attainment with the standard. There are also 10 various what are called infrast ructure elements of 11 state plans that have to be submitted to us for 12 any -- either a primary or seco ndary standard and 13 all of these requirements apply . 14 In the case of the primarystandard, the Clean 15 Air Act has some specific requi rements that have to 16 be met, reasonably available co ntrol technology; 17 reasonably available control me asures in the case 18 of ozone; reductions of 15 perc ent of VOC, volatile 19 organic compounds. There is aninspection and 20 maintenance requirement for ozo ne. There are a 21 whole lot of specific requireme nts related to the 22 primary standards, particularlyfor ozone. For the 23 secondary -- and there are veryspecific dates laid 24 out by which the standards must be met. 25 In the case of secondary s tandards, there are

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1 no specific dates. The statute merely says that 2 the standards must be met as ex peditiously as 3 practicable. And the statute d oes require the 4 state to submit implementation plans for the 5 secondary standards and those s tandards, just as 6 primary standards, trigger a ne w source review 7 requirements. And the states, you know, do develop 8 these plans and EPA often issue s rules to help 9 states meet those plans consist ent with our 10 authorities under the Clean Air Act. Does that 11 help answer your question? 12 DR. RUSSELL: Praveen. 13 DR. AMAR: Thank you. A quick question, the 14 connection between Title IV andwhat you just said 15 about the standard setting proc edure, and you said 16 Title IV wasn't providing requi site protection at 17 this time, but I'm just thinkin g even if it were, 18 this process still stands alone on its own? 19 MS. WEGMAN: It does. Andjust to be clear, I 20 mean, Title IV's job was not toprovide requisite 21 protection. Title IV set up th e system to reduce 22 acid rain and put in place caps and allocations and 23 requirements for sources to mee t those caps and 24 reductions. It was not designe d to provide 25 requisite protection.

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1 DR. AMAR: But hypothetica l, suppose it were, 2 that Title IV had done -- 3 MS. WEGMAN: You're right. We would still 4 need to set -- 5 DR. AMAR: We would still be here, right? 6 MS. WEGMAN: We would abso lutely still be here 7 setting a National Ambient Air Quality Standard. 8 It's an independent requirement of the law. 9 DR. RUSSELL: Ellis. 10 DR. COWLING: Lydia, what are the additional 11 Title IV requirements that must be -- I mean, the 12 cap is the obvious one. Are th ere other provisions 13 of Title IV that we all ought t o have in our minds 14 as we offer counsel and advice? 15 MS. WEGMAN: I haven't rea d Title IV recently 16 enough. Jason, do you want to speak to that? 17 DR. LYNCH: Not right now. 18 MS. WEGMAN: My best recol lection is there is 19 a cap. There are allocations f or utilities that 20 they have to meet to meet the c ap. There are 21 reporting requirements, but it' s all designed to 22 meet the cap in the acid rain p rovisions. 23 DR. COWLING: And the cont inuous submission 24 monitoring is a part of that? 25 MS. WEGMAN: Uh-huh. Moni toring provisions,

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1 monitoring and reporting provis ions are part of the 2 acid rain sections. 3 DR. COWLING: Do you thinkwe all ought to 4 reread Title IV? 5 MS. WEGMAN: You are more than welcome to read 6 Title IV. It's like the Consti tution. It's one of 7 those things that's good to rea d every now and 8 again. 9 DR. COWLING: Are there --I mean, if there 10 are additional things we ought to have in mind as 11 we -- 12 MS. WEGMAN: To be honest, Ellis, I don't 13 think you need to read Title IVto do your job here 14 today. There are separate stat utory provisions 15 related to the National Ambient Air Quality 16 Standards and those are the pro visions that we need 17 to meet in setting the standard . 18 My only point here is that there are separate 19 acid rain provisions. They go down one track and 20 we have to go the down the trac k of setting the 21 ambient air quality standard. 22 DR. COWLING: We have plen ty to do today, as 23 you said. 24 DR. RUSSELL: Thank you ve ry much. So, Bryan? 25 DR. HUBBELL: One thing, j ust a follow up on

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1 that, one way to think about it is the Acid Rain 2 Program was about emissions. I t was not about 3 environment or environmental ef fects. It's about 4 emissions. And the standards a re about setting a 5 benchmark for environmental eff ects. 6 So moving on to the new Po licy Assessment, I 7 wanted to talk a little bit abo ut the structure to 8 remind you that while we have t he same number of 9 chapters as we did last time, i t's a different 10 structure. We've moved some of the chapters 11 around, consolidated others andadded a few. 12 The first four chapters ar e the same as in the 13 first draft, covering known or anticipated 14 ecological effects in Chapter 2 ; considerations of 15 adversity to the public welfare in Chapter 3, 16 adequacy of the current standar ds in Chapter 4. 17 Chapter 5 is now the combinatio n of the previous 18 drafts, Chapters 5 and 6. We c onsolidated those 19 and tried to streamline that ba sed on the comments. 20 I'm not sure we were 100 percen t successful, but 21 we're on our way. 22 Chapter 6 is now the co-pr otection chapter. 23 Chapter 7 is the new chapter inresponse to your 24 advice to include a chapter on uncertainty, 25 variability and sensitivity. C hapter 8 is now an

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1 ambient air monitoring chapter, which consolidates 2 a lot of the monitoring discuss ions from the 3 previous draft. And then Chapt er 9 is again the 4 concluding chapter. 5 So overarching changes mad e in our second 6 draft in response to your comme nts, we did try to 7 improve consistency in the unit s used throughout 8 the document; and we did add a definitions table, a 9 master definitions table to Cha pter 1. 10 Again, there are still a r emaining few things 11 that we need to fix, but we're working towards it. 12 It's remarkable how many differ ent units are used 13 in the various different types of studies. So 14 trying to pull it all together and make sure 15 everything has been consistent has been a 16 challenge. 17 We did combine Chapter 5 a nd 6 into an 18 integrated chapter that really talks on the options 19 for the elements of the standar d. It focuses on 20 aquatic acidification. That's our new synthesis 21 point in Chapter 5. We added C hapter 7 integrating 22 discussions of uncertainty and sensitivity 23 analyses, again, related to howthey have 24 implications for the AAPI form of the standard 25 rather than just a broad discus sion of uncertainty.

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1 We added Chapter 8 on moni toring issues. We 2 did try to expand our discussio ns of the role of 3 nitrogen deposition and N-limit ed systems in a 4 number of places throughout the document. And, 5 again, we're looking for your r eactions to whether 6 we've adequately covered that. 7 And we've expanded discuss ions of the options 8 for the individual elements of the AAPI form of the 9 standard in an attempt to try t o provide more 10 specificity in how we're dealin g with certain types 11 of issues like aggregation, spa tial aggregation, 12 such as how we deal with reduce d nitrogen and so 13 forth. 14 So Chapter 2 the primary d ifferences there, 15 we've streamlined the chapter s omewhat and we 16 added, per your advice, we adde d a new table that 17 summarizes the assumptions and limitations of the 18 various ecological effects mode ls that we've used 19 in our review. 20 In Chapter 3 we have addednow a discussion of 21 decisions regarding protection of aquatic resources 22 that have been made by communit ies and NGOs and 23 states and also by the EuropeanUnion when they 24 were considering which critical loads to set for 25 protection against aquatic acid ification across the

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1 European Union. 2 We've modified a number of the figures, 3.4 3 and 3.5 were the original figur es that had the 4 Class I areas and showed NOx an d SOx deposition in 5 Class I areas. Now we've expan ded those to focus 6 in on all the various types of natural resources, 7 state and local parks and wilde rness areas as well 8 as Class I areas. 9 We've clarified how econom ics might factor 10 into determining adversity. An d, as part of that, 11 we've added an additional asses sment, monetized 12 value of acidification damages in the Adirondacks 13 using a study by Banzhaf, et al . And, again, this 14 is an attempt to match economic s to looking at the 15 changes in NOx and SOx that mig ht be expected from 16 moving from various different l evels of ANC 17 targets. So we've tried to addadditional context 18 by looking at the dollar values . 19 We've also added a number of tables that 20 summarize the evidence or infor mation that's 21 available on the values of ecos ystem services that 22 might be affected by NOx and SO x deposition. And 23 we've also tried to include a b roader context for 24 ecosystem service values and, a gain, descriptions 25 of the damages that might be du e to NOx and SOx

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1 specifically where we're able t o do so. Again, 2 there was still quite a bit of limitations of 3 what's actually available, but we tried to 4 summarize what was there better . 5 Chapter 4 the primary thin gs we did here was 6 move things around. We've move d the assessment of 7 the CMAQ performance discussionto Chapter 7 on 8 uncertainty. We've moved the m onitoring -- a lot 9 of the monitoring discussions t o Chapter 8. We 10 have added some additional plot s per your 11 recommendations looking at sulf ur and some 12 additional nitrogen plots, comp aring NOy and total 13 nitrogen, for example. And we' ve added a 14 discussion regarding nutrient e nrichment effects in 15 both managed and non-managed sy stems. Again, this 16 is an attempt to try to more ca refully discuss the 17 nitrogen role. 18 Chapter 5 is probably the -- it is the largest 19 chapter in the document and the most complex and 20 where we spent most of our effo rt. We did combine, 21 again, Chapters 5 and 6 into th is second draft 22 Chapter 5. It now includes opt ions for the 23 atmospheric indicator, the aver aging time, the 24 form, and levels of components of the form; for 25 example, the discussion of targ et ANC values and

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1 looking at percentage of ecosys tems to be covered. 2 The focus of the chapter h as now been really 3 refined to focus almost entirel y on aquatic 4 acidification, with understandi ng the co-protection 5 of other effects as presented i n Chapter 6. We 6 really have reduced our discuss ions of attempting 7 to try to think through terrest rial acidification 8 in this round of the standards. 9 Our new content includes amore complete 10 conceptual diagram outlining ea ch step to develop 11 the tradeoff curves and the AAP I. There is a large 12 reliance now on critical load m odeling, which, 13 again, we're looking for your i nput on. We have a 14 section that compares critical loads calculated 15 using steady state versus dynam ic modeling. We 16 have a section that compares th e SSWC-based 17 critical loads using two differ ent approaches for 18 calculating the preindustrial b ase cation 19 weathering. That's the F-facto r versus direct 20 MAGIC derived base cation weath ering rates. 21 We've expanded the critica l loads dataset that 22 we have. It now includes over 7,500 sites. And 23 we've worked to try to develop some methods to 24 exclude catchments in which aci dification has 25 resulted from either high organ ic acid content,

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1 acid mine drainage or naturallylow base cation 2 weathering. And this is a test , again, to focus on 3 those areas sensitive to acid d eposition and also 4 responsive or likely to be resp onsive to reductions 5 or decreases in NOx and SOx con centrations. 6 In addition, we've include d a number of 7 options for spatial aggregationof components of 8 NOy and SOx to be able to devel op a tradeoff curve 9 in AAPI equations in a regional ly aggregated way. 10 I will say that we spent alot of time on 11 developing these types of optio ns and options that 12 we're going to talk about todayare one subset of a 13 much larger set that we've cons idered. Tara has 14 got some additional informationabout why we ended 15 up going in the directions we h ave gone. You know, 16 this is probably the most chall enging aspect of 17 what we've been working on is h ow do you develop 18 something that is nationally re presentative in 19 scope to be a national standard , but allows for 20 this understanding of the diffe rences in 21 sensitivity to different waterb odies. 22 So we recognize that this is in some ways a 23 very subjective part of the ana lysis, but it's also 24 one we've tried to develop usin g the best available 25 information that we had. So we understand the

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1 challenges in trying to review this. We had a lot 2 of challenges in developing it. We need 3 conversation as to either are w e on the right 4 direction or do we need to cont inue to go back and 5 look at this more? 6 Some of the major options that we looked at 7 were starting with a sort of st rawman was to be 8 able to just say, okay, what if we chose one 9 standard for the whole country? We talked about 10 that. That was, well, a strawm an. 11 We then said, well, is the re something we can 12 do that's better than that with out getting too 13 complex? And so we tried to di vide the U.S. into 14 acid-sensitive categories and t hen spatially 15 aggregate population of critica l loads. And that's 16 the basis for selecting the tar gets that we worked 17 with. Coming up with ways to s patially average the 18 nitrogen uptake and retention t erm; and to be able 19 to spatially and temporally ave rage the reduced 20 nitrogen terms because, again, all these have to 21 match to form the standard. 22 The notorious G-dot term, which no one really 23 liked, has been removed from th e first draft and 24 has been disaggregated so that each component is 25 represented in the AAPI equatio n separately for

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1 clarity and completeness. And we also have new 2 sections that are now covering the components of 3 the AAPI equation, including sp ecifically a 4 discussion of justification for looking at various 5 target levels of ANC; and also a section, which was 6 mostly sent to you under separa te cover, hopefully 7 everybody received that additio nal set of 8 materials, that was looking at the implications of 9 selecting different percentages of waterbodies that 10 we might identify to reach the target ANC levels. 11 So hopefully everyone got that additional piece of 12 information. 13 Chapter 6, again, this is the chapter looking 14 at co-protection for other effe cts if you have a 15 standard that focuses on aquati c acidification. 16 The main addition in this chapt er was adding 17 discussions of impacts of the a quatic acidification 18 on nutrient enrichment for terr estrial nutrient 19 enrichment and aquatic nutrient enrichment and we 20 continued to have the section t hat talked about 21 terrestrial acidification as we ll. 22 Chapter 7 this is the new chapter you 23 requested, which we agreed was a major improvement 24 to pull all the uncertainty inf ormation together. 25 We have sections that are focus ed on the major

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1 areas of the standard, includin g the discussions of 2 ecosystem effects, ecosystem se rvices and benefits, 3 CMAQ modeling, the different co mponents of AAPI and 4 the critical load and ANC model ing. 5 Our focus is how uncertain ty and variability 6 might impact the standards. Th at was our intent in 7 trying to focus that way. We d id provide, again, 8 under separate cover, we provid ed a summary table 9 of key uncertainty elements to try to put them all 10 into a readily accessible and c omparable format. 11 The basic conclusion that we generally feel 12 that we have high confidence inthe major 13 components of the effects to in dicators linkages, 14 that's that overall diagram. H owever, there are 15 relatively larger uncertainties in certain 16 subcomponents that are related to where we have 17 observational gaps. For exampl e, we have no 18 measurements of dry deposition. We have less 19 information on base cation weat hering rates and a 20 number of other factors, includ ing reduced 21 nitrogen. 22 So we recognize that some of those components 23 are still highly uncertain. We need to either be 24 able to improve the characteriz ation through 25 additional monitoring and other information as we

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1 go through time, but we also ne ed to continue doing 2 evaluations for some of the mod eling components 3 that we're planning to do. 4 Chapter 8 is an attempt totry to introduce 5 important concepts related to ambient air 6 monitoring. Again, we consolid ated discussions 7 from the first draft, Chapters 4, 5 and 6. This 8 includes now discussions of the ambient air quality 9 indicators; discussions of reac tive nitrogen and 10 sulfur species; measurements th at are related to 11 the AAPI form of the standard; complementary 12 measurements, for example, meas urements of reduced 13 nitrogen; sampling frequency is sues; and a 14 discussion of monitoring method s, recognizing that 15 there is going to be a separate AAMS meeting to be 16 held in early 2011, which is a group that looks at 17 monitoring issues for CASAC. S o that will be a 18 separate meeting that we're hop ing to get scheduled 19 sometime in January or February . 20 And, finally, Chapter 9 is our initial 21 conclusions. Again, this was e xpanded from the 22 previous draft to try to includ e a discussion of 23 staff conclusions regarding opt ions for elements of 24 the standard. This includes di scussions of the 25 indicators; the averaging times ; the form; and

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1 considerations that are relevan t to selecting the 2 levels and the overall options of the standards. 3 We also added a table, aga in, sent under 4 separate cover that summarizes those options, tries 5 to talk about them relative to the issues of 6 spatial aggregation and tempora l aggregation. We 7 have also included some discuss ion of how critical 8 uncertainties might influence t he AAPI. 9 And this notes, and I'm ho ping that we can 10 clarify this and make sure that everyone 11 understands, the differences be tween the target ANC 12 and what the AAPI level would b e. And, again, this 13 is trying to highlight the impo rtance of 14 considering uncertainty and oth er factors, such as, 15 for example, the times of recov ery and those types 16 of factors in determining the o verall options for 17 the standards; as opposed to th e target ANC, which 18 is one specific element that is used to inform a 19 level of the standards. 20 And, again, we need advice on all of the 21 elements of the standard, inclu ding ranges of 22 levels and combinations of elements of the 23 standards, which is understanda bly a very difficult 24 task. But, again, as Lydia sai d, what we're not 25 necessarily looking for is spec ific values or

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1 specific this is the right answ er. 2 What we're looking for is the ability to 3 provide the Administrator with a reasonable range 4 of options for her to make an i nformed judgment 5 based on it. And that's what w e're looking to you 6 for is to help us develop those reasonable ranges 7 for the various different eleme nts of the standard 8 and also for combinations and o ptions for the 9 overall form of the standard. 10 That's it. Thank you. 11 DR. RUSSELL: Thanks, Brya n. Questions from 12 the panel for EPA at this point ? Praveen. 13 DR. AMAR: Thank you. Youmentioned the AAMS 14 meeting. What's the connectionbetween that 15 meeting and our work here? 16 DR. HUBBELL: Rich? 17 DR. SCHEFFE: It's the sub committee of CASAC. 18 And it's a specific committee t o deal with 19 monitoring issues that arise fr om a lot of the 20 NAAQS reviews. And the first - - one of the first 21 scheduled meetings for the upco ming calendar year 22 is to discuss the monitoring is sues that arise from 23 this review. In other words, t he issues that are 24 laid out in Chapter 8 in terms of moving towards 25 federal reference certificationfor NOy,

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1 particularly sulfate and so for th. That will be 2 discussed more in depth and we' ll get an 3 opportunity to get advice from experts in the 4 measurement community to suppor t, you know, the 5 following rule development. 6 DR. AMAR: I think I under stand it, but I'm 7 trying to figure out the connec tion of our output 8 and their output and how they w ill be -- 9 DR. SCHEFFE: Ted could pr obably answer that. 10 There is some overlap in certai n committees. Ted 11 is certainly on that committee, Rich Poirot. So 12 you'll have overlap in that reg ard between the two 13 committees. 14 MS. WEGMAN: I think, Rich , the AAMS provides 15 more technical advice, as Rich was saying, on the 16 subject for the federal referen ce method; and we'll 17 be folding that advice into the development of the 18 proposal. That's why we're hop ing to have the 19 meeting in January or February because whatever 20 advice we get from them we do w ant to take into 21 account in the proposal. 22 DR. HUBBELL: For example, what we're looking 23 from you is, all right, if you comment that you 24 believe the ambient indicators that we've 25 identified are appropriate, the n that information

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1 can go to the AAMS and they canhelp us determine 2 what the FNR methods might be a ppropriate to 3 actually develop measurements f or those particular 4 indicators. 5 DR. RUSSELL: Rich. 6 MR. POIROT: Bryan, could you give me some 7 sense of how the attainment/non attainment test 8 would work, the metrics by whic h an AQCR or a 9 county would be determined to b e in the attainment 10 and how would we get out of non-- you know, what 11 is actually the test? 12 DR. HUBBELL: Well, the te st in this case, 13 this is, again -- the test is n ot the measure of 14 the ANC. The test is to use th e equation, the AAPI 15 form and to plug in measured co ncentrations of NOy 16 and SO2 plus SO4, and to plug t hose into the 17 equation given the parameters t hat we specify as 18 part of the rulemaking or the methods we specify, 19 plug those in and then compare them against the 20 level of the standard, which wo uld be the level of 21 the AAPI that we determine to b e protective. 22 So, for example, if we cho se an AAPI level of 23 50 just to say, you would take the levels of NOy 24 and SOx in an appropriately mon itored area, put 25 them into the equation that's a ppropriate for that

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1 area, and you would then calcul ate a value that 2 would be compared against that level of the AAPI 3 standard. 4 MR. POIROT: So the degree or severity of 5 nonattainment would be the exte nt to which that 6 sort of combines SOx, NOx, exce eds the AAPI. 7 DR. HUBBELL: That's right . 8 MR. POIROT: It wouldn't b e 11 percent of the 9 links. 10 DR. HUBBELL: No. 11 MR. POIROT: That has noth ing to do with it. 12 DR. HUBBELL: No, that has nothing to do with 13 it. The way that our system wo rks here is that, 14 again, that percentile, the per centage of the lakes 15 that you're trying to protect, that goes into 16 determining the NOx and SOx lev els, NOy and SOx 17 levels that need to be met over an area. 18 Okay. That's why when we say it is still a 19 national center, it's not focus ed on 11 percent of 20 particular lakes in the area. It's saying for this 21 region that we've set up these parameters for, 22 given the NOx and SOx levels th at you measure, are 23 you getting to the critical loa d, essentially when 24 you map it through the depositi on, are you getting 25 to the critical load that will protect 90 percent

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1 or 85 percent of the lakes? 2 So the determination of wh at percentile of 3 lakes to protect is an up-front characterization of 4 what your target critical load is going to be. So 5 the two pieces that determine y our critical load 6 for a particular area that thengets translated 7 into an atmospheric concentrati on are the 8 percentile protection and the t arget ANC. 9 Those two things together, along with other 10 characteristics of your ecosyst em area, those two 11 things together determine what the critical load 12 is. And that determines what y our NOy and SOx and 13 concentrations will be in the a tmosphere. That's 14 what those tradeoff curves are trying to get at. 15 In fact, the tradeoff curves, a gain, are another 16 way of expressing whether or no t you attain the 17 standard. If you actually plot your observed NOy 18 and SOx levels on that tradeoff curve, if you're 19 above the tradeoff curve, then you're out of 20 attainment; if you're below, yo u're in the 21 attainment. 22 MR. POIROT: So each AQCR has its own tradeoff 23 curve? 24 DR. HUBBELL: That's right . That's right. 25 MR. POIROT: Thank you.

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1 DR. RUSSELL: Other questi ons? I'll ask, but 2 there is just one tradeoff curv e for each AQCR, 3 right? 4 DR. HUBBELL: That's corre ct. And it will be 5 based on their estimate of redu ced nitrogen that we 6 determine for them or that is d etermined through 7 their -- you know, we lay out acouple options of 8 ways of thinking through that. We're still working 9 through options for how to deal with reduced 10 nitrogen. It's based on their reduced nitrogen 11 characterization. And it's bas ed on the critical 12 loads that have been calculatedfor that overall 13 region which they -- in which t hey rely. 14 DR. RUSSELL: Any other qu estions? 15 DR. AMAR: But, to be clea r, you haven't 16 defined AQCR in this report, ha ve you? 17 DR. HUBBELL: No. And Lyd ia can correct me if 18 I'm wrong, we don't need to con sider necessarily 19 how the nonattainment area will look at this point. 20 It's really something that can be determined 21 through the implementation proc ess. 22 MS. WEGMAN: Yeah. That w ill be worked out as 23 we start thinking about -- assuming we get the 24 standards set, thinking about d esignations and how 25 to define the appropriate size of the area which

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1 should be designated nonattainment. 2 DR. RUSSELL: And just lik e now those areas 3 can go across state boundaries and everything. 4 MS. WEGMAN: Yes. We do h ave areas now. 5 DR. HUBBELL: In the case obviously when you 6 look at our maps, the focus of the maps is not 7 state boundaries or geopolitica l boundaries because 8 we're not talking about human p opulations. The 9 focus is on ecosystems, which c learly cross a 10 number of boundaries. 11 MR. POIROT: Well, I guess we'll come to this 12 discussion later, but this is k ind of the question 13 period. So understanding the i mplication of these 14 various different ways that youhave of picking 15 percentages of waterbodies to b e protected was very 16 difficult for me to grasp. And , in addition, it 17 seems like it's inherently and unavoidably a 18 somewhat arbitrary kind of a pr ocess. 19 I guess I was wondering si nce in effect what 20 we're trying to do is create th is quasi-artificial 21 ANC, which ironically is someth ing we could just go 22 to the lake and measure, is the re a way that that 23 kind of a test could actually b e applied sort of 24 retrospectively? Let's say we pick a particular 25 scheme of, you know, grouping i n the lakes and

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1 ecoregions together and so fort h and come up with 2 an answer that ends up putting an area out of 3 attainment, could the state the n go back and 4 measure the ANC in the lakes an d say, wait a 5 minute, we got it wrong, actual ly, the real 6 distribution is different than that that was 7 projected by the approach that we used? 8 I'm just wondering if ther e is a way to 9 interject some reality on the g round or in the 10 lakes in a way to make this arb itrary decision 11 somewhat less critical than it would otherwise need 12 to be? 13 DR. HUBBELL: The standard s are in our 14 five-year review cycle. And obviously as new 15 information becomes available b etween reviews that 16 information gets included in th e next review. So 17 when we set our standards now, it's based on the 18 currently available informationand the best 19 science available at that time. 20 So while it is true that s tates can go out and 21 measure and say, well, somethin g is not right here, 22 that can then be introduced in the next review 23 cycle, five-year review cycle, which given we're 24 talking about standards that ar e averaged over 25 three to five years, it's a ver y reasonable interim

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1 guide post to set, you know. 2 The other thing to recogni ze is that one of 3 the reasons why it wouldn't be appropriate to just 4 say let's go out and measure AN C is that there are 5 other factors that are changingthat can affect ANC 6 as well. What we're trying to do, in fact the way 7 we've set up the forum, is to i solate, to 8 understand how changes in NOx a nd SOx might affect 9 or are anticipated to affect AN C levels. But 10 because we can't control everyt hing else, it would 11 be inappropriate to just measur e ANC because it's 12 not the thing that we're truly targeting. We're 13 truly targeting NOx and SOx con centrations to try 14 to reduce or degrees -- I mean to increase the ANC 15 levels. 16 DR. SCHEFFE: One other th ing too, Rich, that 17 would be a great scenario if yo u could go out and 18 measure ANC and you actually sa w that you had a 19 high level of ANC. That would be a great scenario, 20 but in all likelihood you proba bly would have the 21 other scenario where because th e response time, the 22 lag time in the system that youmay be actually 23 reducing your air quality, but the lag time is 24 going to be so great to actuall y show a beneficial 25 ANC result in the water too. S o you have that

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1 consideration as well. 2 DR. HUBBELL: Within one t o two years, 3 obviously, as you go further th rough time, you'd be 4 able to see this response. Tha t's always been one 5 of the problems with trying to look at ecosystem 6 impacts in a direct way is that there is this lag 7 time. And, again, what -- you know, by using the 8 models and by using informationwe have, we can 9 judge and say, well, based on o ur best information 10 we expect that change in NOx an d SOx will 11 ultimately get us to our target critical load and 12 our target ANC level. 13 DR. RUSSELL: And last que stion, Dale, because 14 then we'll have to go to a publ ic comment, but 15 we'll have a chance to ask ques tions later. 16 DR. JOHNSON: As lag time, what is the 17 mechanism for the lag time? Is the lag time in the 18 actual emissions; is it a lag t ime in the soil 19 recovery? 20 DR. SCHEFFE: It's mostly a lag time in the 21 biogeochemical system, you know , throughout the 22 soils in the system. 23 DR. HUBBELL: Soils are ce rtainly one of the 24 reasons -- 25 DR. JOHNSON: Well, I thin k that's an issue

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1 because I think when soils acid ify in these acidic 2 environments -- 3 DR. RUSSELL: And, Dale, g et closer to your 4 mike if you could. 5 DR. JOHNSON: Sorry. I th ink when soils 6 acidify, either naturally or be cause of pollution, 7 they don't deacidify. They are not going to come 8 back unless you lime them. So this entire effect 9 of bringing up this capacity in tensity thing would 10 really stop development. And s o your lag time in 11 that case where you have interl acid (phonetic) 12 anions in an already acid soil, there is -- very 13 short, there is no lag time, mi nutes. I don't 14 think that's quite getting thro ugh. 15 DR. HUBBELL: Jason, do yo u have a response to 16 that? 17 DR. LYNCH: Dale, I mean, I don't disagree 18 with you in terms of your comme nt. If you take a 19 case study and you model the re sponse back and what 20 you can find in many systems is that once you bring 21 down the influx of acid anions, the soils that 22 we're losing say base cations o ff of an 23 exchangeable site, we'll begin to reacquire those 24 over time. And then you can th en have in a sense a 25 lag between the benefit or redu cing acid anion and

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1 what actually results within th e surface water 2 condition. 3 DR. JOHNSON: I'm not quit e sure I follow. 4 You're saying the base saturati on will increase? 5 DR. LYNCH: The base satur ation, yeah, you 6 know -- 7 DR. JOHNSON: Why would it ? Maybe this is too 8 technical for this particular p oint, but I don't 9 see why it would. 10 DR. LYNCH: In terms of improvement. I know 11 when we look at and use some of the models to do it 12 you begin to improve those cond itions for sure. 13 So, I mean, I'm happy to talk i n more detail in 14 terms of -- 15 DR. JOHNSON: Models may s ay that, but I don't 16 think that's ever been seen in reality. 17 DR. LYNCH: Okay. 18 DR. RUSSELL: Okay. And I recognize there may 19 be more questions, but it's 9:2 0 and just because 20 we have people on the line who are expecting to go 21 at about this time, we will sco och over to public 22 comment. And the order is? 23 DR. NUGENT: The first pub lic speaker is 24 Dr. Eladio Knipping from EPRI, and he has materials 25 that are just being distributedto you now. I just

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1 received before our meeting. 2 DR. RUSSELL: And I'll be keeping time. So 3 when the time comes, I'll start waving and cutting 4 you off. 5 DR. KNIPPING: Good mornin g, I'm Dr. Eladio 6 Knipping. I'm in environment s ector of the 7 Electric Power Research Institu te. EPRI is an 8 independent nonprofit organizat ion that conducts 9 research relating to the genera tion, delivery and 10 use of electricity for the bene fit of the public. 11 As the emphasis of the PADis on the 12 protection of sensitive surface waters, my comments 13 today are focused on the scienc e underlying the 14 Atmospheric Acidification Poten tial Index and the 15 result of an uncertainty analys is showing the 16 impact on SOx and NOx concentra tions required to 17 show attainment. 18 The primary concern is tha t the uncertainty 19 associated with EPA's approach to estimating 20 critical loads and mapping thos e to atmospheric 21 concentrations is so large that its use in defining 22 the requisite level of the stan dard is 23 questionable. EPA cites this u ncertainty as very 24 small. Our computations show o therwise. 25 Some of the key points con tained in our

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1 comments are as follows: Deter mination of the 2 critical deposition load is hig hly dependent upon 3 historical values of pre-indust rial base cation 4 concentration in 1850 through 1 860. Those values 5 were never measured. EPA propo ses to estimate 6 those values using hindcasting with the MAGIC model 7 or using an F-factor approach. The latter method 8 was developed for Scandinavian countries that have 9 much less diverse bedrock and s oils than in the 10 United States. 11 Testing of the MAGIC model going forward in 12 time raises doubts about its ab ility to simulate 13 from far back in the past. The EPA should consider 14 that both deposition and surfac e water data are 15 available for the last 20 to 30 years, a period 16 with decreasing SOx and NOx dep osition. This 17 period must be simulated accura tely to gain 18 confidence in the models. Onlythen can one move 19 forward in time with the models to develop approach 20 for evaluating sensitivities todeposition rather 21 than try to hindcast conditions from over 150 years 22 ago that were not measured. 23 Cation exchange is missingcompletely from the 24 processes leading to the AAPI e quation. Moreover, 25 surface water pH is largely det ermined by the

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1 fraction of precipitation that flows laterally 2 through deeper soil horizons an d cation exchange in 3 these soils. 4 In the Adirondacks, surfac e water sulfate 5 concentrations have decreased w ith decreasing SOX 6 deposition. Surface water nitr ate concentrations 7 have also decreased though to alesser degree. 8 Note the ANC increased only sli ghtly. This is 9 because the base cation concent ration being largely 10 induced by the strong acids als o decreased. Thus 11 the predicted increase in ANC b y the MAGIC model 12 did not materialize. 13 Base cation weathering inp uts play a critical 14 role in SSWC applications, but are likely to be 15 highly uncertain due to the use of hindcasting and 16 the underconstrained nature of the weathering 17 formulations used in the MAGIC model. 18 VSOx and VNOy are atmosphe ric transfer 19 functions calculated from model simulations. The 20 atmospheric model and the model configuration, such 21 as grid resolution can make a l arge difference in 22 the calculated VSOx and VNOy pa rameters. 23 With respect to the differ ence of atmospheric 24 model there is a large differen ce between CMAQ and 25 CAMAX. I would remind everyone that CAMAX is the

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1 model that EPA OAQPS has used i n developing the 2 currently proposed transport ru le. This introduces 3 uncertainty and the definition of a secondary NAAQS 4 using EPA's approach. 5 A full discussion on these topics and other 6 concerns are described in our f ull comments and 7 will be covered in the forthcom ing report to be 8 submitted before the filing dea dline. 9 At this moment I would lik e to illustrate the 10 combined impact of all these is sues on the levels 11 of a proposed standard. 12 We have conducted uncertai nty analysis using 13 EPA's equations and models by a pplying the Monte 14 Carlo technique as well as othe r methods with the 15 combination of our and EPA's es timates of 16 uncertainty in the individual t erms for an example 17 in the Adirondacks. Note that the values plotted 18 are within 1.5 standard deviati ons from the mode of 19 the probability distribution, r epresenting an 20 87 percent confidence interval. 21 These results do not inclu de the LNHx term and 22 its associated uncertainties. The results are for 23 a single lake. Multiple lakes results and results 24 in other regions with less avai lable data will have 25 wider variance and confidence l imits.

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1 By the way, I did not incl ude the uncertainty 2 in the LNHx term because this d istribution would 3 become so wide that it would re quire more than the 4 time I have allotted to actuall y walk you through 5 the steps so that you can see w hy that distribution 6 becomes so much wider. 7 In every case we found lar ge overall 8 uncertainties that compromised practical usefulness 9 of the equations and models in helping define the 10 requisite level of any standard . 11 In the proposed approach, whatever standard is 12 established will be based on hi ghly uncertain 13 methods, including under-constr ained estimates of 14 preindustrial conditions. Howe ver, the best 15 available information regardinghow surface waters 16 will respond to changes in acid ity deposition is 17 the change measured in response to decreased 18 deposition over the past two de cades. 19 Only mechanistic models th at can accurately 20 represent this observed respons e can build 21 confidence in the ability to pr edict responses to 22 future changes in deposition. Establishment of a 23 standard requires a technicallyrigorous basis and 24 must not ignore high-quality re search regarding the 25 response of surface waters to c hanges in

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1 deposition. 2 I'd be happy to explain th is more in detail if 3 you folks would like. 4 DR. RUSSELL: Thank you. Any questions for 5 Eladio at this time? Chris. 6 DR. FREY: The question onthe inputs for this 7 analysis, are the distributions of variability or 8 uncertainty use based on three- year or five-year 9 averages? 10 DR. KNIPPING: That is cov ered in the report. 11 Right now I don't have that inf ormation with me, 12 but these are -- I will note th at these 13 uncertainties are within the pa rameters that EPA 14 used in its own uncertainty ana lysis. 15 So we're not making it anybroader. We're 16 using parameters that are withi n EPA's uncertainty 17 analysis. And, again, this doe s not cover the LNHx 18 term. That would make this dis tribution so broad 19 that I would really want to hav e more time to 20 explain how each individual par ameter affects the 21 distribution. 22 DR. RUSSELL: Praveen. 23 DR. AMAR: I'm in the last statement you made 24 about not ignoring high-qualityresearch. I know 25 you said lots of things. What do you have in mind

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1 there, or maybe you already men tioned it? 2 DR. KNIPPING: It's all inthe full report 3 comments. I think that we needto look at the 4 variability of the air quality models. We need to 5 include information regarding e cosystems impacts. 6 There was mention of lag time, but we also need to 7 consider cation exchange and ho w that affects the 8 response of ecosystems to chang es in deposition. I 9 think that these things have no t been addressed 10 with the level of rigor that I believe is necessary 11 to inform the process. 12 DR. AMAR: Are there certa in publications or 13 reports or otherwise that you w ant us to look at? 14 DR. KNIPPING: Right now y ou have a report 15 that summarizes all that inform ation, including 16 citations and the results of th e current analysis 17 that we are performing. 18 DR. RUSSELL: And by that report it's the one 19 that's seen right here? 20 DR. KNIPPING: These are - - this is a 21 preliminary version of our full report. Our full 22 report will be submitted before the November 12th 23 deadline. 24 DR. RUSSELL: Thank you. Aaron Flynn. Aaron. 25 MR. FLYNN: Good morning. My name is Aaron

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1 Flynn. I'm an attorney with Hu nton & Williams. I 2 represent the Utility Air Regul atory Group or UR. 3 We have a significant number of concerns with the 4 procedural, legal, scientific a nd policy choices 5 that EPA appears to be pursuingbased on the 6 information contained in the cu rrent draft of the 7 Policy Assessment Document. 8 And I will only address a few of those 9 concerns in the comments here. The regulatory 10 comments that EPA is considerin g during this review 11 represent significant departure s from established 12 practices under the NAAQS progr am; and accordingly 13 it is essential that the agencyprovide the public 14 with adequate time to review an d comment on the 15 various draft documents that wi ll inform this 16 review of the secondary NAAQS f or NOx and SOx. 17 The secondary Draft PolicyAssessment was made 18 available only 19 days before t his meeting and 19 additional significant material was released on 20 September 23rd. This has preve nted UR from fully 21 developing comments for present ation to CASAC and 22 we hope the panel has had more time to work with 23 the document than we have, but we anticipate 24 submitting more extensive comme nts to EPA by 25 November 12th, the deadline for comments to the

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1 agency. 2 At each stage of this revi ew EPA has 3 introduced new concepts fleshin g out some of the 4 policy positions under development as part of this 5 review. Even at this relativel y late stage of the 6 NAAQS review process, however, there remain 7 significant issues that have no t been addressed in 8 the second draft of the Policy Assessment. 9 The document itself notes that a number of 10 additional analyses and policie s issues will likely 11 be included in the final draft, although what they 12 might entail or what they might conclude is not 13 clear at this point. Moreover, despite new 14 additions to this draft of the document, it remains 15 difficult to envision preciselyhow the 16 Administrator is to piece toget her and jointly 17 assess the various potential co mponents of the 18 standard that EPA staff describ es. 19 In addition, how the staff 's recommended 20 standard will be implemented an d the various policy 21 questions that must be resolvedto allow for 22 implementation remain exception ally vague. The 23 Policy Assessment notes, for in stance, that the 24 nation's monitoring networks ar e largely inadequate 25 to fulfill implementation needs for a NAAQS, such

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1 as the one EPA staff recommends . Similarly, the 2 document notes that FRM and FEMdesignations remain 3 a substantial stumbling block, as we have discussed 4 already this morning. 5 It remains entirely unclea r how the 6 designation of attainment and n onattainment areas 7 will take place or how the spat ial extent of the 8 nonattainment will be determine d; and, despite some 9 of the conversation we've had t his morning, how 10 states will determine what step s to take to provide 11 for attainment and how to demon strate that it will 12 be achieved remains an open que stion. Nor is it 13 clear how states are to establi sh in the future 14 whether the NAAQS has been atta ined. 15 These crucial matters shou ld not continue to 16 be a mystery at this phase of t he review. UR 17 believes that these matters mus t be fully assessed 18 and presented by EPA in this do cument and that they 19 merit CASAC review and input tothe Agency. UR, 20 therefore, urges CASAC to reque st that the Agency 21 provide a Draft Policy Assessme nt that completely 22 analyzes the relevant issues fo r CASAC review and 23 comment. 24 Finally, UR remains highlyskeptical of the 25 legality of EPA staff's recomme nded secondary NOx

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1 and SOx NAAQS and acidification -based standard will 2 likely conflict with the Title IV Acid Rain Program 3 in our opinion. And, further, UR is concerned that 4 the AAPI conflicts with the Cle an Air Act's 5 requirement that a NAAQS prescr ibe a single, 6 nationally uniform level of acc eptable atmospheric 7 concentrations of a particular criteria pollutant. 8 The AAPI is designed to do just the opposite. 9 Whatever the scientific merit o f the staff's 10 approach, it must be consistent with the Act. 11 In sum, the current draft of the Policy 12 Assessment continues to suffer from what UR 13 believes are real and very cons iderable 14 deficiencies. The document sti ll does not address 15 issues that are crucial to stat e regulators and EPA 16 itself. UR hopes the CASAC pan el will take these 17 concerns into account and reque st revisions to the 18 Policy Assessment. 19 Thank you very much for yo ur consideration. 20 If you have any questions, I'd be happy to attempt 21 to address them. 22 DR. RUSSELL: Thank you, A aron. Questions? 23 Seeing none. Thanks. Ellis? 24 DR. COWLING: I read the s tatement that is 25 under your heading, procedures, Procedural

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1 Concerns: "The regulatory opti ons EPA is 2 considering during this review represent 3 significant departures from est ablished practices 4 under the NAAQS program." I ag ree. But this EPA 5 committee or this EPA group, in cluding the 6 developing ISA and IEA, are doi ng exactly what the 7 National Research Council recommended in its report 8 in 2004 recommending changes inthe NAAQS review 9 processes in order to achieve m ore significant 10 multi-pollutant approaches in a ir quality 11 management. I presume that you 're appreciative of 12 the documentation that the Nati onal Research 13 Council report contains that dr ives them to 14 conclude that exactly what you said must be done. 15 MR. FLYNN: Our point real ly is that given the 16 significant changes and the fac t that the Act 17 itself has not been significant ly changed, we do 18 require as members of the publi c a period to 19 comment on and to adequately re view what the agency 20 is doing and how these changes may or may not be 21 consistent with the Act. 22 DR. RUSSELL: Any question s? Thank you. 23 Chris. 24 DR. FREY: I just wonder o n the legal point 25 raised, and as to whether the s tandard has to be

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1 nationally uniform and whether the standard is 2 heading in a direction that's n ot nationally 3 uniform, is that a legal issue from the perspective 4 of the EPA general counsel who may still be in the 5 room or is that an issue we canaddress and move on 6 with? 7 DR. MACIOROWSKI: The role of CASAC is to 8 comment on scientific and techn ical issues. 9 Certainly as the agency proceed s back through 10 rulemaking there are a number o f available options 11 that the agency has and is to c onsider broader 12 public comments, economics, leg alities and so on. 13 CASAC is a scientific advisory committee and its 14 focus should be on the underlyi ng science that's 15 going on. 16 So in terms of the legalit ies we have no 17 lawyers on this panel. We have certain lawyers in 18 the room who sort of nurture th ese processes for 19 the agency. We have public whoare very concerned 20 about legal issues and all thos e things are 21 ultimately relevant to the fina l decision making 22 process. However, CASAC's role is fundamentally 23 focused on science and it's a s cience advisory 24 committee. 25 DR. FREY: I understand th at, but if there is

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1 a constraint, I mean, we're loo king at a Policy 2 Assessment Document that's look ing at policy 3 options and I think it is reaso nable to ask a 4 question about what, if any, co nstraints we may 5 have. 6 DR. HUBBELL: I'm sure tha t Leah will jump in 7 here if she needs to, but, to b e clear, our 8 supposition going into this is that we are in fact 9 establishing a national standar d. The form of that 10 standard is such that you're co mbining NOx and SOx 11 to compare against a national l evel, which is 12 determined based on a target AN C value. The target 13 ANC value is a national standar d. 14 The way that we meet it th rough different 15 combinations of NOx and SOx tha t vary throughout 16 the country, but the metric tha t we are comparing 17 against is a national standard. It is not a 18 regional standard. It is a nat ional standard. 19 MS. WEGMAN: If I could ju st note quickly, we 20 think what we are doing and wha t we are considering 21 is consistent with the Clean Ai r Act, which isn't 22 to say it will be agreed with b y all parties. That 23 is our view, that the approach we are taking is one 24 that we believe is consistent w ith the Clean Air 25 Act.

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1 MR. FLYNN: I'll just add that I certainly 2 appreciate that you're operatin g under the 3 supposition that it's a legal a pproach. We would 4 really like to see -- and I agr ee with you that it 5 would be nice to see in the Pol icy Assessment 6 Document a fuller legal explana tion. 7 DR. RUSSELL: Thank you. John Jansen. Go 8 ahead. 9 MR. JANSEN: Good morning. My name is John 10 Jansen, principal scientist for Southern Company. 11 Southern Company has serious co ncerns about the 12 staff's recommendation on the s econdary SOx -- 13 secondary NAAQS for NOx and SOx . In short, the 14 recommended NAAQS is problemati c for various legal 15 and scientific reasons and refl ects fundamental, 16 practical incompatibilities bet ween the NAAQS 17 program and the welfare effects that EPA is seeking 18 to address. 19 The staff's efforts to lin k ambient 20 concentrations of SOx and NOx t o the ecological 21 indicator ANC through use of th e AAPI is fraught 22 with uncertainties that EPA sta ff greatly 23 under-represent, an unsupportedand grossly 24 simplified assumption. Further , important 25 parameters, such as base cationdeposition as well

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1 as base cation exchange, are ig nored. 2 EPA staff acknowledges the need for a national 3 uniform standard, but has desig ned a standard 4 that's anything but nationally uniform. It is not 5 a uniform level of ambient NOx and SOx. A uniform 6 level of AAPI or, in reality, ANC is not a 7 pollutant in the ambient air. A uniform level of 8 ANC can be overly protective insome areas of the 9 country. For example, Florida lakes having 10 thriving fisheries despite low pH, low DOC and low 11 ANC, they have those thriving f isheries because of 12 low aluminum and so it would be overprotective. 13 Moreover, many of the agen cy staff's 14 assumptions are invalid. Depos itions to NOx and 15 SOx concentration ratios are no t constant as the 16 agency continues to brush aside complications in 17 pursuit of the standard. For e xample, by using 18 extensive spatial and temporal averaging to 19 minimize the inherent variabili ty of the ratio, it 20 is necessarily becoming increas ingly divorced from 21 reality and incompatible with c ritical -- other 22 critical aspects of the standar d. 23 For example, the definitio n of area over which 24 the percentage of lakes meetingthe acceptable ANC 25 can easily conflict with this a veraging offense,

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1 and I'm assuming area is now AQ CR, but maybe not -- 2 maybe that's not the case. 3 While we understand the re ason that EPA has 4 decided essentially to exclude reduced nitrogen 5 from the AAPI, doing so places the entire burden on 6 attaining the NAAQS on SOx and NOx. This is 7 another reason why the NAAQS pr ogram is ill suited 8 for this task. 9 EPA is evaluating differen t bases for 10 determining the area over whichthe percentage of 11 waterbodies meeting the ANC lim it is assessed 12 ranging from one population of the entire United 13 States to using sensitivity cla sses, ecoregions or 14 clusters. It remains unclear p recisely how the 15 various areas will be defined a nd how relevant 16 ecosystem characteristics withi n them will be 17 identified. 18 It is unclear how these va rious areas will 19 relate to the designation of at tainment and 20 nonattainment areas. Further, how will these areas 21 relating to the deposition-to-c oncentration ratios? 22 The size of the area has seriou s implications for 23 how large and how seriously var ious uncertainties 24 are as well as for implementati on issues. 25 What will be the role of t he states in all of

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1 this complexity? There are als o considerable 2 shortcomings in the databases E PA is relying on. 3 While EPA has relied on CMAQ toproduce some of the 4 these databases, the performanc e of CMAQ and 5 reliability of its deposition c alculations, as 6 coupled in the NAAQS approach, cannot be evaluated 7 without adequate data. 8 There are similar uncertai nties in existence 9 and representativeness of the o ther databases, such 10 as the deposition of reduced ni trogen, the various 11 geological, soil and vegetative cover datasets, the 12 water quality, quantity and bio tic resources. 13 There is also a question in my mind as to the 14 rationale for the 5,280 waterbo dies that are used 15 to represent the thousands of l akes, rivers and 16 streams in the United States. 17 The considerable gaps in t he nation's air 18 monitoring networks renders exi sting network 19 inadequate for assessing compli ance with the 20 secondary NOx and SOx NAAQS. I ndeed a substantial 21 amount of work is required on F RM issues, which has 22 been identified. Further, a st andard taking a AAPI 23 form will also likely require t he calculations 24 necessary to determine complian ce to be included in 25 whatever FRM is approved -- is developed.

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1 These examples illustrate the NAAQS program is 2 not an appropriate mechanism fo r regulating 3 ecosystem acidification. The AAPI strains the 4 parameters of the NAAQS programand a more 5 reasonable alternative approach es should be 6 investigated. Thank you. 7 DR. RUSSELL: Thank you, J ohn. Questions for 8 John? Ellis, I see you. 9 DR. COWLING: John, when I read this statement 10 this morning that is in the nex t to the last 11 paragraph of your statement: " The substantial 12 amount of work will be requiredbefore adequate 13 federal reference methods and e quivalent methods 14 can be established." And I cou ldn't help but 15 remember when we were working t ogether in the 16 Southern Oxidants Program, you were very much 17 concerned about measurement met hods and you made a 18 huge investment, you and the So uthern Company, you 19 together with the other coopera tives made a huge 20 investment in developing the Se arch Program. 21 I wonder if you could comment on your 22 eagerness to join with EPA in f ulfilling your hope 23 that this additional work wouldbe accomplished by 24 making investments of the sort that you did in 25 developing Search?

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1 MR. JANSEN: Well, certain ly we would want to 2 make sure that all the work we have invested in is 3 utilized in this process, there is no doubt. The 4 NOy techniques that we have use d in deploying the 5 Search certainly are a form tha t could be 6 considered in establishing an F RM. But we think we 7 know how to do that, but I've a lso seen quite a bit 8 of debates about those kinds of methods in the 9 past. 10 So yes, you know, we certa inly will bring our 11 expertise to the -- to the tabl e, but it's more 12 than just SO2 and sulfate and N Oy. It's the 13 equation itself. I think there is a serious 14 consideration has to be given t o what portions or 15 if not the entire equation itse lf needs to go 16 through this process. 17 The analogy I would cite i s the improve 18 equation. We're talking about a secondary standard 19 for PM, talking about using an equation. Well, the 20 way that equation is being usedin the actual 21 setting of the standard I wouldsuggest serious 22 consideration needs to be givento that being part 23 of the FRM. And if it is in th e process to vet 24 that equation or this equation, the AAPI is going 25 to be a process that's going totake some time.

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1 DR. RUSSELL: Praveen. 2 DR. AMAR: Quick question about your last 3 statement about AAPI stretchingthe NAAQS program 4 too much and one should look at alternative 5 approaches, reasonable. What a re you thinking? 6 MR. JANSEN: Well, within the constraints of 7 the Clean Air Act, I don't knowexactly what I'm 8 thinking. We do have Acid RainTitle IV as a 9 separate response to this issue a couple decades 10 ago. Is that an appropriate th ing? Of course, 11 that requires Congressional act ion. 12 We do have serious emissio ns reductions that 13 are occurring under other porti ons of the Act and 14 the question is, is that adequa te? Is setting a 15 standard equivalent to the prim ary standard 16 adequate to long-term improveme nt in the 17 environment? 18 I'm not a lawyer. I'm goi ng to rely on UR to 19 make those arguments, but I thi nk there are other 20 alternatives that ought to be c onsidered. And what 21 I say you can't put a square pe g in a round hole. 22 And that's sort of the way I th ink about what we're 23 trying to do here. We're striv ing too hard to make 24 something fit that doesn't fit. 25 DR. RUSSELL: Thank you. John Heuss, are you

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1 on the phone? 2 MR. HEUSS: Yes, I am. 3 DR. RUSSELL: You may begi n. 4 MR. HEUSS: Thank you. I am with AIR, 5 Incorporated. Of course, I wil l be providing 6 written comments to the agency for the Alliance of 7 Automobile Manufacturers. 8 The PA revisits the approp riateness and 9 feasibility of setting secondar y NAAQS to address 10 effects resulting from depositi on. Previous 11 reviews EPA decided that second ary standards were 12 not an appropriate approach to address deposition 13 effects. As we discussed earli er, both EPA and 14 Congress regulated deposition t hrough Title IV. 15 Nothing has changed to alter th e fundamental 16 limitations that led to those d ecisions. As the 17 previous speakers noted, the --that deposition is 18 a regional, not national, conce rn. A national 19 uniform standard is not appropr iate. 20 Ecological indicators the EPA recommends is a 21 measure of water quality and ca n't substitute for 22 uniform national standards. Th e criteria for NOx 23 and SOx cover a portion of the sulfur and nitrogen 24 compounds that cause deposition -related effects. 25 In particular, reduced nitrogenis important, but

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1 not subject to regulation. 2 The air quality includes b oth regulated and 3 unregulated compounds. Importa ntly, we think that 4 there is no unique link betweenground-level NOx 5 and SOx species and the deposit ion that may lead to 6 effects. The assumption that s urface-based 7 measurements of these species a t any site are 8 indicative of the surface-baseddeposition has not 9 been demonstrated and is likelyflawed. Total 10 deposition at most sites is dom inated by wet 11 deposition and the chemical composition of the 12 precipitation is determined lar gely by in-cloud 13 reaction. Thus wet deposition of the species will 14 be a function of the gas and pa rticle 15 concentrations at cloud level, not at surface 16 level. 17 Another concern we raise i s even as CMAQ 18 provided reasonable estimates o f total deposition 19 of some of these species, it ap pears to do it for 20 the wrong reasons and we provid e examples. 21 Consequently, the reliance on C MAQs being proposed 22 by EPA appears to be flawed. 23 Another important issue is the beneficial 24 effects of nitrogen deposition need to be weighed 25 along with any adverse impacts in the

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1 Administrator's decision on the National Ambient 2 Air Quality Standard. 3 The written material we pr ovided to CMAQ 4 raises issues of implementation . Importantly, 5 there is no fundamental acidify ing potential for 6 the NOy. Individual components of NOy will 7 determine the dry deposition of those components. 8 Ground level concentration s of NOy are not a 9 satisfactory link to wet deposi tion and are not 10 even a satisfactory link to the dry deposition 11 since a different mix of NOy co mponents will result 12 in a different amount of nitrog en deposition as 13 deposition velocities for the N Oy component species 14 vary widely. 15 The PA is incomplete in ma ny ways, as has been 16 noted, with regard to the ecore gions, how many, 17 what actual measurements would need to be made in 18 each, how attainment would be d etermined, how 19 control areas and tips would be developed. 20 If an AAPI standard were s et, new monitoring 21 networks would need to be put i n place. That's 22 already been mentioned. Since EPA recommends three 23 to five years of monitoring, an y designations would 24 not occur for the foreseeable f uture. This would 25 delay any additional controls u nder the present

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1 standard until well after the n ext five-year review 2 is completed. 3 In the meantime, NOx and S Ox emissions will 4 continue downward under various existing and 5 planned proposed programs. For example, the 6 on-road motor vehicle control p rogram will reduce 7 NOx emissions by about 50 perce nt over current 8 levels. 9 In addition, EPA's Transpo rt Rule calls for a 10 70 percent reduction in annual power plant SO2 11 emissions and a 50 percent redu ction in annual NOx 12 emissions. That's in 2014 comp ared to 2005 13 baseline. That's for a 28-stat e area. 14 The PA doesn't address the important question 15 of whether all these programs a re sufficient to 16 adequately protect the public h ealth. It should. 17 The question of whether current levels are adverse 18 is not enough. You really have to look at whether 19 or not the future levels that w e know will be there 20 will be adverse. 21 So, finally, based on AIR' s review, the 22 proposed approach is a regional deposition standard 23 using the critical loads approa ch dressed up and 24 sold as a National Ambient Air Quality Standard. 25 The approach is incompatible wi th the NAAQS

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1 provision of the Clean Air Act. 2 We think EPA should take t he information in 3 the PA, turn it into a report t o Congress as an 4 update to the 1995 report on th e feasibility of 5 acid deposition standards under Title IV. 6 In addition, there really isn't anything 7 keeping states from working tog ether now using 8 regional agreements to address any remaining acid 9 deposition concerns. 10 Thank you for your attenti on. And if there 11 are any questions, I'll try to answer them. 12 DR. RUSSELL: Thank you, J ohn. Questions for 13 John? 14 Okay. In that case we canmove on to the 15 schedule. We are already just a wee bit behind. 16 As I said, I will try to push u s forward so we can 17 have sort of a number of discus sions later on in 18 terms of some of the bigger pic ture issues. 19 Starting first, charge questionone. Laurie. 20 MS. CHESTNUT: So charge question one is 21 focused on Chapter 3. The defi nitions of 22 adversity, are they appropriate to consider in 23 determining what constitutes adversity to public 24 welfare relative to the NOx andSOx secondary 25 standards?

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1 As a first remark, I just want to say, 2 acknowledge that this chapter i s much improved from 3 the first draft and very respon sive to the comments 4 that were made on that. I thin k there is still 5 some -- some details that I'm p robably repeating 6 from the last round of comments on it, but on the 7 whole it's much more clear and the context is much 8 better established for the quan titative results 9 that are presented. 10 I think it's quite clear t here is a well 11 documented link between the lev el of ecosystem 12 services with the indicator ANCand welfare effects 13 that the numbers are focusing o n the recreational 14 fishing, but the addition of th e results for total 15 value are very, very helpful th ere. 16 I think I, and I saw on so me of the other 17 comments too, had questions abo ut the presentation 18 of the results in tables I thin k it's 3-2 and 3-3, 19 just -- I was confused of wheth er these are 20 additive or incremental and the text needs more 21 explanation about the different -- how the numbers 22 relate to the categories of the ANC changes that 23 are considered there, which kin d of comes back to 24 how is that helping form the we lfare implications 25 of the target of 20, 50 versus a hundred ANC. So

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1 that's important that that's cl arified. 2 And I think the rest of th e comments that I 3 have on this come back to, well , two categories. 4 Whenever there is still this te ndency to talk about 5 the numbers that can be talked about, and 6 forgetting to repeat the big pi cture of -- people 7 care about the preservation of ecosystems in their 8 natural state and at a quality that supports the 9 species, the fauna, the flora, the stuff that 10 should be there. 11 So they don't just care ab out being able to 12 catch the fish. They care that the lake is in a 13 condition that supports the spe cies that you'd 14 expect to be there if there was n't human pollution. 15 So this kind of gets in a littl e parenthesis of 16 nonuse value, but I think it ne eds to come forward 17 even stronger that that is a bi g part of what 18 people care about. 19 We see it, there is eviden ce from the actions 20 of communities and the statutes and in the 21 willingness to pay for studies when those questions 22 are asked, the values. So it's all there. It's 23 just keep the story, you know, comprehensive. And 24 it gets a little lost in the --I think it's 25 better -- it's better in the aquatic section where

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1 the emphasis is now. 2 But, along the same lines, while these 3 ecosystem services clearly have value, the 4 characterization of how they're being harmed or 5 diminished by the deposition at current levels 6 could be improved. I know we c an't get to a bottom 7 line dollars on it, but over wh at geographic area 8 is there dieback of the red spr uce and the maple 9 trees? What percentage of thes e forests are, you 10 know, what's the mortality rate or how can -- can 11 information that was in the pre vious documents be 12 brought forward here to describ e the extent, the 13 magnitude, even though it's in qualitative terms, 14 of what the impact of the depos ition is, not just 15 these are important resources? I think that's 16 clear. These are important res ources. How are 17 they being hurt? 18 DR. RUSSELL: Okay. And b efore going on, just 19 remember I will want to lead di scussion -- 20 discussants to take charge of w riting up the 21 response. So just keep that inmind. 22 So if you're a lead discus sant, as the 23 discussion goes on, just jot no tes as to what other 24 people have said, since this ev ening you can write 25 up the -- the group responses t o the charge

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1 question. Keep that in mind. Praveen. 2 DR. AMAR: I agree with al l the things Lauri 3 said, but a few other comments too. One with 4 respect to public welfare and C hesapeake Bay. I 5 thought it would be useful if t he adversity concept 6 was more clearly discussed and separately allocated 7 to NHX, that is, not just the N Oy. The document 8 does talk about it's only inter ested in NOy. 9 That's one major comment. 10 The comment before I say m ore things, I think 11 sections 3.3.2 and 3.3.3 are aneconomics framework 12 in adversity. We don't say thi ngs, you know, I 13 mean, I enjoyed reading those t wo pages and 14 explaining to me what that mean t. That's a 15 compliment to the writers. 16 And Figure 3.6 it's good t hat we have the 17 nitrogen and sulphur depositionto different maps, 18 one for the east and one for th e west. But one for 19 the west has the scale, if you look, has the 20 highest scale. It goes all the way from 300 to 21 1,300 equivalent factors per ye ar. And I think we 22 should split it. I mean, I was n't sure where the 23 maximum deposition nitrogen sul fur was in the west. 24 That scale is just too large, 3 00 to 1,300, all in 25 one color. So if it's possible to show where the

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1 highest levels are. 2 And one more comment about the -- I guess it's 3 the revealed preferences. We d o talk about NGOs 4 and state governments and other efforts to address 5 it. I thought we all looked on e thing, as a 6 country, we had a real preferen ce through Title IV. 7 We did manage the 10-million-to n reduction of SO2; 8 and to the extent that's about $5 billion worth of 9 benefit, I think it should incl ude not just the 10 states and NGOs and communities but this country as 11 a whole. That's it. Otherwise , it's a very good 12 chapter. 13 DR. RUSSELL: Thank you. Panel? Dale. 14 DR. JOHNSON: I had three things there. One 15 was page 3.7, somewhere in ther e the Department of 16 Energy was not mentioned. Theyfunded a lot of 17 environmental research. Havingworked at the 18 National Lab for a few years, I would say you ought 19 to consider that, including some air pollution 20 work. 21 Table 3.1 is incomplete. You don't 22 acknowledge that soils are filt ers for good water 23 quality. On the other hand, so ils can be 24 pollutants themselves. And cli mate in that table 25 is interesting, talk about regu lating climate and

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1 so forth? I didn't know we wer e able to do that. 2 I think what's implied her e is carbon 3 sequestration, which is summari ly dismissed and is 4 irrelevant; and yet there is th ree full pages of 5 discussion of growth increase a nd negative effects 6 on fire systems in the southwes t, which is 7 completely true, I lived in tho se systems, but 8 that's exactly the same phenome non that causes 9 carbon sequestration in other s ystems. 10 So not -- once again, the same thing, it lacks 11 balance. You need to have some consideration, 12 growth increase might be desira ble here, it's 13 undesirable there, but let's ta lk about the whole 14 picture. 15 DR. RUSSELL: Other commen ts. Naresh? 16 DR. KUMAR: This is just ageneral comment. 17 This is one of the chapters tha t I would like to 18 review, but I couldn't find the time. And I just 19 wanted Angela and Ted to know t hat two and a half 20 weeks was just not enough for me, but anyway, to 21 read all the chapters and I wou ld really like more 22 time for this review. With oth er things happening, 23 it's hard to find the time unde r those constraints. 24 DR. MACIOROWSKI: That's w hy there is a 25 committee.

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1 DR. RUSSELL: Other? Othe r comments? Andre. 2 DR. BYTNEROWICZ: I have j ust a technical 3 comment related to Figure 3-2, which isn't mind 4 earthing, but I think it shouldbe corrected. It's 5 the European data on eutrophica tion. And you're 6 saying that on the right-hand s ide you have 7 acidification. Actually, this is effect of sulfur 8 deposition itself, not acidific ation as a part of 9 concentration. So that should be corrected. 10 DR. RUSSELL: Thanks, Andr e. Moving on. 11 Ellis, question two and three. 12 DR. COWLING: Two and thre e, let me just read 13 the question and then I'll offe r my own. 14 DR. RUSSELL: I wouldn't w orry about reading 15 it, just for expedience. 16 DR. COWLING: I'll try to be concise, but 17 okay. In the light of -- I thi nk it's important we 18 focus on what the question is i n the light of the 19 panel's views on the appropriat e definitions of 20 adversity that Lauraine just ta lked about. Do you 21 agree that the current levels o f NOy and SOx are 22 adverse? And my quick answer i s yes. And the 23 question -- I think Chapter 3 m akes a very nice 24 presentation of certain facts a bout the Clean Air 25 Act. It gives a long list of e ffects on

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1 ecosystems, but it doesn't give a guidance about 2 what is an adverse effect. AndI thought what EPA 3 has done is created a working d efinition; and I 4 think the working definition wh ich talks about 5 disruption in ecosystem structu re and function were 6 a good definition. 7 It wasn't in the Clean Air Act, but that's the 8 one that has been working prett y well so far. And 9 I must say I'm delighted that y ou're taking 10 seriously ecosystem effects. S o thanks for what 11 you're doing. 12 And this significant disru ption is presented 13 and I thought the quotation tha t you took from the 14 ISA, just one of those, the sci entific evidence is 15 sufficient to infer a causal re lationship between 16 acidifying disposition and effe cts on 17 biogeochemical and biota and aquatic ecosystems. 18 That's the kind of firm stateme nt that gives 19 conviction to the recommendatio ns that you're 20 asking for CASAC to respond to. 21 The third question: Has s taff appropriately 22 applied this approach in review ing the adequacy of 23 the current standards and poten tial alternative 24 standards? And, once again, I say yes. I believe 25 that EPA staff has very appropr iately taken up

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1 these matters. And the very sh ort-term present NOx 2 and SOx standards simply don't apply to long-term 3 acidification effects. 4 So the present standards a re designed to give 5 a degree of protection against fuller injury and 6 that's not what a full realizat ion of what 7 protection of ecosystems ought to involve. 8 Acidification and nutrient enri chment are very, 9 very important. And I think th at the indicators 10 that have been suggested are ap propriate. 11 So I look forward to looki ng at all the 12 different -- all of the differe nt parts of the 13 standard, the indicator, the av eraging time, the 14 level and the static method of calculation. So I'm 15 looking forward to protecting a quatic ecosystems to 16 start with and going from there to all the other 17 kinds of ecosystem effects that are mentioned, 18 particularly in Chapter 6. Tha t's enough for me. 19 DR. RUSSELL: Thank you, E llis. Dale. 20 DR. JOHNSON: Mine will be the same theme as 21 before and that is that certain ly the -- by 22 limiting it to the aquatic effe cts or largely 23 limiting it to aquatic effects, you're not looking 24 to -- I don't know of any benef it to aquatic system 25 or other side of the story, aci difying is negative.

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1 When the terrestrial effec ts are considered, 2 again, there needs to be more b alance. I'm not 3 against your idea of trying to increase -- trying 4 to tighten regulations, that's not the point. The 5 point is balance. And it's jus t not there. 6 I spent over a decade work ing with elevated 7 CO2 at community and all, and t he whole thing was 8 about forest growth is going toincrease with 9 elevated CO2 unless we have a n itrogen limitation. 10 There was no -- hardly any thou ght at all about 11 changing nitrogen deposition. So here we are all 12 about nitrogen deposition, not considering elevated 13 CO2 and the growth interaction of that. And so to 14 me there is a huge disconnect h ere. There needs to 15 be some expansion of unintendedconsequences let's 16 call them. That's my point. T hat's my main point. 17 DR. RUSSELL: Thank you, D ale. Panel? Very 18 good. Which does move us to qu estion four and, 19 Dale, you're still on tap. 20 DR. JOHNSON: Well, I don' t know if there is 21 anything much more to add to wh at I've already 22 said. I've got a long disserta tion there about it 23 in my write-up that you can see . 24 The question is: Is this document -- I'm 25 starting to ask myself does thi s document and is

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1 this whole effort a mission to increase standards 2 or is it supposed to be -- and I assume that my 3 role is supposed to be -- if so , my role is 4 supposed to be the scientific c ritic. As a 5 scientific critic, I'll say it' s too narrow. It 6 doesn't consider the unintendedconsequences; 7 whether you want to call them b eneficial or 8 negative, I don't care. 9 There is great debate in t he literature at 10 this point about nitrogen depos ition, carbon, 11 climate change and so forth. And I can't fathom 12 that this would go forward with out that coming up 13 again in some fashion. To summ arily dismiss it now 14 makes no sense to me whatsoever . 15 So it's the same thing I'v e been saying for a 16 couple years now and it's all w ritten out. So I'll 17 just leave it at that. 18 DR. RUSSELL: Thank you, D ale. Lauri. 19 MS. CHESTNUT: I don't hav e much to add on 20 this. I think we can see in th e document there is 21 more attempt to acknowledge tha t there is potential 22 upside or downside implications , but that that's 23 not the focus. I think the iss ues that Dale is 24 raising about the carbon it's g oing to keep coming 25 up.

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1 DR. RUSSELL: Okay. Kathy . 2 DR. WEATHERS: It occurs t o me now, Dale, as 3 you're talking, buried in the N eco term is nitrogen 4 uptake by biosystem. So, in es sence, buried in 5 that term is stimulation of gro wth, the extent that 6 nitrogen stays within the syste m, stays in the 7 biomass and doesn't go out. I wonder if it's 8 possible to identify that as a process that is 9 recognized, that's utilizing ni trogen for what 10 you're calling, you know, a pos itive? 11 DR. JOHNSON: Yeah. And s imilarly the 12 discussion on fire, you know, t he negative effects 13 of increased growth on fire, th at's the same 14 phenomenon. It's just the ques tion of how you look 15 at it. And I don't think -- I think that there 16 is -- I think if you had the pe ople from the 17 elevated CO2 committee, for example, in here then 18 they might say, well, you know, what's this 19 nitrogen deposition going to in teract with CO2 in 20 the future? What's it going todo to carbon 21 sequestration? 22 I don't argue that this is going to offset the 23 negative effects on water. Tha t's not the point. 24 I just don't think it's a compl ete assessment. You 25 can never come up with all of t he unintended

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1 consequences, of course. But t his is one that, to 2 me, having worked on this stuff , is glaring. 3 DR. RUSSELL: Other panel members? Thank you. 4 Praveen, question five. 5 DR. AMAR: So the big Chap ter 5 and we have 6 question five simply asking wha t they think about 7 the revised conceptual framewor k for this AAPI 8 standard we are talking about; and do we agree with 9 the structure; and does it do agood job of various 10 linkages? I guess in many ways conceptual 11 framework is what we had seen i n the first draft. 12 So I think it does a good job. In fact, I 13 thought it was very well though t out. That's what 14 I said last time. 15 And I think I still have o ne point which I 16 made before, which has to do wi th maybe the 17 opportunity to address ammoniumor chlorine 18 explicitly and not taking into account, which is 19 the language we use now. I thi nk it takes the 20 opportunity down the road for a ctual reductions in 21 ammonia. 22 So when this thing gets implemented, ammonia 23 needs to be taken into account. Maybe there would 24 have been a transfer like we ha ve for SOx and NOx 25 and treat ammonia as a pollutan t, which I still

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1 think 4 to 5 million-tons per y ear. Unlike SOx and 2 NOx, it's not going down, it's going up. And still 3 there is no procedure here to a ddress ammonia. 4 That's my major comment. It was the one I had 5 made before. Otherwise, I thin k, not discounting 6 that, I think it does a good jo b of what you're 7 trying to accomplish. 8 DR. RUSSELL: Myron. 9 DR. MITCHELL: Because the re is a couple of 10 major issues I'd like to bring up that were 11 discussed in other gatherings o f this group, and 12 that is clearly CMAQ is an impo rtant central focal 13 point of these activities. AndI think that's 14 obviously appropriate based upo n the amount of 15 emphasis and effort put into CMAQ. 16 However, I think within it s present form, 17 there is not an adequate analys is of and 18 verification of CMAQ results. It's almost curious 19 that CMAQ is used for dry depos ition, which is very 20 difficult to validate, but thento go to wet 21 deposition, you go to NADP. Bu t actually CMAQ 22 actually does calculate a wet d eposition component. 23 Why not do that comparison to s ee how good that is? 24 I also recognize CMAQ now is calculating 25 meteorological conditions is no w using measured

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1 meteorological information. DoI have that 2 correct? 3 DR. SCHEFFE: Well, a coup le things. We 4 actually do use CMAQ for both w et and dry. And I 5 think what you're seeing is we' re in a transition 6 period where we start off usinga lot of the NADP 7 for wet and dry and we're trans itioning toward 8 using a lot more CMAQ for both wet and dry. 9 The other part of this, be cause of the 10 tychastic nature of precipitati on and the 11 difficulty in terms of pairing in time and space 12 observations and modeled estima tes, we've gone to 13 doing some adjustments of the p recipitation field 14 with measured observations of p recipitation to do a 15 prism adjustment approach and u sing the chemistry 16 that's developed by CMAQ. And that has led to much 17 greater pairing, much greater p airing in time and 18 space between the observations and the predictions. 19 DR. MITCHELL: I got a lit tle confused. I 20 thought from reading in the doc ument for wet 21 deposition NADP data was going to be used and CMAQ 22 for dry. 23 DR. SCHEFFE: It has to dowith the 24 deposition. Some parts of the analysis, I think 25 even in Chapter 3 you may have seen there is a map

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1 there that talks about CMAQ, dr y deposition and EDP 2 wet deposition. Some of the ea rly analyses that 3 went into both the ISA and RIA went into that. 4 That has gradually been changin g over time. 5 DR. MITCHELL: My major po int it seemed like 6 there was a major opportunity i mportance to 7 actually include this validatio n clearly within the 8 document. It's going to come u p again and again 9 how well does this model valida te. 10 DR. SCHEFFE: Excellent po int. We agree 11 completely with that. 12 DR. MITCHELL: I guess my other point had to 13 do with some of the formulation s of the AAPI index. 14 And I have a concern about some of the components, 15 particularly on the overall ass umption that sulfur 16 goes in and sulfur goes out. T here is pretty good 17 evidence that that is not the c ase for a number of 18 different systems. And we alsohave systems we 19 know that have had previous sul fur loadings that 20 the amount of sulfur coming out is fairly high. 21 So I think not accounting for an important 22 component like that, which coul d actually cut one 23 half of the AMQs and ANC will a ctually result in 24 under-protecting systems becaus e they are leaching 25 out the mobile sulfate ion, whi ch will result in

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1 acidification over time. 2 There is a couple specificthings within the 3 document. There is a statement to the effect about 4 nitrate coming out of the snowp ack and that's 5 associated with the episodic sn owbelt 6 acidification. All kinds of st udies have shown 7 that that nitrate associated wi th snowmelt does not 8 come from the snowpack; 95 perc ent of it comes from 9 either the forest or the middle soil. That's a 10 mistake that needs to be correc ted. 11 DR. HUBBELL: Just so I un derstand, so is it 12 when the snow melts it's washin g through the soil? 13 DR. MITCHELL: Exactly. T he nitrate is not 14 coming from the snow. It's com ing from nitrogen, 15 ammonia mineralite, and nitrate base within the 16 soil. 17 DR. RUSSELL: Thank you, Myron. Rich. 18 MR. POIROT: I don't have a lot to add. I 19 noted I think it was Ted's comments, written 20 comments that indicated this is by far the most 21 complicated NAAQS review that w e've seen in recent 22 years; and I certainly want to second that, but to 23 also kind of go back and think about, you know, the 24 whole concept of a secondary st andard to protect 25 against welfare effects. This is kind of exactly

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1 the kind of effect that could w e develop secondary 2 standards to protect against, w e should. I think 3 it's a very appropriate and alb eit complicated 4 approach, but it's necessarily complicated. 5 Ecosystems are complicated. 6 And so, anyway, I really w anted to express my 7 appreciation and admiration for the way in which 8 you've taken the limitations an d constraints of the 9 Act and developed what I think is a fairly coherent 10 framework that would allow us t o go from 11 measurements of certain sulfur nitrogen species in 12 the air in a way that would be protective against 13 ecosystems. So I really apprec iate that. 14 And Praveen had mentioned the failure to 15 include reduced nitrate and red uced nitrogen as a 16 component, but I was very pleas ed to note the 17 change from the last PA in whic h now reduced 18 nitrogen is viewed as a varyingaspect rather than 19 a fixed constant, such that if I assume then if 20 ammonia deposition were -- redu ced is the wrong 21 word -- 22 DR. AMAR: Lowered. 23 MR. POIROT: -- brought do wn, then the 24 required reductions in the othe rs would be less and 25 vice versa. So I thought that was an excellent

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1 revision and very responsive tothe comments. 2 That's all I have. 3 DR. RUSSELL: Thank you. So I took it that 4 those are primarily responsive to question five. 5 So at this point we have a brea k at 10:30. So 6 we're still before that painful ly enough. So back 7 to Praveen. 8 DR. AMAR: Question six. 9 DR. RUSSELL: The all-impo rtant one. 10 DR. AMAR: Which is not fo r me to answer. 11 DR. RUSSELL: Sorry about that. Are there 12 other panel comments on questio n five? Dale. 13 DR. JOHNSON: I think this is in question 14 five, the steady state model, I think it was page 15 516 probably discussed that mor e, but that appears 16 to assume that base cation outp ut from a system 17 equals weathering, correct? 18 DR. LYNCH: No. 19 DR. JOHNSON: No? 20 DR. LYNCH: No. 21 DR. JOHNSON: Then I need clarification on 22 that. 23 DR. LYNCH: Is it okay to do it now? 24 DR. RUSSELL: Uh-huh. Ple ase speak to the 25 mike a little closer.

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1 DR. LYNCH: So the weather , it's supply at 2 that point within the waterbodyand so the surface 3 water is going to integrate all the components. So 4 the base cation weathering fromthe soil and the 5 rocks are going to contribute t o that. Deposition 6 from the atmosphere is going tocontribute to that. 7 And it's going to go into the s ystem that then is 8 going to be releasing it in ter ms of the stream. 9 So it's integrative of the ecos ystem, not just 10 what's coming out in terms of t he weathering 11 process per se. 12 DR. JOHNSON: Okay. I hadthe impression 13 preindustrial calculations assumed that the base, 14 however we got base, cation exp ort was equal to 15 weathering; the system was stea dy state, in other 16 words? 17 DR. LYNCH: Uh-huh. 18 DR. JOHNSON: If it is a s teady state that 19 means soils never acidify. Tha t can't true. They 20 do always acidify unless you're in the desert. 21 Something is not clicking here. Maybe you and I 22 can sort that out. 23 DR. LYNCH: Right. I unde rstand -- I sort of 24 understand what you're saying i n terms of that, in 25 terms of your point of view. Y eah, and what's --

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1 if we could talk off line, that would be awesome. 2 DR. JOHNSON: Something is not -- I'm missing. 3 I want to second Myron's c omment on sulfate 4 because I think the Coweta and the Shenandoah 5 watershed is about 80 percent o f the incoming 6 sulfate retained. Even if the sulfate emissions 7 are down 40 percent, therefore, they're still going 8 to break through some day and s ulfate is going to 9 go higher. 10 DR. LYNCH: And that is co rrect, but in terms 11 of the steady state model, it's saying that 12 retention we're going to let th at go through it. 13 Now, the question is are we und er or overestimating 14 within the specific question co uld be -- could be a 15 reality. 16 DR. MITCHELL: It could be both. Someplace 17 you're going to go over, depend ing where things are 18 at with regards to the sulfur s tatus of that soil 19 and the soil properties. 20 DR. LYNCH: Right, or it m ay not break 21 through. 22 DR. MITCHELL: Not some pl aces. It would just 23 absorb even more. 24 DR. LYNCH: Yeah. And tha t absorption may be 25 in terms of that process. And, you know, I was

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1 talking with Jack Cosby with th e University of 2 Virginia and they both have sit es where they tried 3 to find that sulfur that has be en there for 30 4 years and they can't find it, b ut it's not coming 5 from through the system. 6 DR. MITCHELL: I guess the point, Jason, I did 7 some quick calculations and loo ked at some of the 8 figures, and fairly modest esti mates of sulfur 9 input would be half of those ki nd of ANC changes 10 you're predicting. 11 DR. LYNCH: Okay. 12 DR. MITCHELL: You get twofor one for sulfur. 13 DR. LYNCH: That's right, you do. 14 DR. RUSSELL: Naresh. 15 DR. KUMAR: I think from atheoretical 16 standpoint, the framework looks fine, but its 17 practical usefulness can only b e determined showing 18 its robustness. I don't believ e that has been 19 fully evaluated by EPA. 20 And, as Myron said, a lot of the confidence of 21 the framework depend on the mod els, are using data, 22 which is very sparse. And unle ss a full content of 23 the analysis -- I realize we wi ll discuss that 24 later on, but unless that can b e done and fully 25 evaluate the robustness of this framework, just the

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1 theoretical framework and I thi nk I have doubt on 2 its effect and usefulness. 3 DR. MITCHELL: I guess wha t my point is, it's 4 been a tremendous amount of eff ort in CMAQ in the 5 development. And I guess I'm s uggesting that EPA 6 should recognize, obviously, ti me and money 7 available. I suggest that grea ter emphasis on the 8 validation that's already prese nt versus more 9 refinement of a more and more d etailed model would 10 be better in terms of what we'r e trying to do here. 11 DR. RUSSELL: Thank you. Tell you what, it is 12 10:30. And I think we can prob ably break at this 13 point and then come back for qu estion six. 14 So let's do that. We'll s tand adjourned until 15 10:45. 16 (Brief recess.) 17 DR. NUGENT: This is the t ime of the meeting 18 where we actually increase the deluge for everyone, 19 more paper. I just want to let you know we will be 20 distributing right now Chris Fr ey's written 21 comments. In your packet on th e left side, we have 22 a compilation of members' comme nts we received by 23 noon yesterday, but we've addedto the back of that 24 packet Dr. Weathers' comments a nd Hanson's -- 25 Husar's, Rudy Husar's and Hanso n. I'll be

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1 developing other compilations o f comments and send 2 them around so you can have ele ctronic copies of 3 everybody's comments in case th at's useful as 4 discussants prepare their summa ries. So you'll 5 actually have the electronic te xt and we'll post 6 that on the website too so you' ll have access to 7 it. 8 DR. RUSSELL: Thank you, Angela. 9 So now we jump in probablyone of the big 10 questions, questions six. So s tick with Praveen. 11 DR. WEATHERS: Can I comme nt? One of the last 12 things Myron said is the time s pent on talking 13 about validation or verificatio n would be time well 14 spent. And I agree with that c ompletely. I think 15 it's an overarching theme. I d on't know if you 16 have an answer to that, but I t hink we as a group 17 need to talk about what that wo uld look like. 18 Maybe now is not the time to talk about it. 19 Maybe it's in the overarching questions to talk 20 about, but I think it's a reall y, really important 21 point and something we should d iscuss, what would 22 verification of this whole thin g look like. 23 DR. RUSSELL: I think that might come under 24 when we talk about Chapter 7 'c ause that's the 25 chapter on evaluation of uncert ainty and

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1 variability and essentially all the components 2 thereof. 3 DR. WEATHERS: I just want ed to flag that. 4 DR. RUSSELL: Praveen. 5 DR. AMAR: Question six, I have a question I 6 want to ask, but, quickly, ques tion six talks about 7 what we think about the appropr iateness of 8 considering single national pop ulation of 9 waterbodies in establishing sta ndards and what do 10 we think about alternative subd ivisions in the U.S. 11 to identify the spatial boundar ies of populations 12 of waterbodies in acid-sensitiv ity categories. And 13 specific questions A, B, C, the use of Ecoregion 14 III, Roman numeral three, areas to aggregate 15 waterbodies; ANC to further agg regate Ecoregion 16 III; and finally the relative a ppropriateness of 17 various methods going from one country, one nation 18 and yes, no binary sensitive/le ss-sensitive 19 classes, cluster analysis basedon sensitivity 20 classes, and finally individual ecoregions. 21 And my answer is I did tryand I tried to read 22 that part of the Chapter 5. I don't think I got it 23 completely, but I can see these . The option one, 24 which says the whole country as one unit and 25 providing for a single depositi on. Somehow I think

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1 it's too easy, simple and also its weaknesses, I 2 think, are too many to really t hink this is the 3 preferred approach; that is, ov erprotection for 4 least sensitive waterbodies andunderprotection for 5 areas that are most sensitive. 6 Then there is difficulty i n the three 7 sub-options under second option , 2-A, 2-B, and 2-C. 8 They're based on the concept of level III 9 ecoregions. I know somebody un derstands what that 10 means more than I do. I think it's not well 11 written, it's not well explaine d to a person like 12 me. I didn't get it. And I wa sn't sure how this 13 divides the country into 120-pl us acid-sensitive 14 categories. Reference is made to the work by 15 Omernik. Is that the way it is said? 16 There are profound words. I didn't get 17 exactly why that approach was c hosen and other 18 words -- other references too. Maybe as a group we 19 can figure that out. And betwe en options 2-A, 2-B 20 and 2-C the approach based on c luster analysis, 21 which is option 2-B, at least g ets me -- you know, 22 I think it seems to be the righ t balance. Maybe 23 I'm just having a level of comf ort based on other 24 work I've seen on cluster analy sis, at least based 25 on five clusters.

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1 And, again, I don't know w hether that's the 2 right approach or not, but defi nitely going all the 3 way where you divide 120-plus e coregions may be too 4 detailed. So those are my resp onses. I don't 5 think they're the best answers, but that's what I 6 got out of reading that part of the chapter. 7 DR. RUSSELL: Thank you. Myron? 8 DR. MITCHELL: I'll pass f or right now. 9 DR. RUSSELL: You're goingto take a pass for 10 now. Rich? 11 MR. POIROT: I had kind of the same experience 12 as Praveen related in terms of I tried really hard 13 and I just couldn't get it. I just didn't quite 14 understand the distinction betw een the different 15 options that you were proposing . And I just didn't 16 own them, you know, in a way th at I felt I could 17 really contrast one to the othe r even to understand 18 what -- what's the gain? What are we trying to 19 narrow down or improve upon? 20 So none of them seemed ina ppropriate to me. 21 As I read through them, every o ne seemed kind of a 22 logical progression, but then w hen I got done with 23 them, I didn't really feel like I had a good basis 24 personally to feel like one was better than 25 another. And I feel like that' s something that the

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1 Administrator is going to need some better 2 explanation, clearer explanatio n -- or at least I 3 am -- to really get it. 4 You know, on the one hand it seems like the 5 single population suffers from this 6 oversimplification concept and overprotection and 7 underprotection. But then how do you -- and there 8 is one point where there is a v ery eloquent 9 sentence in there it talks abou t the goal is, you 10 know, sort of the balance of ef ficacy and 11 complexity and hitting just the right point. And 12 from that perspective somehow t he five clustered 13 approach seemed to make sense t o me. 14 First of all, the clusteri ng scientifically 15 appeals to me. The beginning s tarting point with 16 the ecoregions appeals to me ve ry much in the sense 17 that it's very consistent with the sort of 18 environment first perspective. The whole idea that 19 we're going to start with the c haracteristics of 20 the environment, that's our beg inning place really. 21 So I really like that even thou gh I don't know 22 Omernik or whoever he is, but i t makes sense. And 23 then the clustering, according to similar values, 24 makes sense. That kind of an a pproach is I think 25 scientifically quite valid and seems appropriate

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1 here. 2 So other than that, you kn ow, it's hard for me 3 to really say I like one approa ch. Just the way 4 that you were showing them comp aratively, it didn't 5 work for me or, you know, I was kind of pining back 6 for the days of the staff paper s and almost hoping 7 that you might pick an option o r a couple of them 8 and advocate, tell us what's go od about this one 9 versus the other one, what's th e advantages and 10 disadvantages. It's almost lik e there was this 11 missing kind of "and staff reco mmends." So it's 12 kind of like putting that back on us. And I don't 13 know, but I have a strong sense of that. 14 Earlier when Bryan was tal king about -- 15 talking about the area of nonat tainment or whatever 16 and I think you said something about we haven't 17 necessarily determined how the spatial extent of 18 nonattainment would be divided because it occurred 19 to me disaggregating ecoregions into the 20 traditional county could get ve ry complicated. 21 DR. HUBBELL: Again, we're not -- at this 22 point we're not required to det ermine how we would 23 establish nonattainment. You k now, what we're 24 trying to figure out is what's an appropriately 25 protective level of the standar d and then you have

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1 to figure out how you would act ually implement that 2 through an establishment of a n onattainment area. 3 It's pretty clear to us it 's not going to look 4 like a county or anything else. It's going to look 5 like something else. The quest ion is: Is it a 6 nonattainment area around a lak e or over an entire 7 ecoregion? That's the kind of discussion that 8 needs to take place in terms of implementation. 9 What we're trying to estab lish within these 10 regions, regions or broader, is what is population 11 of lakes that you evaluate to d etermine the 12 appropriate critical load match ing a target ANC 13 value? That's what we're tryin g to determine. 14 MR. POIROT: So that's off our table even 15 worrying about how a region of nonattainment would 16 be -- 17 DR. HUBBELL: Right. But it is very much on 18 your table to help us figure ou t what's an 19 appropriate spatial scale for t he population of 20 lakes we should consider when w e're determining 21 what a critical load should be to cover or protect 22 that particular population of l akes and streams. 23 That's very appropriate and ver y helpful. 24 MR. POIROT: Just as an ex ample, there was one 25 place in which you talked about one of the options

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1 and included a mention that whe n it was applied to 2 the Adirondack case study area that it appeared to 3 correctly separate between and distinguish between 4 those lakes that did have low ANCs and those that 5 were less sensitive, that's goo d. More of that 6 kind of a clear basis for disti nguishing among the 7 options I think would be helpfu l for the panel 8 decision process. I think that 's all I have. 9 DR. RUSSELL: Myron. 10 DR. MITCHELL: So I -- my thoughts on this I 11 already indicated having, obvio usly, a single kind 12 of standard makes it simple in terms of presenting 13 it, but I think in terms of sci entific defense of 14 this, it would throw out all of the past work 15 associated with the known major causes of 16 variability of the deposition a nd nutrient level 17 effect. 18 So I think having those ec oregions, especially 19 having some of those ecoregions which correspond to 20 regions used in the past to des ignate different 21 waterbodies bodies and classify ing them makes the 22 most sense in terms of moving t his forward. I 23 think otherwise this would be s cientifically very 24 difficult to defend. 25 I think the real challenge would be some of

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1 the areas which have not had a high amount of 2 investigation, what to do with those areas. Maybe 3 those areas have already been i ndicated not to be 4 ones that are sensitive anyway. So it may not be 5 that much of a problem. 6 So I'm supportive of comin g up with ecoregions 7 and coming up with metrics base d upon past analysis 8 that can be used for defining t hese in a meaningful 9 sense. 10 DR. HUBBELL: If I might j ust say for one 11 moment trying to clarify this, when we talked about 12 the rationales for going with d ifferent approaches, 13 there were really two things th at were critical to 14 us in considering this, and per haps this didn't 15 come through in the document. One was does going 16 to a more defined spatial chara cterization, does 17 that allow you to more carefull y address the 18 differences in sensitivity? Inother words, does 19 it show up in a different criti cal load? That's a 20 clear way to measure that. Youhave a different 21 critical load between different areas. In some 22 cases, you know, when you went to sensitive versus 23 nonsensitive, there was a big d ifference between 24 those two areas. 25 When you went to the full range of all the

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1 ecoregions some of those were d ifferent and some of 2 them weren't. The question is could we build it up 3 again? That's where the cluste r analysis idea came 4 in. 5 The second issue is that w hen you go to a 6 smaller spatial scale because o f the fact that 7 we're using observed water chem istry data to try to 8 develop critical loads, you hav e some areas that 9 have relatively sparse data andbecause those data 10 are not based on a random sampl ing of all the 11 waterbodies within those ecoreg ions, when you have 12 a sparse set of data, we're not clear whether 13 you're getting -- what part of the distribution 14 you're getting when you look at that set of 15 critical loads. It may actuall y represent the 16 upper percentile of sensitivitywithin that 17 ecoregion or it might represent the full 18 distribution. 19 So the tradeoff when you g o to a smaller 20 ecoregion is that you have less confidence in the 21 ability to characterize critica l load values. As 22 you scale up, you're hopefully getting a better 23 overall estimate of the distrib ution across all the 24 ecoregions included in that clu ster. 25 That's the tradeoff is dat a availability and

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1 data sparseness and the abilityto characterize the 2 distribution with the ability t o actually get more 3 specific critical load informat ion for subregions. 4 That's the tradeoffs we're tryi ng to characterize. 5 Again, some of graphics were in tended to show that 6 and perhaps they weren't as cle ar in terms of 7 getting that, but that was the principle we were 8 trying to come up with. 9 DR. RUSSELL: Rudy. 10 DR. HUSAR: It seems that one of the reasons 11 that it is difficult to assess the difference 12 between possible options that's in uniform national 13 and regionalized is that it is not -- in your 14 presentations you do represent the characteristics 15 spatial and otherwise of the in dividual component 16 of this AAPI piece, but unless one actually goes 17 through the entire sequence, inother words, what 18 does AAPI really look like out there? Okay. What 19 is the nature of that pattern? Does it actually 20 pass the does-it-make-sense tes t, you know, as a 21 thing? Therefore, not only tha t one doesn't -- you 22 can't see that, sense making, b ut also you cannot 23 make -- you definitely cannot v alue or judge the 24 difference between one uniform approach and the 25 other one.

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1 DR. HUBBELL: So, in other words, instead of 2 just going through the critical loads take it all 3 the way through? 4 DR. HUSAR: Carry all thos e calculations all 5 the way through so you have a f eel for that. Don't 6 set the standard. Don't set th e AAPI levels. It 7 is just to see what is the 10, 20, 50, 100 of what 8 that index look like so that yo u can actually see 9 what are the what I would call the quality 10 consequences of all of those ma ny, many opaque, 11 somewhat opaque factors that ar e embedded in that. 12 DR. GREAVER: I guess the idea behind sort of 13 separating what was happening a t the sites where we 14 had critical loads versus what was happening with 15 some of the air characteristics was we really 16 wanted to focus in and figure o ut how do we define 17 what is an acid sensitive area. 18 So at the last CASAC meeti ng on the first 19 Draft PA we thought that we wou ld use bedrock 20 geology to do this. And we wer e going to use a 21 method that was published by Su llivan, et al. in 22 2007 and did these -- correlati ons between acid 23 sensitivity and lithology. Wel l, we then tried 24 to -- I should note those corre lations were 25 developed for the Shenandoahs.

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1 We then tried to do them i n areas that were 2 glaciated in the Adirondacks, a ll the relationships 3 fell apart. So we knew that be drock geology was no 4 longer what we could use to cla ssify acid 5 sensitivity. 6 We then spent months looki ng at different 7 datasets, different end points. There were two 8 questions: Does it tell us abo ut acid sensitivity 9 and do we have national coverag e? After looking at 10 lots of different approaches, s oil base cation 11 weathering as it was monitored by McNulty in 2008 12 I believe, we looked at that. We looked at DOC in 13 the water. We looked at alkali nity. We looked at 14 ANC. We looked at trying to cl uster those criteria 15 together and using four of themand then see if 16 that would work, what that woul d tell us. And we 17 decided that ANC was the best e cological indicator 18 that told us something about ac id sensitivity. 19 At that point we had a cou ple options. We had 20 Omernik's 1984 alkalinity map. We could draw a 21 circle around the areas that sh owed low alkalinity. 22 Those could be our sensitive ar eas; or is there 23 another way to spatially define ecosystems. As 24 ecologists we know the definiti on of an ecosystem 25 doesn't have a spatial componen t. We know that

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1 critical loads modeling happens at the watershed 2 level. Watersheds there are to o many of them, 3 thousands of them within the U. S. for us to look at 4 each one of those. 5 So the ecoregion concept w as developed 6 starting in 1987 by Omernik. And it was developed 7 to look at water quality, actua lly, not 8 specifically acidification, but it was a tool for 9 policy makers to aggregate and define spatial areas 10 that were similar ecologically. 11 And throughout the past, y ou know, 23 years 12 they've developed better approa ches to defining 13 those ecoregions and there are three levels: One 14 is the broadest. There are 15 ecoregions level 15 ones in the U.S. Ecoregion lev el three that we 16 selected as 87 different areas defined. 17 So at that point we said, okay, knowing that 18 ecoregion is a pretty well acce pted way to define 19 spatial areas in addition to th e fact that ANC is 20 our best indicator of acidifica tion, let's use the 21 two together to try to determin e where the 22 sensitive areas are. And from that point we then 23 said okay what are the critical load -- what are 24 the sites that we have calculat ed critical loads 25 for in each of those ecoregions . For nine of those

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1 ecoregions in the level three s patial definition, 2 we have zero critical load datafor. For some of 3 them we have 700 critical load calculator sites 4 where we can calculate critical loads. So that's 5 what Bryan was referring to ear lier in that some of 6 these ecoregions are really wel l represented and 7 data rich; some of them not so much. 8 So, because of that, we th en went into the 9 clustering technique and we hav e clusters which 10 we're trying to make five categ ories of sensitivity 11 using the ecoregion spatial sca le. So that's sort 12 of a history of our thinking an d some of the steps 13 that we've gone through. Hopef ully that can help 14 as we continue the discussion. 15 DR. RUSSELL: Actually, Ka thy and then Andre. 16 DR. WEATHERS: Part of the process, it's very 17 helpful, both Bryan's and your descriptions are 18 very helpful and they absolutel y need to be 19 captured in this document. The way I was thinking 20 about it is, well, there is one option which is to 21 spatially aggregate by -- limit ed by the data that 22 you have. You just explained w hy that doesn't work 23 so well, the base cation weathe ring or geology. 24 The other is to think abou t process level 25 data. So I like the ecoregion characterization

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1 because it takes into account e cological variables 2 that will influence both deposi tion and processing. 3 So I'd like to encourage you toexplain more 4 clearly in the document what it is you just 5 explained here. It will help u s advise. 6 DR. RUSSELL: Andre. 7 DR. BYTNEROWICZ: Along th ose lines, living in 8 the southwest, I'd like to ask you how confident 9 you feel that you're doing a go od job with this 10 part of the country? Especiall y from the point of 11 view that acidification effects are not so 12 important, nutritional effects of nitrogen 13 deposition are a key factor. S o could you indicate 14 to me a little bit more how youfeel about 15 acidification effect for the aquatic ecosystems and 16 the next -- 17 DR. HUBBELL: I can tell y ou we don't feel 18 good about the nutrient enrichment part of it. 19 Obviously the assessment we didfor co-benefits 20 will suffer from the sparseness of data that's 21 available. Maybe Jason can tal k about coverage 22 that we feel like we have in th e southwest. 23 DR. LYNCH: Sure. In term s of the data 24 sources that went into calculat ing the critical 25 loads, we really focused on the national surveys

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1 that EPA has done over 30, 40 y ears. So they date 2 back to the 1980s. And then he avily used data as 3 part of the EMAP program both i n the northeast and 4 in the west. 5 And one key point to empha size about those 6 datasets are that they really f ocus on sensitive 7 areas within the U.S. in terms of the acidification 8 and so the majority of the wate r quality 9 measurements were in regions th at were soon to be 10 sensitive to acidification. It doesn't necessarily 11 mean that they are showing effe cts. 12 And so out west depositionmay have been such 13 that you don't have large effec ts within for 14 acidification, but the potentia l to be too 15 acidified was there. And so th ey did do a fairly 16 sophisticated survey of westernsites and we used 17 that data. 18 Having said that, most of that, the area that 19 they focused on is kind of the northern part of the 20 western. So the southwest, to the most part, is 21 under-represented. 22 We then moved into some ne wer datasets. There 23 is the Weightable Stream Surveythat was done. It 24 concluded in 2007. So I refer to that date. Most 25 of the data was collected early2000s. That does

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1 provide some coverage. It is n ational coverage 2 there. 3 We also looked at the 2010 lake survey that 4 was completed to give some fill ing in, in terms of 5 those coverage. Having said th at, yes, there are 6 definitely regions where we're data limited at this 7 time. For this analysis so tha t we could keep a 8 lot of the data sources consist ent, we really chose 9 to use the EPA-sponsored water quality data. There 10 are state data out there that c ould be rolled into 11 this analysis, just that we did n't use that at this 12 time. 13 DR. RUSSELL: Dale. 14 DR. JOHNSON: Yeah, as lon g as you bring up 15 the southwest, I'll bring up La ke Tahoe where there 16 is a lot of research going on a bout atmospheric 17 deposition and pollution becaus e the watershed is 18 about two-thirds water. The te rrestrial buffering 19 for all of that is zero. So it 's straight into the 20 lake and atmospheric input. Soextremely 21 important. 22 DR. RUSSELL: Rudy. 23 DR. HUSAR: Now, I recogni ze that there are 24 all the effort that went into i dentifying the 25 sensitivity, but I was thinkingmore of the

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1 combination of atmospheric conc entration, 2 deposition and then the sensiti vity together so 3 that we see what is the nature of that pattern that 4 actually arises from the combin ation of those. 5 Because that to me, as far as I 'm concerned, that's 6 what your proposal is. The ess ence of the proposal 7 there is this index that is mea nt to be measured to 8 be used as the quote standard. 9 DR. HUBBELL: Yeah, I agre e. 10 DR. RUSSELL: Ladies first . Lauri. 11 MS. CHESTNUT: Thank you. I just have a 12 question that's come up while y ou're talking about 13 it in terms of these categories . Are all the 14 parameters that go into that, d o they have to be 15 the same for the category, like the ammonia 16 deposition or the transformatio n from ambient to 17 deposition? So is that -- are those, you know, for 18 any given category are those pa rameters all the 19 same? So do we have to think a bout what division 20 there needs to be so the functi on is specified 21 right? 22 DR. HUBBELL: Well, I mean , within the 23 calculation of the critical loa ds those are 24 calculated based on the individ ual lakes that we 25 have information on, the water chemistry, the

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1 streams and lakes, waterbodies bodies, the lakes 2 and streams. The information w e have on the 3 individual waterbodies, but it' s a total critical 4 load for sulfur plus nitrogen - - actually, yeah, 5 sulfur and then adjusted with n itrogen with the 6 Neco terms. 7 MS. CHESTNUT: So it's kin d of an average 8 across? 9 DR. HUBBELL: No, that's i ndividual lakes 10 within an area. Then you calcu late critical load 11 and you take the distribution o f critical loads. 12 Where the question about spatia l aggregate comes in 13 is when you introduce reduced n itrogen and try to 14 figure out how to adjust for re duced nitrogen. 15 DR. GREAVER: Well, spatia l aggregation for 16 the critical loads question on it because you have 17 to define which sites in your p opulation are in 18 your critical loads. And that then affects the 19 distribution and how you select which percentage of 20 those waterbodies. 21 DR. HUBBELL: That's not a veraging as much as 22 it is -- you're still calculati ng for each 23 individual lake. It's just a question of which 24 ones get included in that distr ibution. That's 25 what is determined by your spat ial extent for

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1 selecting lakes and streams. 2 There is also a separate s tep of, we have to 3 figure out what reduced nitroge n to subtract out of 4 the available nitrogen that youhave to work with 5 to get your NOx-related critica l loads. And that's 6 another question -- that's why we propose a couple 7 different ways that you could d eal with it. One is 8 you can average it over the ent ire region, which 9 would be, you know, might be ap propriate and we're 10 still thinking through this. I t might be 11 appropriate to make sure you're covering the entire 12 ecoregion if you're thinking of one monitor for the 13 entire region. You might want to have an average 14 that represents that entire reg ion or you might 15 want to have a different percen tile of the 16 distribution of reduced nitroge n values within that 17 region. 18 The other option is to mat ch the reduced 19 nitrogen to the area you're goi ng to intend to 20 represent with your monitoring. Within an overall 21 ecoregion you want to make sure that you monitor 22 the lakes and streams that are most important 23 within that region. You might want to have a 24 monitor in place to represent aparticular portion 25 of that ecoregion. And you mig ht want to make your

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1 reduced nitrogen match that par ticular area that 2 you're monitoring for. 3 So there are still options for dealing with 4 that. And we're still playing through how that -- 5 what the implications would be for overall 6 protection within the ecoregion . So we may be 7 trying several different ways o f looking at reduced 8 nitrogen and seeing does it res ult in the specific 9 level of protection that we ant icipate, in terms of 10 the percent of what waterbodies that are actually 11 protected when you see a partic ular level of NOx 12 and SOx. 13 So those are the things we 're playing through 14 the system to see how it would impact the overall 15 level of protection at a partic ular target ANC 16 value. We haven't completed al l those calculations 17 yet. But, again, I do think th at in the end you're 18 going to have some aggregation of ammonia and 19 you're going to have some aggre gation of the 20 transfer ratios that convert NO x to deposition. 21 And they may not match the exac t averaging -- 22 spatial averaging -- or, excuse me, spatial unit 23 that you use to determine your population of lakes 24 and streams. Is that clear at all? 25 MS. CHESTNUT: Yeah, I thi nk so. I guess what

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1 I'm trying to get at in terms o f grappling with 2 this question is I think we sta rt off with 3 sensitive and not sensitive bec ause we know we at 4 least need the two categories. And every -- every 5 division into more groups adds administrative work, 6 data work, you know, it adds di fficulty and 7 therefore cost and complication s, and what's gained 8 with each. 9 DR. HUBBELL: Right. 10 MS. CHESTNUT: So where is the tradeoff and 11 what's the right balance? One of the things this 12 whole thing is about is allowin g -- is this 13 requisite, you know, finding a standard that's 14 requisite to protect the sensit ive areas and not 15 overconstrain areas that aren't sensitive. And 16 that's one of the things I kept trying to see if I 17 could understand here. And I w as having trouble 18 seeing is -- yeah, you mentione d the difference 19 between the critical loads for the two groups which 20 gives you a sense of, okay, the se areas are not 21 sensitive are not as constraine d. And -- but how 22 does moving to more disaggregat ion, does it -- does 23 it allow more flexibility for t he less sensitive 24 areas? Does it make them bigge r in a way? Is 25 there a bigger way that we're n ot going to be so

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1 worried about it -- 2 DR. HUBBELL: It's more li ke when you cluster 3 those ecoregions, what it does is bring more 4 populations together. So when you take the 5 distribution of those values an d you say, okay, 6 here is a critical load distrib ution and we select 7 90 percent say, for example, yo u're trying to 8 protect 90 percent, if you take 90 percent of the 9 overall combined distribution a nd then apply that 10 critical load to all the ecoreg ions within that 11 cluster, okay, then you may be overprotecting some 12 and underprotecting some. 13 So the question is if you then disaggregate 14 those clusters, do you get a su bstantial difference 15 in the critical loads that have to be met for 16 different ecoregions or are the y largely the same? 17 It all depends on how much simi larity there are in 18 those distributions. 19 One of the things we're tr ying to do with the 20 clustering is bring together th ose groups that are 21 not likely to have big differen ces in their 22 critical loads. So that you ca n reduce that 23 burden, that complexity without giving up much in 24 terms of the flexibility of cha nging the critical 25 loads that each region might ha ve to achieve.

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1 The real question in looki ng between these is 2 how much difference do you get in the critical 3 loads; and is that worth the ex tra complexity? 4 When you think worth, what does that mean? It 5 means do you give them more clo se to their true 6 requisite protection level or d o you not? And if 7 they're very close to each othe r, given the 8 uncertainties and various other things we've got in 9 this, is it worth taking the ot her step? 10 Fundamentally it's going t o end up being a 11 policy call as to whether that' s worth it. What 12 we're looking for guidance on i s, is the types of 13 options we've laid out, does th at capture the types 14 of things you can think of that are representative 15 of sensitivity differences that might be 16 appropriate to consider when yo u decide whether or 17 not it's a real difference in t he critical load? 18 And, you know, one of the things that we tried 19 to point out through this in al l these methods in 20 every ecoregion or every group of ecoregions there 21 are some more sensitive and some less sensitive 22 lakes and streams included. Th ere are almost no 23 places in the country where it' s all sensitive 24 lakes or it's all nonsensitive lakes and streams. 25 So there is always going t o be that

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1 distribution in each of those e coregions. The 2 question is really what's goingon in the tails of 3 the distributions and are they similar enough that 4 we can combine them and feel th at we're giving an 5 overall level of protection? 6 There is going to be a pol icy call that's 7 required, but it should be info rmed by which 8 differences are real versus whi ch differences are 9 simply implied by methodologies . We want to get at 10 real differences in sensitiviti es so that we can 11 try to adjust the critical load s. 12 I don't know if that was h elpful at all or 13 not, but it is a difficult choi ce. And one thing 14 we can certainly try to work onmore is here's the 15 chart, if you go to Figure 5-12 . Are you at 5-12? 16 Page 5-44, sorry. In this part icular figure, what 17 we're trying to demonstrate is the differences 18 between the different options t hat might be 19 available. And so we have opti on one, which was 20 the one nation using all the la kes and streams. We 21 had option two, which was split ting it into option 22 2-A, which was splitting the co untry into sensitive 23 and nonsensitive, and then opti on 2-B, which is 24 using five clusters. We don't show the results for 25 all the individual ecoregions.

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1 What this shows in fact if you look at the 2 deposition load to cover 90 per cent of the lakes in 3 a particular population, if youlook just between 4 the one nation and the sensitiv e and less 5 sensitive, you see that the cri tical load for 6 sensitive regions is very simil ar to the critical 7 load for the nation when you ju st use the one 8 nation. It's 26 versus 27. Th is is the critical 9 load for both nitrogen plus sul fur. 10 When you look at the criti cal load for the 11 less sensitive area, it's twice as big. So you can 12 say, well, that's a pretty sign ificant difference 13 if you allow for nonsensitive l akes to have a 14 separate critical load. It mea ns in those areas 15 they're going to have to do les s to be able to meet 16 the standard. It makes sense g iven that 17 flexibility and the fluctuationin sensitivity of 18 the lakes. 19 When you go to the cluster s, you can see, 20 well, three of the clusters are actually close to 21 each other, looking, again, at the 90 percent 22 deposition load. You see that the cluster one, 23 cluster two and cluster four ar e all around, you 24 know, 25 to 30. But clusters t hree and five are 25 quite a bit different, they're 48 and 72.

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1 In that case you can say t here is still 2 benefit in going to five cluste rs rather than going 3 to two. You might say, well, m aybe we should 4 combine clusters one, two and f our. Maybe they're 5 all similar enough that we can combine them. There 6 is still some tweaking that canbe done. 7 The idea is to try to findthat balance of 8 where you're gaining in terms o f ability to have 9 flexibility versus where you're losing in terms of 10 complexity. This is sort of wh at we're trying to 11 use for metrics for comparison. 12 DR. RUSSELL: Bryan, thank s. Actually, I will 13 point out to the committee one of the things you 14 said is you're still working th rough a lot of 15 issues associated with that. I think that's 16 something -- I realize you can' t give it to us 17 right now, but that's the sort of thing I think we 18 almost need to really fully adv ise you on, you 19 know, some of the parts of the standard. 20 DR. HUBBELL: Certainly, w e understand that. 21 What we're hoping is to get you r -- again, this is 22 the first time you've seen any of this. 23 DR. RUSSELL: Right. 24 DR. HUBBELL: What we want is reaction to this 25 as well. It doesn't seem like a good thing to do.

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1 It doesn't seem like reasonable metrics to be able 2 to compare. Again, we went thr ough way more 3 methods than I want to try to l ay out in this 4 document, but it's not an easy task to come up with 5 a way to divide the country up in a way that allows 6 flexibility. This has not beendone before. 7 DR. RUSSELL: We appreciat e it's not an easy 8 task. 9 DR. HUBBELL: The questionis are we bringing 10 the scientific information, the critical load 11 information, the sensitivity in formation, are we 12 bringing it together in a way t hat makes sense for 13 you scientifically as you consi der it and its 14 usefulness for policy? That's what we're looking 15 for. 16 DR. RUSSELL: Charlie. 17 DR. DRISCOLL: So I guess I agree with a lot 18 of comments that have been said , particularly 19 Rudy's comments to try to work through some of 20 these issues, particularly give n where the 21 emissions are; and do the clust ers make sense given 22 the distribution of emissions a cross the country, 23 the importance of sulfur in the east versus the 24 importance of nitrogen in the w est. 25 I have the sense that one is too few and,

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1 whatever it is, 87 is too many. So I think, you 2 know, five makes sense if you l ook at a map, a 3 figure, I think it's 5-11, to me that sort of looks 4 about right given the levels of bins of ANC and 5 what we're talking about as sen sitivity. I think 6 like that is in the ball -- bal l game. But I 7 worry -- I like the cluster app roach. It makes 8 sense, but I worry about as youmove forward with 9 this, you're going to presumabl y, if you go 10 forward, you would probably addon other 11 considerations like we've talke d about, nutrient, 12 nitrogen and other consideratio ns. And there are 13 efforts that are coming down th e pipe. There is 14 this big Forest Service initiat ive to try to 15 develop empirical loads for nit rogen that are based 16 on the ecoregion approach. So if you use a cluster 17 approach, does that cause probl ems with broadening 18 this to include these other iss ues that are on the 19 back burner? 20 So I think that that's an important 21 consideration. It would be some -- it would be 22 nice if you could use ultimatel y, you know, however 23 many years down the road use th e same basic 24 approach for acidification, nut rient, nitrogen and 25 so on and so forth, so that thi s approach is

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1 consistent for these different effects. So I'm not 2 answering the question very wel l. I'm just 3 throwing out a few thoughts. 4 DR. GREAVER: Could I resp ond to that? One of 5 the things I like about using t he clustering 6 approach is we're clustering ec oregions. If I 7 remember correctly, that Forest report on empirical 8 nitrogen approach uses the ecor egion concept to 9 assign those loads. I think th ey're compatible in 10 that sense. Maybe the clusters would be 11 disaggregated a little bit if w e then did a 12 nutrient or just an empirical n itrogen critical 13 load. 14 DR. DRISCOLL: I would agr ee if you can do 15 that and retain the cluster app roach if that's how 16 we're going forward with nitrog en. It seems like 17 this is a huge effort to pull a ll this nitrogen 18 information together. It couldbe improved 19 certainly, but you think it's apotential resource 20 to take it to the next step andaddress these 21 nitrogen issues in the west. 22 DR. RUSSELL: Naresh. 23 DR. KUMAR: I think I go b ack to Lauraine's 24 question that if you have to ag gregate LNHx terms 25 and NOy terms having five clust ers is too few

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1 because LHNx is going to vary s o much across the 2 regions. So I just don't under stand what is the 3 difficulty in having the 77 eco regions? Other than 4 if some of the regions don't ha ve enough data, 5 could those regions be combinedtogether and maybe 6 they could have a data from all the other regions 7 taking an average. At least th e ecoregions, if you 8 have it there, I think individu al -- 9 DR. HUBBELL: To be clear, I mean, these 10 sensitivity regions, they're no t the end in terms 11 of you come up with the distrib ution of critical 12 loads and pick the critical loa d that represents 13 the 90 percent protection over that entire class of 14 sensitivity, but you can then f urther refine the 15 tradeoff curves, the critical l oads for NOx and SOx 16 based on more spatially refinedestimates of 17 ammonia. And you can also, aga in, to develop the 18 concentration-based critical lo ads you can use more 19 spatially refined estimates of VNOy and SOx. It's 20 not that you have to then avera ge over that entire 21 cluster for that particular par t of the variable. 22 It's just used to establish the basic critical load 23 for acidity that's used. 24 DR. RUSSELL: Rich. 25 MR. POIROT: I wonder if w e could go back and

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1 look at that Figure 5-12 for a minute. That's 2 actually one of the places wher e I lost you. And 3 maybe I could find it, you can explain it to me. 4 But I guess I was -- I had beenfollowing along 5 with this proposed cluster appr oach thinking that 6 the Cluster 5 was the most sens itive and had the 7 lowest mean ANC and so forth. And I guess I must 8 have gotten that wrong; or if t hat's true, then why 9 does it have the highest deposi tion of all of the 10 clusters to protect the 90 perc ent level? I guess 11 I expected to see some more log ical pattern of 12 clusters in that figure and I d on't understand why 13 it's not there. 14 DR. GREAVER: So probably Figure 5-12, we have 15 it in Figure 5-5, we noted in F igure 5-12 16 parenthetically what the mean ANC level value was 17 for the five clusters. Cluster 5 actually has the 18 highest ANC value. It's 167, s o that corresponds 19 quite well to the highest. 20 But your point is a good o ne because when you 21 see Cluster 3 and 4, Cluster 3 has a lower ANC 22 value, yet a higher what we're defining deposition 23 metric. So Clusters 3 and 4 th ere is a little bit 24 of inconsistency between that mean ANC level and 25 the 90th percentile critical lo ad.

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1 DR. HUBBELL: Part of that is the difference 2 between the mean and looking at the more sensitive. 3 When we're looking at 90th perc entile critical load 4 that protects the 90th percenti le lake, it may not 5 be all matched with what the me an ANC value for the 6 overall distribution is. If th e distribution has a 7 very long tail, it could end uphaving a very big 8 difference between the mean ANCand what the 90th 9 percentile critical load values end up being 10 protecting 90 percent of the la kes and streams 11 within that cluster. 12 And that actually is the c ase and we probably 13 should put the median in as wel l as the mean ANC so 14 you can get an idea of the over all shape of the 15 distribution a little better. That's probably 16 what's causing some of the conf usion. 17 DR. RUSSELL: Other questi ons from the panel? 18 Thank you. 19 DR. HUSAR: Just a quick question, maybe 20 suggestion regarding the Figure 5 all summarizing 21 the outcome of many of these op tions. Would it be 22 possible to take that same info rmation that went 23 into producing this kind of comparison to expose 24 more of the underlying parts of that, such as would 25 making the same thing spatiallyand doing more than

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1 just in Figure 5-12 or 5-13, wh ich illustrates some 2 aspects of what the nature of t he spatial 3 consequence is of those assumpt ions? In other 4 words, the reason seems to be w here I get confused 5 it's kind of opaque as to what goes into these 6 summaries. So if they are brok en down and exposed 7 as pieces, maybe it would be mo re easier to 8 understand. 9 DR. HUBBELL: We can certa inly try. It's a 10 little hard because a lot of in puts -- these 11 critical loads derived from the SSWC model which 12 integrates everything up to tha t point. So it's a 13 little difficult to then tease out sort of 14 individual parts. 15 So we can take it from thi s point and go 16 forward in terms of saying what happens when you 17 combine that with reduced nitro gen and the other 18 parts of the AAPI equation. Bu t the first parts of 19 the AAPI equation are really de termined by the 20 critical load modeling. It's h ard to disaggregate 21 them unless you're saying in te rms of doing more 22 maps we can. If you're saying doing more maps, we 23 can certainly do that. 24 DR. HUSAR: Doing more map s to separate the 25 deposition part from the sensit ivity part.

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1 DR. HUBBELL: We can do mo re maps, for sure. 2 DR. GREAVER: We have some . I'd like to 3 highlight two maps. They might be helpful. In 4 Figure 5-10, what we have there -- and that's on 5 page 5-37, what we have there i s a map of the U.S. 6 with the ecoregions at Level II I outlined. And 7 those that are colored red we c onsidered sensitive 8 using our ANC criteria. Those that have no color 9 or color, I guess it's white, w ould not be 10 sensitive. 11 So for this example what w e did is divided our 12 population of 7,500 critical lo ads into two 13 categories, sensitive and not s ensitive, and looked 14 at the distribution. And in Ta ble 5-4, it talks 15 about the sample size and the a ssociated Neco 16 values that go with that. Thenon Figure 5-11, 17 that shows the different catego ries or which 18 ecoregions are considered in wh ich of the five 19 clusters based on the mean ANC value. And then we 20 give more of the statistics tha t go along with the 21 critical load populations or I should say sites for 22 the critical loads to be calcul ated. Those 23 populations has been outlined f urther in Table 5-5. 24 In this case there are 7,5 00 -- population of 25 7,500 sites is then divided int o these five

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1 categories and the sample size ranges from 216 to 2 2,500. We have big populations for each of these 3 clusters. Then when we finallyget to our single 4 ecoregion approach, we don't pr ovide a map there. 5 We provide a map of the ecoregi on, each of them 6 individually earlier on. And T able 5-6 goes 7 through each and every one of t hem, each of those 8 87, and it gives you the mean a nd eco-value, the 9 number of critical loads that w e had calculated for 10 that ecoregion, the mean value for that, the 11 standard error; and then once w e looked at the 12 distribution, the 90th percenti le, 75th percentile 13 and 50th percentile. So we tri ed to present these 14 statistics. 15 DR. HUBBELL: We can poten tially map out more 16 of those. We could look at the se tables and turn 17 them into maps. Maybe that wou ld be helpful. 18 DR. HUSAR: Yeah. When th ere are exposed 19 companion maps of both the sens itivity that Tara 20 has been explaining how those a re arising from, at 21 the same time to see also what is the nature of the 22 deposition maps so that you hav e at least some 23 feeling as to why is it that th e certain cluster, 24 let's say, whatever are up ther e, why are they 25 sensitive? Is it primarily due to the high

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1 deposition that is driving that or because of their 2 surveyed high sensitivity? 3 DR. GREAVER: That's a goo d point. ANC, our 4 ANC indicator integrates those two things because 5 ANC is a consequence of both na tural sensitivity 6 and your loading. So that's wh y we chose ANC to 7 base the sensitivity on. 8 DR. RUSSELL: Rich. 9 MR. POIROT: So you sent u s as an attachment, 10 this series of maps that show w aterbodies that 11 would show critical load of 50 and 20 12 microequivalents per liter. I guess I was 13 wondering is there another kindof question -- like 14 isn't part of this categorizati on process really 15 aimed at avoiding under and ove rprotection? 16 So is there a companion ma p to these that 17 rather than showing -- or at th e same time you're 18 showing us the different ANC le vels, is there a way 19 to show graphically under and o verprotection? 20 DR. HUBBELL: Possibly. 21 DR. GREAVER: We played wi th that. We tried 22 to do a bar graph, bar graphs, like we did in 23 Figure 5-12 for all the ecoregi ons; but, as you can 24 imagine, with the 87 different ecoregions it's a 25 really, really large graph, but it does give you

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1 visually, you know, some idea o f who is being 2 underprotected and who is beingoverprotected. 3 What we ended up doing is we produced Figure 4 5-14. What this is, is for the se 87 ecoregions, we 5 plotted out what's the 90th per centile deposition 6 metric for each of those and so-- and then 7 percentage of the ecoregions pr otected. So if you 8 protect 100 percent of your eco regions at the 90th 9 percentile value, your depositi on metric is 13. 10 Then we also give the values fo r 90, 75, 25, et 11 cetera. 12 So this is a way that we t ried to compress all 13 87 of those into one figure andgive you some idea 14 of the relative sensitivity andthe amount of 15 underprotection and overprotect ion for a given 16 deposition metric. 17 DR. HUBBELL: I think, aga in, we can certainly 18 continue exploring ways of tryi ng to map out for 19 individual ecoregions and parti cular sets of 20 waterbodies what the level of o ver or 21 underprotection is. We can con tinue to work 22 through that and try to come upwith better ways to 23 present that information certai nly. 24 DR. RUSSELL: Praveen. 25 DR. AMAR: I'm looking at Figure 5-9, the

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1 ecoregions and you have A.B.C, 8.2.3, what is that, 2 the .2 and .3? 3 DR. GREAVER: That's a nam ing mechanism they 4 use. 5 DR. AMAR: Subcategories? 6 DR. GREAVER: It is actual ly. At the Level 7 III ecoregions you have the thr ee numbers, 8.3.1. 8 Level II would be 8.3. Level I would be ecoregion 9 8. Level I you have far less e coregions in the 10 U.S., I think it's about 15. At Level II those 11 become subdivided; at Level III those become 12 subdivided further. 13 DR. HUBBELL: Our apologie s too, we had 14 originally had -- we had a defi nitions table along 15 with these numbers that says ex actly which each one 16 is, what their descriptive titl e is. I don't know 17 what happened to that. It may have gotten somehow 18 cut out. But there is -- there is a distinct 19 mapping, specific word descript ions of each of 20 these ecoregions that exist. S o we'll make sure 21 that we get that out. 22 DR. RUSSELL: Thank you. Unless there is 23 something burning, we probably should move on. 24 So question 7, Andre. 25 DR. BYTNEROWICZ: So gener ally I think the

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1 concept of critical loads of co urse is, according 2 to my understanding, logical an d appropriate for 3 the development of secondary st andards. And this 4 approach links concentrations o f oxidized forms of 5 nitrogen and sulfur with nitrog en and sulfur 6 deposition and their acidifyingeffects on aquatic 7 ecosystems. 8 And what's important this approach also takes 9 into consideration reduced formof nitrogen as a 10 contributor to acidification of lakes and streams. 11 In my previous remarks I mentio ned that it's 12 important to have in mind how i t links to the 13 effects on terrestrial consiste nce and nutritional 14 effects of nitrogen deposition, but we've already 15 discussed that. 16 In regards to Part A of th is question I have 17 trouble with understanding that . Maybe it's the 18 reason that I'm not a specialis t in this area, but 19 I think a portion of the docume nt should be better 20 or clearer origin. And I thinkI would probably 21 try to modify a question becaus e the question for 22 me was confusing and what is th e appropriateness of 23 generalizing the factor. For me, it would be more 24 logical, at least for me, if I wanted to discuss 25 that would be is the proposed methodology for

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1 obtaining BCo values adequatelydescribed and what 2 the panel opinion is on extrapo lating the exchange 3 for the Adirondack lakes and so uthern Appalachian 4 streams to the rest of the U.S. I think that kind 5 of understanding of the problemwould help us, not 6 being so specific about the F a pproach. 7 And Part B what are the vi ews of the panel on 8 filtering criteria, I think it' s a reasonable 9 approach in regard to applicati on of the first 10 screen, those ANC values below the target ANC 11 values I think is logical, clea rly described. 12 Use of the second screen t he removal of all 13 the BCo values below 10 microequivalents per liters 14 per year, I had problems unders tanding why this 15 particular value is used. Mayb e it's somewhere in 16 the text, maybe I missed it. I have to admit I 17 like to have a little bit more time to read the 18 document. So maybe I have miss ed something because 19 of the lack of time. 20 In regard to the first scr een for acid mine 21 drainage and the organic acidit y, I have no 22 problems with understanding the m and I think they 23 are good. That's what I have. 24 DR. RUSSELL: Thank you, Andre. Kathy. 25 DR. WEATHERS: I don't hav e too much to add to

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1 that, I agree. Although based on a conversation 2 that Charlie and I had this mor ning, I thought the 3 filtering approach was a good i dea. But one 4 question is why take out the na turally acidified 5 lakes? Why not leave them in a nd see how it comes 6 out in your analysis? Leave th em in and adjust the 7 percentage of lakes that are pr otected. 8 So I know it was responsiv e to our questions 9 and comments last time around t hat you did the 10 filter. 11 DR. HUBBELL: We did consi der leaving them in 12 and adjust the percentage or ta ke them out. We 13 determined if we took them out when we selected the 14 percentage and went forward wit h that, those lakes 15 would still receive some protec tion. We just 16 wouldn't be targeting them beca use they're already 17 below the amount of ANC that we could possibly hope 18 to achieve. 19 So the idea was that, you know, that you base 20 your critical load distributionand your target 21 critical load on those that are both sensitive and 22 likely to be responsive and the n you accept that 23 you'll get additional protectio n for those that are 24 not responsive to atmospheric d eposition. 25 DR. WEATHERS: You might r econsider taking

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1 that class of lakes out up fron t, filtering the 2 acid mine drainage, yes, you mi ght reconsider. 3 Charlie, I don't know if you wa nted to add to that. 4 DR. RUSSELL: Charlie, you 're up. 5 DR. DRISCOLL: So I agree with what Kathy 6 says. I feel, I think fairly s trongly, that it's a 7 mistake to remove high DOC lake s and the very 8 acid-sensitive lakes. 9 I agree, acid mine drainag e, that's fine, that 10 makes good sense to eliminate t hose from 11 consideration because you're fi ltering on the front 12 end and then you're filtering o n the back end to 13 protect some level of lakes, 90 percent, 14 70 percent, whatever the value is that's 15 determined. You can always fla g those systems and 16 indicate that those systems nev er had an ANC above 17 50 and maybe that's criteria fo r, you know, why 18 they wouldn't achieve protectio n. It seems to me 19 if you include them, these lake s, it's a more 20 transparent part of the process . 21 The other thing is your va lues are, at least 22 for DOC, are arbitrary. You're selecting 10 23 milligrams per liter. That's avery high value, 24 but there are lakes or surface waters in very 25 sensitive areas that can be -- that organic acids

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1 can influence the acid-based ch emistry at 2 relatively low concentrations. 3 So I think a value of 10, you know, indicating 4 that those are naturally acidicorganic acids is 5 arbitrary. And those systems t hat have high levels 6 of DOC and naturally occurring organic acids can 7 also show effects of acidic dep osition. They can 8 show elevated sulfate. They ca n show elevated, you 9 know, inorganic aluminum. Why not include them and 10 just flag them as part of the a nalysis? 11 I know New York would be v ery upset if you got 12 rid of some of those systems be cause there is a lot 13 of lakes in the Adirondacks tha t fall into those 14 categories that you're throwingout on the front 15 end. 16 In terms of the other ques tions about the 17 critical loads approach, I thin k that makes sense. 18 I endorse that. It's widely us ed throughout the 19 world and it made sense that we use something like 20 that. 21 And then the other questio n was the F-factor 22 approach. And I agree that usi ng a steady state 23 approach like the F-factor appr oach might be a good 24 initial analysis, but I think, as I said 25 previously, ultimately we need to know the time

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1 scale of recovery. And so I th ink parallel efforts 2 for applying dynamic models nee d to be done. 3 That's going on in a number of case studies now. 4 DR. RUSSELL: Kathy. 5 DR. WEATHERS: Just a ques tion on the F-factor 6 approach since all of us seem t o be fairly confused 7 what the question was. What qu estion did you want 8 answered? 9 DR. HUBBELL: What we want ed was an answer to 10 what Andre was saying, which is have we 11 appropriately evaluated the ava ilable information 12 to characterize base cation wea thering and is this 13 a reasonable approach given the available data we 14 have? 15 DR. LYNCH: What Bryan sai d, that's what we're 16 trying to get at. Is this a re asonable approach 17 given the availability of data and where we are on 18 the science today? 19 DR. WEATHERS: But you're also using not just 20 the F-factor approach to get at base cation supply 21 weathering, right? Is that wha t I understood 22 from -- 23 DR. LYNCH: Yeah. Well, o kay, just to 24 clarify, I mean, the idea behin d the base -- the 25 F-factor is this idea if you ha ve acid anions on

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1 the soil, they're going to caus e some level of 2 leaching. And so we want to re move that out of the 3 calculation in terms of estimat ing the critical 4 load. 5 And so where you have sens itive systems that 6 becomes very important because then you can be 7 using the water quality data de pending on where you 8 took it. In terms of its histo ry, you can be 9 overestimating what the base ca tions flux to that 10 system would be. And so the F- factor is saying, 11 well, it's probably something l ower than -- lower 12 than that. 13 When you have systems witha lot of base 14 cations, you know, in a sense t he value becomes one 15 and it's less important. And s o that's where 16 that's coming in. It's trying to get us a way to 17 correct for that value. 18 And so what we're trying t o get at is it's 19 not -- I mean you can do dynami c modeling and 20 compare and there is two graphs and two case 21 studies in there in the Adirond acks and the 22 southern Appalachians. And we' re going to do even 23 more comparisons there. That s hows that if you use 24 those two methods that if you'r e generally on the 25 low end, so 80 microequivalents or less of ANC, you

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1 know, you get pretty good compa risons. Where it 2 begins to fall apart in the Adi rondacks is when you 3 get higher values. And in gene ral it's more 4 scattered in stream systems in terms of that. 5 And so, you know, is it ap proach -- do we want 6 to refine that approach? Defin itely. But what 7 we're looking for is this a way-- is it okay to 8 move forward with this or is th ere better 9 approaches that we should be th inking about that, 10 you know, we can be looking to be modeling, et 11 cetera? 12 DR. HUBBELL: One of the c ritical things Jason 13 said if it performs well, where we're most 14 interested in the range of minu s 50 to a hundred of 15 ANC, you know. We're not as co ncerned about the 16 really high ANC values because they're not likely 17 to be affected by these standar ds, those areas, 18 because they're going to have s uch high critical 19 loads that they'll allow for a regular deposition. 20 DR. SCHEFFE: I think for consistency the 21 F-factor approach was used in a ll the critical load 22 calculations nationally. 23 DR. LYNCH: It's easy to d o it. Can I go back 24 and ask Charlie a question, bas ed on a comment? 25 DR. RUSSELL: Sure.

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1 DR. LYNCH: The concern, C harlie, for why we 2 added in the DOC criteria was t he case of say 3 Florida. And an example there is you wouldn't 4 necessarily want to constrain o r, you know, 5 overregulate in Florida. And s o that's, you know, 6 Pacific and midwest the aciditymay be driven more 7 naturally. We don't want to ov erprotect in that 8 system. We're trying to create a balance. 9 DR. HUBBELL: The issue is if we leave them in 10 there when we do our percentage s, you can say, 11 well, you can adjust the percen tages; but the 12 percentage of targeted lakes mi ght have to vary 13 quite a bit between the differe nt types of systems. 14 If we're looking for a consiste nt percent of 15 waterbodies to protect across t he country, better 16 to take out things we don't wan t to protect first 17 so we can say consistently we'r e trying to protect 18 90 percent. 19 If you leave those in, youmight say, well, in 20 Florida we only want 70 percent because 25 percent 21 are naturally acidic lakes. It made it more 22 complicated to think about how to set a single 23 parameter as a target percentag e throughout the 24 country. 25 DR. DRISCOLL: It's been along time since

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1 I've looked at data in Florida. And I know that 2 they are -- they're interestingsystems. And they 3 do, some of them, have high DOC , but they also have 4 very high chloride as I recall. And you could have 5 conditions where chloride couldimpart natural 6 acidification if the sodium is retained on the 7 exchanger. 8 I understand, you know, th e problems with 9 Florida; but, you know, I thinkthat there are also 10 issues, as I indicate, in areas like the 11 Adirondacks or the upper midwes t where there are 12 high DOC systems where there ar e impacts as well. 13 So I'll have to think about Flo rida more, but I 14 think these other systems are r elevant as well. 15 DR. HUBBELL: If there is another criteria 16 that can be used to screen out Florida than just 17 saying Florida lakes are out, i f we can come up 18 with another criteria, obviousl y, that's something 19 we could use. It's trying to f ind what are the 20 criteria that are most useful f or screening out 21 lakes that would be responsive to and sensitive to 22 deposition. 23 DR. DRISCOLL: I'd have togo back and look at 24 the Florida systems. Like I sa id, it's been a long 25 time since I did. I'd have to try to refresh my

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1 memory. 2 DR. RUSSELL: Any other qu estions, comments? 3 DR. SCHEFFE: Just one mor e part. 4 DR. RUSSELL: Rich. 5 DR. SCHEFFE: Let's assume , you know, we use 6 this 10 cut off of 10 microequi valents for DOC, 7 what's in the Adirondack lakes that most of those 8 lakes were not screened out, wo uldn't that 9 alleviate some of the concerns you have? Because, 10 again, the concern about some o f these naturally 11 heavily organic waters, I mean, I think Bryan's 12 point is really something we ar e real concerned 13 with in terms of some consisten cy in terms of 14 population of protecting waterb odies. 15 So how would you respond t o that if, you know, 16 in essence when we look at this , most of those 17 sensitive waterbodies in the Ad irondacks are 18 actually included in the compil ation? 19 DR. DRISCOLL: That's fine . I understand that 20 there will be some, you know, t hat there will be a 21 lot of lakes in the Adirondacks , but there will 22 also be a lot of lakes that hav e background ANC 23 values below 50, and there will also be a fair 24 amount of lakes with DOC values that are high. 25 So I'm not saying that at the end of the day

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1 you wouldn't filter those out. I'm just saying 2 when you come up with your targ ets, you can flag 3 those values so that that's, yo u know, part of the 4 decision making process in term s of justifying the 5 target value of 90, 95, 80, wha tever -- whatever is 6 come up with. It's just an alt ernate approach to 7 do this. 8 I think rather than havingtwo screens, one on 9 the front end, one on the back end, why don't you, 10 to the extent you could, have o ne screen and 11 everybody understands that? 12 DR. RUSSELL: Thank you. Andre, you're still 13 up. 14 DR. BYTNEROWICZ: I guess question eight, yes. 15 DR. RUSSELL: Question eig ht, yes. 16 DR. BYTNEROWICZ: Well, I think the proposed 17 approach makes sense and utiliz es the best 18 available knowledge on levels o f distribution of 19 reduced nitrogen. And in terms of not having a 20 separate sample for ammonia I t hink is the way to 21 go. 22 I have a remark regarding distribution of 23 concentrations on the spatial s cale and due to high 24 ammonia deposition velocity andpossibly the steep 25 concentration gradients ammoniasource areas, I

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1 think that should be taken intoaccount. And, 2 therefore, averaging reduced ni trogen concentration 3 over large areas may lead to mi ssing smaller areas 4 where ammonia concentrations ma y be seriously 5 elevated with potential high ge opolitical and 6 ecological effects. Therefore, option two, I think 7 I would vote for that because i t allows for a 8 conditional spatial refinement of sensitive areas 9 to reflect the heterogeneity of NHx deposition. 10 And following that, as we discussed in our 11 previous meetings, and you did discuss in your 12 previous documents a much bette r understanding of 13 spatial and temporal distributi on of reduced 14 nitrogen, especially among the U.S., is critical. 15 And efforts should be continuedto assure that we 16 can accomplish this goal at the national scale. 17 That's what I have to say. 18 DR. RUSSELL: Thank you. Kathy. 19 DR. WEATHERS: Yeah. Are there any other 20 options? I agree that includin g this is really 21 important, but are there any ot her options for 22 spatial refinement, which is I think what we're 23 talking about here, it would be desirable to not 24 only have ammonia and ammonium deposition, but have 25 better spatial refinement than we get with the CMAQ

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1 model. 2 DR. HUBBELL: If you look at page 9-8, there 3 is an interpolated ammonia map that is based on 4 current CMAQ modeling. Clearly , you could go into 5 the individual grid cell and us e that value, but is 6 that appropriate and representa tive of the area 7 you're trying to cover with und erstanding of the 8 NOx and SOx concentrations that are going to be 9 then combined with that to dete rmine the overall 10 loading. So that's what we're trying to get, 11 again, that balance. 12 Our current thinking on th is, again, you could 13 go with the ecoregion size and do an average over 14 that. You can try to come up w ith some smaller 15 groupings similar to polygons b ased on the credence 16 values. You can come up with s ome polygons that 17 represented areas of more relat ively uniform 18 ammonia deposition that could b e then bend 19 together; or you could simply s ay, you know what, 20 we're representing area of 12 k ilometers with our 21 monitor and we're going to use a 12-kilometer grid 22 cell to match that. Those are the options we could 23 go to. 24 It's not clear to me what is the most 25 appropriate overlap between tho se two, between the

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1 NOx and SOx, ambient concentrat ions and the 2 deposition of ammonia. Advice on that would be 3 very welcome. It's not a hundr ed percent clear to 4 me what is appropriate to matchthose two together. 5 It's clear we want to do that. 6 DR. WEATHERS: That is a c hallenge. It seems 7 to me, my gut call is they've g ot to be matched to 8 the scale that CMAQ is modelingright now. In part 9 that's because it would also be desirable to have 10 better spatial resolution for t he NOx and SOx 11 deposition, which concentration s may be more 12 uniform over that area, but dep osition is not and 13 it's based on vegetation of sub surface and that 14 sort of thing or dry deposition . 15 So this is that devil in t he details of the 16 spatial scales, matching spatia l scales, scaling up 17 and scaling down the various fa ctors in the AAPI 18 and for the deposition. So my call would have that 19 be the same as the CMAQ. 20 DR. HUBBELL: Yeah. One o f the things we're 21 looking at too is the depositio n transference 22 ratio, averaging them over that same spatial scale 23 that we're interested in becaus e it is, again, 24 because of these issues that th e concentrations are 25 not going to match the depositi on at a very fine

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1 scale, but over a broader scale they may match much 2 better. That's one of the thin gs that we'll 3 continue to explore as well is how does the spatial 4 scale affect the relationship b etween the 5 concentrations and the depositi on. 6 DR. WEATHERS: Yeah. And the links back to 7 one of the appeals of the ecore gions, because, in 8 fact, it's the vegetation type that will influence 9 this deposition if that's clust ered together. 10 DR. HUBBELL: Yeah, okay. Thank you. 11 DR. RUSSELL: Charlie. 12 DR. DRISCOLL: So last time we met I had a 13 comment about the effects of ni trate deposition 14 versus ammonia deposition on wh ether or not they 15 would have an equivalent effect . So I went back 16 and did a little work on this. 17 So we actually did some --a number of 18 simulations looking at the trad eoffs between 19 nitrate and ammonia. And I tho ught that there 20 would be some effect, but the e ffect, at least from 21 our model calculations, is rela tively minor, only 22 one or two microequivalents per liter relatively. 23 We did it for a number of systems, some that 24 show fairly high nitrogen leach ing and some that 25 show relatively low nitrogen le aching. From that

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1 standpoint, which I brought up last time, that does 2 not seem to be a consideration. 3 DR. RUSSELL: Panel? 4 DR. BYTNEROWICZ: If I cou ld. 5 DR. RUSSELL: You certainl y may. 6 DR. BYTNEROWICZ: I forgot to mention when I 7 had my time, there is a new pap er by Robin Dennis, 8 Science Atmospheric Pollution R esearch. It's a new 9 journal just published. He's t alking about 10 distribution of ammonia and cha nging basically the 11 common knowledge that ammonia c an be transferred 12 over a long distance. I think it's a very valuable 13 new piece of information. 14 DR. SCHEFFE: That's in Ch apter 7, actually. 15 I used that very liberally in C hapter 7 in terms of 16 talking about some of the impro vements in CMAQ, 17 especially in characterizing ammonia. 18 DR. HUBBELL: And that is, again, another 19 reason to potentially consider broader spatial 20 averaging rather than just refi ned because there 21 are other gradients, you can se e from the 22 deposition map, there is some p retty fine gradients 23 around major source areas and i t's probably a good 24 idea to really again -- these a re the things we can 25 look at as we think about imple mentation issues as

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1 well, but defining that spatial area that's 2 represented by this particular input to the 3 modeling I think is very import ant. Again, we're 4 going to continue to try to dev elop those 5 relationships and form that bef ore we get to the 6 rule. 7 DR. BYTNEROWICZ: Just to respond to that, but 8 it has to be done cautiously be cause our data from 9 Sierra Nevada shows that over adistance of 10 70 kilometers, running from Cal ifornia central 11 valley into eastern Sierra, youcan reduce on the 12 average ammonia concentration f rom about four or 13 five micrograms per cubic meter to around one or 14 two. So it's not a very steep gradient, you know. 15 DR. HUBBELL: Sure. 16 DR. SCHEFFE: Obviously, i t's going to vary 17 quite a bit for terrain and veg etation features 18 that go along those transects. 19 DR. BYTNEROWICZ: What's i nteresting when we 20 compared the transect with what we saw 20 years 21 ago, the gradient at that time was much stronger 22 because we were going down to a bout one microgram 23 per cubic meter or below. So i t looks like with 24 the change of gasoline formulat ion and higher 25 emissions of ammonia we are hav ing larger, stronger

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1 effect over a larger scale. 2 DR. RUSSELL: Kathleen. 3 DR. WEATHERS: Question: Actually, Charlie, 4 your simulations what I think y ou just said 5 translating into the terms that are being used here 6 is that ammonia deposition woul d actually go into 7 the Neco term. Is that right? It doesn't come out 8 as nitrate if you add more ammo nium? It would 9 functionally go into the tradeo ff curve as a bigger 10 Neco term over time? 11 DR. DRISCOLL: Possibly. What I did was I 12 took for a series of watersheds in the Adirondacks, 13 I looked at a range of hypothet ical nitrate ammonia 14 deposition. And I was thinkingsince ammonium is 15 cation, if you altered it, you would have a 16 different response than nitrate , which is an anion. 17 There were differences in the way I thought 18 they would go, but they were re latively subtle. I 19 think for 20 sites we looked at maybe one or 20 two microequivalents per liter variation. Because 21 ammonium is more acidifying, th ere was a little bit 22 greater effect with ammonia tha n nitrate. Nitrate 23 is more alkalizing, but it was fairly subtle. 24 DR. WEATHERS: Yeah. The reason I'm asking is 25 I'm thinking about the way you' ve conceptualized

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1 the tradeoff curves and where ammonium deposition 2 and Neco sit and whether in ter ms of process that's 3 something you can or would like to take into 4 account? Does it actually tran slate into a bigger 5 Neco term? 6 DR. SCHEFFE: So what we d o with the Neco 7 term, we consider both nitrate and reduced nitrogen 8 to be exactly equivalent in ter ms of its effects on 9 the ecosystem. So Charlie had raised the question, 10 well, that might not necessaril y be true in terms 11 of how it goes. So what we're hearing from Charlie 12 is the assumptions we're using for Neco, we would 13 keep it pretty much the same th e way we represent 14 it in the equation form. 15 So in concept, the Neco te rm it can be looked 16 at it's going to be acting on a ny form of nitrogen 17 that deposits. We do separate out and we do have a 18 relationship between Neco and r educed nitrogen to 19 kind of account for, you know, hypothetically how 20 much reduced nitrogen can be ta ken up, you know, by 21 the whole system and we look at it in those terms 22 as well. 23 DR. RUSSELL: Any other qu estions? Looking at 24 the time, I think we'll break f or lunch. If you 25 look at -- well, we actually ha ve about ten more

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1 minutes. I'll keep it here for ten more minutes. 2 With that, Naresh. 3 DR. KUMAR: Question nine. 4 DR. RUSSELL: Question nin e. 5 DR. KUMAR: That's the dep osition transference 6 ratios TNOy, TSOx. I didn't se e any other changes 7 in these. I don't know whether I missed anything 8 or not. 9 DR. HUBBELL: We changed t he name. 10 DR. KUMAR: Yeah. Major c oncerns means these 11 are very predictable things bet ween aggregate 12 concentration and deposition an d devising a model 13 that can't be evaluated because of a lack of data. 14 So you looked at some of t he variability using 15 a model, variability in concent rations. Some 16 equations can be large, but I w as wondering why not 17 also look at the variability fr om different models 18 because, you know, CMAQ and oth er models are being 19 used by different agencies thanEPA. Just trying 20 to see how stable the issue is using different 21 models. Also something which i s not completely 22 looking at different mechanisms , I think that needs 23 to be done. 24 DR. SCHEFFE: Yeah. If I could respond, those 25 are good points. And so yeah, we would want to

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1 look at the differences relatedto interannual 2 variability in meteorology. We would want to look 3 at differences with regard to e missions and we'd 4 want to look at differences wit h regard to 5 different chemical mechanisms a nd treatments there. 6 So we do have some example s of variability, 7 some spatial variability as wel l, as well as some 8 response to different emission scenarios that we're 9 really, you know, those -- we'r e very optimistic 10 about the results of those. Wh en we look at the 11 difference between the base cas e in 2005 and moving 12 into the future in 2030 where w e see approximately 13 50 percent reduction in NOx and40 percent 14 reduction in SOx, and we see qu ite a bit of 15 stability retained in those rat ios, which is very 16 important. 17 We do have to do those oth er analyses and we 18 have those planned. And it's amatter of trying to 19 find -- what we really want to do is have the 20 analyses of isolating the chemi cal mechanism using 21 the same meteorology and the same emissions 22 scenario so we can kind of lookat what is the 23 effect of different chemical me chanism treatments 24 on that. And so that's one of the things that we 25 really intend on having done be fore this document

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1 becomes final. 2 DR. HUBBELL: That's also true for the model. 3 One of the problems we ran intois finding 4 something that's the same in te rms of inventories 5 and everything as the CMAQ run is not easy. 6 Because we also often have to t ry to find existing 7 modeling runs that have been do ne because there is 8 a huge demand for modeling in E PA and not a lot of 9 resources. We've been trying t o take advantage of 10 existing runs. Unfortunately, there wasn't a 11 matching exact one for CMX and CMAQ. 12 DR. KUMAR: Just looking a t that, and seeing 13 how variable it is, is useful. 14 DR. SCHEFFE: I agree. Ev en though it's 15 mixing all those different proc esses together, it 16 is useful. It's something we'r e trying to kind of 17 nail down as well. 18 DR. RUSSELL: In fact, I w ouldn't see there is 19 much need to look at exact matc hes for something 20 like this. 21 DR. HUBBELL: You inflate the two things. 22 Although we've established emis sions aren't 23 important in terms of it's not introducing 24 variability, it won't be as biga deal. But if 25 you're using a different emissi ons inventory with

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1 KMx than you are with CMAQ, the n you're getting 2 both the emissions and modelingdifferences that 3 might be impacting. 4 DR. SCHEFFE: It would imp ortant if you have 5 big differences you'd want to k ind of have some 6 insight in terms of what perhap s is causing those 7 differences. 8 DR. RUSSELL: Right. But my view is if this 9 is going to work that well, the re better not be 10 that big of a difference. 11 DR. HUBBELL: You have to be stable with 12 everything. 13 DR. SCHEFFE: That's a goo d point. 14 DR. HUBBELL: It's diagnos ing what you would 15 do with it. 16 DR. RUSSELL: Right. The first thing I would 17 do is say is this a hard stop? 18 DR. HUBBELL: Fair enough. 19 DR. KUMAR: Also, the vari ability I assume is 20 being driven by wet deposition patterns from year 21 to year. But maybe you can als o verify, is it -- 22 does the wet deposition ratio c hange or even the 23 dry deposition ratio change whe n you go from one 24 unit to another? 25 DR. HUBBELL: That could b e looked at as well.

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1 DR. KUMAR: That's all I h ave. 2 DR. RUSSELL: Rudy. 3 DR. HUSAR: Not much new t o add here. It 4 still seems natural and meaning ful to use the CMAQ 5 for making those estimations of the deposition, 6 different parts of the depositi on. The aggregation 7 procedure also makes sense lump ing them in 8 deposition. 9 The word -- the statement here that, well, if 10 indeed those estimates let's sa y on the deposition 11 do indeed match the observation , but this is now -- 12 the problem is that the model e stimation of the dry 13 deposition in particular in one of your tables is 14 off, a 40 percent difference inthe sulfur dioxide 15 simulation. That simply indica tes that something 16 about the deposition particular ly outside is not 17 quite right. If the model over predicts by 18 40 percent that means it is not removing 19 adequately. So the estimate of the dry deposition, 20 which is one of the biggest, pr obably biggest, 21 terms in your overall depositio n is going to be 22 off, substantially off, okay. 23 Now, and that's the part t hat later on in 24 Chapter 7, you know, is not dea lt with because you 25 don't necessarily have enough d ata, et cetera, to

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1 see neither the magnitude, nor the variability, nor 2 for that matter where the spati al is for that 3 region. 4 So that's still a hang up, you know, issue 5 with those, fixing, making sure that that overall 6 mass balance within the model d oes actually come 7 out right. 8 DR. SCHEFFE: Yeah. Those are really good 9 points. And I think one of the things -- what's 10 come to light when we look at t hings because we've 11 been using these models for air applications so 12 often and so familiar, and diff erent questions and 13 different challenges arise whenwe look at it from 14 a deposition perspective. And having that split 15 between sulfur dioxide in parti cular to sulfate, 16 you know, is increasingly more important in these 17 applications. You know, the 40 percent is not -- 18 that's not what I would say is a generalizable 19 number in terms of the ratio be tween CMAQ and 20 sulfur dioxide, but nevertheles s there is a trend 21 for CMAQ to be overpredicting s ulfur dioxide. 22 There is also some concern s with regard to the 23 very limited amount of observat ions that we have in 24 the CASTNET network for sulfur dioxide as well and 25 how accurate those measurements are.

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1 So there is a lot of work as we move forward. 2 I think Myron was making those points. We really 3 have to be looking at that more and more carefully. 4 I agree with you. It's very important; that sulfur 5 mass balance is very, very impo rtant for this 6 process. 7 DR. HUSAR: Yeah. And jus t to highlight the 8 emphasis that you could now con tribute to that 9 whole fixing, including the CMAQ, would in fact be 10 on the sulfur dioxide dry depos ition because so 11 much in the past was about the sulfate. 12 DR. SCHEFFE: Sure. 13 DR. HUSAR: Now, the thingis this is about 14 the other part, which actually is the bulk of 15 the -- 16 DR. SCHEFFE: I agree, emp hasis now. 17 DR. HUSAR: This is just aroutine procedural 18 kind of a point over here, I st ill have some 19 concern about the reading of th is thing callid 20 transfer something or another. 21 DR. SCHEFFE: Transference . 22 DR. HUSAR: Transference r atio. It's the same 23 as I stated before. Depositionvelocity is not a 24 physical entity. It happened t o arise from the 25 ratio of deposition to concentr ation. So,

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1 therefore, there is no reason t o invent a new term 2 for deposition velocity that ma y be either dry 3 deposition velocity or wet depo sition velocity in 4 the ratio of deposition or tota l deposition 5 velocity. In that case, you wo uld avoid, among 6 other things, the confusion tha t it causes, the 7 issue within your own document. If it's named five 8 different ways in different sec tions of the 9 document, ambient concentration , deposition, 10 transformation ratio quite a bi g difference. 11 DR. SCHEFFE: It's suppose d to be X'd out. 12 DR. HUBBELL: We tried to catch that. 13 DR. HUSAR: And things lik e that. It's just 14 my favorite expression on that when you have enough 15 natural complexity in the syste m there is no need 16 for artificial complexity intro duced. 17 DR. RUSSELL: I think we a re the ones that 18 suggested a different name was advisable because it 19 isn't either a dry deposition p hilosophy or wet 20 deposition philosophy. So I th ink we're the ones 21 who requested that. 22 DR. SCHEFFE: Rudy, we've gotten as much of 23 the other kind of comments as t o how dare you call 24 this thing a deposition philoso phy or deposition 25 ratio because deposition only, only corresponds to

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1 individual species. So when yo u aggregate things 2 there were a lot of people that were set off that 3 we were calling it a depositionphilosophy. 4 DR. RUSSELL: CASAC has ch anged its mind on 5 things before. 6 DR. HUBBELL: We're happy to call it whatever 7 you want to call it. 8 DR. HUSAR: Maybe I would like to have a 9 conversation with the person wh o -- 10 DR. RUSSELL: I don't reca ll who actually 11 first did that. Praveen. 12 DR. SCHEFFE: Yeah, it was Praveen. 13 DR. RUSSELL: Talk to Prav een. 14 DR. AMAR: I used to be th e deposition person 15 too. But I think transference too, how do you say 16 it, transference ration, yeah, I think it makes 17 sense because it's simply a mod eled number. You're 18 dividing all your deposition toall your 19 concentrations on a wet basis. 20 So, anyway, my comment in addition to what 21 Naresh had to say, I think you mentioned on page 56 22 about that some of the sulfate is found in coarser 23 fractions and CMAQ does not add ress coarse 24 fractions of PM and then you no tice something to 25 the effect that you are going t o address that in a

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1 monitoring chapter, which I hav e not read 2 thoroughly. Have you addressedthat issue? 3 DR. SCHEFFE: I think ther e was probably some 4 carryover from earlier versions . Current versions 5 of CMAQ do incorporate coarse p article treatment in 6 there, okay. 7 DR. AMAR: So that's not a n issue then. 8 DR. SCHEFFE: It's always -- characterization, 9 of course, particles in general is an issue, but 10 one of the points that we were trying to make and, 11 to be honest, it ends up being in the noise 12 probably, but what happens is w hen you look at -- 13 forget about models or mantras when you consider 14 all the distributions of partic les in the air, we 15 know, you know, from the variou s studies that the 16 vast majority, 80, 90 percent o r more, of particles 17 are in the fine fraction, less than two and a half 18 microns, okay. 19 And initially we were just under the 20 assumption, all right, we couldbasically not worry 21 too much about the coarse fract ion because so much 22 of it is in fine fraction. But because of the 23 different deposition velocities , where you start 24 getting into direct gravitional effects with large 25 particles, that small tail that 's in that larger

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1 size fraction can have conseque nces in terms of 2 contributing a lot to the actua l deposition of 3 sulfate. But, having said that , sulfate deposition 4 is relatively small compared tototal sulfate 5 deposition. 6 DR. RUSSELL: Though, bein g specific, I 7 thought CMAQ coarse fraction yo u do not have 8 sulfate growing into -- growinginto the soil. 9 DR. SCHEFFE: I think we n eed to check on the 10 specifics of that, but the newe r versions of CMAQ 11 have started to incorporate coa rse particle 12 treatment. 13 DR. AMAR: To be clear the n, the document says 14 it might be a big issue. What I'm hearing from you 15 that it may not be and, therefo re, we don't need to 16 address it? 17 DR. SCHEFFE: Well, but, a nyway, with regard 18 to CMAQ, regardless of how that treatment is, 19 whatever particle sulfate mass is there, it will be 20 incorporated into a mass balanc e context, 21 regardless of, you know, what p art and size 22 distribution. That's all beingincluded there, 23 okay. 24 From a monitoring perspect ive this has other 25 implications where we are recommending that we have

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1 an open inlet to capture all th e particle sizes. 2 DR. RUSSELL: It has the a bility to calculate 3 the transference ratio and the uncertainties 4 therein? True? 5 DR. SCHEFFE: I've got to think about that 6 because the way it's all kind o f embodied in the 7 model -- so that would -- 8 DR. HUBBELL: I think -- 9 DR. RUSSELL: What I'm say ing is since you're 10 using CMAQ you can't calculate a transference 11 ratio, but CMAQ doesn't really capture the sulfate 12 in the large -- in the coarse p article, the 2, 5, 13 10, but then you're measuring w hat's happening in 14 the two, five to ten and applyi ng a CMAQ 15 transference ratio that's reall y only based on the 16 up to PM 2.5. There is a littl e bit of sloppiness 17 there. 18 DR. SCHEFFE: Yeah, there is. There is some 19 what I would call inconsistencythere. 20 DR. RUSSELL: Much better word. Thank you. 21 Other panel questions or commen ts? Myron. 22 DR. MITCHELL: I guess it' s kind of based upon 23 some other comments about the C MAQ application, 24 looking at the chapters, my und erstanding that 25 looking at these transference r atios was done from

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1 CMAQ runs from 2002 to 2005, wh ich would probably 2 capture a fair amount of meteor ological variation 3 but very little in terms of emi ssion variation. It 4 seems a little presumptuous to me to indicate there 5 is low variation. I'm looking at changes in 6 emissions over time and attribu ting that and saying 7 this is capturing that. I thin k that needs to 8 be -- 9 DR. SCHEFFE: It's a good point, but we did 10 have a 2030 emission scenario i n which there were 11 30 percent reduction in NOx and40 percent in 12 reduction in SOx in that domain . That's what we're 13 talking about in terms of its a bility and 14 variability in emission changes . 15 DR. MITCHELL: Looking at some of these 16 changes like wet and dry deposi tion ration, looking 17 at long-term actual like CASTNE T, I'm concerned 18 that you're basically looking a t what is already in 19 the model and calculating out t he model and saying 20 the model works. That's not a very valid -- that's 21 not a very firm foundation. 22 DR. HUBBELL: Sure. Sure. There is some ORD 23 data, some folks at ORD who are thinking about this 24 and we're trying to get that an alysis done. 25 They're looking at the co-locat ed sites where you

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1 have both the concentration mea surements and the 2 deposition measurements. 3 DR. MITCHELL: Then I get -- I look at Figure 4 5-20 on page 558, I look at the se ratios between 5 deposition and concentration, p articularly I was 6 curious about the sulfa form. I have a hard time 7 figuring out what in the heck w ould cause -- what 8 do you do with marine sulfate a nd how does -- what 9 is driving that pattern? It do esn't make any sense 10 what I could think about what w ould drive sulfur 11 deposition in concentrations? What goes on in the 12 coast? 13 DR. HUSAR: Because by tha t time it's mostly 14 wet deposition, all the gas is gone and -- and 15 therefore -- 16 DR. MITCHELL: That part I know. It's like 17 marine aerosols would be gigant ic, like 18 50 kilometers. 19 DR. HUSAR: It's kind of t he artifact of the 20 inversion -- 21 DR. MITCHELL: This seemedcurious to me. 22 DR. HUBBELL: What it's sh owing is that when 23 you get off the coast, the conc entrations are very 24 low. So the deposition-to-conc entration ratio -- 25 the deposition is mainly wet de position and not as

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1 related or deposition -- 2 DR. MITCHELL: Concentrati ons of marine 3 sulfate. 4 DR. HUBBELL: You're not g etting that -- 5 DR. MITCHELL: How is that covered? It's a 6 question? 7 DR. SCHEFFE: No. What we need to do actually 8 there is a few things going on. There is the 9 intermixing of a lot of the mar ine kind of 10 processes that are markedly dif ferent than what's 11 going on land. And then you al so have some 12 boundary effects that come intoplay as well. And 13 so we need to have a better -- we need to have a 14 better description of what's go ing on. 15 We see that with a lot of things. You can 16 look at almost any kind of a mo del output. These 17 might be transformation ratios. We can look at 18 concentration patterns for many , many different 19 species and we see incredible g radients. We can 20 get a better description of tha t for you. 21 DR. HUBBELL: To be fair t o the model, most of 22 the valuations were focused on what's over -- 23 DR. MITCHELL: I understan d. I know the 24 Oceanic Department is looking a t critical loads and 25 looking at the sensitivity area s, and I was

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1 wondering how the modeling is w orking then. 2 DR. RUSSELL: Not to cut u s off, we're going 3 to have a cold lunch if we don' t break. We have a 4 hot lunch. So let's get back a t about 1:10. 5 (Lunch recess.) 6 DR. RUSSELL: Correct me i f I'm wrong, I think 7 we're up to question 10. 8 MR. POIROT: I have that. 9 DR. RUSSELL: Yes. 10 MR. POIROT: Before we lea ve the last 11 question. 12 DR. RUSSELL: Yes. 13 MR. POIROT: Regarding the se transference 14 questions, I ended up having a confidence crisis 15 over the weekend in terms of ho w much I worried 16 about the NOy, TNOy function. I thought I was 17 comfortable with it the last ti me around, but we 18 hadn't really been able to see the details of it. 19 I wish the EPA people were here . 20 DR. RUSSELL: Shall we tab le that one? I 21 think we can get through number ten pretty quickly. 22 MR. POIROT: Okay. 23 DR. RUSSELL: And we can g o back to number 24 nine because yes, it wouldn't b e bad if EPA were 25 here to finish those other ones up. Question 10

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1 is -- 2 DR. COWLING: Are they not coming up? 3 DR. RUSSELL: They are, bu t they don't get 4 lunch served to them. Sometime s it's not as quick 5 for them to turn around. 6 And keep in mind this is g ood timing, we can 7 discuss things. If we need to ask EPA questions, 8 we can wait for them to return. 9 DR. KUMAR: A number of th em are on the 10 averaging time of three to five years. Is that 11 appropriate given the AAPI stan dard? So I don't 12 see any change in that. I will stick with that. 13 I'll agree that's an appropriat e time. 14 DR. RUSSELL: Praveen, I t hought ten would be 15 quick. 16 (Dial tone heard over the speaker.) 17 MR. McNAMARA: I didn't doanything. The 18 system must have disconnected i tself. I'll re-call 19 it. 20 DR. RUSSELL: Any other --the things 21 discussed on question nine that we don't need EPA's 22 input on? If you would like toget the feel of the 23 panel, I guess make some statements to the panel 24 about questions. 25 DR. KUMAR: One question I have EPA has done

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1 -- looked at these issues for 1 2-kilometer 2 resolution, and we know things can change if we one 3 resolution to another. Is ther e a need to also 4 look at these resolution -- the se ratios with a 5 different resolution? Everythi ng else is still the 6 same, but the resolution change s. Would that have 7 an effect and speak to the stab ility of this issue? 8 DR. HUBBELL: We might hav e some runs where we 9 have 36 kilometer and 12 kilome ter and we could 10 look at that as well. And we w ere also talking 11 about doing some comparisons if you do, you know, a 12 12-kilometer grid cell by itsel f compare NOy to 13 total deposition and expand out to a grid square, 14 keep going out that way and see how they change. 15 That's another way to look at i t. 16 DR. RUSSELL: Is that some thing you all are 17 doing right now? 18 DR. HUBBELL: No. I thinkit's very doable. 19 We have the data to do that. I made a note to 20 myself to do that. 21 DR. RUSSELL: Rich, back t o you. 22 MR. POIROT: I was thinkin g, you know, that 23 these ratios are sort of critic ally important, and 24 yet we can't touch them and exp lore them. It would 25 be nice if we could see them inmore detail, I

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1 mean, different ways. 2 I found, you know, just fo r example, there are 3 some figures on page 728, Figur e 7-12 that show 4 these box whisker plots of the variability or the 5 coefficient of variations of th ese ratios over 6 time, as you model, I think thi s is over the longer 7 term change in emissions. So t hat idea of having a 8 metric, however it works, that remains stable over 9 time as emissions are changed i s really important; 10 and these figures gave me bette r confidence than I 11 otherwise would have had. 12 But I guess I'm wondering are there other ways 13 you can show this information s ince I just don't 14 know what these kind of box whi sker plots are 15 supposed to look like? That th ey're close to zero 16 in terms of the change over the period that feels 17 good to me. But maybe -- is th ere a better way 18 that you could display that inf ormation? Because 19 to me that's a very compelling kind of an argument. 20 Just before that you had these other plots showing 21 the change over the -- over the recent years or I 22 assume it's just the meteorolog y that's changed 23 mostly. 24 I noticed you inverted tho se. It's an inverse 25 of the ratio. I'm sure you hada good reason for

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1 doing that. Since I don't knowwhat it is, I'm 2 tempted to ask if we could see those the other way 3 around. Because wouldn't it be sort of the gross 4 overpredictions that we would w ant to be 5 emphasizing rather than the lar ge underpredictions 6 in terms of the where -- how th e outliers fall? 7 But, again, the stability acros s time gives me 8 confidence. 9 On the other hand, then I went back and looked 10 at the scatter plot in Chapter 4, I don't know if I 11 can find these. On page 437, i f I read it 12 correctly, we're seeing total o xidized nitrogen 13 deposition versus NO2, NOy and nitric acid limited 14 to the Adirondacks region. Andthere is almost no 15 correlation at all between the NOy and deposition. 16 And that made me start to wonde r is NOy really the 17 right indicator? I kind of thi nk it is, but I 18 don't know if there is somethin g wrong with this. 19 Am I misinterpreting it in a wa y that -- 20 DR. SCHEFFE: When do you want me to respond? 21 MR. POIROT: Jump in any t ime. 22 DR. SCHEFFE: So one of th e CASAC members 23 requested that draft. I think it was Rich Poirot. 24 And it was a good idea. I thin k it was in the 25 context of the argument that wa s being made that,

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1 you know, NO2 isn't a particula rly good indicator 2 for what we're trying to accomp lish here. 3 So in addition to the maps you have showing 4 that the NO2 concentration are not as significant 5 let's say in rural areas compar ed to urban areas, 6 why not regress in a line with deposition. So I 7 took a shot at that. It was inthat context and 8 yeah, I was not pleased with th at. I was tempted 9 not to include it, but I figure d, well, wait a 10 minute, I was asked to do that and it's what's the 11 results show. It represents so me of the challenges 12 here. 13 Now, I will say a few thin gs. It is not 14 surprising to me to see poor co rrelations between 15 NOy and total nitrogen depositi on for a number of 16 reasons. And some of those rea sons have been 17 pointed out by some of the comments that there are 18 different things going way abov e in the higher 19 levels of the atmosphere than w hat's going on at 20 the surface, particularly wet d eposition. 21 But in the other parts of that too is this was 22 done on an individual grid cell basis, these 23 regressions. And I know we've had a lot of 24 discussions today about spatial aggregation and we 25 really need to come back with amuch more clearer

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1 explanation about what our inte ntion is in terms of 2 how we're going to base critica l loads and then 3 ultimately how we're going to b ase the calculations 4 on spatially aggregated areas a nd what the basis 5 for that will be. But we are n ever -- I shouldn't 6 say never. We are unlikely to ever apply these at 7 12-kilometer grid base. 8 A more representative regr ession would have 9 looked at the Adirondacks aggre gated spatially as a 10 whole and take time slices and then look at those 11 regressions. Because what's ha ppening is as much 12 as there is an interference goi ng on, a noise 13 that's being introduced by nitr ogen dioxide. 14 Because nitrogen dioxide doesn' t deposit, for all 15 intents and purposes, because o f the soil 16 deposition velocity, there are a number of grid 17 cells that are in proximity to urban areas with 18 relatively high nitrogen dioxid e concentrations 19 throughout the Adirondacks. Sothat's what is 20 creating a lot of the scatter y ou see. You don't 21 see that of course with somethi ng like nitric acid. 22 It's much, much tighter. 23 It does raise the obvious question. Part of 24 the response to all of that is that in trying to, 25 you know, explain some of the t hinking that's going

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1 on here, in trying to have an ambient indicator, we 2 wanted an ambient indicator tha t does a lot of 3 things. 4 We want an ambient indicat or that's 5 representative of NOx, you know , by virtue of the 6 Clean Air Act standards, by Cle an Air Act language 7 that's out there. NOy is certa inly compatible with 8 that. 9 We are also concerned withif we just looked 10 at one individual species, let' s say, like nitric 11 acid or perhaps total nitrate o r something, then 12 you have to be concerned with, well, what about the 13 total reservoir of acidifying p otential that's 14 offered by nitrogen in the air? And if we were to 15 eliminate NO2, for instance, we would be missing 16 some of that potential. And yo u get into a lot of 17 issues in terms of how do you a ccount for wet 18 deposition? You want to tie we t deposition to this 19 process. 20 There are other things tha t can be done. We 21 could kind of look at different ways of that AAPI 22 equation where we would separat e out some of these 23 individual species and some of those terms. But 24 what it comes down to eventuall y is when we start 25 looking at reductions over time in emissions, those

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1 reductions in emissions are goi ng to be reducing, 2 you know, those NOy concentrati ons. Those 3 reductions are also going to in troduce reductions 4 in deposition as well. And I t hink some of the 5 relationships we have to look a t in a better 6 fashion, we did a little bit of that with 7 transference ratios, is lookingat what happens 8 when we change the emissions of nitrogen; and what 9 happens then to the relationshi p of that to 10 concentrations in the air and t o deposition. And 11 that would be maybe another wayof looking a that. 12 But it is -- it is very ch allenging. And 13 right now the way of the form e quation is, it does 14 in a mass balance and in an ade quate mass balance 15 manner tie together a lot of fe atures that are 16 going on in wet and dry deposit ion with ambient 17 concentrations. And there are, as has been pointed 18 out, there are a number of issu es where there are 19 incommensurabilities with the r elationship between 20 an ambient indicator and other processes that are 21 going in the atmosphere. That' s what we're living 22 with. That's part of the reaso n why we feel 23 strongly that we have to use a model that captures 24 those processes in all the diff erent dimensions. 25 DR. HUBBELL: I'll point o ut in the risk and

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1 exposure assessment we looked a t changing NOx and 2 then the resulting changes in d eposition and 3 concentrations. And if you rec all, I'm recalling, 4 if I'm remembering myself corre ctly, you saw a 5 commensurate reduction in each one. You saw a 6 proportionately the same kind o f reductions in NOy 7 or it might have been NOx at th at time and the 8 deposition of nitrogen. 9 So it was clear that reduc ing or decreasing 10 NOx emissions affected both the ambient indicator 11 and the deposition measure in aproportional way. 12 Which is another reason why we felt the indicator, 13 the changes were correlated wit h each other was a 14 good indicator for looking at s tandards 'cause the 15 changes are correlated with eac h other. 16 MR. POIROT: And I agree w ith that. I guess 17 one of the reasons actually I w as wondering about 18 that a little bit was just to s ee if it would be 19 possible to make an alternative calculation of 20 transfer function that was base d on nitric acid and 21 nitrate. The reason and only r eason -- well, 22 several, the indicators themsel ves inherently are 23 more directly associated with d eposition, but, 24 number two, having something th at's kind of already 25 measured or is measurable by, l et's say,

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1 CASTNET-type methods. Because -- we're getting 2 ahead of ourselves on the topic . I don't want to 3 go there too far, but, you know , in the event that 4 we're not able to rule out a bi g new national 5 continuous NO2 network, is ther e something else 6 that we can approximate that wi th reasonably well 7 supplementing that occasionally ? 8 So that's kind of why I wa s interested in 9 that. What would the answer tothat -- you could 10 do the same thing in the model, just the ratio of 11 those two things. 12 DR. SCHEFFE: Yeah. And I actually have gone 13 through that. I actually have split up and 14 reformulated that AAPI equationto separate out 15 nitrate kind of -- actually, a lot of it came out 16 of discussions with Monford community about we do 17 have the availability of doing it through CASTNET 18 to measure total nitrate. And the total nitrate 19 measurement in CASTNET is a fai rly well regarded 20 measurement, not the individual components, nitric 21 acid and particle nitrate; but when you combine 22 them, that is a fairly well reg arded measurement. 23 So that certainly could be done . 24 It then raises some other questions though 25 that, as I said, you are missin g a very important

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1 potential reservoir of other sp ecies because it's 2 all the species that contribute . There are a lot 3 of unknowns. As we move forwar d we've had a lot of 4 the internal discussions. It's like, well, there 5 is a debate in the community ab out how important 6 NO2 deposition is. The Canadia ns believe it is a 7 lot more important than what's currently believed 8 in terms of the way we treat it here in the States. 9 So there is a lot of issue s in terms of moving 10 forward, in terms of getting be tter 11 characterization of deposition of all the species 12 of nitrogen. And to leave some of them out, you 13 know, it goes against the grainas well. It's a 14 challenge. 15 But to answer your questio n, yes, that 16 mechanically is not that diffic ult to do with 17 regards to CASTNET. 18 DR. RUSSELL: Kathleen. 19 DR. WEATHERS: Yeah, I'd l ike to underscore 20 that request. I think it speak s to the fact that 21 there are uncertainties everywh ere in all of these 22 calculations and it's one way t o look at 23 comparisons of CMAQ to CASTNET and also look at 24 deposition. Despite the fact t hat it's modeled, it 25 gives us some balance for under standing where CMAQ

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1 sits relative to other measures of deposition we 2 have. I think it's really impo rtant to calculate a 3 speed for nitrate and compare t he concentration 4 deposition in CASTNET. 5 DR. RUSSELL: Other panel questions, comments, 6 discussions? Ellis. 7 DR. COWLING: Rich, as youwere talking about 8 all the forms of reactive nitro gen, the INC 9 committee offered the advice th at NOy was the best 10 way to deal with the oxidized f orms of nitrogen. 11 There are other chemically redu ced forms of 12 nitrogen. And then there are t he organic forms of 13 nitrogen about which we are sti ll in the great 14 uncertainty. But it appears th at there are, if you 15 collect precipitation, there is a fraction of the 16 nitrogen which is not -- not in organic, either 17 oxidized nor reduced; and, ther efore, and at least 18 according to Hans Spurrow's mea surements, that is 19 some times. 20 I'm just introducing the a ssurance that NOy 21 was a good choice because not o nly did a CASAC 22 member recommend it, but the IN C committee also 23 urged that you consider NOy as the choice so far as 24 the oxidized forms are concerne d. But there are 25 the organic forms, those are me ntioned in Chapter

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1 7, as is appropriate of course. And maybe there 2 are some -- we're trying to app roximate total 3 reactive nitrogen deposition an d its acidifying, 4 and essentially the nutrient en richment kinds of 5 effects. But the more use that we make of the 6 phrase "total nitrogen," the mo re likely we are to 7 have our minds affixed around w hat is really 8 important in ecosystem response . 9 DR. SCHEFFE: Thank you. Other -- you didn't 10 want a response to that? Did y ou? Just a comment. 11 DR. RUSSELL: Other panel discussions? Thank 12 you. Question 11, Charlie. 13 DR. DRISCOLL: Okay. It s eems like I was 14 assigned many multipart questio ns. I'm not sure if 15 there was some message that's b eing sent to me, but 16 I'll try to muddle through them . 17 Anyway, so there was a fai r amount of 18 discussion in the report on the aspects of 19 selecting an ANC and the implic ations of that. So 20 I think that there were a numbe r of values 21 considered. I think the ones t hat were probably 22 considered given the most atten tion was probably 23 20, 50 and 100 microequivalents per liter. And I 24 think one of the challenges her e is that the 25 response, the biological respon se is not really

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1 fixed by a level of ANC, but re ally it's a 2 continuum with relatively clear facts that lower 3 ANCs and diminishing as you get to higher and 4 higher ANCs. 5 So I think that, you know, the treatment that 6 was presented in the document w as -- was 7 reasonable. There is a lot of uncertainty 8 associated with this. But it s eems like, you know, 9 what was presented was fine. 10 I mean, at the end of the day you have to pick 11 a value, right? And if I read between the lines, 12 it looks like 50 is the value t hat you would, you 13 know, if you had to pick a valu e, that's what it 14 would appear that you're endors ing. And I think 15 that that's a defensible positi on. It's certainly 16 moderate. If you take a hundre d, you'd be very 17 conservative and 20 is probably-- there are pretty 18 clear effects at 20. So I thin k 50 is a nice round 19 number and it's probably somewh at defensible. It 20 considers the impacts of episod ic acidification. 21 So I feel, you know, I feel fai rly comfortable with 22 that value. I think it's proba bly fairly 23 defensible. 24 DR. HUBBELL: To be clear on this, because I 25 don't want to be misunderstood, what we're looking

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1 for is really just, again, a ra nge of potential 2 options that are able to be con sidered by the 3 Administrator in making a judgment about what's 4 adverse or not adverse and what target ANC would be 5 likely to lead to protection of public welfare. So 6 it's more looking for a range. 7 So what we were trying to lay out is what 8 happened at different -- what w e see is happening 9 at different levels of ANC that would then form a 10 potential range. 11 DR. DRISCOLL: Would you m ake a recommendation 12 for a value that might be consi dered? 13 DR. HUBBELL: We recommend-- we're not making 14 a recommendation. We'll draw s ome conclusions 15 about what range might be suppo rted by the science. 16 DR. DRISCOLL: I think the values that are 17 laid out and the literature ass ociated with that I 18 think is appropriate. I think it's fine. 19 DR. RUSSELL: Andre. 20 DR. BYTNEROWICZ: I cannot add too much to 21 that. I basically agree that c onsidering ranges 22 from minus 50 to plus 50 equiva lents per liter 23 makes sense. And the standard of 50 seems to be 24 reasonable. And it looks like it's based on what 25 you have provided, the analysis you have provided

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1 and based on what the Europeans and some of the 2 U.S. states are doing. 3 In regard to Part A, 11 Pa rt A of this 4 question is that probably a bet ter discussion 5 should be provided for how thos e proposed values of 6 20, 50 and 100 would mean to th e surrounding 7 terrestrial because it speaks i n various eco-zones. 8 I think more specific informati on could be provided 9 and not only -- there is I thin k it's Chapter 6 you 10 have a graph showing various le vels of deposition 11 related to sensitive indicators for terrestrial 12 ecosystems. It's a good graph, but I think more 13 text would be needed to explainwhat you are trying 14 to do, I mean, linkage between aquatic and 15 terrestrial. I'd like to see i t and it may be 16 between Chapter 5 and 6. 17 DR. HUBBELL: So are you s uggesting that we 18 give explicit weight to those c o-benefits and 19 picking a level of ANC? 20 DR. BYTNEROWICZ: Yes, 20, 50 versus 100, what 21 it means to the terrestrial. S o for the east coast 22 it may be sugar maple and spruc e. 23 DR. RUSSELL: Dale. 24 DR. JOHNSON: I don't have any issue with the 25 ANC targets picked, but there i s again -- seems to

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1 be an underlying assumption or model prediction or 2 something that these delays tha t we're delaying 3 with response and then a delay with recovery. And 4 I think underlying that we've a lready discussed it 5 a little bit during the break, but is the idea that 6 the soils are somehow going to recover to a less 7 acidic condition when depositio n is reduced. 8 I don't think there is anyevidence -- I'm not 9 aware of any study ever done th at shows that that 10 would occur. Models might pred ict it, but I don't 11 think it's supportable. 12 So the soils might remain acid. You remove 13 the mobile anion and the soil s olution and the 14 streams and lakes become less a cid, but not the 15 soil. I think that's a scenari o you should take a 16 close look at. 17 DR. RUSSELL: Thank you. Panel? Questions, 18 comments on this? Lauri. 19 MS. CHESTNUT: In terms of the broadest 20 question, I think it makes sens e the range of ANC 21 that you are looking at here, b ut the way that this 22 document is kind of summarizingin language some of 23 the benefit of going from, you know, higher than 50 24 confuses me. And the example i s the last bullet in 25 the executive summary where it says that target

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1 levels above 50 may provide add itional protection; 2 however, overall health of aqua tic communities may 3 not be impacted. And that seem s to contradict to 4 me what it says in, for example , Table 2-1 where it 5 says that between 50 and 100 fi sh species' richness 6 begins to decline. Are there s till some sensitive 7 species that are not going to r eturn unless you get 8 above 50? I'm not clear on thi s. 9 I think if -- and even if the populations are 10 there, but they're not as healt hy or not as robust, 11 it seems like there is still --it seems like the 12 benefit, the potential benefit of going beyond 50 13 is being underplayed in this la nguage versus what 14 we've seen in the evidence. I don't know. 15 DR. HUBBELL: We'll work o n that one. There 16 is agreement. 17 DR. RUSSELL: Other panel members? Very good. 18 Moving on. Charlie, you're sti ll in charge. 19 DR. DRISCOLL: Part A. Pa rt A. 20 DR. RUSSELL: No. 21 DR. DRISCOLL: 11-A. 22 DR. RUSSELL: I think most of the people 23 included 11-A in their comments . 24 DR. DRISCOLL: Okay. We c an move on to 12. 25 DR. RUSSELL: Yeah.

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1 DR. DRISCOLL: Okay. I th ink that the -- I 2 think that the approaches that were considered for 3 assessing these alternative per centages to protect 4 is appropriate. One of the cha llenges here is a 5 lot of information, the biologi cal information are 6 based on spatial surveys. So y ou have a range of 7 water quality conditions and yo u see organisms 8 responding to those range of co nditions and you 9 infer a relationship. And you infer that 10 relationship is going to work t hrough time. And 11 there is not a lot of very goodtemporal biological 12 information. There is a little bit of information 13 though and it suggests that the organisms don't 14 necessarily respond to the same -- in the same way 15 across those chemical changes. 16 So I guess my only comment is that there is 17 some uncertainty associated wit h biological -- the 18 temporal biological response is going to be in the 19 same patterns that they are spa tially. And it 20 might be useful to have a littl e bit of text 21 associated with that, if you ca n understand what 22 I'm saying. 23 DR. HUBBELL: So just to r epeat to make sure I 24 did get it, so what you're sayi ng is that the 25 current effects in relationshipbetween effects and

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1 ANC or pH levels or whatever th at we're observing 2 now if we're attempting to prot ect 90 percent by 3 picking a critical load of the current distribution 4 that if we change the NOx and S Ox levels in the 5 deposition that response may no t be proportional to 6 that 90 percent. In fact, you may not end up with 7 the same percent protection bec ause some are going 8 to respond more than others in ways we are not able 9 to tell from our existing scien tific literature. 10 Is that correct? 11 DR. DRISCOLL: Yeah. I gu ess what I'm trying 12 to say is that we have spatial patterns and we're 13 assuming that those spatial pat terns will hold 14 through time for a given site. We don't -- I mean, 15 there are not a lot of data to, you know, support 16 or refute that. And so probabl y would be good to 17 clarify that that's an assumpti on that's, you know, 18 made here and response will rea lly depend on, you 19 know, how these organisms respo nd, you know, to 20 these changes over time. 21 DR. RUSSELL: Andre. 22 DR. BYTNEROWICZ: For me aquestion came to an 23 issue of toxicity, which is dam aging individual 24 species versus biodiversity cha nges. And what 25 should be more important or are we looking for some

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1 kind of common denominator? Sothat's something 2 which I didn't see discussed an d I thought I'd like 3 to see discussed more. 4 DR. HUBBELL: So -- so -- so relevant to an 5 entire ecoregion, for example, we're talking about 6 protecting 90 percent of the la kes from, you know, 7 an ANC of 50 or 20. What you'r e suggesting is we 8 should evaluate it based on not only individual 9 responses, but whether that wil l preserve 10 biodiversity across a broader s et of waterbodies? 11 DR. BYTNEROWICZ: Yes. Th at's basically what 12 I would like to see because mor e protection -- the 13 most protection you can provide would also provide 14 better protection for biodivers ity, if I recall, 15 from what you were saying versu s toxicity. So I 16 don't know what would be kind o f a silver bullet 17 for what we're trying to accomp lish. 18 DR. HUBBELL: Well, I mean , just to clarify 19 that, I mean, the way we were d iscussing 20 biodiversity wasn't whether youchose 20, 50 or 100 21 as your ANC target. When we're talking about the 22 percent of lakes, it's a questi on of if you protect 23 90 percent of lakes from an ANCof 50, one of the 24 pieces of information we provid ed was do you also 25 protect the remaining percentag e of the lakes from

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1 going below say 20, which is, y ou know, where 2 really bad things start happeni ng. 3 So you could balance that by saying, okay, 4 well, if we covered 95 percent of lakes, would 5 that -- would the remaining 5 p ercent, would they 6 then be protected? In other wo rds, are you gaining 7 at least some minimal level of protection for the 8 lakes that you are not targetin g for the highest 9 levels of ANC? That's really w hat the analysis was 10 trying to look at. Not so muchwithin the 11 individual lakes are we protect ing against subtle 12 damages to biodiversity versus loss of fish 13 species. 14 So I'm not sure exactly ho w to consider the 15 biodiversity question regardingacross lakes. 16 Maybe it makes sense within a r egion maybe to think 17 about do we have some lakes tha t have some species 18 and some lakes that have other species. I'm not 19 sure exactly how you quantify t hat. 20 DR. BYTNEROWICZ: Well, I' m not either. 21 That's why I was questioning it . 22 DR. HUBBELL: Maybe just qualitatively 23 discussing. 24 DR. RUSSELL: Dale. 25 DR. JOHNSON: Not much to add. I was confused

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1 by the DL factor. And I see co mponents in it, but 2 how it ended up being the merit levels, I'm not 3 sure. I don't know if I missedsomething or 4 getting feeble minded or what? 5 DR. HUBBELL: No. We have a lot of terms 6 dealing with deposition. The D L is the deposition 7 load that is equivalent to the critical load that 8 we will protect a particular pe rcentage of the 9 lakes from -- at a target ANC v alue. So we say DL 10 percent 90, it's saying for an ANC of 50, that's 11 the critical load that will pro tect 90 percent of 12 the lakes in that particular re gion. 13 DR. JOHNSON: But numerica lly somehow was it a 14 model output? 15 DR. HUBBELL: It's based o n we take the 16 critical loads from the SSWC mo deling for all the 17 lakes and streams within that p articular spatial 18 area and we arrange them in a d istribution and you 19 find the critical load that wil l protect 20 90 percent. 21 DR. RUSSELL: Panel? All right. That takes 22 us to 13 and Chapter 6, Lauri, that's you. 23 MS. CHESTNUT: Okay. So C hapter 6 is the 24 co-matters. I think this is a really helpful 25 analysis. You know, we can tal k about it. You can

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1 do a lot of other things. I'm not sure given all 2 the challenges here what the ut ility is of doing 3 more, but I think there are some interpretations 4 maybe that could be pushed a li ttle more with what 5 you've already done. 6 One of the questions that came to mind for me 7 in, for example, the terrestria l. So we know by 8 just focusing on the aquatic we 're not necessarily 9 setting levels that are going t o protect against 10 the terrestrial acidification f or the nutrient 11 enrichment issues. And this is a nice little 12 analysis that looks at how clos e you might get, but 13 the question I was left with wa s one of the 14 conclusions here is that for se nsitive aquatic 15 systems, the sensitive terrestr ial ones close by 16 would get, in most cases, suffi cient protection. I 17 don't have a clear understandin g of how co-located 18 those things are on a national scale. So is 19 that -- are they mostly usuallyin the same place 20 or are they spread out? 21 DR. HUBBELL: Within the s ame watershed 22 generally the way the analysis was done. 23 MS. CHESTNUT: So there is a little more that 24 could be said here about the implications that this 25 is going to protect a lot -- a big share of the

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1 terrestrial systems. 2 DR. HUBBELL: What it does not address -- this 3 is an area we need to develop m ore in the write-up. 4 It does not address to a great extent what is the 5 implications for areas that are not co-located with 6 a waterbody or a sensitive wate rshed, because 7 clearly regional reduction in N Ox is probably going 8 to have some impacts, but it's very difficult to 9 determine how that's going to a ffect. 10 MS. CHESTNUT: Right. Andmy question is how 11 many, you know, what share of t he sensitive 12 terrestrial ecosystems are not co-located with 13 sensitive aquatic? I mean, not that you can -- I 14 don't know how precise you can get, but. 15 DR. HUBBELL: We can look into that. 16 MS. CHESTNUT: Something - - are you getting 17 most of it or are you getting 1 0 percent of it? 18 DR. HUBBELL: I think we c an try to look into 19 that. 20 MS. CHESTNUT: Okay. And I think with the 21 nutrient, you know, it was a cl ever thing to look 22 at the Chesapeake and the TMDLs ; and while it looks 23 like the deposition change woul dn't necessarily get 24 you all the way, I didn't -- towhat might be a 25 target from that share, I didn' t have a sense of

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1 where we're starting from. 2 So, again, yeah, it doesn' t get you all the 3 way, but does it get you halfwa y? Does it get you 4 90 percent? Is it getting 10 t en percent? Get 5 some context for that to get a sense of -- 'cause I 6 think it kind of feeds into the uncertainty issues 7 overall of, okay, we're not qui te sure we're 8 getting these numbers quite rig ht, but if we know 9 the benefits are really -- incl ude a lot of other 10 things and we're getting a goodshare toward them, 11 then maybe you're more comforta ble with some of the 12 other uncertainties. So I thin k it's important in 13 a whole picture. 14 And the other thing I want to -- I don't 15 expect that this chapter and th is document is going 16 to get into this, but I would l ike to see a list of 17 all the other co-benefits that -- of reducing these 18 emissions from -- to fine parti culate, human 19 health, ozone, crops, visibilit y any of the effects 20 where there is no specific thre shold. If there is 21 a gradient, then any reduction in these emissions 22 is going to mean that there is a whole list of 23 other co-benefits. 24 So it's a critical issue w hether, again, there 25 is a threshold you have to get to before you get

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1 any benefit or if you're lookin g at an effect where 2 there is a gradient. I mean, t hen each -- then 3 there is going to be some benef it and I think it's 4 worth mentioning even if it's j ust a list here that 5 there would be other benefits o f reducing these 6 blues. 7 DR. RUSSELL: Ellis. 8 DR. COWLING: Instructions , he says getting to 9 question number 24 was the most important thing to 10 do. So I'm going to be very sh ort in my answer to 11 this question and I'll support what Lauri just 12 said. If we choose to try to d ecrease the harm 13 that is occurring in aquatic ec osystems, there will 14 be substantial benefits also inother ecosystems. 15 And, therefore, whether we can easily quantify them 16 or not, we ought to go for it. End of statement. 17 DR. RUSSELL: Panel? Verygood. 18 MS. CHESTNUT: Don't hesit ate. 19 DR. RUSSELL: Yeah, charge question 14, Rudy. 20 DR. HUSAR: Uncertainty, v ariability, 21 sensitivity, the new chapter --the new chapter is 22 good. It really brings togethe r those issues that 23 have been raised throughout in a single chapter and 24 the individual uncertainties. Those uncertainties 25 that can't be dealt with, not e ven not necessarily

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1 quantified, but can't be dealt with are being dealt 2 with, but there are the lingeri ng questions about 3 the other uncertainties that ar e not easy either to 4 quantify or explain their cause s, okay. 5 Well, I would just start w ith the surprise 6 CMAQ, okay, in that the SO2 ove restimation, 7 substantial overestimation, 40 percent is a large 8 number, is an uncertainty that wouldn't need to be 9 discussed and dealt with more i n terms of the 10 consequences of that; that is, that that is the 11 place where much of the deposit ion actually of 12 these so-called acidifying agen ts are happening and 13 that's the one that's unknown. 14 So while it is useful to k eep showing how well 15 the sulfate deposition matched by the model, the 16 fact is that the same CASTNET d ataset could 17 actually be used to show how th e SO2 variation, for 18 instance, throughout the five-y ear simulation has 19 been changing, in spite of the fact that we 20 understand that the data are we aker there. So 21 that's one that the -- that's o ne concern on the 22 thesis of the sensitivity -- onthe uncertainty 23 analysis. 24 Another aspect is more of the general approach 25 as to what do we -- what does t he sensitivity

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1 analysis incorporate? In other words, is it really 2 looking at the overall system k ind of sensitivity, 3 particularly the propagation of errors all the way 4 from the beginning, unless of c ourse we think of it 5 in terms of the flow of these m aterials from the 6 source, transport transformatio n, removal and then 7 through the deposition into the body. 8 Seeing how the propagationgoes all the way 9 through, one would get an idea as to, now, what is 10 the importance of the fact that let's say the 11 deposition has such an uncertai nty? In what way -- 12 which part of that curve on the other side, on the 13 effects side, where are you on the curve? Are you 14 on the steep part of the curve or not? So, 15 therefore, that sensitivity of the overall system 16 might help. Now, so that was t he second comment. 17 The third one is coming ba ck to the general 18 comment that it would really be helpful to know as 19 to what are the major houses. Essentially have a 20 better understanding of why thi ngs are the way 21 these pictures are showing the way they are. In 22 other words, if you look at the systems, there 23 are -- there are stressors and there are stressees. 24 Now, the stressors are the inputs, the drivers 25 on the front end, fine. Then t here are the

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1 stressees, the sensitivity of t hese species. In 2 these analysis it would really be helpful to know 3 as to where is the stressee. T he stressor is the 4 driver for the behavior of the system; and where is 5 the stressee, the sensitivity o r the weakness let's 6 say of the ANC. And that kind of a large-scale 7 analysis or quantification of e xplanation would 8 really be helpful. 9 DR. RUSSELL: Thank you, Rudy. Naresh. 10 DR. KUMAR: I agree that d iscussion of 11 uncertainty and sensitivity ana lysis is improved 12 from the last version, but I th ink a complete 13 quantity analysis has not been done and I don't 14 understand why it has not been done because it can 15 be done. In a case I had actua lly recommended an 16 approach last time. We mention ed the word 17 propagation. I'll talk more ab out that. So that's 18 something to, again, go back an d see how that can 19 be done. 20 So the uncertainty, the wa y it has been 21 evaluated was the quality of th e data. There is 22 some quantitative uncertainty a nd some confidence. 23 Overall what the panel had requ ested last time has 24 not been done. So going back t o that, I think what 25 we asked last time was to maybe look at the

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1 uncertainty. 2 DR. HUBBELL: The last time, to be clear, 3 because we tried to pay attenti on to this, it was 4 determined that the propagationof uncertainty was 5 unlikely to be possible. That we could look at the 6 individual sensitivities, whichwe did, through 7 constructing elasticities and t rying to look at the 8 covariants of the approaches, b ut the panel -- in 9 the letter that the panel sent out said that it was 10 probably unlikely that we couldfully propagate 11 uncertainties and come up with a full quantitative 12 treatment in the consensus lett er. 13 There were some individual responses, but, 14 again, it was understood that t here is really not 15 any -- one thing, we don't have quantitative 16 uncertainties for most of the e lements. 17 DR. KUMAR: I think even i n the letter the 18 panel had recommended that EPA conduct a 19 sensitivity study to correctly answer this 20 associated with the different c omponents and 21 propagate every step to arrive at ensemble of sorts 22 and NOy response to meet a give n standard because 23 that range that would give us aconfidence 24 interval. 25 DR. HUBBELL: In the conse nsus letter, we had

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1 this back and forth through the letter, we felt 2 it's not something we can do at this point. We can 3 and we did try to come up with individual 4 uncertainties and look at indiv idual sensitivities, 5 but because we don't have proba bility distributions 6 for most of the components, we didn't feel it was 7 possible to do a full Monte Car lo-type simulation. 8 I thought at least in our discu ssions that that was 9 something that the panel as a w hole agreed with, 10 that it was not feasible to do that at this point. 11 Again, if you want to change th at, that's fine. 12 But we took it from the consens us letter that that 13 was not something we were beingasked to do. 14 DR. KUMAR: The letter on September 15th 15 stated that the panel recommend ed. I assume this 16 was a consensus recommendation last time in the 17 letter. 18 DR. HUBBELL: I don't have the letter in front 19 of me. 20 DR. RUSSELL: We have to l ook at the April 21 letter. 22 DR. KUMAR: I'm reading fr om this one, the 23 charge questions. 24 DR. HUBBELL: There were t wo different issues, 25 one in the front letter and one in the specific

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1 charge question. There was con flicting 2 information. I remember the co nversation. I just 3 know there was no way we could actually do a 4 propagated uncertainty through everything. 5 DR. KUMAR: 'Cause I belie ve you do have some 6 understanding of the dangers of different 7 components, yes, maybe? 8 DR. HUBBELL: Some. We di d try to do the -- 9 DR. KUMAR: You could prop agate those limits 10 of those dangers toward every s tep and either do 11 that through propagation or do a Monte Carlo. So, 12 again, example that I guess -- could be done. 13 DR. HUBBELL: We'll consid er it. Again, I 14 don't think it was something th at was very feasible 15 for us to try to do. 16 DR. RUSSELL: I think our comment probably had 17 more to do with we fully unders tand you do not have 18 a quantitative estimate of all the pieces that go 19 into an AAPI. So you would hav e had to then -- 20 DR. HUBBELL: Make up stuf f. 21 DR. RUSSELL: -- making upsome uncertainties. 22 DR. HUBBELL: We were not comfortable doing 23 that. 24 DR. RUSSELL: I'm sure we would have told you 25 that we couldn't agree with the made up

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1 uncertainties. 2 DR. KUMAR: You don't have -- you could be 3 very careful and have a bit of uncertainty and have 4 a known answer. Still I can se e how the other 5 uncertainties play into all a r ange of NOy as far 6 as substance. That's what's cr itical to figure out 7 the range on that. That would give us some 8 confidence interval in this app roach. 9 DR. RUSSELL: Rudy, you ra ised your hand 10 again. 11 DR. KUMAR: I was not done . 12 DR. RUSSELL: Sorry about that. You breathed. 13 DR. KUMAR: There is an A, B and C. I don't 14 know if you want us to go on toall of those 15 together or not. 16 DR. RUSSELL: Yes. 17 DR. KUMAR: So number two is on the model 18 CMAQ, the performance I think, again, the 19 performance on CMAQ model is st ill incomplete even 20 after the request by the panel. Last time we had 21 recommended the model propose N O, NO2, nitric 22 oxide, NOy from different netwo rks where you had 23 routine measurements be include d -- including the 24 network, for which we had like ten years of data on 25 those components, and still the re is no mention of

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1 why that was not done. 2 And also the Table 7-1 sho ws performance 3 statistics for a species. I th ink I had mentioned 4 it last time also that using a normalized mean 5 statistics is misleading for an nual average 6 quantities. I can go over, if we have time, why 7 that's misleading. 8 Normally when I do papers, I publish it 9 showing that normal statistics. They have to show 10 mean normal. And there is a di fference. If the 11 panel wants, I can explain that , but I think we 12 should be showing a mean normal statistic when 13 we're using annual average quan tity. 14 So I will go to Part D. P art D was discussed 15 in a previous charge question o n the TSOx and TNOy 16 how we look at the variability in that in different 17 means. 18 DR. NUGENT: I'd ask you t o ask the -- you 19 provide comments next. 20 DR. HUSAR: About not bein g able to examine 21 propagation efforts. Well, fir st of all, there are 22 certain differences between sys tematic errors that 23 seem to be existing in the CMAQ ; that is, if on the 24 average CMAQ overestimates appr oximately 25 40 percent, well, that's a diff erent kind of an

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1 error than let's say some kind of a random error 2 for which you may not know the distribution 3 function. 4 So if indeed, let's say, s ulfur dioxide is 5 overestimated 40 percent, there should be no 6 ambiguity or conceptual or nume rical difficulty 7 propagating that, saying what h appens if you would 8 then remove that 40 percent andthen you see what 9 is the consequence on the outco me on the curve. So 10 at least systematic errors coul d be actually 11 examined. 12 DR. HUBBELL: We could do that with the 13 elasticities that we provided. That's simply 14 measuring for a one percent cha nge what's the 15 expected impact on the AAPI. S o it would be 16 relatively straightforward. If you have a 17 40 percent error in SO2, we cou ld propagate that 18 through. So that's doable. Th at's not the same 19 thing as doing multiple sources of errors and 20 propagating them through. 21 I want to make sure we're clear on this, what 22 the letter said, it acknowledge s a probabilistic 23 listing assessment of uncertain ty at this time. 24 It's not likely to be practical within the range of 25 this review of the secondary st andards. So that

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1 was the, you know, front page o f the consensus 2 letter, which is why we didn't focus on that as an 3 activity. 4 DR. HUSAR: So the propaga tion is not 5 necessarily doable because of t he distribution 6 functions, but should definitel y be possible. 7 DR. HUBBELL: Which we agr ee with in terms of 8 -- and, again, we can focus on what we identify as 9 the critical quantitative known-- not known, but 10 estimates of uncertainties in i nitial parameters. 11 It's fairly straightforward to multiply that by the 12 elasticity. 13 DR. RUSSELL: Panel? Myro n and then Dale. 14 DR. MITCHELL: I guess I j ust want to -- I 15 guess we're on the same page he re with what Rudy 16 just said is for these uncertai nty analysis to 17 focus on anything that actuallycould be 18 reformulated in some of these b asic relationships 19 and use that for uncertainty. And also if there is 20 something which has not been in cluded in the 21 current index, like what happen s if you actually 22 add reduced nitrogen, how is th at going to affect 23 the overall relationships acros s some of these 24 sites. 25 I would say there are some major processes

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1 that aren't included. That kin d of conceptual 2 model level of air also should be -- this is not a 3 statistical analysis, but it's also just looking at 4 some major -- some of the major features in the 5 model may change, but would be the outcome of that 6 output. 7 DR. RUSSELL: Dale. 8 DR. JOHNSON: First of all , back to the table 9 of Myron and Ellis, I think it should include also 10 the reduced benefits of reducin g sulfur deposition, 11 whether quantifiable or not. And for uncertainty, 12 I don't know what you do about this, but there are 13 uncertainties that are hard wir ed into some of 14 these models. The premises hav e a bit model on A-5 15 and examined premises for that, the assumptions for 16 that model; and out of the five , four of them are 17 demonstrably false. 18 So what would happen if yo u started including 19 changing these things? I don't know how you 20 quantify that, but that's a rea l significant source 21 of uncertainty. 22 DR. RUSSELL: Kathy. 23 DR. WEATHERS: I thought t he elasticity 24 analysis was a real useful thin g. And underscoring 25 what someone said, I think chan ging those terms to

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1 maybe a 40 percent difference, the depositions, the 2 key term and maybe base cations , whatever the terms 3 are that were like -- you're li kely to be off by a 4 huge percentage, go ahead and m ake that change. 5 Again, I'm not arguing bec ause we're plus or 6 minus 40 percent, 50 percent, 1 00 percent 7 understanding that means that t his should all down 8 the tubes, but I think being re alistic about making 9 those changes much bigger perce ntage than just 10 one percent. 11 DR. HUBBELL: Again, the o ne percent is simply 12 a scalable uncertainty. Elasti cities are not an 13 uncertainty calculation at all. It's a sensitivity 14 calculation that can be appliedto sensitivity 15 factors. 16 DR. WEATHERS: Right. But it's telling us 17 something about the model, the AAPI model, how it 18 responds to big differences in the input terms, 19 right? 20 DR. HUBBELL: Sure. 21 DR. WEATHERS: So there ar e some places where 22 real uncertainties are huge andchanging those to 23 reflect that I think would be u seful. 24 DR. SCHEFFE: Could I add a couple 25 clarifications?

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1 DR. RUSSELL: Short, yeah. 2 DR. SCHEFFE: So in terms of, just to be 3 clear, the model itself is not used as the 4 indicator in nonattainment, att ainment kind of 5 setting. And the way -- and we do acknowledge, you 6 know, there is some work to be done with getting, 7 you know, the sulfur calculatio n correct. That is 8 a concern that we have, but tha t manifests itself 9 in terms of uncertainty in term s of how that's 10 translated to the transference ratio. That's kind 11 of how we would have to look at that. 12 So a 40 percent -- being o ff 40 percent in an 13 important component like SO2 do esn't necessarily 14 translate in being off 40 perce nt in a parameter 15 that goes in the AAPI. They ar e much different 16 things. That's how we would ha ve to look at that. 17 DR. WEATHERS: I was kind of lumping that, 18 thinking about, well, it could easily be off for a 19 particular area, a particular l ake or watershed 20 40 percent in actual deposition . 21 DR. RUSSELL: And I will a ctually make a 22 comment, this is something I ha d done over the 23 weekend with the spreadsheet yo u had sent me was 24 actually turn it around and do my 25 back-of-the-envelope uncertaint y assessment on the

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1 concentrations that would be es timated to go along 2 with a certain AAPI. So if yousort of turn that 3 AAPI equation around instead of looking at the 4 elasticities of the AAPI to the inputs to look at 5 the elasticity or the uncertain ty of, you know, the 6 thing that's actually going to be represented -- 7 going to be what's monitored tothe various inputs. 8 Because, you know, the AAPI, th at's a hard and fast 9 number, you're going to set tha t. 10 So if you turn that around , one thing at least 11 I found, and you may have done this as well, is 12 that the uncertainty of those c oncentrations -- 13 yeah, the uncertainty of the as sociated 14 concentration is quite sensitiv e to that 15 transference ratio, even thoughthe elasticity 16 suggests that the AAPI is not t hat sensitive to 17 that. You can turn that around . That doesn't come 18 through in the current document . 19 And the other thing is tha t you need to take 20 account of covariants because a s your covariants -- 21 covariants matrix shows, you kn ow, the R squared 22 between TSOx and TNOx is about 80 -- .8. 23 So, you know, they're, not surprisingly, very 24 highly correlated. So looking at those two 25 separately would underestimate the uncertainty. I

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1 think you have probably done th at and sort of seen 2 what that means. 3 DR. HUBBELL: We have beenlooking at this 4 question of the NOx and SOx andhow sensitive they 5 are to these and thinking about covariants a little 6 bit. Of course, the issue withthe NOx and SOx 7 it's a tradeoff curve, so there are multiple 8 quantities. You can make some assumptions and say, 9 well, what would the maximum SO x be if you had NOx 10 being zero and vice versa? I'mcurious how you set 11 that up. 12 DR. RUSSELL: I said what would be the 13 necessary -- so I had to simpli fy it because yes, 14 it is a necessarily complex thi ng. I just said 15 what is the necessary reductionin the sum of this, 16 if we sort of treat them havingthe same ratio of 17 the transference ratio. 18 DR. HUBBELL: Which isn't quite right, but 19 close. 20 DR. RUSSELL: It's not qui te right, but if you 21 look at the concentrations, it' s not tremendously 22 far off. That's just how I came up with it. I 23 think that's very important to recognize what 24 the -- you know, how that actua lly impacts this 25 thing you're measuring in terms of really the

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1 percent or fraction of lakes th at you will 2 ultimately be protecting at a s pecific level, is 3 that that level of uncertainty could really impact 4 that being overprotective or un derprotective. 5 DR. HUBBELL: Yeah. 6 DR. RUSSELL: Charlie. 7 DR. DRISCOLL: So I think this uncertainty 8 analysis is very important and we'd recommended 9 that you work on it last time. You've done this. 10 But, you know, as I go through this and I read, you 11 know, what you've done I worry a little bit because 12 the uncertainties can be very h igh in some of these 13 components. And I think it's i mportant not to lose 14 sight that we have a tremendous amount of empirical 15 data over a long period of time where we measure 16 surface waters and we see how t hey respond to 17 changes in deposition. And the re are very clear 18 mass and chart balance constrai nts. 19 So I think that there is much more confidence 20 in understanding and quantifyin g how systems would 21 respond moving forward given th e past information 22 that we have on soils and surfa ce waters than comes 23 through in this document. And I'm not really sure 24 how to put that in terms of unc ertainty analysis, 25 but I think, you know, we know how these things

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1 have responded over the last 20 , 30 years; and I 2 think we have a pretty good ide a how they're going 3 to respond over the next 10, 20 years just because 4 of mass and charge balance cons traints. And I 5 think it's important that we do n't lose sight of 6 that because it provides import ant information to 7 put the uncertainties in contex t. 8 DR. RUSSELL: Rudy. 9 DR. HUSAR: Yes. One thin g material that is 10 already in a well-defined, bala nceable media indeed 11 such consistency checking is do able. 12 But on the driver's side, on the input side 13 there are still these major unc ertainties as to 14 what is it that actually causes and what is 15 actually the magnitude of the a ctual depositions 16 themselves. 17 And so a methodological su ggestion here, this 18 is both for the group and to th e EPA, is indeed the 19 recommendation that one should at least for the 20 next decade when these same top ics will be coming 21 up that an ensemble or a set of these models to be 22 used just the same way as in Eu rope, those ensemble 23 multi-model exercises give you a feel as to what is 24 the nature and the range of unc ertainty by virtue 25 of the fact that you use differ ent instruments,

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1 quote, unquote measuring or qua ntifying this stuff. 2 So this will be a recommen dation to write up 3 this part of the section. You might see this 4 tomorrow as a suggestion. 5 DR. RUSSELL: Other commen ts on this one? 6 Moving on, did you have -- 7 DR. WEATHERS: I want to a gree with Charlie. 8 I think that having the big pic ture up there front 9 and center is really important. And I guess that's 10 why I like the sensitivity anal ysis because it 11 collapses some of the big piece s and you can look 12 at what a huge percentage chang e might mean to the 13 sensitivity of the entire AAPI. So I think your 14 point is really important, Char lie, and I think 15 sensitivity analysis is one wayto look at the big 16 picture. 17 DR. RUSSELL: Thank you. So we are 15. And 18 that again is Rudy. 19 DR. HUSAR: What is me? 20 DR. RUSSELL: Fifteen are the panel's views on 21 the insights provided by the AAPI, maybe you 22 included this, sensitivity anal ysis and actually we 23 did discuss it, the evaluation. 24 DR. HUSAR: Nothing new. 25 DR. RUSSELL: I think we a ctually got into it.

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1 DR. HUSAR: It's the same. I can tell that I 2 would not know the -- other tha n the fact that with 3 regard to the elasticity, well, the question is 4 what is the nature of those ass umptions by which 5 you are performing, that you ar e including the 6 preservation of? The one perce nt kind of 7 preservations are okay, of cour se, you know, if you 8 just look at the -- just the sm aller changes, but 9 what if you take those irregula rities that happen 10 on the front and back end and a ll of a sudden that 11 40 percent may -- you said, wel l, it may not be a 12 40 percent change in something or another on the 13 back end. What if a 40 percent data result in 14 80 percent change in the back e nd simply because of 15 the inherent measurements. 16 DR. HUBBELL: I think that 's fair. I tried to 17 get some of that by looking at various points on 18 the curve and doing marginal ch anges along those 19 different segments of the respo nse. But, as I 20 think I mentioned in the write- up, some of the 21 variables even switches signs. Q, for example, 22 which is the runoff, switches s igns at one point. 23 At one point it causes the AAPI to increase. 24 In some points it causes the de crease. Knowing 25 where that inflection point is and if you cross it

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1 by some large change is fair en ough. So we can 2 certainly look at that and char acterize for 3 large-scale change what is the potential for 4 percent response. 5 DR. RUSSELL: Thank you. Any other -- I think 6 we already got -- no, Naresh wa nts more on 15. 7 DR. KUMAR: Fifteen, right ? Just short, I 8 agree, the variation of the ela sticity response is 9 a good way to adjust the sensit ivity for the 10 different components. I would recommend that the 11 same be done for turning aroundthe source and NOy, 12 that's the end result and we ca n guarantee the 13 sensitivity of those quantities of different 14 components of the AAPI. 15 DR. HUBBELL: Yes, we agre e. 16 DR. RUSSELL: Question 16, Charlie. 17 DR. DRISCOLL: Okay. I di dn't really have 18 much to comment on, on the spec ific question 19 concerning the uncertainty for MAGIC and the SSWC. 20 There was some discussion in th ere that more needs 21 to be done. It's been only don e to a limited 22 extent. You folks did a fair amount as part of 23 this analysis for the REA. So I think that I guess 24 I would agree that it would be useful to continue 25 to do these uncertainty analysi s.

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1 I think though, as Rudy sa id, I think there 2 are other aspects to evaluate t hese tools that 3 should be considered going forw ard. Probably don't 4 have time to do it, you know, b etween now and 5 December, but things about comp aring different 6 types of approaches, different types of models and, 7 you know, either structural dif ferences in these 8 models that would be important to understand and to 9 try to evaluate the components of the models, for 10 example, improve the Neco term, which I think is 11 pretty soft. It's pretty hard to evaluate that. 12 Might be other tools to do that . 13 Another area that it seems to me in need of 14 attention is to look at the rol e of organic acids. 15 We talked about basically throw ing out the high DOC 16 waters, but there may be ways o f simulating DOC 17 that could be considered in fut ure efforts. So I 18 think that there are -- uncerta inty issues are 19 important, but I think there ar e also some, you 20 know, looking at structural components of the 21 models would be helpful going f orward. 22 DR. RUSSELL: Chris. 23 DR. FREY: I don't really have a lot of 24 comments on MAGIC or SSWC becau se those go beyond 25 my own expertise. I thought th e write-up was

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1 readable for someone who is not an expert in those 2 models. 3 Maybe I'll just -- I have some maybe more 4 general comments about Chapter 7. One is that I 5 don't think there is a very cle ar framework 6 throughout the chapter. I thin k this applies to 7 these two models as well on the spatial and the 8 temporal scope of the quantitie s for which variable 9 and uncertainty are being chara cterized. And 10 because variability and uncerta inty both are 11 sensitive to geographic averagi ng and temporal 12 averaging, without that context , it's not clear the 13 meaning of many of the characte rizations, including 14 the summary Table 7-1. 15 And then some of the analy ses presented in the 16 chapter, you know, they don't s eem consistent with 17 later in Chapter 9 with the spa tial scales or the 18 temporal scales, probably more so the temporal 19 scales. You know, if the stand ard might ultimately 20 be based on a three to five-yea r averaging period, 21 then any assessment of uncertai nty should be based 22 on a three to five-year averagi ng period. And that 23 should be discussed in Chapter 7. 24 So there is an unavoidable linkage between 25 Chapter 7 and Chapter 9 as far as where are things

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1 going with the Policy Assessmen t. If the goal is 2 to assess uncertainty, to infor m the choice of 3 alternative, you know, levels a nd forms and so on, 4 then it ought to be on a consis tent time and 5 spatial scale. So that's one g eneral comment I 6 have. 7 Another is maybe it's not critical to this 8 document, but there isn't reall y a framework given 9 for -- I mean, there is some fr amework given for 10 the uncertainties, but since ul timately it becomes 11 a qualitative analysis, I thinkperhaps in the REA 12 there is more detail and a meth od for that. But 13 giving the reader a little bit of an idea that this 14 isn't -- well, that there is so me structure to it 15 and it's not completely an ad h oc process might be 16 helpful. 17 And then there is always I guess questions 18 about the tier of assessment, l ike this is a 19 qualitative assessment. It did n't go to a 20 quantitative assessment. Those issues can be 21 discussed in the context of a t ier approach in 22 dealing with uncertainty and wh y the analysis 23 mostly stops at a sort of tier one or tier zero, 24 maybe sometimes go to a quantit ative sensitivity 25 analysis. That could be more c lear to the reader.

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1 And then just the comment maybe not related to 2 charge question 16, but on thes e extrapolating a 3 elasticity to 40 percent error, obviously, that 4 works if it's a linear response . If the response 5 is not linear, then that would not be a good idea. 6 DR. HUBBELL: I wasn't sug gesting we'd 7 multiply it. We actually run asystem. 8 DR. FREY: Thanks. 9 DR. RUSSELL: Panel? Ques tion 17, Charlie, 10 you're up again. 11 DR. DRISCOLL: This is pro bably even more 12 dangerous than to ask me multip art questions, 13 asking me what are, you know, r esearch and 14 monitoring. I mean, we could g o on for days I 15 think on a monologue for this. 16 So I think there are a number of things that 17 were identified in the report t hat were appropriate 18 in terms of particularly lookin g at some of the 19 aspects of deposition, you know , uncertainty in 20 terms of ammonia; and the, you know, actually what 21 are the values of a deposition that are occurring; 22 what are the sort of sub-grid s cale effects and how 23 those link to watershed models. 24 I mentioned previously iss ues about response 25 of organic acids and also bette r datasets to track,

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1 you know, the recovery of soils and vegetation and 2 surface waters and aquatic biot a, so those are just 3 a few, but there are many more. I'm sure a lot of 4 other folks here could add in alot more, 5 particularly on the atmosphericside. 6 DR. RUSSELL: I think that is referring people 7 to individual comment goes a lo ng way because there 8 are just so many things that we really need to have 9 research on here. So, you know , if there is 10 something that is burning, I'd bring it up now or 11 up for discussion, but I like C harlie's approach to 12 that. So, Chris. 13 DR. FREY: Yeah, on charge question 17, I 14 guess at first I couldn't figur e out what part of 15 the chapter this referred to, t hen I figured out it 16 was the modeling gaps and the d ata. I didn't go 17 back and check other Policy Ass essments for the 18 other criteria. So I don't remember if that 19 subheading is the one that's us ed elsewhere, but I 20 think if it's really the goal i s to focus on 21 research and data collection ne eds, maybe the 22 heading could clearly say that. And then if there 23 were an introductory paragraph that would help me 24 with that section. 25 So I think -- I tried to f igure out what were

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1 the research needs, and this wo n't take very long, 2 but it just seemed to me that t he chapter or that 3 section focused on things like occult deposition 4 from clouds and fog, lightning- generated NOx, the 5 role of organic bound nitrogen, better soil and 6 agricultural emissions of -- it wasn't clear -- it 7 sort of implied NOx, but I thin k it must have meant 8 ammonia and NOy and not NOx. And then more data 9 for sensitive ecosystem areas a nd sort of general 10 areas of need. You know, those all seemed 11 reasonable to me. I'm not an e xpert in those 12 topics, but it made sense. 13 I think what was missing t hough was there was 14 not a reflection of the Table 7 -1, which gives, you 15 know, a long list of uncertaint ies and whether 16 they're low, medium and high ra nges or biased or 17 the state of knowledge. And it seems like from 18 that table one can infer some a dditional research 19 needs, just some examples -- I tried to find which 20 of those uncertainties were hig h in some way. 21 So, for example, the prein dustrial based 22 cation concentrations listed as having high 23 magnitude of uncertainty and a high knowledge base 24 uncertainty. So one might thin k, oh, that should 25 be a priority for future data c ollection or model

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1 development. So I was surprise d that wasn't in the 2 discussion. 3 Dry deposition genericallyfor both nitrogen 4 and sulfur was listed as havinga medium magnitude 5 of uncertainty and a medium hig h knowledge based 6 uncertainty. It seems like tha t might merit some 7 discussion in terms of future r esearch. And also 8 the ecological indicator regard ing ecosystem 9 services seemed to have both a medium high 10 magnitude of uncertainty and al so a negative bias. 11 I think that needs more discuss ion. 12 And then there were issues that were brought 13 up early in the Policy Assessme nt that are 14 basically set aside because the re is not enough 15 information to address them now . So examples are 16 the terrestrial acidification a nd aquatic system 17 nutrients enrichment. 18 So what are the research n eeds for those so 19 that they could be part of the next assessment? 20 And then I think we've heard al so comments about 21 addressing unintended consequen ces, which might be 22 appropriate. 23 In the recent CASAC PM pan el review on the 24 second Draft Policy Assessment for PM, there was 25 some discussion about developin g a follow-on

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1 workshop to focus on research n eeds to inform the 2 next revision of the NAAQS. An d if the research 3 agenda is big enough or signifi cant enough, maybe 4 something similar might be cons idered for this set 5 of pollutants and effects as we ll. 6 DR. RUSSELL: Panel? Andr e. 7 DR. BYTNEROWICZ: On page 7-11 you're 8 discussing ammonia and see it's dealing with this 9 particular pollutant. In the e nd you said you were 10 considering I think it's accord ing to Dennis's 11 paper 2011, using the sensitivi ty analysis for two 12 sources probably in North Carol ina. My suggestion 13 would be these are probably bigstationary sources. 14 It would be nice to do somethin g similar also 15 somewhere else in the country l ooking at multiple 16 sources of ammonia because that would be a key 17 thing. 18 DR. SCHEFFE: Sure. Just for clarification, 19 that was probably the only empi rical data that that 20 study was based on, but then of course the 21 parameterization from that is b rought in too and 22 applied nationally. That's a v ery good point to 23 make. 24 DR. BYTNEROWICZ: I mentio ned that because 25 we're having new things on ammo nia in the west,

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1 which could be used probably. 2 DR. RUSSELL: Others? 3 DR. AMAR: Back to ammoniaagain, I think one 4 reason would be, I think that's probably an 5 extension of that, with the loc al nature or 6 regional nature or in between n ature of ammonia I 7 don't think is clear in this do cument. There is 8 some evidence it's not as local , but maybe do a 9 more systematic analysis of amm onia and its nature. 10 DR. RUSSELL: Rich. 11 MR. POIROT: I just wantedto add that I 12 thought the whole chapter was r ather well done. 13 And this kind of sets a new bar for subsequent 14 NAAQS. They should all include a Chapter 7 like 15 this. And I additionally like the coupling of the 16 identification of the research needs with the 17 delineation of the uncertainty, very appropriate. 18 I just wanted to say nice job. Now, do it next 19 time. 20 DR. RUSSELL: And fill in the blanks with 21 numbers. 22 DR. SCHEFFE: That's the h ard part. 23 DR. RUSSELL: Yes, it is. Okay. So moving on 24 to monitoring, Rich, you get togo through all 25 three questions. You don't eve n have any help on

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1 it. 2 MR. POIROT: No. I notice d Paul Hanson 3 couldn't give any comments. We ll, the chapter 4 before we get to the charge que stions, right away 5 the chapter starts out with wha t I thought was a 6 nice listing of the different multiple objectives 7 that might be addressed by moni toring. Almost 8 always we get hung up on monito ring this for 9 compliance determination, perio d. And to a certain 10 extent it absolutely has to be and meet that 11 objective. 12 And, you know, when we hav e our research hats 13 on, our science hats on, of cou rse we can think of 14 all kinds of other things that will help us add to 15 the list, but in this case I th ink it's especially 16 relevant, these additional obje ctives really fit 17 here very well. Yeah, maybe we can get by with the 18 modeled calculation of reduced nitrogen, but not 19 for long, you know. Plus, it's within our grasp. 20 It's something that actually ca n be done. 21 And so the idea of providi ng some of that kind 22 of information rather than need ing to rely on the 23 model, you know, would be reall y helpful. Of 24 course, we want to improve the model and the 25 process, our understanding of t he processes and

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1 subsequent NAAQS reviews is I t hink actually pretty 2 important and the whole idea of accountability, 3 which really was the whole basi s of the CASTNET 4 network in the first place. 5 So in this particular case I think the 6 secondary objectives are very i mportant. And I 7 might add as well that until th is morning's 8 presentation I wasn't aware the agency plans to go 9 to the AMS committee for some a dditional feedback 10 on measurement issues because I was kind of writing 11 my pre-meeting comments with th e anticipation that 12 this might be the last shot at it. So I might have 13 been overly arching in some cas es. 14 At any rate, the first cha rge question asked 15 about our opinions of using an open inlet to 16 capture all particle sizes for sulfate in 17 particular. And sort of the fo llow-up questions is 18 our opinion on using the CASTNE T filter packs as a 19 future reference method for sul fate. Again, I 20 think this would be a good topi c for the AMS 21 committee to address in more de tail. 22 I had taken a few counterp oints, made a few 23 counterpoints to the need for a n open-face 24 collector and so forth. One of the most important 25 of which is yes, we believe tha t larger particles

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1 with a much larger deposition v elocity, gravitional 2 settling component can contribu te a lot more to 3 total sulfur deposition; and, f or that matter, to 4 total nitrogen deposition espec ially if we're 5 concerned about coastal estuari es and places where 6 it's not just acidification tha t's the issue, but 7 as we get into the marine envir onment, for example, 8 we would expect to see some coa rse particle 9 nitrogen deposition, could be p otentially 10 important. 11 But the issue though is th at simply by letting 12 those bigger particles into our collector gives us 13 no information about what fract ion of the total is 14 from those larger particles. S o we're really not 15 very much more ahead of where w e would be if we had 16 to rely on fine particle measur ements plus a fudge 17 factor. We still have to have a fudge factor 18 either way. So I don't oppose it. I actually like 19 the idea of using that kind of an open-faced 20 approach for deposition relevan t measurements and 21 so forth. 22 So even though I am picky at it, I actually 23 support it. And, further, I wo uld support 24 consideration of something like that for nitrogen, 25 particles of nitrogen depositio n as well because I

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1 don't think that the monitoringapproach should 2 necessarily be exclusively limi ted to the 3 acidification issue if one of t he objectives is to 4 support future evolution of thi s. 5 I -- the next charge -- sh ould I stop there? 6 DR. RUSSELL: Go through t hem all. 7 MR. POIROT: Asks about ou r views on requiring 8 measurements of ammonia and amm onium to assist in 9 implementation of the standard. Certainly I think 10 that those measurements would b e very helpful, 11 especially for ammonia. 12 I think ammonium is measur ed reasonably well 13 in our collective networks, but what's missing I 14 think is the gas phase ammonia measurements. There 15 is a small component of NADP th at's beginning to 16 make some measurements using pa ssive samples. It's 17 really just not right what a sh oestring budget 18 that's being cropped together w ith this. It's a 19 pretty important thing and mayb e this would be our 20 opportunity to advocate those k inds of measurements 21 in a more formal way because th ey are important. 22 So I certainly am a supporter o f that aspect of the 23 proposal. 24 And then, finally, the las t charge question 20 25 gets into our views on having asubset of sites

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1 that would make measurements of some of the perhaps 2 even continuous measurements of some of the other 3 NOy species, nitric acid, true NO2, NO and so 4 forth, particularly nitrate. A gain, you know, the 5 science side of me says this wo uld be great. This 6 would be excellent. I get a li ttle concerned 7 though about our ability to act ually go out and 8 roll out a new rural detailed s et of new NOy and 9 continuous SO2 sites that for t he most part don't 10 exist. 11 Perhaps we're not supposedto consider those 12 implementation phase difficulti es, but sooner or 13 later we'll have to deal with t hem. And so that 14 gets back to one of the reasons why I was wondering 15 before about whether a calculat ion of the nitrogen 16 deposition couldn't be derived from the kinds of 17 measurements that are collectedalready by CASTNET 18 methods; that is, specifically the particulate and 19 nitric acid measurements that a re routinely made 20 with CASTNET. Could we use tho se as a way of 21 estimating total nitrogen depos ition using the same 22 kind of ratio -- model ratio as you're now using 23 for total NOy? 24 The reason being that if w e could, that would 25 allow an expansion of this basi c CASTNET network

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1 maybe to cover the broader spat ial area with many 2 sites. And then we could enhan ce that with a 3 smaller number of sites, makingthe continuous NOy 4 and continuous SO2 and some of these other things 5 rather than saying we can't get started unless we 6 had continuous NOy and SO2 as o ur base network. 7 So that was the one kind o f a twist I wanted 8 to suggest considering, you kno w, maybe there are 9 certain aspects of the CASTNET program itself that 10 would be healthy to put to some scrutiny and get a 11 little bit of review there. 12 You know, another thing I wanted to mention 13 though is if this would be a si tuation where if the 14 CASTNET-type measurements were used, we would have 15 a network operated by EPA and i ts contractors, 16 funded by money that's taken ou t of the state 17 monitoring pot and then you wou ld come and let us 18 know whether we were in complia nce or not. Some of 19 my colleagues, my boss, for example, might not look 20 kindly on that. 21 I, actually, don't oppose it and think it 22 would be interesting to actuall y meld some of these 23 together rather than considerin g -- insisting that 24 our turfs are all different, we really should be on 25 the same side here. Along thos e lines, there are

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1 some, as Rich knows, rural end- course sites. And 2 bringing in some CASTNET measur ements at some of 3 those sites and maybe along wit h some, you know, 4 true NO2, all of a sudden we co uld start to answer 5 a lot of these questions a lot better. 6 So somewhere I think there is room for some 7 compromises and combinations of different 8 approaches. So those were my c omments. 9 DR. RUSSELL: Panel? Myro n. 10 DR. MITCHELL: I guess I j ust want to kind of 11 amplify on some of Rich's comme nts. It seems like 12 there is an opportunity in this chapter to look at 13 some of the previous findings, including 14 uncertainty where some of the m ajor problems are; 15 where the concerns are; where t he data needs are; 16 and use this in terms of examin ing where the 17 monitoring community needs to g o. Whether that's 18 actually having less CASTNET si tes where they're 19 doing more things or looking at integration across 20 the different monitoring networ ks, there is a good 21 opportunity here to take -- to give some useful 22 recommendations to the communit y. 23 DR. RUSSELL: Thank you. Any other comments 24 from the panel? 25 DR. AMAR: One point, than k you. I'd like to

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1 add on to what Rich was saying, and we had this 2 discussion last night. If CAST NET, and I'm not a 3 monitoring expert, but if CASTN ET, an existing 4 network, can address what we're trying to do here 5 later on in the implementation of AAPI versus some 6 extensive monitoring network lo cations, measurement 7 methods, frequency, the cost an d, again, from a 8 state's perspective, we do -- w e do worry about 9 those things, whether, you know , a good standard 10 proposed here could actually be implemented based 11 on a huge network which require d quite a bit of 12 investment which wasn't forthco ming. 13 DR. RUSSELL: Ellis. 14 DR. COWLING: I'd like to mention the results 15 of conversations that I had in preparation for this 16 meeting with John Walker and wi th Robin Dennis and 17 learning about how many collabo rative endeavors are 18 ongoing right now within EPA de aling with Canada 19 and their perspectives on the v arious challenges of 20 measuring all the NOy species a nd the chemically 21 reduced forms and the organic f orms. And the Dutch 22 have instrumentation, which is proven quite 23 effective at least in the Dutchenvironment and 24 maybe in other parts of Europe as well. 25 So I don't know if it's ap propriate for a PA

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1 to include the little writing o n what's going on 2 inside EPA right now, but I was impressed. If it's 3 appropriate, I would certainly recommend that some 4 mention be made of these ongoin g collaborative 5 efforts that are going on in wh ich there are 6 scientific progress that's bein g achieved in other 7 parts of the world and by instr umentation, which is 8 also being tested collaborative ly in this country 9 and in other parts of the worldwhere there may be 10 some bright ideas and methodolo gies and ways of 11 dealing with uncertainties and errors and so on 12 that maybe we haven't thoughtfu lly evaluated as 13 yet. 14 DR. RUSSELL: Rest of the panel? I think -- 15 MR. POIROT: Just one thin g I meant to say but 16 forgot was that as much as I li ke these secondary 17 objectives that are listed here , in some ways I 18 don't know if they can be fullyjustified in terms 19 of this NAAQS alone; at the same time I don't think 20 they really need to be. This o pens the door I 21 think to a lot of things that r elate to improving 22 and evaluating the model perfor mance that have we 23 might say co-benefits to many o ther pollutants. 24 So that's just one point t hat I'd like to 25 maybe try to raise that in our letter thinking what

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1 our collective comments would b e here. Some of 2 these are very well justified n ot from a secondary 3 SOx, NOx perspective alone. 4 DR. RUSSELL: Thank you. And with that, it is 5 2:45 and time for the break. W e're right on 6 schedule. 7 (Brief recess.) 8 DR. RUSSELL: Committee, f irst important 9 question so we can get some of this done. I think 10 we have -- we paired it down totwo choices really 11 for restaurants tonight. One i s Lebanese, that's 12 supposed to be very good. And the other one is 13 Indian, which is also supposed to be very good. 14 Lebanese one runs, what, 20 buc ks a head? 15 DR. FREY: Ten bucks a hea d. 16 DR. RUSSELL: Indian is mo re expensive. 17 DR. WEATHERS: How far awa y? 18 DR. RUSSELL: Five for the Indian. It's in 19 Morrisville, which isn't too fa r. 20 DR. AMAR: Indian is in Mo rrisville, the same 21 distance. Do you have it down? 22 MR. POIROT: No. I rememb ered that Lebanese 23 came up. So hands for Lebanese ? Okay. Indian? 24 Lebanese it is. 25 So the next question how m any people want to

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1 go tonight to the Lebanese? Ma ke it ten; 6:30 or 2 6:00? Why don't we shoot for 6 :00. The earlier 3 the better. We may actually le ave earlier 4 depending on how quickly we canget done here. 5 DR. JOHNSON: Leave here a t 6:00? 6 DR. RUSSELL: Leave here a t 6:00. That should 7 give everybody time to make a f irst draft of 8 their -- 9 DR. BYTNEROWICZ: Very opt imistic. 10 DR. RUSSELL: -- or at lea st talk to your 11 co-supporters in drafting it an d then we can go out 12 to dinner. The lobby at 6:00. 13 So with that, we're gettin g to the conclusion 14 chapter; and in some ways actua lly these last four 15 questions sort of bring up thin gs that we've 16 already discussed. 17 What I want to do is start thinking of the 18 bigger picture at this point to o; and that is, what 19 should we actually be recommend ing, you know, EPA 20 and I put 24-D, as being a veryimportant question, 21 it asked us what would we look at as being the 22 components of the standard. Th at's the advice they 23 want. And typically, actually, in a CASAC meeting, 24 the last one, the panel starts giving advice 25 specifically as to the standard . That's what they

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1 asked us. 2 Typically at this point we would be evaluating 3 the staff's recommendations as to the standard as 4 well and their reasoning for th at. So in this case 5 we're doing it a little bit mor e free form, if you 6 will. So we want to start thin king about how we 7 can answer that big question, w hat is really 8 missing from this report to be able to adequately 9 inform both us as well as the Administrator in 10 terms of what is important, wha t she might decide 11 as the appropriate level of the standard. 12 So what's really missing a nd where we think we 13 should go from here in that is this document really 14 ready to go on? Are we comfort able with it? Where 15 do we want to proceed on makingrecommendations 16 about the standard itself? So to get into the big 17 questions, I think what we talk ed about so far 18 today in the discussion gets us a long ways in 19 terms of sort of laying the fou ndation for that 20 discussion. And then I think w e have to have that 21 discussion before we finish up this process. 22 So, with that, we'll still go through the 23 questions, but when we get to t he end of 24-D, I 24 think that's -- we want to star t having the broad 25 discussion about where we are, where we think this

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1 document sits in terms of goingforward. So, with 2 that, 21 is Chris. 3 DR. FREY: Okay. I strugg led with this 4 question because I wasn't reall y sure if there was 5 something behind it that I was missing. And maybe 6 just a general context maybe inthe flavor of Ted's 7 introduction is, you know, all the NAAQS are 8 subject to some uncertainty in terms of the 9 science. And so I think sort o f the bottom line 10 question is, is there strong en ough, high enough 11 degree of confidence in the sci ence as we currently 12 understand it that, you know, astandard setting 13 process is needed that goes bey ond the current 14 secondary standard? 15 And so when we talk about the overall 16 characterization of uncertaintyas it relates to 17 the determination of an ecologi cally relevant 18 multi-pollutant standard for NO x and SOx, I think 19 ultimately that becomes a quali tative or 20 dichotomous question, yes or no . There is a basis 21 for a standard and the more qua ntitative aspect of 22 how exactly do we set the stand ard. 23 It seems that I think the document does a good 24 job of explaining that the curr ent standard is not 25 adequately protective of aquati c acidification and

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1 the associated adverse effects; and that there 2 seems to be a high degree of co nfidence that, you 3 know, therefore, a more stringe nt standard of some 4 kind is needed. And so I thinkthat's an important 5 point and, you know, as we get into the details of, 6 you know, what ANC level and wh at AAPI number to 7 use, and how to do the tradeoff between NOy and 8 SOx, I think the key question i s, well, is there 9 fundamentally enough evidence, you know, as 10 imperfect as it is that that's the direction to go? 11 As far as answering the ch arge question 12 specifically, you know, I felt that Chapter 7 13 covered a lot of issues and we brought up a lot 14 more comments related to that t hat I don't see a 15 need to repeat right now. I gu ess though a 16 challenge might be in Chapter 9 maybe to either say 17 more or say why we don't need t o do this, but it 18 seems like in each of the steps of coming up with 19 particularly the level of the s tandard, you know, 20 there is a starting point withi n ANC, and then that 21 informs an AAPI, and then that informs a NOx, SOx 22 tradeoff. And are there uncert ainties that would 23 lead to biases in those steps? And do those biases 24 need to be corrected? And if s o, can they be 25 quantified.

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1 Maybe that's in my view on e of the kind of 2 bottom line questions. And I d on't -- this is not 3 my area of domain expertise. I can't really answer 4 that question, but I hope that the panel can. So I 5 think that's all I'm going to s ay on question 21. 6 You want to discuss 21 before w e go to 22? 7 DR. RUSSELL: We can do 21 and 22 at the same 8 time. 9 DR. FREY: All right. Twe nty-two is an A, B 10 and C with lower case Roman numeral subsections. 11 So you may regret that we went on to that. 12 DR. RUSSELL: Actually, ma ybe I will. Thank 13 you. So let me move on, Charli e. 14 DR. DRISCOLL: In the inte rest of time I 15 really don't -- we've talked ab out uncertainty 16 before. I don't really have an ything else to add 17 beyond what I've already said. 18 DR. RUSSELL: And Myron. 19 DR. MITCHELL: I guess I j ust want to indicate 20 I think EPA did a good job show ing the prudence of 21 a multi-pollutant standard. I think you should be 22 commended for that. I think it will be important 23 to doing some modification chan ges, updates. We 24 talked about some better -- imp roved validation of 25 CMAQ and also making sure that within the

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1 considerations of the aquatic s ide that DOC is 2 included and on the terrestrial side it includes 3 some other alternative sources for mobile add-ons, 4 such as sulfur. 5 DR. RUSSELL: Panel? Nare sh. 6 DR. KUMAR: Just one more thing in addition to 7 what I mentioned earlier on int o a lack of complete 8 analysis or uncertainty. As I think about this, 9 I'm struggling with one thing. Chris mentioned 10 when he said framing the NAAQS standard, let's take 11 an example, we have a high deal of confidence that 12 once you remove, you know, NOx, SOx, SO2 that 13 you're going to get a reductionin sulfate, very 14 high degree of confidence. Mod els may not give you 15 exactly what's observed, but yo u know that if you 16 review SO2, you're going to get a reduction in 17 sulfate. 18 And I'm struggling here ha ving shown that if 19 you reduce SOx and NOx ambient concentrations that 20 you are going to see an improve ment in ANC and how 21 much of that will be linear as the AAPI question 22 shows or not. The MAGIC model has really shown 23 what has been observed in the l ast 20 or 30 years. 24 I'd like the panel's views on t hat because I'm not 25 an expert on that.

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1 DR. RUSSELL: So, Charlie. 2 DR. DRISCOLL: Well, that' s what I was trying 3 to indicate earlier, that there is a lot of data -- 4 well, at least for some regions , you know, 5 acid-sensitive regions, New Yor k, New England, 6 Pennsylvania, southeast, certai nly less so in the 7 west that there are fairly goodrecords of how 8 sulfate and nitrate have decrea sed over time and 9 what the response of ANC is. And they're fairly 10 consistent with the frameworks within the models. 11 And they're constrained by char ge balance 12 relationships. 13 We have a pretty good ideaof how much ANC is 14 going to change in response to the change of 15 sulfate and nitrate. So I thin k there is a lot of 16 information to basically bolste r the uncertainty 17 analysis and constrain it rathe r than just looking 18 at it from a statistical perspe ctive. 19 So I think that will be ve ry useful to come 20 forward. I think maybe it's insome of the earlier 21 documents, the ISA, but it does n't really come 22 through with me here. So I thi nk that that's 23 useful information to put uncer tainty analysis in 24 context. 25 DR. RUSSELL: You seem lik e you had something

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1 else to say. 2 DR. KUMAR: I will ask Ang ela if we have the 3 letter, are you going to show i t? 4 DR. NUGENT: Would you lik e to show it? 5 DR. KUMAR: I would like t o show the target 6 from last time. There was some confusion as to 7 what the panel had asked. We'r e talking 8 uncertainty. I think it would be good to show 9 that. 10 DR. RUSSELL: So, as we're doing that, I'd 11 like to ask, Chris, Charlie -- Myron, I guess 12 you're still up, then I'll ask a question. Myron. 13 DR. MITCHELL: For 22? 14 DR. RUSSELL: Twenty-one, actually, I 15 forgot -- 16 DR. MITCHELL: I already g ave my comments. 17 DR. RUSSELL: You did? Doyou think the 18 characterization -- I'll ask Ch ris -- the 19 characterization in Chapter 9 w as appropriate? 20 DR. FREY: The characteriz ation of 21 uncertainty? No, actually, I p ut this under charge 22 question 22, but one of the thi ngs I noticed is in 23 Chapter 7 there was a nice -- o r at least a 24 relevant paragraph that it migh t better go in 25 Chapter 9. This was on page 73 7 near the bottom

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1 that talks about kind of the bo ttom line and it 2 said there is no apparent direc tional bias in the 3 uncertainty regarding the biolo gical, chemical and 4 physical processes incorporatedin the AAPI, and it 5 goes on. 6 And it seems like that kin d of discussion 7 really needs to be in Chapter 9 because Chapter 8 9 should either convince the re ader that there is a 9 high degree of confidence in ea ch of these metrics 10 used as the basis of the possib le secondary 11 standard; or that if there are uncertainties that 12 we understand if there is a dir ectional bias in 13 them, and we have some idea of confidence bounds so 14 that either we could choose to do a bias correction 15 or consider a confidence bound in selecting a 16 level, you know, for example. 17 So that particular text I think either could 18 be repeated or could be moved t o Chapter 9 and 19 maybe elaborated in terms of, y ou know, given an 20 ANC, what does that apply to ou r knowledge of the 21 AAPI? What does that imply for the tradeoff curve 22 for NOx and SOx? How well do w e know that? And 23 should we be correcting any bia ses that might 24 exist? 25 So I think to that extent Chapter 9 could

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1 have, I don't know, not a repea t of Chapter 7, but 2 at least touch on the key infer ences from Chapter 3 7 that inform the standard set. 4 DR. RUSSELL: Okay. I wil l actually say that 5 when I read the paragraph and t he conclusions on 6 the uncertainty, it still didn' t really inform me 7 about the uncertainty in the re sulting 8 concentration that would be der ived from all the 9 uncertainties and all the piece s of the AAPI. 10 Again, the AAPI, you know, you set a number for 11 that. 12 So in some ways, the elast icities you 13 calculate of the AAPI to the in dividual components 14 is not as important as the sens e -- or the 15 sensitivity of the concentratio ns are to the 16 individual component of the AAP I. That has to come 17 through here I think. And to t he degree that you 18 can also inform us as to what t hat would mean for 19 potential uncertainties I thinkthat would be 20 important. 21 Anything else on 21? Twen ty-two. 22 DR. KUMAR: Discuss that o r what? Charlie, 23 question 13, I think that will really explain what 24 we want. 25 DR. NUGENT: This is the c over letter. This

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1 is the language of the cover le tter and I just 2 want -- that didn't come up. S o I thought I would 3 show that and then go to questi on 13. 4 DR. RUSSELL: Question 13, yes. This is 5 basically saying in our last le tter we didn't think 6 a full probabilistic uncertaint y analysis was 7 practical. 8 DR. KUMAR: We said a sens itivity analysis 9 should be conducted and we expa nd that in the 10 question 13, what exactly step- by-step approach was 11 recommended in the consensus le tter. So I just 12 wanted to mention that. 13 So if you look at the last line there, that's 14 where we recommended a sensitiv ity study to 15 characterize uncertainty where you propagate 16 uncertainty in that respect, ar rive at an ensemble. 17 That's noted in this letter. I f you go further 18 down, this is an approach, we s aid, okay, where you 19 don't know the exact range, youhave a probable 20 range, use a probable range for Neco, use two 21 different approaches, propagate those ranges. This 22 very clearly defines what we as ked to be done. 23 DR. HUBBELL: Yeah. Again , I think we 24 interpreted it differently in t erms of what the 25 initial statement was and focus ed more on

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1 individual sensitivities becaus e of the 2 complexities in doing this. Bu t, again, we can 3 certainly investigate it, but, again, given the 4 substantial amount of effort th at's required to do 5 this on a systematic basis acro ss all the variables 6 we just need to evaluate that. It is not a trivial 7 exercise to do it. 8 DR. RUSSELL: Thank you. Okay. Charge 9 question 22, Chris. 10 DR. FREY: Okay. This is a multipart question 11 and so the first part has to dowith insights that 12 could be gained into potential alternative 13 additional secondary standards using the AAPI form 14 by considering several things. And I don't think 15 I'm the right person to answer this question 16 because I don't have domain exp ertise on these 17 topics, but it did strike me th at none of these 18 topics was particularly mention ed at all in Chapter 19 9. And Chapter 9 could maybe m ore clearly make the 20 linkage between adverse effects and the standard. 21 So, for example, there cou ld be a discussion 22 of what are the key hazards ass ociated with aquatic 23 acidification and maybe discuss some of these of 24 mortality and pH and ANC, but I don't really have 25 anything to add to this particu lar part of, you

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1 know, Part A of the charge ques tion. 2 So I guess the question is whether the panel 3 feels that the document adequat ely addresses these 4 issues or if these are missing issues in further 5 discussion in Chapter 9. 6 DR. RUSSELL: We can actua lly take 22-A, B and 7 C, so do each one -- each subpa rt -- well, not 8 sub-subpart -- subpart separate ly. So, Charlie. 9 DR. DRISCOLL: Okay. Well , I guess I had a 10 few thoughts on some of these p ieces. In terms of 11 mortality of aquatic organisms, I am assuming the 12 person who framed this is refer ring to like in situ 13 bioassays and things like that. And I don't know 14 of any studies beyond ones that were cited in the 15 report. So I don't know if the re is any other 16 information that could be gaine d from that. 17 In terms of the relationsh ips with 18 biodiversity, I mentioned some minutes ago about 19 the different, you know, the sp atial patterns which 20 these are built, are they goingto translate to 21 temporal patterns? So I think a little bit of lip 22 service on that would be useful . 23 I didn't understand 2-A-ii i, relationship 24 between pH, aluminum and ANC, i s that the 25 interrelationship between -- fo r a given ANC, how

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1 does it affect pH, how does it affect aluminum, 2 things like that? I wasn't -- 3 DR. HUBBELL: I think I di dn't write this 4 question particularly well. Wh at I was trying to 5 get at was we went through a pr ocess in Chapter 5 6 of justifying certain ANC level s using all these 7 different types of information. 8 The question was is that j ustification enough 9 or is it, you know, should we g ive it a lot of 10 weight and actually determine t he range of the 11 AAPI? Again, recalling that th e AAPI is partially 12 based on the target ANC level a s well as these 13 other considerations about timi ng of recovery, 14 uncertainty, all these other fa ctors. 15 So it was more intended tosay how does this 16 information play into actually picking the specific 17 levels of the AAPI? That's wha t we were trying to 18 get at. I didn't ask the quest ion particularly 19 well. Using the AAPI form was supposed to push you 20 in that direction. I don't thi nk I did a very good 21 job. 22 DR. DRISCOLL: Okay. Well , I think I get 23 where you're coming from. I th ink there have been 24 discussions in previous documen ts, such as the REA, 25 about the use of the ANC. I th ink it makes sense

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1 given, you know, that this is amanagement action 2 and the challenges of measuringpH and aluminum and 3 different fractions of aluminumthat ANC is 4 probably the appropriate indica tor. But that said, 5 some of the slop that you see i n terms of these 6 biological responses are undoub tedly due to 7 variations in pH and aluminum a cross systems where 8 you see a comparable level of ANC because fish 9 don't understand ANC, at least that's what I'm told 10 anyway. So I think that ANC ap proaches, I endorse 11 it, I said that before and I sa y it again. 12 Your number IV, I was -- I was very interested 13 in the document where you had t hese various target 14 levels for either pH or ANC by various states, but 15 I don't recall that there was alot of 16 justification given for why -- I can't remember. I 17 think New York put 6.5 or 6 andTennessee put 18 something else and Vermont put something else and I 19 didn't recall there was justifi cation for that. I 20 guess given that the states are going to implement 21 this, it would be probably usef ul to have some 22 information about what their th inking was when they 23 established those values. Is t hat where you're 24 coming from on this last commen t here? 25 DR. HUBBELL: Yeah. Inter estingly enough,

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1 some of them specifically menti on a particular 2 species; and that, you know, th ey chose 6.0 or 6.5 3 whatever to protect brown trout or something like 4 that. I think, you know, that' s what -- some of 5 their justifications are focuse d on macro indicator 6 species that they felt like peo ple understood and 7 grabbed onto. 8 Again, it was more in the range these are 9 indicators that people thought this was adverse and 10 kind of that understanding, tha t broad public 11 understanding of adversity be b rought forward into 12 helping us pick a level; maybe not, maybe we don't 13 have to wait on that. It's jus t a question as an 14 indicator of adversity, is that a useful benchmark 15 that can help us identify some levels of target ANC 16 that might be considered as we move forward? It's 17 just a question of how much wei ght can you put on 18 those or maybe put on those rel ative to other 19 pieces of information we have, more direct 20 scientific findings. 21 DR. DRISCOLL: Well, I gue ss, you know, I'm a 22 little familiar with New York, but I certainly am 23 not familiar with the other sta tes. I know that in 24 Europe it's problematic when th ey do critical 25 loads. Different countries set different

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1 indicators and different levels for those 2 indicators. So that's one of t he challenges going 3 forward. I think it is useful information to find 4 a background on why they select ed where they did. 5 DR. HUBBELL: Some are not . 6 DR. DRISCOLL: I guess tha t's all I had on 7 that first part. 8 DR. RUSSELL: Myron. 9 DR. MITCHELL: I kind of i nterpreted that's 10 what you wanted. I thought the document did a good 11 job of indicating although ANC is not a perfect 12 indicator in terms of all the a dverse effects of 13 aquatic systems, it's probably one of the more 14 robust single indicators we cancome up with. 15 DR. RUSSELL: Panel? Okay , 22-B. 16 DR. FREY: 22-B, the appro priate role of 17 qualitative and quantitative ch aracterizations of 18 uncertainty in developing stand ards using the AAPI 19 form. I think this just goes b ack to the comments 20 I made just a few minutes ago. The paragraph that 21 was in Chapter 7 that I was quo ting partly from 22 concludes by saying that there is support for an 23 AAPI that is somewhat higher th an the target ANC; 24 and that's in part because the level of the AAPI 25 should be relatively high in a buffering context,

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1 which the language is a little awkward, but to 2 account for the existence of un certainties in 3 several components and then the re is also a time 4 lag issue related to response d ynamics. And I 5 didn't see that translated intoChapter 9 in terms 6 of informing, perhaps setting t he level of the 7 standard. 8 So that's an example of wh ere if you -- as you 9 go across these linkages from ANC to AAPI to the 10 pollutant concentrations, if inparticular there is 11 a need for bias correction, tha t really should be 12 discussed in Chapter 9 and an a lternative could be 13 developed based on any such bia s correction. 14 DR. RUSSELL: Charlie. 15 DR. DRISCOLL: I feel like I've talked a lot 16 about uncertainty and I don't h ave anything to add 17 beyond what I've already said. 18 DR. RUSSELL: Myron. 19 DR. MITCHELL: I'm pretty much in the same 20 place Charlie's at, talked abou t different types of 21 uncertainty and how that can be improved in terms 22 of putting out this information . 23 DR. HUBBELL: If I could j ust try to clarify a 24 little bit. This is a difficul t set of questions. 25 So what I was looking for in th at question was more

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1 specifically, given what we hav e now said about all 2 the uncertainties, what you kno w about the 3 uncertainties, what's available in the literature, 4 what I'm looking for in thinkin g about the specific 5 range of values or ranges of st andards, are there 6 specific things we should consi der about the 7 uncertainties that would lead t o one particular 8 adjustment or consideration of the range versus 9 another? In other words, wouldyou suggest we 10 should make the range narrower; should we make it 11 broader; should we make overall the whole thing 12 higher or the whole thing lower ? 13 In terms of specifically w hen you get to point 14 of setting an AAPI and setting a standard, how does 15 uncertainty play into that? No t just simply 16 thinking about better character ization of 17 uncertainty, but translating th at into something to 18 do with the standard. Does it change the 19 considerations? 20 DR. RUSSELL: Myron. 21 DR. MITCHELL: I would sug gest, Bryan, that in 22 that area the most important th ings are there 23 processes or inputs that are no t included in the 24 AAPI, and how would including t hose affect that 25 standard? That's the major fac tor.

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1 DR. HUBBELL: Okay. That' s the SO2 and 2 sulfate. 3 DR. MITCHELL: Exactly, an d DOC in the waters. 4 DR. HUBBELL: All right. 5 DR. RUSSELL: Panel? Rudy . 6 DR. HUSAR: Lacking the co rrections of bias 7 corrections that has already be en done for the 8 presentation, you predict a mod el and you just kind 9 of adjust it to give texture toit with the real 10 presentation. Well, similar ki nd of bias 11 adjustment could also be done f or SO2 and that way. 12 You see, you're exposing yourse lf to real 13 substantial questions about it. 14 DR. SCHEFFE: Quick respon se. We could do 15 that with precipitation because of all the 16 observations. There are not th at many observations 17 for SO2, particularly in rural areas. That's one 18 thing. It's a little more comp licated by the way 19 SO2 is used and the transferenc e ratio is embedded 20 in the modeling. So there need s to be further -- 21 DR. HUSAR: But at least t ry it. 22 DR. RUSSELL: So, Bryan, a ctually to -- maybe 23 I'm -- what you just said, see if I'm somewhat 24 interpreting it correctly, is t hat relative to the 25 health-based standards one of t he things that

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1 formed the lower end where we s et the health-based 2 standard is the uncertainty gro ws in terms of the 3 likely health effects as you ge t lower. Is that 4 the same sort of question givenwhat we understand 5 about the uncertainty, how does that influence 6 where we might set the AAPI? H ow does it work into 7 the actual setting the AAPI? And given the 8 uncertainty might be like this, we might set it one 9 place and if it was like that, we might set it 10 another place. 11 DR. HUBBELL: Find a point on the range. 12 DR. RUSSELL: I think that really -- your 13 question was at that point is g iven our 14 understanding of the uncertaint y, should we set the 15 AAPI higher or lower, maybe it shouldn't affect it 16 at all? Excluding the biases, maybe we just say we 17 have to recognize this is uncer tain and go forward 18 with our best estimate. 19 DR. HUBBELL: I think that 's what I was 20 looking for. Karen, do you hav e any official 21 comments? 22 MS. MARTIN: No. I think what Ted is saying 23 now is appropriate. 24 DR. HUBBELL: I think that 's what we're 25 looking for.

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1 DR. RUSSELL: The panel ge ts that. I think 2 that is an important considerat ion because, again, 3 when we start talking later abo ut what might set 4 the standard and all the compon ents thereof, how 5 does our understanding of uncer tainty influence 6 that. 7 DR. HUBBELL: Thank you. 8 DR. RUSSELL: Anything els e from the panel on 9 that one? C. 10 DR. FREY: So C is asking about I guess some 11 temporal aspects that might be considered in 12 setting the standard in terms o f setting the time 13 trajectory of the response, the effect of episodic 14 acidification events; and then also asks for us to 15 consider whether setting the st andard should also 16 be done in a way that is protec tive of other 17 adverse effects, such as terres trial ecosystems 18 acidification or excess nutrien t enrichment. 19 I don't really personally have much to 20 contribute here because this is not my area of 21 expertise, but it seems like we also heard some 22 discussion about spatial variab ility maybe even 23 within a region; and to the ext ent there is spatial 24 and temporal variability such t hat there is small 25 geographic areas or short time periods that need to

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1 be protected, that might imply some kind of 2 correction or adjustment. 3 And, you know, as far as t he protecting 4 against other adverse effects, I don't have a 5 personal opinion about it. I g uess the question 6 there would basically be operat ionally should the 7 standard be more stringent thanit might be only 8 for aquatic acidification, if t hat would lead to 9 protection for these other effe cts. I guess that's 10 my understanding of the questio n. And I don't 11 personally have the answer to t hat, but the panel 12 might. 13 DR. RUSSELL: Charlie. 14 DR. DRISCOLL: Okay. So I think that there is 15 information that is available o n the response to 16 changes in the ANC through use with dynamic models. 17 And so, from our experience, toreach steady state 18 for systems in the Adirondacks or systems in the 19 northeast it depends on how youdefine steady 20 state. You know, they never re ally come to steady 21 state, but maybe something on t he order of 200 22 years, something like that. I' m sure for the 23 southeast it's longer given the accumulation of 24 sulfur in the soil. So it's a pretty long time 25 frame.

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1 The other thing I think is relevant with 2 effect to the trajectory analys is is in terms of 3 how the F factors change. And you can track F 4 factors through dynamic models. And they do go 5 through a hysteresis pattern, s o that informs the 6 assumption about a constant eff ect and how that's 7 used in the reconstruction. Yo u could also do that 8 for time series data. There ar e hysteresis in time 9 series data that might help inf orm -- form this. I 10 think it's going to be a long t ime for these 11 systems to come to steady state . 12 In terms of episodic acidi fication, I think 13 that there was quite a bit of i nformation on that 14 in the ISA. And generally ther e is, you know, for 15 work that we do in the northeas t, we lose about 50 16 microequivalents per liter, sometimes more, but 17 that's probably a good ballparkfigure. I think 18 that's part of the reason for h aving a target ANC 19 on the order of 50 because it h elps protect against 20 episodic acidification. 21 And co-protection, so I th ink Dale spoke a 22 little bit about that in that t his is about 23 terrestrial acidification. AndI was interested in 24 the analysis that was done abou t co-protection for 25 terrestrial acidification. So, from my experience,

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1 there have been quite a few stu dies across the 2 country that have looked at time series of soils, 3 repeated measurements of soils. And Dale knows 4 much more about this than I do, but they virtually 5 all show loss of base cations. So I think that's 6 consistent with what he is sayi ng, is soils are 7 reacidifying at least in wet ar eas. There is not 8 examples of them accumulating b ase cations, maybe a 9 few, but the vast majority are losing. Where if 10 you look at surface water value s, they're pretty 11 much all, at least in the north east, they're 12 increasing in ANC. 13 So in my mind that speaks to the fact that, 14 you know, maybe soils are more sensitive than 15 surface waters because soils ar e, you know, are 16 continuing to acidify or at lea st maintain their 17 conditions, where there is some recovery of surface 18 waters. But that said, undoubt edly if you reduce 19 the load there would be co-prot ection benefit 20 associated with it. 21 So I don't think anybody i n this room would 22 argue that there would be a cer tain amount of 23 benefit. We might argue about the degree of that. 24 One thing that I wanted toadd in though the 25 thing you didn't do was you hada little bit of

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1 information on mercury and meth ylation of mercury. 2 So you downplayed that probablywith good reason. 3 But I think there is also -- inthe northeast there 4 is a pretty strong relationshipbetween ANC and 5 biotic mercury concentrations. I don't think 6 anybody knows why it is. But, in fact, I was 7 looking at it today for zooplan kton and fish and 8 loons, and if you increase the ANC by a few 9 microequivalents per liter, if you follow the 10 empirical relationships, you kn ow, they're very 11 sensitive to ANC, extremely sen sitive to ANC. So I 12 think, you know, if you increas e ANC, you would 13 have to get some benefits in te rms of biotic 14 mercury, which haven't been men tioned in this 15 document at all. 16 DR. RUSSELL: Myron. 17 DR. MITCHELL: Obviously, it's a major 18 challenge in terms of using the aquatic AAPI form 19 and looking at how that is goin g to affect 20 terrestrial systems. We know t hat terrestrial 21 systems are time framed substan tially different. 22 We also know that in some of th ese systems things 23 like an uptake and retention se em to be highly 24 variable. We don't understand what's causing that 25 variability. That's going to c ause some problems.

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1 Clearly the loss of base c ations, maybe not 2 just base cations, it might be specific cations, 3 such as calcium, seems to be a real critical 4 nutrient for certain tree speci es, particularly 5 sugar maple. And then we don't know that there is 6 going to be other factors happe ning over time, 7 there is going to be changes inclimate, CO2 8 concentration, which can have a n effect both on the 9 aquatic and terrestrial compone nt. That's going to 10 allow -- that's going to make t he predictions more 11 difficult. Some could be enhan cing, some it will 12 make it more difficult to reachsome of these 13 targets. 14 DR. RUSSELL: Panel? Dale . 15 DR. JOHNSON: Follow up onthat soil 16 acidification. I don't know of any study where 17 soils in human regions have spo ntaneously increased 18 in base saturation. The only i ndications I can 19 think of is on Walker Branch wh ere we had some 20 calcium-rich vegetation, trees fall down and die 21 and decompose and they releasedtheir calcium back 22 in the soil, liming. Other tha n that, natural 23 acidification processes, includ ing tree uptake and 24 carbonic acid leaching will con tinue. So they 25 don't recover I don't think. I t's a hypothesis.

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1 DR. RUSSELL: Panel? 2 DR. HUBBELL: Could I ask one more question, 3 please? 4 DR. RUSSELL: Yes. 5 DR. HUBBELL: Charlie, yousaid you agreed on 6 the dynamic models recovery cantake 200 years or 7 more. One of the things we tri ed to discuss in the 8 document was if you then want t o try to see some 9 type of change and movement tow ard your target ANC 10 within the next 20, 30, 50 year s, a generation or 11 generations from now, is there a way to understand 12 that relationship so that you c an set a target load 13 in the 50 to 100-year time frame that would match 14 sort of what that steady state response would be? 15 In other words, if I reall y wanted to get to 16 ANC of 50 by -- in 100 years or 50 years, maybe 17 it's not possible, but if I wan ted to get there in 18 50 or 100 years, is there a wayto adjust the AAPI 19 in such a way that it would get me there? Would I 20 need to set an AAPI of 80 to ge t an ANC of 40? 21 DR. DRISCOLL: I think youcould develop -- 22 I'm an engineer, we do this all the time -- a 23 safety factor, you know, to tryto look at -- I 24 mean, I'd have to go in and act ually do some 25 calculations to suggest what th at might be, but I'm

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1 sure with MAGIC calculations yo u could pull that 2 out. It's a model, but, you kn ow, at least it 3 would be something. But I thin k -- so I was moved 4 in the last report to put in a little figure that 5 Ted, I know at least, liked sho wing differences 6 between a target load value andsay 2030 in a 7 steady state value. And it's, you know, it's 8 pretty substantial in some case s. But I think 9 there is enough experience withenough models that 10 one could try to do something o n that regard if you 11 wanted to. 12 DR. RUSSELL: Does that cl arify it? Okay. 13 Twenty-three. Kathy. 14 DR. WEATHERS: This is ano ther one of those 15 questions that may require some clarification. It 16 seems like there is confusion f rom a number of us. 17 This asks the question about wh ether the existing 18 standards for NOx and SOx shoul d be retained to 19 provide protection against dire ct adverse effects 20 of vegetation due to gas phase exposures. It seems 21 to me that there was justificat ion for that in a 22 document you provided, but it w asn't clear 23 whether -- whether we're talkin g about an 24 additional standard here. What 's the purpose of 25 this question and how does it f igure into this?

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1 DR. HUBBELL: The purpose of the question is 2 to say right now we're protecti ng almost entirely 3 by this new set of standards an d a new form, 4 completely different averaging times and so forth. 5 The question is, you know, does this become a 6 replacement standard or does it become an 7 additional standard? 8 What we're trying to figur e out is based on 9 the fact that there is no evide nce to suggest that 10 all of a sudden direct exposure s are not 11 phytotoxic, you know, shouldn't we potentially 12 think about retaining the exist ing standards while 13 adding an additional standard t o cover depositional 14 effects? 15 This is a question to the panel, do you agree 16 we should retain the existing s tandards in their 17 existing forms to protect again st those specific 18 phytotoxic effects? 19 DR. WEATHERS: My answer t o that is yes based 20 on the information here, but th ere is still an open 21 question about whether the new standard would 22 result in air concentrations th at are lower or 23 higher than this standard. 24 DR. HUBBELL: Yes. Given they're not matched 25 well in terms of temporal and s patial things, the

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1 chances that they would actuall y, you know, exactly 2 protect in the same way are pro bably not that high. 3 The question is do you still ne ed this existing 4 standard to make sure you prote ct against those 5 effects? 6 We have not evaluated what would happen to 7 those. Again, given that we've established that, 8 you know, almost everybody meet s the current 9 standards and we're talking abo ut something 10 additional, what we're really t alking about is 11 preventing things from going ba ckwards because of 12 high powering or annual concent rations. 13 DR. WEATHERS: So my answe r is that was 14 desirable. I think that was th e answer of others 15 too. 16 DR. RUSSELL: Any disagree ment on that? 17 Charlie. 18 DR. DRISCOLL: I'm probabl y going to expose my 19 ignorance here, but are there r eally -- are there 20 issues of nonattainment for thi s standard? I 21 didn't think there were any or very few issues for 22 nonattainment for the standard where the emissions 23 are going to go down. 24 DR. HUBBELL: It's not nec essarily clear that 25 they're going to go down in all locations at the

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1 exact time frame. That's the question. One of the 2 standards, for example, is a ve ry short-term 3 standard and one is an annual s tandard. We're 4 talking about three to five-yea r standards. 5 Clearly you have places where y ou have short-term 6 peaks that are not protected. The question is do 7 you leave protections in place or do you think it's 8 appropriate to move away from t hose? 9 DR. DRISCOLL: Well, see, it would be good to 10 see how this all plays out, but my read on the 11 situation is that as it current ly stands, it's not 12 really a problem and if we have this new standard 13 if this would go forward that w ould be much more 14 comprehensive. And I would thi nk it would be 15 desirable to have something tha t was more 16 comprehensive than have the cur rent standard. 17 DR. HUBBELL: To be clear, you can have both. 18 DR. DRISCOLL: I know, I'mjust trying to 19 eliminate some bureaucracy. So , anyway, I guess I 20 have some, you know, I feel dif ferently than my 21 colleagues I guess about the st andard. 22 DR. WEATHERS: Only insofa r as the bureaucracy 23 is the issue. 24 DR. DRISCOLL: Yeah. If i t's not -- if there 25 are no issues concerning nonatt ainment and it seems

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1 unlikely that the emissions are going to increase 2 in the future, why do we need i t? 3 DR. RUSSELL: Well, one qu estion might be, and 4 you can correct me if I'm wrong , let's say that 5 they didn't go forward with a n ew standard 6 deposition. We certainly don't want to recommend 7 that they get rid of the old st andard, old 8 secondary standard. 9 DR. HUBBELL: Yeah. I thi nk that's an 10 important distinction is that i f you made the 11 recommendation that it should b e removed entirely, 12 that's different than saying th at you think it 13 should only be replaced by a ne w standard or exists 14 in addition to the new standard . There are some 15 subtleties in terms of what youwould like to 16 happen to it, assuming that eit her the standard 17 went forward, the new standard went forward or did 18 not go forward. That's a good question. 19 DR. DRISCOLL: I'm not competent to talk about 20 phytotoxicity, but I feel like if this new approach 21 is more comprehensive and it's going to be more 22 protective, then I wouldn't rea lly see any reason 23 to retain the old standard if t he new standard was 24 going to go forward. 25 DR. WEATHERS: Is there a question where you

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1 run into a situation with trade off curves that you 2 could end up with higher let's say SO2 3 concentrations and lower NOx an d they would be high 4 enough to effect vegetation? 5 DR. HUBBELL: Possibly so. And the other 6 thing to remember is the spatia l differences are 7 fairly important here because w e're talking about 8 focusing on aquatic acidificati on and the 9 phytotoxicity protection would exist everywhere. 10 That's just a question. 11 MR. POIROT: There are some new monitoring 12 requirements for SO2 that we do n't know how those 13 are going to turn out or what k ind of 14 concentration. 15 DR. RUSSELL: Praveen. 16 DR. AMAR: I'm confused. Are we suggesting 17 that the new standard could rep lace the existing 18 standard, or we will have two s tandards, one for 19 direct effects one for AAPI? 20 DR. HUBBELL: That's essen tially what we're 21 asking you is do you want to --given that we're 22 moving forward with this new pl an for a standard, 23 do you also recommend retainingthe existing 24 standard to provide that extra protection in areas 25 or under, you know, time period s that might not be

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1 covered or protected fully by t hese new 2 deposition-based standards? 3 DR. AMAR: I understand bu reaucracy, so we are 4 we saying that we will have twodifferent 5 processes, two different steps? 6 DR. HUBBELL: Well, existi ng standards are in 7 place already. We would simplyretain those. I 8 don't think that requires any n ew -- retain, you 9 don't have to do anything new, correct? It 10 requires no action. It just ma intains the existing 11 protections. 12 DR. AMAR: It requires some kind of planning 13 process for states, no? 14 DR. HUBBELL: No, because it's simply 15 retaining the existing standard . There would be no 16 change. So there would be no n eed for new sets or 17 new actions. 18 DR. AMAR: I'm thinking implementation, I 19 know. But I'm saying there mus t be some 20 implementation requirements of existing SO2 21 standards. Implementation mean ing what do states 22 have to do, submit a plan? 23 DR. HUBBELL: They've alre ady had to do that. 24 DR. AMAR: They will also do that in the 25 future.

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1 DR. HUBBELL: Only if the standards were 2 changed. Let Karen speak to th is. 3 MS. MARTIN: I was just th inking about the 4 question this way: Do you beli eve that there is a 5 scientific basis to have a thre e-hour average SO2 6 standard at the level it's at t o protect against 7 direct effects of exposure to S O2? That's a 8 question. Do you believe that is still a relevant 9 standard to protect against eff ects that should be 10 protected against? 11 The issue of whether a newstandard, were it 12 to be set, multi-pollutant AAPI -related standard, 13 it's hard to imagine a three tofive-year average 14 standard protecting against all instances of 15 three-hour average peaks. And, therefore, since 16 one can't -- wouldn't conceivab ly provide 17 protection from the other avera ging time, then the 18 question is, is there a scienti fic basis to attain 19 it? I think that's a fairer wa y to think about it. 20 DR. WEATHERS: That's basi cally is there a 21 scientific basis that vegetatio n is affected, 22 right? Because one of the issu es was, well, no 23 area has been in nonattainment, everyone has been 24 in attainment, is it still an i ssue? 25 MS. MARTIN: That's rather irrelevant to

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1 whether or not -- 2 DR. WEATHERS: That's what I'm saying. 3 MS. MARTIN: -- the standa rd is appropriate 4 based on the underlying scienti fic information. 5 Does it remain an appropriate s tandard presuming it 6 was an appropriate standard whe n it was set based 7 on some scientific evidence, do es that scientific 8 evidence still remain relevant and does the 9 standard still remain relevant? 10 DR. WEATHERS: Right. Andcorrect me, we 11 didn't spend much time in this panel talking about 12 that scientific evidence. So w hat I would suggest 13 in regard to this question is t hat the scientific 14 evidence or the digestion of th at that was 15 presented here suggests that th e standard should 16 remain in effect based on the f act that vegetation 17 would be affected by SO2 concen trations. That's a 18 question I'm asking since I hav e to write the 19 answer to this. 20 DR. RUSSELL: I think actu ally we can go back, 21 but that's when we had gone ove r the ISA, we 22 essentially came to that conclu sion is that there 23 is still that potential even th ough there may not 24 be any nonattainment questions at this time, the 25 science has not changed appreci ably to suggest that

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1 that is no longer the case. 2 So the question, we can di scuss this, though I 3 sort of want to say just becaus e of the bureaucracy 4 we should do away with standardthat could be 5 protective. For one, I mean, t here is actually the 6 issue that it is a terribly dif ferent scale than 7 which we're looking. We have t his very 8 concentrated SO2 in a plume com ing from some source 9 that would not really be impact ing an area that's, 10 you know -- actually, one of th e designs of a new 11 standard, what we're going over now, it would be 12 potentially applying in very, v ery different areas. 13 Sort of the whole parts of the midwest may not be 14 of that great of concern, maybe so, maybe not, we 15 just don't know at this point. 16 So I think if we said get rid of it, we'd have 17 to say that there is no longer the scientific 18 evidence to suggest that it's s upported. 19 DR. WEATHERS: Agreement among the people? 20 DR. RUSSELL: Any other qu estions, comments on 21 that from the panel? 22 Okay. Sort of the big one , if we really think 23 about this in its entirety, we' ll again take this 24 in parts. This is a four-part problem. Judge your 25 time accordingly, as we tell ou r students. So

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1 24-A. 2 DR. WEATHERS: I see this whole series of 3 questions as a reiteration in s ome ways of the 4 questions that were asked earli er and that the big 5 question, as Ted framed it, whi ch is, is this an A 6 to Z document; and if not, wher e are the holes? 7 What are the issues? 8 So my answers to this are, again, are 9 reiteration. So the first part it looks to me 24-A 10 that the research has shown tha t acidifying 11 atmospheric deposition at its c urrent levels 12 results in ecosystem functional effects. And the 13 information in Chapter 2 to 4 r einforce that. So 14 was it your intention to reiter ate? 15 DR. HUBBELL: The intentio n was to reiterate 16 and ask you again to provide yo ur judgments as a 17 panel on the options or ranges for the various 18 different elements. After the first point -- after 19 A -- B, C and D are talking abo ut picking a target 20 ANC value; picking an appropria te percent of 21 waterbodies to protect; and the n taking that and 22 helping us put it all together into what would an 23 AAPI standard or options for anAAPI standard look 24 like, including those various d ifferent items. 25 DR. WEATHERS: Right. So this is really

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1 asking the question, given what 's proposed, the 2 averaging time, form and level. What do you think 3 about that? 4 DR. HUBBELL: Form and lev el, but also 5 including the complexities that we have here, which 6 is target ANC value, percent of waterbodies to 7 protect; and to the extent you care to opine on it, 8 helping us narrow down the spat ial averaging, for 9 example. If you think it's app ropriate to go after 10 a target ANC of 30 because you' re focusing on, you 11 know, the five bins of sensitiv e areas, that kind 12 of compilation of things. That 's what we're 13 looking for. 14 DR. WEATHERS: My inclinat ion is to take that 15 as a whole. 16 DR. RUSSELL: B, C and D? 17 DR. WEATHERS: Yeah, take that as a whole. 18 And my response is that I thinkthat the indicator 19 and average time to form the le vels that you pose 20 in those ranges make sense. Th ere is a 21 justification for them througho ut this document. 22 The challenges I think tha t haven't been 23 addressed in this document, to which I certainly 24 don't have an answer, has to dowith the spatial 25 averaging, how it is that you a ggregate and lump

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1 across the country, whether it' s about the critical 2 loads or it's about the ecoregi ons. So I think 3 that there is some missing piec es there in order to 4 make a determination. 5 And then how big a problemit is. This goes 6 back to the uncertainties quest ion. How big any 7 particular aspect of AAPI actua lly is that we 8 don't -- that we can't constrai n some of those, the 9 base cation, how much of it -- it's clear that 10 concentrations result in deposi tion; that there are 11 ecological effects from deposit ion; that ANC is a 12 reasonable indicator of aquaticacidification. 13 So, again, I think the que stions come back to 14 you all to refine this spatial aggregation pieces. 15 There is not enough informationin this document to 16 give some suggestions about tha t, from my 17 standpoint. And to frame the u ncertainties and the 18 sensitivities in a way that wou ld I guess as 19 scientists make us comfortable about saying yeah, 20 the AAPI is reasonable and just ifiable. 21 DR. HUBBELL: On the spati al aggregations 22 issue, do you feel that there i s enough information 23 to get rid of any of the option s that we've laid 24 out? 25 DR. WEATHERS: To get rid of any of them?

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1 Probably the one nation. 2 DR. HUBBELL: That's prett y clear. 3 DR. WEATHERS: But what I would like to see 4 more of is the reasoning behindsome of the spatial 5 aggregation. Again, I'm lookin g for some way to 6 either line up the limitations of the data in terms 7 of spatial aggregation, so we'l l have everything 8 spacially aggregated in multipl es of CMAQ windows 9 or process level information. That's the 10 limitation or to aggregate in away that you have 11 with ecoregions in some sort of defensible way that 12 says we're lumping things toget her because we know 13 these ecological regions have e ffect on regions of 14 the AAPI in particular ways. 15 DR. RUSSELL: Rich? 16 MR. POIROT: I agree with Kathy almost on a 17 point-by-point basis. I guess I felt like, you 18 know, once we get by the advers ity question, which 19 I think you made a good case an d you've supported 20 it well, the target ANC value s eems like somewhat 21 an easier part of the decision. There seems to be 22 a pretty clear huge point in th ere. I think you 23 can justify that quite well eve n at several 24 different levels. 25 I wouldn't necessarily adv ocate though making

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1 that decision and then, you kno w, moving on because 2 I don't have a sense of how all of the parts of it 3 might fit together. It may wel l be that a slightly 4 more or less lenient ANC level will fit better with 5 the selection of percentage lin ks and that sort of 6 thing. But anyway it seems to me you've got a 7 pretty good basis for a pretty clear recommended 8 level or range without too muchvariation. 9 As we have been talking ab out earlier, there 10 are just -- to me, the implicat ions of the options 11 for selecting percentage of lin ks to be protected 12 wasn't for me explained with en ough clarity that I 13 felt like I could easily choose among them. 14 I might not encourage you to take the one, the 15 one population option off the t able just because it 16 actually helps to clarify the o thers. It shows in 17 a way why that might not be a g ood choice. So I 18 would leave it in there I guess . 19 But, again, I think that t he trick is to 20 explain these more clearly. An d I keep reflecting 21 back to the old days, not that long ago, of the 22 staff papers where I used to, y ou know, what I used 23 to like about them when we were talking about 24 getting rid of them was that yo u guys do all the 25 heavy lifting and we would just have to come back

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1 with our judgments on whether y ou had made some 2 good choices or not. 3 Now it's sort of feeling l ike you're asking us 4 to do the heavy lifting and somewhere in between 5 those two extremes there has go t to be some 6 compromise, but I think it woul d help if you showed 7 us clear examples of what some of the advantages 8 and disadvantages of some of th ese options are. 9 That's just what I couldn't see clearly here. 10 Maybe it was just too new. I'dhave to read it 11 another time. So that's all I had to add to that. 12 In terms of the -- are we moving on through 13 all of these parts, Ted? 14 DR. RUSSELL: Yeah. 15 MR. POIROT: In terms of t he last question, 16 Part D, I had suggested earlier that the 17 consideration of could this tra nsfer TNOy, could it 18 be calculated in other ways tha t would be almost as 19 good or just as good? That's my only 20 recommendation for a slight var iation. I don't 21 even consider it a variation re ally. It's just 22 somewhat of an accommodation, e specially given the 23 monitoring constraints, could amethod that could 24 utilize simple CASTNET-type mea surements be 25 utilized on a near-term basis e ven as we're

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1 collecting more detailed inform ation to refine it. 2 That was my only suggested poss ible variation. I 3 don't consider it a large one. 4 DR. RUSSELL: Lauri? 5 MS. CHESTNUT: So we're do ing the whole thing, 6 A through? 7 DR. RUSSELL: A through D. 8 MS. CHESTNUT: So trying t o sum things up, I 9 think in the case for adverse e ffects due to 10 aquatic acidification at curren t levels is well 11 established and there is even asense of the, you 12 know, significance of that; tho ugh I have to keep 13 reiterating I feel that the eco system services has 14 to -- should always include the nonuse concepts, 15 that public welfare is affectedby the protection 16 of these resources in their nat ural state even if 17 people don't get direct use fro m them. 18 I'm not sure that the info rmation about the 19 degree to which there is advers e effects in the 20 other categories has been broug ht forward enough. 21 It is sometimes described as th is is -- it can 22 cause these kinds of things, bu t I keep wanting to 23 see so how much of an area is a ffected; you know, 24 what percentage of the forest; or what -- not just 25 that these are important resour ces, but this level

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1 of deposition is causing this much impairment, even 2 if dollar values, total numbers can't be put on it. 3 I was a little concerned i n several places in 4 the document that the potential benefit of going to 5 ANC levels higher than 50 seeme d to be kind of 6 downplayed. I mentioned that i n some of the 7 language. And there seems to b e some inconsistency 8 between some of the presentatio n. I wasn't also 9 clear if there is also some -- what that -- why 10 it's -- there is increasing unc ertainty about what 11 the benefit would be, probably beyond 50. Is it 12 that we don't know about how th e lakes will -- the 13 waters will respond; or is it t hat we don't know 14 how big the benefits are once w e have a resource 15 that at least has all of the pi eces that should be 16 there and then it's just kind o f getting less 17 acidic? So I'm still a little -- I think that 18 could be tightened up to give m ore information 19 about the base system to make t hose decisions. 20 This percentage of the wat erbodies, I came 21 back to a question about, well, in an area like the 22 Adirondacks now, what percentag e are below those 23 levels now? I mean, we're not talking 50 percent, 24 are we, is it 10 percent? I me an, I don't know 25 what -- it seems to me if we're looking at 50, 75

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1 or 90, it would be useful to se e that alongside how 2 many are below, what percentage are below 50 now 3 under the current conditions. 4 And if those waterbodies t hat would not 5 respond to reductions in emissi ons, pollution 6 levels, or deposition levels ar e excluded, I'm not 7 sure why a hundred percent isn' t in the set. 8 What's the justification for a target less than a 9 hundred percent if it's not fea sibility? 10 So this question I think C harlie raised about 11 do you leave them all in and th en make some 12 adjustment for the fact that so me won't be 13 responsive, but if you've takenthe unresponsive 14 ones out, then I need to see wh at's the 15 justification for -- or I'd lik e to see what's the 16 justification for, is it uncert ainty or is it 17 feasibility? 18 DR. HUBBELL: Well, I mean , in the primary 19 standards, for example, it's al ways well understood 20 that we're trying to protect se nsitive populations, 21 but not necessarily every sensi tive individual. 22 And we're trying to get at that same concept here, 23 that we're trying to protect th e sensitive 24 population. That is a policy question as to what 25 is a reasonable percentage to t arget in terms of

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1 the sensitive population. It's not incorporated 2 explicitly, when you do the pri maries, they don't 3 pick a number and say we're goi ng to protect 4 95 percent of the population. It's more of a 5 consideration. But here, becau se it determines the 6 critical load, we have to pick the specific 7 percentage, which makes it more difficult because 8 then we have to justify that sp ecific percentage. 9 So I understand the point that, you know, once 10 you fill it out, that means eve rything that is left 11 is part of the sensitive popula tion, but it doesn't 12 mean that we have to protect ev ery individual in 13 that sensitive population. 14 MS. CHESTNUT: I agree, bu t I think that needs 15 to be justified. Plus I'm not sure what is an 16 individual on this scale. Yeah , we don't protect 17 every fish, every tree, but a w atershed, a lake, a 18 stream, is that an individual? 19 DR. GREAVER: That is an i ndividual in the 20 sense of this population of wat erbody. A waterbody 21 is an individual. We should no te given the 7,500 22 waterbodies that we have now if we protected 23 100 percent of them, we would h ave zero allowable 24 deposition. That's one of the reasons. 25 DR. SCHEFFE: It gets backto the discussion

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1 in terms of screening out water bodies and 2 everything else because if you go at the tails of 3 that distribution, you would ha ve, as Tara says, 4 you would have zero critical lo ad allowable for the 5 most sensitive waterbodies. It becomes unstable 6 using that kind of metric. Not unstable, totally 7 unfeasible. 8 DR. HUBBELL: Not even jus t unfeasible, it 9 becomes I think inappropriate b ecause you're not 10 trying to protect every one of those individual 11 lakes. 12 MS. CHESTNUT: Right. And , you know, one lake 13 may not rise to the level of anadverse effect. So 14 there is -- 15 DR. HUBBELL: That's part of the discussion. 16 MS. CHESTNUT: -- that's k ind of why I'm 17 asking, well, so where are we n ow? We have this 18 conclusion that there is advers e effects now. So 19 what percentage are below these levels now? 20 DR. LYNCH: So if you just look at critical 21 loads for Adirondacks, you can think of it two 22 different ways. If you look at monitored sites 23 within it where you have data e xceedance based on 24 current deposition through 2008 , 2009, it's about 25 40 percent. If you then take t he E-map

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1 probabilistic population and yo u just model that, 2 which is a smaller number of la kes, but those lakes 3 are supposed to be represented through weighting 4 factors, the percentage around 30 percent that 5 don't meet and that's an ANC of 50. 6 DR. HUBBELL: So, again, I think, you know, 7 obviously if we chose somethingthen more than 8 70 percent, we would be requiri ng some reductions 9 in NOx and SOx. So I agree wit h you that we have 10 to find a way to justify these. Ultimately it's a 11 justification that's based on p olicy decisions 12 that's informed by the science. 13 And part of I think what y ou have asked before 14 and what we're trying to unders tand, there was 15 another comment and we mentione d this, what are the 16 characteristics of those lakes that are left behind 17 that don't get the full set of protection that get 18 a lesser set of protection? 19 And, you know, we're still looking at that, 20 and Ginger I think was doing so me work on this. 21 It's a mixed bag. There is no characteristic of 22 those lakes. They're not all g iant lakes, small 23 lakes, or heavily recreated lak es. It's a mixed 24 bag. So it's difficult to say do you gain 25 something special by going anot her 5 percent

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1 coverage. 2 MS. CHESTNUT: And I thinkthat the analysis 3 of what -- so if you get 90 per cent above 50, you 4 get so many percent above 20, i t's helpful to put 5 some of that in perspective. B ut it does seem like 6 in terms of like what's a reaso nable range that 7 50 percent -- you're looking at 50, 75 -- 8 50 percent is not enough, you k now. 9 DR. HUBBELL: And that's h elpful to know that 10 that's the judgment of what youthink. 11 MS. CHESTNUT: I don't kno w if that's a 12 uniform thing. It strikes me t hat the protection 13 is, you know, somewhere between75 and 100 and, you 14 know, I understand there is rea sons why you back 15 off from 100. But is 90 the to p, should it be 95? 16 I don't know. 17 DR. RUSSELL: Open it up. Panel comments? 18 Naresh. Actually, I think it w ould be good if 19 everyone formulates their thoug hts on this one as 20 to how comfortable one is in ma king such 21 recommendations and at the end of the day what 22 should we, as a body, recommendif Bryan asked for 23 ranges on these various compone nts of the standard. 24 And, you know, I guess in the p ast before my time, 25 they actually one time went aro und the table and

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1 voted on things. I'm not sure we need to do that, 2 but still getting everybody's i ndividual input I 3 think would be good. Naresh. 4 DR. KUMAR: I think two is sues, one is what 5 level of ANC is protective agai nst adversity. I 6 see there is enough discussion in Chapter 5, a 7 range between 20 and 50, let's say, that could be 8 chosen, but the form of the sta ndard is not ANC. 9 The form of the standard is AAP I. That's where I 10 have a problem because I think, given the lack of 11 complete quantities in answer i n the analysis, I 12 don't think the Administrator w ould have a high 13 degree of confidence in a parti cular level of AAPI 14 would indeed provide either a r equisite level of 15 protection or be overly protect ive. 16 And the way that it uncert ainty has been 17 described qualitatively has a p otential to give a 18 false sense of confidence in th e overall 19 uncertainty. I was looking at a discussion on page 20 72 and top of 73 where, you kno w, possible what the 21 low level of -- low level of co nfidence means. And 22 confidence is low, AAPI could b e adjusted upwards 23 or downwards depending on where you want to put 24 emphasis, whether you want to p ut emphasis on 25 providing a requisite level or whether you want to

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1 put an emphasis on not being ov erly protective. 2 So I think I would add to that if the level of 3 confidence is too low, it makes A, B standard 4 questionable because it's not r obust enough in that 5 case. 6 I know some of the members of the panel have 7 presented that the discussion o f uncertainty in 8 this document is much more thanthe previous 9 standards, but, again, we have to realize that what 10 we're talking about is very complex; and a lot of 11 the complexity cannot be evalua ted because of a 12 lack of data. So there is a ne ed to have a 13 quantitative evaluation of unce rtainty. And unless 14 we can really gain confidence i n that, I think it's 15 premature to talk of any levels of annual standards 16 on the form of the AAPI. 17 DR. RUSSELL: Other input? Ellis, you were 18 about to say something. Dale? 19 DR. COWLING: Dale had his hand up first. 20 DR. JOHNSON: Mine won't t ake long. You know 21 what I'm going to say. It need s more balance I 22 think. I don't share your fait h in the models. 23 Not that they're bad, but all m odels are bad, per 24 that wonderful article by Oresk es in 1994. And if 25 the models -- I've heard that i n some cases MAGIC

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1 predicts pH 6 and high-based sa turation in 1860 in 2 some of these northeast soils. If that's the case, 3 I know it's wrong. It can't be . 4 So what I think I'd be mor e convinced by is 5 something Charlie recommended, go look at those 6 datasets that have actually sho wn a response of 7 aquatic systems through reducedsulfur inputs. 8 It's happened and it's publishe d and Charlie's told 9 you so. 10 So I think that approach w ould be good, a good 11 way to look at it. Maybe take the approach that 12 the CO2 modelers do where they take the CO2 signal 13 and de-convolute it and try to figure out all the 14 factors affecting it. Somethin g like that would 15 convince me a lot more than wou ld a modeling 16 exercise, especially in the ste ady state model, 17 which I don't think is of value . That's it. 18 DR. RUSSELL: Ellis. 19 DR. COWLING: I'd like to make a comment about 20 question 2 or 2-B rather -- 24, I've misspoken 21 three times now, regarding targ et values for the 22 ANC. I think the figure that i s on page 571, which 23 is labeled 5-23, that's the fig ure number, is a 24 figure that offers an opportuni ty to understand or 25 to communicate a lot of these r elationships. This

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1 particular plot shows ANC on on e axis and pH on the 2 other. But you could make that kind of a curve, 3 and take real data to produce i t and put a whole 4 bunch of different X and Y coor dinates on that 5 draft and decorate it with some of the biological 6 effects, like mortality or degr ees of biodiversity, 7 and aluminum concentrations ver sus ANC. Plotting 8 all those things against ANC an d then trying to tie 9 that to an AAPI says well. 10 So commend that particular figure as a very 11 valuable communication asset as you go about the 12 business of talking about -- ab out the target 13 values of ANC that would be app ropriate in a 14 variety of circumstances in the sensitive regions 15 of our country. So I hope you look at 571 and 523 16 as something to use as a model for communication 17 purposes. 18 DR. RUSSELL: Other commen ts? Praveen. 19 DR. AMAR: Thank you. I'mgoing to take what 20 Rich has said earlier and I've been stirring at 21 this question for quite some ti me with regard to 22 what you said. And I think Ric hard said, which I 23 seem to like, what is missing h ere I think, you 24 know, after three years of this work and 25 recommendation, and I thought m aybe you were going

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1 to make a recommendation to EPAsaying based on all 2 we have heard throughout the ye ars, we think this 3 is what you need to do with res pect to ANC and 4 AAPI. And how does one make --decision making in 5 the presence of uncertainty? W e talked about 6 Chapter 7 and there is a lot of uncertain things, 7 but you still make a decision; and you say then the 8 consequences of that decision m aking is the 9 plusses, the minus, the benefit s. 10 Questions like in my mind, which we've been 11 talking about in a time traject ory of recovery. If 12 we had ANC of 20, 50 or 100 app roximately in the 13 AAPI, how many lakes will recov er in the next 20 14 years, 50 years, 30 years? I d on't have a sense of 15 scale of what we do here and wh at will happen in 16 years to come. And maybe that' s part of the 17 recommendation that EPA propose s a certain AAPI 18 that says here are the conseque nces of meeting that 19 and the time trajectory of that . I mean, I don't 20 have a sense of it, but I thinkit might be very 21 useful in the context of this d ocument. 22 DR. RUSSELL: So I'm goingto try to twist the 23 discussion in a second, but bef ore going to sort of 24 twisting it, EPA, do you have a ny questions for us 25 at this point?

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1 DR. HUBBELL: I don't. Ka ren, do you have any 2 follow-ups? 3 MS. MARTIN: No. 4 DR. RUSSELL: Okay, then. How I'm going to 5 twist -- yes, Chris. 6 DR. FREY: I guess somethi ng I think may be 7 missing here is, you know, at l east with the 8 primary standard there is usual ly some assessment 9 in the -- I think in the PolicyAssessment of the 10 health benefit, for example, of an alternative 11 standard. And, you know, for e xample, if we set PM 12 at this level or at that level here is the avoided 13 number of adverse health effect s. 14 What I didn't see in Chapt er 9 was suppose we 15 use ANC of 20, or suppose we us e ANC of 50, what 16 would be the benefit after, I d on't know, 5, 10, 20 17 years, whatever it would be, wh at's the avoided 18 adverse effect? And I don't kn ow if that's because 19 it's not possible to do that an alysis, but that 20 might also help crystalize the questions about the 21 uncertainties because in interp reting those kinds 22 of estimates one could say, wel l, we think this is 23 an underestimate for this reaso n or it's an 24 overestimate for that reason an d, therefore, we 25 should be over or underconfiden t in setting the

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1 level. And I don't know, I gue ss I'm just curious 2 if there is a reason why there isn't that kind of 3 analysis here or whether it's p ossible to do that? 4 DR. HUBBELL: It's really difficult to do 5 that. And, again, given where we are with the 6 document, you know, we obviousl y could have -- we 7 could choose, you know, an aggr egation method and a 8 percent waterbodies and an ANC target and say, 9 okay, if we were to meet that w hat would that mean 10 in terms of changes in ANC leve ls and then try to 11 back through that now. 12 There is an assessment -- there is a 13 discussion at least in Chapter 3 where we talk 14 about, you know, going to an AN C of 20 or going to 15 an ANC of 50 in the New York ar ea, it gets, you 16 know, around a billion dollars in annual benefits. 17 And we talk about the fact that , obviously, if you 18 extrapolate that to other locat ions because we 19 don't have good data on that, i f we were to 20 extrapolate it, it would lead t o substantially 21 larger benefits. 22 That exercise could be don e. And certainly, 23 again, the difference there is that's focused on, 24 you know, for a target ANC, youmet every one, as 25 opposed to an AAPI which embodi es the percentile

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1 and the other factors. So it c ould be done. 2 Again, the data is very limitedin terms of 3 specific damage functions that are broadly 4 extrapolatable to a lot of diff erent streams and 5 river types -- I mean streams a nd lake types. 6 So I think, again, it's a question of how 7 broad we can make the assessmen t. Certainly in 8 certain case study areas it's a lready been done and 9 could be done probably with some assessment of how 10 the uncertainty would play out, but, again, it's 11 going to have a lot -- it's goi ng to have a lot of 12 uncertainty in the calculation itself. 13 Again, for primary example s it's a little more 14 straightforward. Certainly the re are large 15 uncertainties as well in those assessments, but 16 there is a lot more history inv olved in doing them 17 and there is a lot more scrutin y that they've been 18 put through because of the mult iple reviews. And 19 it's not -- again, it's not cle ar that the same 20 kind of data is available to us . 21 DR. RUSSELL: Rudy. 22 DR. HUSAR: Yeah, the ques tion is to what 23 would make -- what makes me unc omfortable and that 24 is that I don't seem to have a view, an answer to 25 the question as to why is it th at after you go

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1 through this AAPI calculation, what is it -- why is 2 it that you would have, let's s ay, a lake's in 3 compliance, other one would not ? 4 In case of a primary stand ard because of the 5 sense -- because all population s of all people are 6 equal, the cost of the actual d amage is clearly air 7 pollution, dirty air, no questi on about it. But 8 now when you have this kind of an AAPI where you 9 have this balancing situation t hat on one hand you 10 have the driver that caused the pollutant, the 11 stressor, but then on the other hand you have a 12 compensating factor on the othe r side. 13 Now, wouldn't that be the situation that, 14 well, it could very well be tha t you have a 15 relatively flat deposition fiel d, but then what 16 really is causing a problem is the fact that that 17 particular population is not ab le to protect itself 18 or whatever. And so that kind of assessment of 19 totality, at the very coarsest level, I thought 20 that would be helpful. I'm not getting it from 21 these, but it could be calculat ed. So to break 22 down that AAPI at least into th ose two major 23 components. 24 DR. HUBBELL: I'm not sure I followed that. 25 So what would you specifically be breaking it out

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1 into? What are the two compone nts? 2 DR. HUSAR: You're suppose d to have some kind 3 of deposition -- the index that is associated with 4 the driver, you know, the depos ition kind of 5 driver. And suppose you normal ize it to one or 6 something, okay, all right; andyou say, okay, then 7 you have a corresponding index for the sensitivity 8 on the other side. 9 DR. HUBBELL: So you want to split the 10 equation in there as two pieces ? 11 DR. HUSAR: So that by loo king at say, okay, 12 this particular lake is highly sensitive even 13 though the concentrations are t he same or the 14 deposition is the same, but it' s highly sensitive; 15 therefore, the reason is it's i n noncompliance is 16 because of that. 17 In other situation it is b ecause of the high 18 stress. It is relatively opaqu e because of 19 sensitivity, but if you stress it high enough, it's 20 going to break. So separating those two and 21 identifying quantitatively is s omething that you 22 could do. 23 DR. SCHEFFE: Let me respo nd. The AAPI does 24 actually do that. It does sepa rate the sensitivity 25 with regard to the ecosystem co mponents and how

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1 that controls and the depositio n components and how 2 that controls. And I think wha t you're asking for 3 though makes sense. I think wh at you're asking for 4 is some other sort of a more ge neralizable analysis 5 that looks at these different w aterbodies, I don't 6 know exactly at what kind of sp atial scale, and to 7 add some intelligence as to the se are the types of 8 waterbodies in these locations that are 9 intrinsically more sensitive. These are the ones 10 that intrinsically tend to be m ore dominated and 11 affected by deposition than oth ers. And I think 12 that's kind of a reasonable kin d of analysis. I 13 think that does make some sense , but I want to be 14 clear that the AAPI does do tha t, it does separate 15 the sensitivities. 16 DR. HUSAR: You guys don't show it. If it has 17 the form, the separation is the re, but you're not 18 convincing -- you're not convey ing that in the 19 document as to show now how do those two interact 20 in creating this result. 21 DR. HUBBELL: So say we we re to have that, I'm 22 trying to figure out how that w ould -- how would 23 that help us inform what the le vel of the statement 24 ought to be or the form? I'm n ot sure. It would 25 be interesting to know.

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1 DR. HUSAR: It's not neces sarily including the 2 level, but it's more of kind of on the confidence 3 side. 4 DR. HUBBELL: It's more th e uncertainty and 5 confidence. 6 DR. HUSAR: Confidence. B ecause if, for 7 instance, it turns out that the sensitivity, let's 8 say, varies only by 10 percent, but the magnitude 9 of the stressor varies by a fac tor of 10, well, 10 clearly that's where you have t o figure that's 11 where you have to put your sens itivity analysis and 12 uncertainty on the one that rea lly does vary, that 13 actually does, is the causal fa ctor. 14 On the other hand, if it t urns out that this 15 other one that's vary -- sensit ivity varies a heck 16 of a lot more, that's where youhave to put your 17 effort in defending. It's more of a defensibility 18 rather than setting the actual value. Value 19 setting is clearly going to be policy. 20 DR. RUSSELL: Anything els e from the panel 21 before I twist things around? 22 Okay. Thank you. So I'm sitting here, you 23 know, and I want some help fromthe panel in that 24 we're about to write what I thi nk is our most 25 important letter yet in this pr ocess. I may be

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1 wrong on that, but I think this is the one a lot of 2 people are going to really readbecause we are 3 about to the point of helping t o advise most 4 specifically on the standard. And we've got this 5 document in front of us that we 've now read through 6 maybe a few times. 7 And one of the questions I think we have to 8 address in the letter is how re ady is this document 9 to go forward in terms of advis ing -- well, first, 10 how well it's advised us or inf ormed us and how 11 will it inform the Administrato r in making this 12 rather tough choice, given how complex this system 13 is. And wrapped into that ques tion, I mean, 14 wrapped into that is how would it advise on each of 15 the pieces of the standard that we've sort of I 16 think glanced around, but haven 't really gotten any 17 too specific except say we are having troubles with 18 some of the specificity since w e don't really have 19 a great feel for it. And at th e same time there is 20 always a question are we ready to -- I mean, should 21 we proceed forward with this ty pe of standard at 22 all given its complexity and ev erything, all the 23 values that go with that and th e knowledge that we 24 have at this point? I mean, interms of EPA has 25 done a tremendous job I think i n sort of laying

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1 this out and saying these are t he things that 2 really should go in it. We've come up with some 3 comments on the individual piec es, some of the 4 uncertainties. 5 How ready are -- I mean, a re we ready to also 6 put our names to a document say ing go forth, it's 7 there? And if not, why not; if it is, why it is. 8 So that's where I'm sort of sit ting at this point 9 and I want to get people's comments on that, raise 10 that discussion and see what pe ople think. 11 Do people see what I'm say ing? I mean, if I 12 didn't -- I hope people underst and, at least enough 13 people understand that they canstart a discussion 14 such that we will understand. Dale. 15 DR. JOHNSON: I'm not. Yo u know the reason 16 why. I just described it. 17 DR. RUSSELL: Andre, you'v e been quiet. 18 DR. BYTNEROWICZ: Catchingup on my lack of 19 sleep. I think the concept is good and I am really 20 happy that we got to this point , but I'm not ready 21 to vote for that yet because of the level of 22 uncertainty. 23 DR. RUSSELL: So when you say that, be 24 specific. 25 DR. BYTNEROWICZ: Well, fo r me a black box is

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1 the AAPI. It's what's behind t hat. So if I don't 2 see step by step that there are lots of uncertainty 3 and especially transformation o f ANC to AAPI and 4 deposition and also major compo nents leading to 5 that deposition of specific che mical compounds, I'm 6 not convinced we are there yet. 7 DR. RUSSELL: If that was given -- because I 8 think that's actually somethingreasonable they 9 could do, maybe not to us, but to the 10 Administrator -- do you think t hat would close the 11 loop? 12 DR. BYTNEROWICZ: For me, it would get me to 13 like 90 percent. 14 DR. RUSSELL: Okay. I'll tell you on the 15 health-based standards 90 perce nt is not a bad 16 thing. 17 DR. WEATHERS: So could we back up? 18 DR. RUSSELL: He votes yes . 19 DR. BYTNEROWICZ: Not yes, not yet. 20 DR. RUSSELL: What he saidis given a 21 comprehensive uncertainty analy sis associated with 22 the AAPI, he could be 90 percen t there. Actually, 23 I think -- is that -- 24 DR. BYTNEROWICZ: Eighty-f ive. 25 DR. RUSSELL: Eighty-five. We keep talking,

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1 it will go down. I should defi nitely not have said 2 yes. I don't think that's what he said. Lauri? 3 MS. CHESTNUT: Doesn't tha t depend on what the 4 uncertainty analysis shows? 5 DR. RUSSELL: And it could . That's something 6 we have to think about. 7 DR. MITCHELL: I guess I w ould suggest within 8 the comments from the panel andthe interchange, it 9 seems like it's a great opportu nity, EPA has done a 10 great job of trying to put toge ther a very complex 11 standard in which there are twoelements with all 12 their different chemical specie s and to not have 13 that -- and also we recognize t hat there certainly 14 are significant environmental e ffects associated 15 with acidification of waters as well as soils. So 16 certainly it is an opportunity and need to go 17 forward. 18 On the other hand, some important limitations 19 in terms of what has been done up to date -- not 20 that there has not been a lot d one, clearly a lot 21 of work has been done -- have b een indicated that 22 would seem to solidify this andat the end of the 23 day make it go forward in an ea sier way. 24 Particularly I like the suggest ion of doing some 25 hindcasting and showing how thi s would actually

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1 play out. I think that would g ive a lot of 2 confidence that this is a worka ble thing and show 3 what the limitations are. Some thing like that 4 would really help I think, at l east myself, in 5 terms of this. I just don't kn ow how to do that 6 step wise in terms of the proce ss. For me what 7 happened -- to go back and see what the past was 8 and start out using the model k nowing what the 9 chemistry has been in measured components. 10 DR. JOHNSON: To the past through known 11 measurements. 12 DR. MITCHELL: Yeah, knownmeasurements. We 13 don't want to hindcast other me asurements. That's 14 not helpful. 15 DR. RUSSELL: I'll be the one to ask, okay, 16 let's say they can't do that wi thin the time frame, 17 remember the time frame which I think is the second 18 slide we've seen today. It's n ot very loose. 19 DR. MITCHELL: Right, I un derstand that. 20 DR. RUSSELL: Assuming tha t's not there, where 21 would you come down? It's a to ugh question. 22 DR. MITCHELL: That's a ha rd -- I guess 23 depends on what other component s got addressed. 24 That's not a make it or break i t situation because 25 other substantial concerns I wo uld like to see

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1 addressed over the next few mon ths. I'm not sure 2 where I sit, somewhere between 75 and 80 percent. 3 DR. WEATHERS: So I have asuggestion, which 4 is I wonder if we ought to crea te that list. If 5 AAPI is what is making most of us uncomfortable, 6 not the big picture, we ought t o create that list 7 very quickly and then ask the question what if 8 these things can be done and wh ich of them are most 9 compelling. So hindcasting is one. I mean, you're 10 the chair. Is that a good sugg estion? 11 DR. RUSSELL: Last week inthis very room we 12 had people send in their votes on something, in 13 essence, looking at that and ge tting all the 14 people's individual concerns in . And we can do 15 that -- actually, we could do i t early -- that's 16 something I'm trying to get out of the group right 17 now is what are these things th at are most 18 uncomfortable? 19 DR. LYNCH: Can I ask a di rect clarification 20 to Myron's question? 21 DR. RUSSELL: Sure. 22 DR. LYNCH: When you mean hindcast -- 23 DR. MITCHELL: That's a ba d term. I meant 24 using past data, which you can actually use the 25 AAPI index. Hindcast was a mis chosen word.

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1 DR. LYNCH: I just want tojust make clear, 2 the idea of using MAGIC to go b ack in time. 3 DR. MITCHELL: No. The id ea is actually use 4 measured data over time where t hose data are 5 available. 6 DR. RUSSELL: So, actually , as we go around 7 the room, if people can answer Kathy's question, I 8 think that would be good. 9 DR. AMAR: Which is? 10 DR. RUSSELL: What are the components that are 11 currently giving people the mos t problems? You 12 want to rephrase it? 13 DR. WEATHERS: I think tha t's it. I think 14 what I've been hearing, certain ly myself, is that 15 we know that air pollution has ecological effects. 16 We know that deposition is asso ciated with 17 concentration in some way and t hat deposition is 18 the relevant flux of interest. We know that ANC is 19 a reasonable indicator of aquat ic acidification. 20 All the pieces of the standard we seem to feel 21 really comfortable with, but th e AAPI is causing 22 pause. I'm trying to figure ou t for myself and 23 others what would, if anything, would cause us not 24 to trip over the AAPI? 25 DR. AMAR: Maybe the answe r to that question

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1 is what's the alternative displ ay? We were 2 introduced to the concept about six months ago, 3 about a year ago. 4 DR. RUSSELL: More like a year. 5 DR. AMAR: We've gone thro ugh that. We saw 6 what the components were, how t hey're calculated, 7 how they're modeled and how the y're measured and so 8 on. I've been thinking about t he alternative 9 because we kind of -- AAPI to me is simply a 10 collection of what we knew. 11 DR. WEATHERS: Again, what I'm hearing is the 12 alternative is this group says this is a great 13 idea, go forward or this group says we're not there 14 yet. I mean, again, so I'm not suggesting that in 15 a short amount of time that eve rything be done. 16 I'm suggesting that there has b een an enormous 17 amount of work done. It's a re ally impressive set 18 of elements. 19 DR. AMAR: I think we're n ot there yet in 20 terms of explaining this to our selves and EPA 21 explaining it to itself, but I think it's more of a 22 communication thing. I was tea ching years ago 23 about what was the line about s imple sentences at 24 least tell the truth. And real ly I don't think 25 we've done a good job of explai ning, writing and

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1 thinking about it, all the vari ous components. The 2 science part we have done well. I don't think 3 we've done the explanation part very well. 4 DR. WEATHERS: I think act ually some of the 5 suggestions about what needs tobe done have more 6 to do with giving us some bound s on our confidence 7 about the elements of the AAPI rather than 8 quantitative uncertainties. Sohindcasting -- 9 wouldn't hindcasting give us so me indication of 10 whether we buy the MAGIC model? 11 DR. MITCHELL: Use histori cal data for 12 evaluation of AAPI. 13 DR. WEATHERS: Right, beca use using a series 14 of models is really a common th ing that's done for 15 climate modeling, for, you know-- 16 DR. AMAR: Primary. 17 DR. WEATHERS: Yeah, it's not new. There is a 18 lot of uncertainty still. 19 DR. RUSSELL: Naresh. 20 DR. KUMAR: So I guess the problem here, I'm 21 hearing also is the confidence in the AAPI and you 22 want to see suggestions from us . I have two 23 suggestions of what can be done to increase the 24 confidence at least for my sake . And I agree with 25 Myron, using the data for the p ast 20, 30 years and

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1 seeing how AAPI would predict achange or whatever 2 in what we're trying to do. 3 Second, I think I mentione d earlier, we know 4 CMAQ cannot be evaluated for ce rtain things, what 5 was the AAPI, but a lot more ca n be done. I've 6 given some specific suggestions earlier; and I can 7 do that again, when the time co mes. That's the 8 second thing is do a more full evaluation of CMAQ. 9 And third would be the quantita tive uncertainty 10 analysis. 11 DR. RUSSELL: Actually, as we go along, it 12 would be good if you note these and e-mail them to 13 me because there is no way I'm going to remember 14 them all. 15 DR. NUGENT: Could you rep eat that, that list 16 you just gave? 17 DR. KUMAR: You want me torepeat it or you 18 want me to e-mail it later? 19 DR. NUGENT: For the minut es, can you repeat 20 it? 21 DR. KUMAR: The first is w hat Myron said. 22 DR. WEATHERS: Hindcastingof MAGIC. 23 DR. KUMAR: Not MAGIC, usi ng the AAPI 24 framework. And number two is I would say complete 25 evaluation of CMAQ that can be done with the data

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1 that's available. And three is complete 2 quantitative analysis of sensit ivity. 3 DR. RUSSELL: Charlie, we haven't heard from 4 you lately. 5 DR. DRISCOLL: Well, I'm n ot uncomfortable 6 with this approach because I th ink that, I mean, 7 there are aspects of it that I think are, you know, 8 I can understand that are probl ematic. But I think 9 from a practical standpoint giv en that you want to 10 try to make calculations over l arge numbers of 11 watersheds and the time involve d that using a 12 steady state model makes sense. But steady 13 state -- I mean, watersheds are not at steady 14 state. They're, you know, dynamic systems. 15 But I think, as I've said a couple times 16 today, that I think we know wit h a fair degree of 17 confidence how these systems ar e responding, at 18 least in terms of acid rain eff ects. So we've got 19 long time series of data; and I think we have, you 20 know, given a unit level of red uction of sulfate 21 and nitrate. I think we have agood idea of where 22 they're going to go in the futu re. And we're 23 getting more and more informati on on the biological 24 response to those reductions. So I'm not -- I'm 25 not I guess as worried about th ings as a lot of

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1 people are I guess. 2 DR. RUSSELL: Lauri. 3 MS. CHESTNUT: When you fr ame the question in 4 terms of where we're at now andare we -- what's 5 our bottom line, are we going t o recommend going 6 forward with the standard or sa y there is not 7 enough, but given the time rest raints, I see it -- 8 I feel a real reluctance after all that's been 9 accomplished of saying, well, i t's not close enough 10 yet, just go home. And I wonde r if there is some 11 way to look at it in terms of w e're confident that 12 it should go at least this far in terms of picking 13 numbers, setting a standard. G oing beyond that, 14 you know, may be beginning to i mpose too much cost 15 or implementation difficulties; or can we say that 16 it should be at least a goal of at least this much 17 while then the details and meth ods in some of these 18 other things are worked out in the next round? 19 DR. RUSSELL: Certainly yo u can use that to 20 sort of advise, give advice, yo u know, I would put 21 it as the uncertainty might sug gest that you go, 22 let's say, do a lower bound andthe choice might be 23 to tighten it in the future. C ertainly that could 24 be a recommendation here is exa ctly that, is saying 25 that there are a lot of things we don't know about

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1 right now, so maybe you should go to a less 2 stringent bound at first. 3 MS. CHESTNUT: Yeah, to ke ep the momentum 4 going. 5 DR. RUSSELL: Because, youknow, I can see 6 some parallels in some of the o ther NAAQS as 7 they've gone. 8 DR. WEATHERS: Can you saymore about that, 9 give an example? 10 DR. RUSSELL: I would actu ally say, you know, 11 that maybe it's a different int erpretation, but if 12 you go back and look at the let 's say a prior PM 13 standard, maybe it would have b een set tighter with 14 more knowledge. And certainly that appears to be 15 the process is that, okay, it w as set at 15 and now 16 there is reasonable chance that it's going to get 17 tightened. I mean, just given the level of 18 uncertainty at first, have it b e a less stringent 19 standard. That can certainly b e part of the 20 thought process. 21 Would you say that's, you know, you all were 22 around -- both of you were arou nd at the last -- 23 not the current PM, but the las t PM standard 24 setting process. Reasonable ch aracterization? 25 DR. COWLING: Yeah.

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1 DR. RUSSELL: Other -- yes , Ellis. 2 DR. COWLING: I'm thinkingback over the last 3 two decades. The National AcidPrecipitation 4 Assessment Program began in 198 0 and ended in 1990. 5 The Voderborg (phonetic) Protoc ol was adopted in 6 1999, recommending that Europe adopt multiple 7 pollutant approaches in air qua lity management in 8 that continent. In 2004 the Na tional Research 9 Council published its report onmanagement of air 10 quality in the United States. In response to those 11 events, the EPA undertook start ing I think it was 12 2006 when the ISA was -- well, it was produced in 13 '06; is that correct? 14 DR. GREAVER: The first dr aft in 2007, but we 15 started in 2006, yeah. 16 DR. COWLING: Okay. And w e had an REA 17 produced in 19 -- in 2007. 18 DR. GREAVER: 2008. 19 DR. COWLING: 2008, okay. And we've now had 20 two rounds of discussions about policy assessments 21 in the wake of the ISA and the REA. I have 22 confidence that you guys can ge t this done in an 23 adequate way by December of thi s year. And I 24 believe that if you do your ver y best that the 25 recommendations that Ted and th e rest of us will

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1 try to write will help you do agood job. 2 And I think it would be a disappointment to 3 all of us who had some role in these various 4 national studies, like SNSF, fo r example, in the 5 1980s and the NAPAP program in the 1990s, or the 6 '80s to '90s, if we miss this c hance to demonstrate 7 a capacity of the United States of America through 8 its Environmental Protection Ag ency to match what 9 Europe has been doing, and Euro pe has its own 10 problems, the Voderborg Protoco l would be realized 11 in 2011, I believe that you guy s continuing the 12 work that was begun in '06 and has been continuing 13 to the present time can by Dece mber produce 14 something you are proud of and that our 15 Administrator will consider ver y carefully; and 16 that we will make progress towa rd managing 17 acidification in aquatic ecosys tems, which is not 18 the whole story; and that we wi ll produce the 19 secondary study that is ecologi cally relevant and 20 will have at least two pollutan ts; and a third one, 21 ammonia added, as given, not th e seventh criteria 22 pollutant, I believe that you c an do this by 23 December. And I will work hardas a member of this 24 committee to do anything I can to help you succeed 25 by your deadline.

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1 DR. RUSSELL: Are there co mments? I think 2 I've heard pretty much from eve rybody at the table 3 on this. 4 Okay. I'd like to end up the day just very 5 quickly go around and each of t he discussant leads, 6 sort of go and give us an idea of how you're going 7 to respond to each one of the c harge questions and 8 that way if we have any questio ns, comments, 9 additions, we will have a chanc e to give it to them 10 before they go and do their wri ting. Keeping in 11 mind that after we break, the i dea is they get 12 together with their co-discussa nts, maybe just for 13 a few minutes and then they wil l be writing the 14 responses this evening, and wit h the idea that you 15 e-mail them to Angela and I sometime this 16 evening -- or this evening is p retty loose. With 17 that, Lauri. 18 MS. CHESTNUT: Well, I thi nk the basic answer 19 is that the definitions of adve rsity presented here 20 are appropriate with a few qual ifications and 21 emphasis that -- and I'm not su re how -- this is 22 like the paragraph you're looki ng for. 23 DR. RUSSELL: Yes, it woul d be a one-paragraph 24 charge to the question. 25 MS. CHESTNUT: I mean, I w ant to make, again,

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1 the point that the public welfa re effects include 2 the protections that don't just use human direct 3 use, but the nonuse values, pre servation of natural 4 systems. That seems like the i nformation that was 5 included in this chapter on the community decisions 6 and is helpful in painting that whole picture. 7 And Praveen had the additi onal point to 8 mention Title IV program as ano ther piece of that 9 evidence. It's already been, s o I think that's 10 worth mentioning there. I thin k that's the main -- 11 the main things. 12 And then always keeping inmind that there 13 is -- or keeping in the forefro nt that there is a 14 lot known about the adverse eff ects even though 15 they can't be quantified all th e way through. I 16 think the descriptions can be b rought forward more 17 consistently 'cause there is th at tendency to just 18 here is what we can quantify an d then kind of not 19 remember well the items. 20 DR. RUSSELL: Sounds good. Ellis. You can do 21 two and three at the same time. 22 DR. COWLING: I promised t o deliver already my 23 contribution. So I'm going to take that over to 24 Dale's response. 25 DR. RUSSELL: Actually, I' m saying in terms

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1 of -- 2 MS. CHESTNUT: Do we have those 3 electronically, each others? 4 DR. COWLING: Yes. You ca n take off what I've 5 written before. 6 DR. RUSSELL: They're post ed, right? 7 DR. NUGENT: Before the me eting last night I 8 circulated to everybody a compi lation of comments 9 that included everybody's comme nts except the four 10 that came in super late last ni ght and this 11 morning. So I'll -- you've got one final, I'll 12 update that for the last commen ts. 13 DR. RUSSELL: So, Ellis, j ust your responses 14 to charge question two and thre e. 15 DR. COWLING: Well, I just handed that over to 16 Lauraine. Can you read the twolines that are 17 underlined in that? 18 MS. CHESTNUT: So under Ch apter 4, question 19 two? I'm a little confused abo ut where we're 20 going. Chapter 3, Chapter 4? 21 DR. RUSSELL: This is supp osed to be the 22 committee's consensus. 23 DR. COWLING: Are there adverse effects at 24 present levels? Yes. And has staff appropriately 25 applied this approach in review ing the adequacy?

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1 Yes. 2 DR. RUSSELL: Very good. Everybody else to 3 give a one-word response to que stion four. Dale. 4 DR. JOHNSON: The same, of course, that there 5 needs to be more consideration of unintended 6 consequences, including interac tions with other 7 environmental conditions, such as global carbon 8 cycling and climate change. La uraine may not agree 9 with that, but I'll put in ther e whatever she sends 10 me. 11 DR. RUSSELL: Praveen, que stion five. 12 DR. AMAR: Question five h ad to do with the 13 structural framework. We're go ing to say that 14 that's on the right track, whic h is really to 15 endorse the AAPI index. And I think there was some 16 comments from Myron, I'll try t o talk to you later. 17 We did mention something about CMAQ that we're 18 talking to. 19 And I had a point about ammonia, taking into 20 account I'd still like to make that point that 21 simply takes into account, and Rich was positive 22 about that compared to what we had done before. So 23 that was the question five, tha t we are on the 24 right track, the concept is rig ht. 25 I don't know how quite to say about the next

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1 question, but to say that's rat her complicated. I 2 still have to figure out what w e're going to say 3 there except the approach of cr eating the United 4 States as one big region is simple. And between 5 the other three approaches, sup port for the cluster 6 analysis, asking for more clari fication still. And 7 I did talk during the break abo ut ecoregions and 8 what they mean asking some more clarified language 9 in that chapter. 10 DR. RUSSELL: Comments on those? 11 DR. AMAR: If anybody has input, send me an 12 e-mail tonight. And I have the comments of all the 13 members. 14 DR. RUSSELL: Andre, sevenand eight. 15 DR. BYTNEROWICZ: Well, se ven basically we 16 agreed that critical load appro ach is good and 17 should be pursued. It's a logi cal way of linking 18 different departments with appr oach on this issue. 19 F-factor is also a reasonable a pproach and it can 20 be used. 21 In regard to filtering, I am changing my 22 original stand and I am agreein g with Charlie and 23 with Kathleen that basically fi ltering should be 24 avoided for different waterbodi es. So that's 25 basically point 7.

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1 Point 8 we agree that the proposed approach 2 makes sense and uses available knowledge. I'd like 3 to make a comment also that que stion of reduced 4 nitrogen species, especially ammonia, should be 5 taken with question and conside ration of steep -- 6 possibility of steep spatial gr adients exist and 7 for the protection of those pot entially affected 8 areas we have to take that intoaccount. And 9 that's basically it. 10 DR. RUSSELL: Any addition s? 11 DR. BYTNEROWICZ: And I wi ll be getting 12 comments from Charlie and from Kathleen. If 13 anybody has any questions, sendthem to me. 14 DR. RUSSELL: Naresh. 15 DR. KUMAR: I think the va riability of NOy 16 availability and those can be e xamined further, 17 namely looking at different che mical mechanisms, 18 different models. There was so me comment from 19 Praveen on the issue of I guess definition of 20 course work, you had a recommen dation there? 21 DR. AMAR: No, I wasn't cl ear because the 22 question itself wasn't clear. They will address it 23 in Chapter 8. I'm not sure whe ther Chapter 8 did 24 address it or not. 25 DR. KUMAR: So I guess sug gesting for --

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1 asking for more clarification. 2 DR. AMAR: I think Rich di d respond. 3 DR. SCHEFFE: I thought it was covered in 4 Chapter 8. We can talk later, but yeah. 5 DR. KUMAR: Also on the va riability, recommend 6 we look at variability for dry deposition and wet 7 deposition transfer functions j ust to see if it is 8 a rainfall variation that's cau sing the changes. 9 Rich Poirot had a comment on looking at NOx 10 and nitrate, CASTNET data for t his comment or was 11 it for some other comment, Rich ? 12 MR. POIROT: Well, I guess it could go here, 13 but it could go maybe elsewhere too. 14 DR. KUMAR: Yeah, if you w ant it under here, 15 then maybe you can send me a fe w lines on that. 16 MR. POIROT: Maybe it woul d be better in the 17 monitoring section. 18 DR. KUMAR: That's fine. Okay. On number ten 19 I think we agreed that the aver age time of three to 20 five years is appropriate. So no recommendation 21 there. 22 DR. RUSSELL: Anything els e from Naresh? 23 Eleven and 12, Charlie. 24 DR. DRISCOLL: So I think what I take from the 25 discussions we're going to conc lude that the

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1 alternative levels of targeted ANC that were 2 considered were reasonable. Th ey go from 3 relatively sensitive to relativ ely insensitive. 4 And I think that they are, you know, to the degree 5 that the science informs this, they are reasonably 6 well -- or linked with adversit y in terms of 7 biological effects. So I was g oing to basically 8 say that. Comments? 9 DR. RUSSELL: Comments? O kay. Thirteen, 10 Lauri. 11 MS. CHESTNUT: I think the gist of it is that 12 the analysis of the co-protecti on benefits is 13 useful and probably sufficient for the purposes 14 here and that there is some co- benefit. 15 I think a suggestion that other benefits and 16 disbenefits, whatever you want to call them, should 17 be at least listed to give a fu ll picture of these 18 pollutants also contribute to t he processes of 19 human health effects through PMand ozone and other 20 welfare effects. And Dale's po int about the 21 potential impacts in the other direction, carbon 22 sequestration and perhaps other nutrient benefits 23 to put the whole thing in some context, but that 24 that's -- can just be a descrip tive list. 25 DR. RUSSELL: Number 14 an d 15, Rudy.

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1 DR. HUSAR: It covers unce rtainty parts, parts 2 of the AAPI, but has not dealt with AAPI as a 3 whole; that is, uncertainty of it as a whole. In 4 dealing with the uncertainty, C hris has suggested a 5 use of a more coherent consiste nt framework in 6 order to formulate the uncertai nty. And Charlie 7 has also pointed out that there are methods of 8 uncertainty estimation that go beyond just simply 9 looking at the pieces of CMAQ l et's say. 10 Naresh brought back the se t of suggestions or 11 ideas that were then specific i deas from the past 12 as to how one could examine andevaluate the 13 uncertainty using multiple, lit erally multiple 14 perspectives. Both Myron and I have been hammering 15 around at the CMAQ and the unce rtainty associated 16 with that. 17 I thought that the main ki nd of a positive 18 kind of emergent contribution t hat might -- that 19 had been arising that was trigg ered by the 20 hindcasting idea, which then wa s now augmented by 21 Naresh as saying well, what abo ut hindcasting with 22 the AAPI as the measure of the hindcasting, right, 23 so that you can actually see ho w it has worked. 24 And it quantitates Charlie's co mments that yes, 25 indeed, there is all this infor mation that is

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1 already available by which we c ould then see how 2 this AAPI really works, which i s what we have not 3 seen. Maybe that way one creat es a level of 4 confidence. 5 In this AAPI I think nobod y has expressed 6 explicit direct concern that th ere is something 7 wrong with it. It is just we w ould like to know 8 more how it really works. 9 DR. RUSSELL: Charlie, 16 and 17. 10 DR. DRISCOLL: So in our d iscussion we talked 11 about the uncertainty associate d with MAGIC and 12 steady state water chemistry mo del. So I'd just 13 try to summarize comments if pe ople have additional 14 things on that, I'll try to addin things that 15 could be considered with respec t to the uncertainty 16 analysis. 17 Seventeen is a little bit problematic. I 18 guess we could have a very longlist. I think if 19 people have ideas, I think ther e are a few things I 20 took notes on that people thoug ht were high 21 priorities, I'll try to list a few very important 22 research and data collection it ems. 23 DR. RUSSELL: Rich. 24 MR. POIROT: Well, the mon itoring questions 25 were quite narrowly focused. I think we might want

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1 to think about a paragraph that we put in the cover 2 letter that's outside of the fo cus of the 3 monitoring questions, and amongother things, would 4 be supportive of the multiple o bjectives that were 5 listed at the beginning of the monitoring chapter 6 and emphasize their special imp ortance for this 7 NAAQS review and that they are also justified for 8 many other reasons. This is a good place for that. 9 We might do something like that . 10 In terms of the specific c harge questions, the 11 first one 18 is asking about is the use of an 12 open-face collector as a potent ial 13 sulfate reference method for th is standard and the 14 specific use of the CASTNET ope n-face sampler as a 15 reference. I guess I'd like tosee us sort of be 16 supportive of that even though we are additionally 17 recommending that the monitorin g subcommittee be 18 consulted on the various approa ches. 19 Ditto for ammonia, ammonium, I think this 20 committee could and should be s upportive of the 21 collection of additional ammoni a measurements not 22 as a necessary component, but a s a highly desirable 23 component and implementing the standard. 24 And, finally, the last que stion relates to a 25 small subset of sites where hig hly sophisticated

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1 measurements of the different m ore exotic 2 components of NOy be conducted. And, you know, my 3 sense on that is that I'm not s ure that we can roll 4 out really a network in the fir st place. I don't 5 know quite how to answer that. 6 Certainly, yes, those addi tional measurements 7 would be useful, but -- and des irable, but I think 8 I'd like to recommend that the -- that we advise 9 the agency to consider optional combinations of 10 existing programs like CASTNET and CORE and the 11 possibility of enhancing existi ng monitoring 12 programs as an alternative to o r a component of 13 monitoring convective specifica lly -- 14 DR. RUSSELL: Actually, ju st thinking about 15 it, in terms of going to AAMS, you might recommend 16 that they enlarge or enhance th e panel during that 17 portion, just to have some indi viduals who are -- 18 who are experts in deposition, measurement and also 19 aquatic effects or some relatio nship there because 20 I think that would be somethingthat would be 21 missing. 22 MR. POIROT: I wish I had gotten more comments 23 from others on this panel becau se we know what's 24 going to happen when we take it to those guys. 25 DR. RUSSELL: We knew.

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1 MR. POIROT: The other guy s are even worse. 2 So if anybody has any additiona l thoughts on the 3 measurements, e-mail them to me . 4 DR. RUSSELL: Chris? 5 DR. FREY: Twenty-one and 22. Twenty-one, my 6 general sense of what could be said there is that 7 the overall characterization of uncertainty is 8 addressed in the responses to c harge questions 14 9 through 17 and is a good starti ng point, but that 10 the panel would like to see fur ther interpretation, 11 preferably quantitatively where possible, of the 12 uncertainties in the components of the AAPI and the 13 AAPI itself, particularly as it pertains to degree 14 of confidence in setting levels of the standard. 15 And I might add, maybe thi s is picking up what 16 Praveen said, and Bryan and I t alked at the break 17 too. It's just explaining this standard to anybody 18 is a challenge. And, you know, maybe one thing 19 that would help is to separate the air and the 20 non-air components of the AAPI. And when we talk 21 about uncertainties, talk about them for 22 air-related parts and the non-a ir-related parts; 23 and get some insight as to, youknow, how much of 24 the uncertainty is related to t hings not related to 25 air versus related to air might be useful for us to

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1 know that. 2 I'm just trying to see if I missed anything 3 from comments that others made 'cause I wrote notes 4 that I can't read. Charlie sai d a few things. I 5 guess the point Charlie was mak ing is that there is 6 a lot of research I guess from an uncertainty 7 perspective is sort of like a w indowing method 8 where, you know, we can do this disaggregated 9 analysis bottom up uncertaintie s and aggregate them 10 to a combined uncertainty, and we can end up with 11 an uncertainty much wider than justified by 12 evidence from the field perhaps because we're not 13 appropriately dealing with cova riances or other 14 kinds of dependencies on the da ta. Considering how 15 the uncertainty is bounded by o ther information and 16 discussing that in Chapter 9 wo uld be helpful. So 17 I think that's question 21. 18 Twenty-two if anybody has any input, feel free 19 to e-mail me and Ted, but I did n't get the sense 20 that there was a whole lot to s ay on Part A. And, 21 you know, maybe we could just r eaffirm that the, 22 you know, the foundation for se tting the standard 23 based on aquatic acidification seems like an 24 adequate basis for setting a se condary standard. 25 Certainly there are other thing s that might be

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1 considered if there was enough evidence to quantify 2 them, but it seemed like on some of these specific 3 points it wasn't clear that the re was much to go on 4 beyond what's already in the do cument. So that was 5 my sense of that discussion. 6 On Part B, this is the app ropriate qualitative 7 and quantitative characterizati on of uncertainty. 8 I think that goes back to what I said for charge 9 question 21; and maybe just rea ffirm that the panel 10 would like to see a little bit further sensitivity 11 analysis of the AAPI in maybe amore holistic way 12 considering not just elasticity , but range 13 uncertainties and maybe how mul tiple uncertainties 14 combined to affect the AAPI; or in the inverse 15 calculation, how uncertainties in the AAPI might 16 affect inferences on NOy and SO x. 17 Part C, I think we had some discussion about 18 whether there was geographic or temporal effects at 19 smaller scales than the spatial and temporal 20 averaging that's the basis of t he options for the 21 standard and whether that wouldmotivate any kind 22 of adjustment to the level of t he standard. I 23 don't get the sense we had a st rong conclusion 24 about that. So it could be something EPA could 25 discuss. If the committee thin ks that EPA should

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1 do something, you know, I can i ncorporate that into 2 the response. 3 DR. RUSSELL: Kathy. 4 DR. WEATHERS: So I think the bottom line on 5 23 is the science hasn't change d appreciably. We 6 are not in favor of increasing bureaucratic 7 hassles, but the standard is se t for something 8 which the science is known, so we can stay. Then 9 there are a couple of other fin e points. 10 MR. McNAMARA: Speak to th e mike, please. 11 DR. WEATHERS: The science didn't change 12 appreciably. And so for that r eason the standard 13 could stay. 14 We also had some questions that if it's useful 15 to you that I write out I will do so, some 16 questions about whether there i s any connection 17 between the standard that is be ing proposed here 18 and the protection for vegetati on. So is it 19 helpful to reveal some of those questions in that 20 discussion we had about bureauc racy? 21 DR. HUBBELL: Not particul arly. But, again, I 22 think, as Karen pointed out, if the science still 23 supports the current standard, that's what's most 24 important. 25 DR. WEATHERS: Yeah. And for 24 I think that

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1 the bottom line is that the pan el agrees with many 2 of the suggestions for target v alues, levels. 3 There are cases in which I thin k the panel agrees 4 because it seems like the scien ce is there and the 5 range is supportive. 6 There are other cases wher e more information 7 would be needed or is needed, s ome clarification is 8 needed. So, therefore, we're n ot making specific 9 recommendations that are differ ent from the ones we 10 made. I'll clarify those. 11 And a question about the b ig pieces, the AAPI 12 components and other questions we'll address some 13 of those concerns and reiterate what we're talking 14 about here relevant to this que stion. It will 15 be -- I don't know what -- Richand Charlie I think 16 you're on this with me. Who el se was on this with 17 me? 18 DR. RUSSELL: Charlie, Cha rlie was 23. 19 Lauraine. It sounds like peopl e are getting tired. 20 With that, I see EPA has a ques tion for us. 21 MS. MARTIN: Recognizing t he time of day and 22 everyone is getting tired, I di d want to make a 23 couple observations that I woul d like to offer to 24 you as you think about how you' re going to develop 25 your letter tonight and tomorro w. One

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1 recommendation to think about i dentifying types of 2 additional work that we might d o that would be most 3 useful and informative to help provide a degree of 4 confidence to move forward withthe kind of 5 standard that I think we hear y ou're all 6 directionally supportive of, if we but did 7 sufficient analysis to have suf ficient confidence 8 in the approach. 9 I would really -- it wouldbe extremely 10 helpful to us for you to articu late those thoughts, 11 prioritize them to the extent y ou can. We always 12 work within time constraints, b ut time constraints 13 aren't always inflexible. And having the 14 opportunity to understand what you all think would 15 be the most useful things for u s to do allows us 16 then to think about potential a lternative paths 17 forward to address those. 18 In doing that, I would als o urge you to think 19 about does the information that has been pulled 20 together in this five-year revi ew cycle -- and by 21 that I mean all the science pre sented in the ISA, 22 the analysis presented in the REA -- do you believe 23 that is a sufficient body of in formation to inform 24 consideration of potential new standards if there 25 were but further policy-relevan t analysis done of

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1 that information; or do you bel ieve that it really 2 takes another several years' wo rth of accumulating 3 research information to have su fficient information 4 to inform those judgments? 5 That's not necessarily wha t I was hearing, but 6 there is a very big difference between those two 7 things. And clearly articulati ng your views on 8 that point as well would be ver y helpful for us to 9 think about alternative paths f orward. 10 DR. RUSSELL: Karen, thank s. That was going 11 to be my parting thing is to --if you recall, one 12 of the things I want everyone t o get their lists of 13 what analyses you think need tobe finished up to 14 get to the state where the document is ready to 15 adequately inform CASAC and the administrative team 16 on how it might be biased in NAAQS. Karen wants 17 that more specifically. 18 So get that information tome because that is 19 I think a very important piece of what we are going 20 to transmit to the agency in th is letter is exactly 21 that. So, with that, I think w e can be adjourned 22 for the day. 23 (Meeting adjourned at 5:25 p.m.) 24 25

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1 STATE OF NORTH CAROLINA ) 2 COUNTY OF WAKE ) 3 CERTIFICATE OF REPOR TER 4 I, MAREN M. FAWCETT, RegisteredProfessional Reporter and Notary Public in and fo r the State of North 5 Carolina, duly commissioned and auth orized to administer oaths and to take and certify deposi tions, do hereby 6 certify that I attended the meeting on October 6, 2010 and that the preceding transcript, w as reported by me 7 verbatim to the best of my ability, and then reduced to typewritten form under my direct sup ervision; that the 8 foregoing is a true and correct tran script of said proceedings to the best of my abilit y and understanding; 9 that I am not related to any of the parties to this action; that I am not interested in the outcome of this 10 case; that I am not of counsel nor i n the employ of any of the parties to this action. 11 12 IN WITNESS WHEREOF, I have here to set my hand, this the _____ day of October, 2010. 13 14 15 __________________________

_ 16 Maren M. Fawcett, RPR Notary Public - North Caro lina 17 Certificate No.: 200621500 068 My Commission Expires: 7/ 31/2011 18 19 20 Maren M. Fawcett, RPR Bryant Court Reporting Service 21 P.O. Box 1401 Cary, NC 27512 22 23 24 25

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