UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C. 20460

April 20, 2005

EPA-SAB-CASAC-05-006

OFFICE OF THE ADMINISTRATOR SCIENCE ADVISORY BOARD
Honorable Stephen L. Johnson Acting Administrator U.S. Environmental Protection Agency 1200 Pennsylvania Avenue, NW Washington, DC 20460

Subject: Clean Air Scientific Advisory Committee (CASAC) Advisory on Implementation Aspects of the Agency ’s Final Draft National Ambient Air Monitoring Strategy (NAAMS) (December 2004)

Dear Acting Administrator Johnson:

The Clean Air Scientific Advisory Comm ittee’s (CASAC) Ambient Air Monitoring and Methods (AAMM) Subcommittee (“Subcommitt ee”) met on December 15, 2004 to conduct an advisory meeting on implementation aspects of the Agency’s Final Draft National Ambient Air Monitoring Strategy (NAAMS or “Str ategy”). The public meeting wa s held at the staff offices of the EPA Science Advisory Board (SAB) in Washington, DC. Members of the Subcommittee are recognized, national-level experts in one or more of the following di sciplines or areas: (1) atmospheric sciences and air qua lity simulation modeling; (2) hum an health effects and exposure assessment; (3) air quality measurem ent science; (4) ecological risk assessment; and (5) State, local agency or Tribal experi ence. The Subcommittee roster is found in Appendix A of this report.

In general, the CASAC finds that the Agency ’s ambient air quality monitoring program is beginning to implement the changes necessary to bring it inline with the NAAMS strategy document. There are and will be a number of scie ntific issues that will arise as the progress is made in reconfiguring the network and as new knowledge with respect to monitoring, modeling, and effects becomes available. CASAC AA MM Subcommittee members’ individual review comments are provided in Appendix B.

1. Background
The CASAC, which comprises seven members appointed by the EPA Administrator, was established under section 109(d)(2 ) of the Clean Air Act (42 U. S.C. 7409) as an independent scientific advisory committee, in part to pr ovide advice, information and recommendations on the scientific and technical aspects of issues rela ted to air quality criteria and national ambient airquality standards (NAAQS) under sections 108 and 109 of the Act. The CASAC, which is administratively located under the SAB Staff Offi ce, is a Federal advisory committee chartered under the Federal Advisory Committee Act (FACA) , as amended, 5 U.S.C., App. The SAB Staff Office established the CASAC AAMM Subcommitt ee in July 2004 as a standing subcommittee to provide the EPA Administrator, through th e CASAC, with advice and recommendations, as necessary, on topical areas related to ambien t air monitoring, methods and networks. The Subcommittee complies with the provisions of FACA and all appropr iate SAB Staff Office procedural policies.

In late 2002, EPA’s Office of Air Quality Planning and Standards (OAQPS), located within the Office of Air and Ra diation (OAR), issued a draft National Ambient Air Monitoring Strategy. OAQPS subsequently requested thatthe CASAC review the draft NAAMS document and provide advice and recommendations to th e Agency on the technical bases and design aspects of the Strategy. The SAB Staff Office announced the formation of the NAAMS Subcommittee of the CASAC on November 5, 2002 (67 FR 67403). The CASAC NAAMS Subcommittee held a public meeting in Resear ch Triangle Park, North Carolina, on July 8-9, 2003 (68 FR 34945, June 11, 2003) to conduct this review of the draft Strategy document. The primary recommendations of the CASAC NAAMS Subcommittee, through the chartered CASAC, included a request for an implementation plan, and added emphasis on rural- and ecosystem-oriented monitoring, support for th e National Core Monitoring Network (NCore) Level 1 program, and training and quality assurance to enhance data co nsistency across the Nation. The CASAC NAAMS Subcommittee’s comple te report from this review is found on the SAB Web page at URL: http://www.epa.gov/sab/pdf/casacl04001.pdf

. OAQPS updated the NAAMS document after the CASAC’s review of the Strategy. The revision incorporated EPA’s responses to the CASAC NAAMS S ubcommittee’s recommendations.

Last spring, the SAB Staff Office a nnounced (69 FR 19180, April 12, 2004) the formation of the CASAC AAMM Subcommittee. This subcommittee replaced the former CASAC NAAMS Subcommittee. Subse quently, OAQPS asked the CASAC AAMM Subcommittee to conduct an a dvisory meeting for the purpo se of providing advice and recommendations on the implementation plan fo r its updated final draft NAAMS, which is posted on EPA’s Ambient Monitoring Technology In formation Center (AMTIC) Web site at the following URL: http://www.epa.gov/ttn/amtic/files/ambient/monitorstrat/allstrat.pdf

.

2. CASAC AAMM Subcommittee Advisory on Im plementation Aspects of the Agency’s Final Draft NAAMS
The purpose of this meeting was to review the progress toward implementation of the Final Draft NAAMS. The OAQPS requested that the Subcommittee provide expert advice and recommendations on the following charge questi ons, which focus on key implementation issues:

1. The CASAC has expressed its support for the Agency’s proposal to redesign the routine PM monitoring network to support PM precursor gas measurements (CO, SO 2 , NO/NOx, NH 3 , HNO 3 ) at NCore Level II multiple-pollutant sites, and for air quality management decisions and to obtain relevant exposure data for research programs. Given limited budgetary resources, does this represent both an appropriate and ade quate balance, as reflected by the relative resource alloca tions provided in Section 11, “Draft

2Implementation Plan,” of the Final Draf t NAAMS Document? In addition, are the relative adjustments inthe training and guidance appr oaches proposed in the draft implementation plan consistent with th e overall objectives of the Strategy?

2. The implementation plan proposes a series of communication actions to advance the NCore Level 2 network, in order to more directly support long-term health effects research and provide better support to ecosyst em assessments through an increased level of coordination. Does the CASAC AAMM S ubcommittee have additional suggestions for addressing this need for integration and communication to the broader community of “users,” including scie ntific researchers ( i.e. , human health, atmospheric, ecological) and State, local and Tribal (SLT) Agency repres entatives? More specifically, what is the most effective manner for EPA both to reach-out to this broad user community and, where appropriate, to incorporate their f eedback and design input on such issues as monitoring site locati ons and parameters?

3. One of the remaining technical issues re lates to harmonizing rural- and urban-based PM 2.5 chemical speciation networks such that both categories of networks utilize consistent sampling and analysis protocols. For example, EPA is considering converting all of the Speciation Trends Network (STN) speciation sites to Interagency Monitoring of Protected Visual Environments (IMPROVE ) samplers and IMPROVE laboratory and sample handling protocols. What are stre ngths and weaknesses of this approach?

4. As EPA implements the National Ambient Air Monitoring Strategy to address multiple monitoring objectives, it will be looking to spatially optimize the ambient monitoring networks. This may mean that some redundant monitors in adjacent, but separate, geopolitical areas ( e.g. , neighboring counties) are “dives ted” from a given network. Although technically sound, these divestments c ould result in data gaps which might, in turn, adversely impact regulatory decision-making. The Agency is willing to adopt alternative approaches for assessing re gulatory issues such as non-attainment designations, so long as such approaches are scie ntifically jus tifiable; hence, the rationale for initiating discussion of thes e issues with the CASAC. Is it scientifically acceptable to generate isopleths of airborne species concentrations through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regulatory d ecision-making process?

Before the discussion of the implementation plan and related issues, the Subcommittee would like to commend the OAQPS staff for the re sponsive manner in which they have revised the original draft monitoring strategy in respons e to the comments provided by the CASAC NAAMS Subcommittee (EPA-SAB-CASAC-LTR-04-001) [the URL for this report is found in the Background section above]. Several memb ers of the present Subcommittee were also members of this earlier group, a nd there was strong approval by thes e individuals to the changes that have been made in the Final Draft NAAMS Document.

The Subcommittee discussed these issues se quentially and this re port will provide the subcommittee recommendations. Individual comme nts from the subcommittee members on each of these issues are provided in Appendix B to this report.

3Question 1

The first issue is that of resource allocation as the redeployment of monitoring resources starts to be implemented. The Subcommittee conti nues to support the need for Level 1 (L1) sites as a means for testing of new monitoring technolo gy and moving it to routine use. Substantial advances in monitoring technology have been obt ained through the EPA Particulate Matter (PM) Supersites. That exercise provided the opportunity to test and refine new in strument concepts. It is recognized that such an effort cannot be sustai ned at the level of the Supersites, but some level of continuing support is critical to continue the improvements in da ta that are needed to provide the underpinning of future regulat ory decisions. Since one of the main purposes of L1 sites would be to help transition new methods into routin e use, it may be useful to develop the L1 sites as cooperative efforts between a research team and state or lo cal regulatory agency personnel.

There was some discussion as to potential sour ces of funding that could be diverted to the establishment of L1 sites. There were sugges tions from several members that Photochemical Assessment Monitoring Stations (PAMS) monito ring could potentially be reduced beyond the recommendations of the implementation plan. It may be that there is not a need for as many standard monitors and that more advanced inst rumentation integrated with a few L1 sites or limited duration special studies might be more ef fective in providing the information needed for making the needed air quality management decisi ons. However, in those locations where it is felt useful to maintain existing data collection, consideration shoul d be given to extending this operation through the entire year. Although it is unlikely that there will be ozone violations in the winter, the data on organic constituents can be useful for understanding exposures to and sources of toxic hydrocarbons and PM 2.5 precursors, for tracking eff ects of changes in gasoline or diesel fuel content, and for evaluating emissions inventories and air quality models.

An important consideration is the allocation of resources for data analysis as an integral part of the network. End uses of the data are too often afterthoughts, and planning for an initial set of data analyses is an esse ntial part of the design process. There are too many examples of inadequate planning and resources to use the data collected by routine network operations and it would be useful to better match the data uses with the effort to acquire the da ta as an integral part of the overall plan. Although all of the possible uses for data cannot be anticipated, many of the typical analyses can be anticipat ed and included in the implemen tation plans together with the requisite budget. CASAC strongly recommends th at the Agency give greater consideration to identification of the amounts of financial and human resources that will be allocated for data analyses and interpretation activities. In this connection we call special attention to the written comments on “outreach and extension of findi ngs” and “analysis and interpretation of monitoring results” by CASAC members in Appendix 2.

There were suggestions that there needed to be more effort placed on time-resolved measurements. Long-term integrated measurements lose critical information. It is generally better to get more detailed time-resolved information for shorter time interv als than to have long time interval integrated measurements. With car eful design and appropria te statistical methods, these episodic measurements can still lead to adequate descriptions of annual averages and trends. There is so much additional benefit to the time-resolved measurements that the effort needs to be made to move strongly in that dire ction. As indicated in the report from the earlier

4Subcommittee on Fine Particle M onitoring, it is important to reta in an appropriate number of integrated filter samplers to provide a basis for comparisons with the past monitoring record and appropriate quality assurance ch ecks on the monitoring program.

Although the commercially-available instruments commonly used for measuring NO x concentrations are appropriate for ensuring comp liance with the health-based national ambient air quality standard for nitrogen oxides, they are not sens itive enough to be useful for making decisions about NO x vs. VOC sensitivity of ozone non-attainment areas. Such information is also important for understanding particulate matter form ation. Most commercial instruments have a minimum detection limit for NO of about 1 ppb, but decisions about NO x vs. VOC sensitivity require instruments that have minimum detection limits of about 0.1 ppb. Similarly there is a need for improvements in other gas phase species methods to provide the sensitivity required for all of the other objectives other than complian ce testing. There is also a need for more measurements of key gas-phase species like NH 3 and HNO 3 . At this time it appears there needs to be additional development efforts to provide semi-continuous measurements of these species and their particle- phase counterparts.

Finally, there needs to be greater consideration of general HC characterizations in NCore. The treatment of carbonaceous compounds is currently a weak part of the monitoring strategy. As a first step, continuous total NMOC measurements should be in cluded in the NCore L2 sites or at least a subset thereof.

With the promulgation of the Clean Ai r Mercury Rule on March 15, 2005 that will require controls on mercury emissions from co al-fired power plants, it is important that monitoring be put in place to measure the atmosp heric concentrations of mercury species. Such an effort should be put in place as quickly as possible so as to gather baseline data before controls can actually be put in pl ace and maintained for a sufficiently long period as to ascertain the changes in atmospheric concentrations that o ccur as a result of these controls. Given that there is likely to be regional caps, as part of a cap and tr ade program, appropriate regional strategies will be needed to provide the necessary accountability data.

Question 2

There is consensus within the committee th at the single most effective way for EPA to reach out to potential users of its data is to make these data easily accessible via the internet. The committee was encouraged by the staff presentation on current plans for Web access, and expressed a desire to move rapidly toward getting this portal into operation with the flexibility to adjust it as experience with its use is obtained. There is concern that there may be bottlenecks between network operation and data availabil ity. We support pushing the access to raw data behind EPA’s “AIRNow” Web site as quickly as possible and would like to encourage their Steering Committee to move things ahead.

Another issue that needs to be addressed is computer-to-co mputer access. For users who continuously update graphical displays or mode l calculations, access for an automatic download of data is an important aspect of the accessibil ity of the data. Providing protocols for such access should be part of the plans for the data access Web site.

5It would be helpful to combine ancillary data from other agencies such as the visibility data from airports into the data base. It may be useful for EP A to discuss the development of combined data sets with the variety of other Federal agencies that have air-quality data sets such as NASA, NOAA, and DOE.

In terms of communications, it may be useful to consider organizing regional workshops to get broader input into network modifications and data use. In particular, this may be the appropriate way to bring the ecological community into the discussions. The move to site more monitoring in rural areas needs the active participation of the ecological community to balance the needs of the air quality mode lers with those interested in understanding the eco logical effects of air pollution. Since ecosystems vary widelyfrom region to region ac ross the country, regional workshops or similar forums can provide a means for meaningful participation by those interested in ecological systems.

It is not clear that additio nal efforts are needed to get the health community involved other than making the data readily -accessible. It is likely thata number of hea lth researchers would make use of data if they are easily accessible. However, changes to the network affect the ability of epidemiologists to use the data and th ere needs to be effective communication with this community to permit EPA to understand the potential impacts of any changes that are planned for the network. The network is being redeployed to serve multiple objectives and regulatory needs will take priority, but good communications can permit maximal exchange of points of view and an opportunity to make better de cisions on the redeployment of monitors.

Question 3
There is strong general support for making substantial changes to the 54 STN Trends sites to ensure compatibility with IMPROVE data . Currently, it is not possible to fully combine STN and IMPROVE data in spatial studies or inmodel evaluations since there are significant differences in sampling and analysis. However, it needs to be fully understood what is meant by IMPROVE-protocol sites. At present, the IMPROVE program controls all aspects of the system from sampling to analysis. STN utilizes state an d local agencies to operate the samplers.

The IMPROVE sampler uses a cr itical orifice rather than active flow control, and thus, provides a less stable particle-size cutpoint. IM PROVE uses 25 mm filters and higher flow rates that have the advantage of having higher areal dens ity of material on the filters as compared with the STN samplers. However, there has been con cern regarding the possibili ty of clogging of the Teflo filters that could lead to invalid samples during extreme events and/or to changes in the cut-point for the cyclone inlets. IMPROVE -protocol sampling has been conducted in Washington, DC; Seattle, WA; and Phoenix, AZ fo r a number of years without clogging being a substantial problem. The IMPROVE experience has been that clogging has only been observed in major fire episodes so it may not be a pr oblem or could be accommodated by changing the sampling protocol to a half-hour within each hourly time interval or by terminating the sample at less than 24 hours if flow rates dr op significantly. These data woul d be flagged appropriately to indicate that they do not represent the full time interval.

6There are existing problems of harmonization of data from IMPROVE and STN that need to be addressed. It has recently been recognized that there are significant differences in the XRF results from the two networks and quite different approaches to the repor ting of errors for the XRF results. There are now on-going discussi ons between RTI, ChesterNet Lab and the University of California at Da vis regarding the XRF analyses and reporting of the XRF errors, and it is anticipated that these differences may be resolved. There may need to be some additional samples run by all of the laboratories in round robin studi es to resolve discrepancies in the values and reported errors, and OAQPS should support these efforts.

There are substantial differences in the organic and elemental carbon fraction (OC/EC) methods. These differences have been reported in the literature. However, there is no “right” answer since the measured species are define d by the analytical method. IMPROVE uses a dynamic blank to correct the OC data while STN uses only field and laboratory blanks. Blank sampling and reporting is thus an area requiring ha rmonization. Another key issue is the type of filter. Because of potential differences in the type of quartz filters used by the STN and IMPROVE programs, it is recommended that the STN use the same filter type as used by IMPROVE ( i.e. , Pall Tissuequartz) to ensu re consistency. There are a number of other issues such as differences in the storage, the analysis of cations, shipping conditions, etc. that need to be harmonized. It should be noted that IMPROVE will soon be changing their method because of the need to replace the existing analytical in struments. A commercial instrument is now available to implement the IMPROVE time-temperat ure protocol. Studies to date suggest that the OC and EC values by both the old and new in struments are comparable, but the values of the thermal fractions can have signifi cant variations. There will then be changes in the data being reported in the IMPROVE network. Therefore, it is an appropriate time to change the STN network to what will shortly be the new IMPROVE protocol so th at there will be comparability between the measurements.

Thus, the key question is whether or not to change the Trends sites to the IMPROVE protocol at this time. If these 54 STN sites are fully converted to IMPROVE, it will guarantee the comparability of the data and thus, permit the comprehensive use of the compositional data obtained in the future. For other sites in th e network, it would be useful to provide this alternative to the SLT organizations that are control these sites. At this time, it is unclear if there is sufficient capacity at the University of Californi a at Davis to handle thes e additional sites. If the filter preparation and analyses are done by th e existing STN contractor, there will still be a problem of data harmonization that needs to be addressed to ensure comparability of results from the different laboratories. The Subcommittee reco mmends that to achieve fully comparable data, it will require that all of the samples be collected in an identical manner with identical samplers. The samples would then be analyzed by a singl e laboratory for any given chemical constituent with a single approachto error estimation, da ta validation, etc.

The decision to change the monitoring approach for the STN and/or the IMPROVE network must also take into account emissions sampling protocols and methods. If the two databases are incompatible, this will inhibit accurately identifying source impacts. Similar studies that compare ambient measurements ( i.e. , between the IMPROVE and STN methods) need to be done for emissions measuremen ts. If one technique (e.g., the NIOSH vis B vis IMPROVE for EC/OC) proves better fo r conducting emissions measurements ( i.e. , provides a

7more stable measurement), this should affect th e choice for use in ambient monitoring (and vice versa). Whichever techniques are ultimately us ed, all parties should r ecognize and account for these tangential impacts and issu es. Thus, there also needs to be the development of source sampling methods that utilize th e same sampling and analytical methods as the ambient network so that the resulting source char acterizations can be used in the interpretation of the ambient aerosol composition data.

Question 4
The generation of surfaces of air quality parameters needs to be generated by a combination of measurements and model simulations. Both measurements and model results have uncertainties associated with them. Measurements are made at specific locations and represent a limited geographical area. Alterna tively, models average results over the minimum size of the grid cell and cannot fully reproduce the local environment.

Thus, the use of integrated predictive/observa tional fields is the preferred approach. While there is much work to be done here, this appr oach will help tackle multiple issues. First, it is probably the best way to ex tend an observation (or sets of observations) both spatially and temporally, if necessary. Second, it can be used in the process of sour ce apportionment (or viceversa: source apportionment can be used in ex tending the use of observations). Third, it will help identify uncertainties in th e representativeness of the observations at a monitoring location. Fourth and finally, it will produce the type of in formation that can be used by groups identified in Question 2.

Therefore, conceptually the combination approach is the appropriate way to proceed. However, we still do not have the best appr oach laid out, and th e enabling technologies developed ( e.g. , software/hardware environments to provide this information). These issues can probably be tackled within three or four years. Such a process should utilize the observations available, both in situ and remote (for example, satellite) as well as PM modeling (with data assimilation). There should be a feedback loop where the information pr ovided by the integrated system utilizes additional approaches to assess the quality of the fields developed (e.g., data withholding, etc.). While this may seem ambitious , EPA should set as a goal, to have a field of source apportioned daily/monthly/yearly PM for the U.S. by 2010 ( e.g. , target PM 2.5 and coarse PM for 2008, with the apportioned fields develo ped by 2010). The work should also include fields of the uncertainties in the integrated daily PM levels an d, at least, in the annual source apportionments. These results should be updated on an ongoing, annual basis. If the resources were currently available, it is likely that this inte grated approach could be achieved by 2008 (using 2006 data).

Thus, we find that the Agency’s ambient ai r quality monitoring program is beginning to implement the changes necessary to bring it in line with the NAAMS strategy document. There are and will continue to be a numbe r of scientific issues that arise both as progress is made in reconfiguring the network and as new knowledge with respect to monitoring, modeling, and effects becomes available. Thus, there is th e need for a continuing process for the ongoing review and assessment of the monitoring program. The CASAC has found it to be very valuable to review and offer its advice and recommendati ons to the Agency in the development of the current monitoring strategy, and further advises th at periodic reevaluation be built into the

8monitoring network plans to ensure that the ne twork continues to meet the multitude of needs that are expected to change over time. Ther efore, we recommend that the CASAC Ambient Air Monitoring and Methods Subcommittee continue to serve in this role. As always, the CASAC wishes the Agency well in this very important endeavor.

Sincerely,

/Signed/

Dr. Rogene Henderson, Chair Clean Air Scientific Advisory Committee

Appendix A – Roster of the CASAC AAMM Subcommittee
Appendix B – Review Comments from I ndividual CASAC AAMM Subcommittee Members

cc: Steve Page (MD-10) Jake Summers (MD-12) Rich Scheffe (MD-14) Anthony Maciorowski (1400F) Phil Lorang (MD-14) Fred Butterfield (1400F) Tim Hanley (MD-14)

9

### Appendix A – Roster of the CASAC AAMM Subcommittee

U.S. Environmental Protection Agency Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advisory Committee CASAC Ambient Air Monitoring and Methods (AAMM) Subcommittee *

CHAIR Dr. Philip Hopke , Bayard D. Clarkson Distinguished Pr ofessor, Department of Chemical Engineering, Clarkson University, Potsdam, NY Also Member: SAB Board

CASAC MEMBERS Dr. Ellis Cowling, University Distinguished Professo r At-Large, North Carolina State University, Colleges of Natural Resources and Agriculture and Life Sciences, North Carolina State University, Raleigh, NC

Mr. Richard L. Poirot , Environmental Analyst, Air Pollutio n Control Division, Department of Environmental Conservation, Vermont Agencyof Natural Resources, Waterbury, VT

SUBCOMMITTEE MEMBERS Mr. George Allen , Senior Scientist, Northeast States for Coordinated Air Use Management (NESCAUM), Boston, MA

Dr. Judith Chow , Research Professor, Desert ResearchInstitute, Air Resources Laboratory, University of Nevada, Reno, NV

Mr. Bart Croes , Chief, Research Division, California Air Resources Board, Sacramento, CA

Dr. Kenneth Demerjian , Professor and Director, Atmospheri c Sciences Research Center, State University of New York, Albany, NY

Dr. Delbert Eatough , Professor of Chemistry, Chemistr y and Biochemistry Department, Brigham Young University, Provo, UT

Mr. Eric Edgerton , President, Atmospheric Resear ch & Analysis, Inc., Cary, NC

Mr. Henry (Dirk) Felton , Research Scientist, Division of Ai r Resources, Bureau of Air Quality Surveillance, New York State Department of Environmental Conservation, Albany, NY

A-1Dr. Rudolf Husar , Professor, Mechanical Engineeri ng, Engineering and Applied Science, Washington University, St. Louis, MO

Dr. Kazuhiko Ito , Assistant Professor, Environmenta l Medicine, School of Medicine, New York University, Tuxedo, NY

Dr. Donna Kenski , Data Analyst, Lake Michigan Air Di rectors Consortium, Des Plaines, IL

Dr. Thomas Lumley , Associate Professor, Biostatistics, School of Public Health and Community Medicine, University of Washington, Seattle, WA

Dr. Peter McMurry , Professor and Head, Department of M echanical Engineering, Institute of Technology, University of Minnesota, Minneapolis, MN

Dr. Kimberly Prather , Professor, Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA

Dr. Armistead (Ted) Russell , Georgia Power Distinguished Professor of Environmental Engineering, Environmental Engineering Group, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA

Dr. Jay Turner , Associate Professor, Chemical Engineering Department, School of Engineering, Washington University, St. Louis, MO

Dr. Warren H. White , Visiting Professor, Crocker Nuclear Laboratory, University of California

- Davis, Davis, CA

Dr. Yousheng Zeng , Air Quality Services Director, Pr ovidence Engineering & Environmental Group LLC, Baton Rouge, LA

SCIENCE ADVISORY BOARD STAFF
Mr. Fred Butterfield , CASAC Designated Federal Officer , 1200 Pennsylvania Avenue, N.W., Washington, DC, 20460, Phone : 202-343-9994, Fax: 202-233-0643 ( butterfield.fred@epa.gov ) (Physical/Courier/FedEx Address: Fred A. Butterf ield, III, EPA Science Advisory Board Staff Office (Mail Code 1400F), Woodies Building, 1025 F Street, N.W., Room 3604, Washington, DC 20004, Telephone: 202-343-9994)

* Members of this CASAC Subcommittee consist of:

a. CASAC Members: Experts appointed to the st atutory Clean Air Scientific Advisory Committee by the EPA Administrator; and

b. CASAC Subcommittee Members: Experts appointedby the SAB Staff Director to serve on one of the CASAC’s standing subcommittees.

A-2

### Appendix B – Review Comments from Individual CASAC AAMM Subcommittee Members

This appendix contains the preliminary and/or final written review comments of the individual members of the Clean Air Scientific Advisory Committee (CASAC) Ambient Air Monitoring and Methods (AAMM) Subcommittee who submitted such comments electronically. These comments are included here to provide both a full perspective and a range of individual views expressed by the Subcommittee members before, during and after the Subcommittee’ s December 15, 2004 advisory meeting on implementation aspects of the Agency’s Fi nal Draft National Ambient Air Monitoring Strategy (NAAMS). These comments do not represent the consensus views of the CASAC AAMM Subcommittee, the CASAC, th e EPA Science Advisory Board, or the Environmental Protection Agency (EPA) its elf. The list of Subcommittee members providing individual comments is provided on the next page, and their review comments follow.

B-1Panelist Page #

Dr. Ellis Cowling ........................................................................................ B-3

Mr. Richard L. Poirot .................................................................................

.. B-11

Mr. George Allen ....................................................................................... B-17

Dr. Judith Chow .......................................................................................

.. B-20

Mr. Bart Croes ........................................................................................... B-29

Dr. Kenneth L. Demerjian ...........................................................................

... B-33

Dr. Delbert Eatough .....................................................................................B-36

Mr. Eric Edgerton .........

............................................................................... B-41

Mr. Henry (Dirk) Felton ..............................................................................

.. B-44

Dr. Rudolf Husar ........................................................................................ B-48

Dr. Kazuhiko Ito .......................................................................................

.. B-53

Dr. Donna Kenski ....................................................................................... B-56

Dr. Thomas Lumley .....................................................................................B-58

Dr. Peter McMurry ....................................................................................

.. B-61

Dr. Armistead (Ted) Russell............................................................................B-65

Dr. Jay Turner ..........................................................................................

.. B-70

Dr. Warren H. White .................................................................................

... B-73

Dr. Yousheng Zeng ....................................................................................

.. B-75

B-2

### Dr. Ellis Cowling

Comments by Ellis Cowling on Implementation Aspects of EPA’s Nati onal Air Monitoring Strategy (NAAMS)

After careful reading of all 12 sections of the Final Draf t NAAMS and many of the 164 public comments and EPA responses in the Addendum to the Final Draft, I offer the following comments especially with regard to the first que stion in the Charge to the CASAC Ambient Air Monitoring Subcommittee.

General Comment 1) With regard to the Agency’s proposal to redesi gn the routine precursor gas measurements (CO, SO 2 , NO/NO yNH 3 , HNO 3 ) at NCore Level II multiple pollutant sites and for air quality management decisions and to obtai n relevant exposure data for re search programs, permit me to mention that scientists in th e Southern Oxidants Study drew the following general conclusion from our major field measurement campaigns in Atlanta and Nashville in 1990, 1992, 1994, and 1999:

“In comparison with research-grade instruments, the commercially-available instruments commonly used for measuring NO x concentrations in air: are not sensitive enough to measure NO reliably, and are not specific enough to measure NO 2 reliably.”

Although the commercially-available instruments commonly used for measuring NO x concentrations are appropriate for ensuring comp liance with the health-based national ambient air quality standard for nitrogen oxides, they are not sens itive enough to be useful for making decisions about NO x vs. VOC sensitivity of ozone non-attainment areas. Most commercial instruments have a minimum detection limit for NO of about 1 ppb, but decisions about NO x vs. VOC sensitivity require instruments that ha ve minimum detection limits of about 0.1 ppb.

Perhaps I missed it, but I was unable to find in the Final Draft Strategy document an adequate discussion of the minimum detection limits for nitrogen oxides and the other precursor gases listed above.

General Comment 2) The preamble to Charge Question 1 asks: “Given limited budgetary resources ... is the info rmation on resource allocations provided in Section 11 with regard to support for PM precurs or gas measurements at NCore Level II multiple pollutant sites appropriate and we ll balanced and consistent with the overall objectives of the Strategy.”

My response to this question is: “Yes, in part, wi th respect to the proposed gas measurements at NCore Level II multiple pollutant sites.”

B-3The specific wording of Charge Question 1 goes on to ask: “Are the relati ve adjustments in the training and guidance approaches in the plan c onsistent with the overall objectives of the Strategy?”

My response to this specific questio n is “Yes, by in large.” But if the question is rephrased -- as I believe it should be -- to read: “Are the relative adjustments in the training, guidance, analysis, interpretation, and communicati on approaches consistent withthe overall object ives of the Strategy?” my response w ould be a resounding “No!”

Sections 1, 2, 9, 11, and 12 of the Strategy all give strong emphasis to analysis, interpretation, and communication of results from the various monitoring networks described in the NAAM Strategy. This is especially true of the statements in Section 1.2 on ‘Goals and Objectives,’ Section 1.3 on ‘Scope of Participants and Key Operati ng Principles’ (most notably) its subsection on ‘Data Analysis and Interpre tation,’ and Section 1.4 on ‘R ecommendations” (especially the statement “A strong public communications progr am is advocated, both at national and local levels.” This is also true of the statements in Section 2.2 on ‘Network A ssessment,’ and Section 2.6 on ‘Communication and Outreach.’ It is especially true of many statements in the early parts of Section 9 on ‘Communications and Outreach,’ (most notably) in Section 9.1.1 on ‘Benefits to State and Local Agencies, Public Interest Groups and the Gene ral Public,’ Section 9.1.2 on ‘Benefits to the research and Academic Community,’ and Sect ion 9.1.3 ‘Benefits to Tribal Communities.’ But the description in Section 9.2 about ‘H ow This Information Will be Communicated’ seems to be both ‘inconsistent and not appropriate ly balanced’ with the statements in Sections 9.1.1, 9.1.2, and 9.1.3. The ‘Fact Sheet,’ ‘Quarterly Newsletter,’ ‘Spe cialized Briefing Presentations’ using ‘packaged slide presentati ons,’ and the ‘Monitoring Strategy Brochure’ all appear to be focused on descriptions of the ‘moni toring program’ rather than to ‘policy-relevant scientific findings’ from the monitoring measurements.’ Various parts of Section 11, especially Sec tion 11.3 on ‘Resource and Funding Strategy,’ and Section 11.3.1 on ‘Implementation Using Current Funding Basis,’ Tables 11-1 and 11-2 and especially Table 11-3 on ‘Proposed summary of re distributed Federal reso urces,’ and even more notably Table 11-6 on ‘Implementation Schedul e’ give little or no information on ‘Data Analysis,’ and even less information on ‘int erpretation,’ ‘communication,’ and ‘outreach.’ In Section 12 on ‘Issues’ the distinction betw een ‘Classical’ and ‘Value’ perspectives is discussed. Please note especially the last part of the section on ‘Value:’ “The real success of the Strategy ultimately will require ... cultural modification upgrades [within both EPA and state, local and tribal communities] that allow for a [more] meaningful dialogue across data generators and data user co mmunities.” In this respect the statements in Section 12.4 on ‘Addressing Data Availability an d Data Analysis Needs,’ and in Section 12.4.2 on ‘Data Archiving, Distribution and Analysis Efforts’ are relevant. So far as I can find in the Strategy docume nt, there is only one monitoring program in which a specific discussion about needs for data an alysis and interpretation is discussed directly with specific dollars allocated for data analysis and interpretation. This is the PAMS program. Please note the first paragraph on page 11-5. It reads in part as follows (see also Table 11-3 on page 11-9):

B-4c. PAMS . PAMS requirements have been scaled down to allow for more specific special studies of interest by local area/regi ons. The current $14 M Federal 105 STAG contribution to PAMS should be reduced to $12M, an amount sufficient to cover the revised, minimum PAMS monitoring requirement s. There has been a wealth of data collected from the PAMS program, but very limited and often sporadic analysis and interpretation of the data. To address this gap and yield value from the PAMS data bases, $0.5M will be set aside for an alysis of the PAMS data. [This amounts to an allocation of only about 4% of the current annual cost of the PAMS program and does not consider cumulative funding for PAMS during years in which analysis and interpretation was ‘v ery limited and often sporadic.’]

My recommendation is that our CASAC AA MM Sub-Committee offers the following recommendations regarding Implementa tion Aspects of the NAAM Strategy: 1) Financial and human-resource allocations for analysis, in terpretation, and communication of monitoring results should be increased s ubstantially for each of the several monitoring programs described in the National Ambi ent Air Monitoring Strategy including the programs for SLAMS, NAMS, PAMS, PM 2.5, Toxics, CASNET, IMPROVE, and the NCore network. 2) A summary table should be deve loped for inclusion in a revised Section 11 that shows the approximate relative allocations w ithin each monitori ng program -- for the monitoring measurements themselves, and se parately for analysis, interpretation, and communication of scientific findings from each of the monitoring networks described in the NAAM Strategy. 3) CASAC should initiate an endeavor togeth er with OAQPS, select ed universities, and various state, local, regional and tribal organizations of air quality managers. The objective would be to: a) Identify individuals and organizations that have been unusually successful in analysis, interpretation, and communication of scientific findings from monitoring networks; and b) Us e these lists to foster and encourage more frequent analysis, interpretation, and communication of results from the several monitoring networks described in the Final Draft Nationa l Ambient Air Monitoring Strategy. In this connection, please see th e attached documents on the Environmental Statistics Program at NC State University

Further Background Information for General Comment 2:

On July 22, 2004, CASAC held a "Consultation on Methods for Measuring CoarseFraction Particulate Matter (PMc) in Ambient Air, Based upon Performance Evaluation Studies Conducted by EPA." At that time I made two poin ts that may be worth repeating in connection with the current CASAC discussions on “Impleme ntation Aspects of the Final Draft of the National Ambient Air Quality Monitoring Strategy.”

Point 1) EPA and many other federal research and monitoring or ganizations need to guard against the tendency to allocate so much of the funds used in monitoring programs and field measurement campaigns to "making careful m easurements" so that inadequate funds are

B-5available for "scientific analysis and interpretation" to determine and communicate to users what the measurements really mean.

These cautionary remarks about problems in field monitoring programs were suggested originally by the late Glenn Cass, formerly of Ca l Tech and later of Georgia Tech, on the basis of his career-long experience in various environmental monitoring programs -- programs in which too much funding was allocated to "measurements" and too little to "analysis and interpretation" of the data and “communication of results” from the field measurements. In this connection, please note the attached excerpts from a paper published in Water, Air and Soil Pollution in 1995. Please also note especiallythe suggestion in the s econd item 9 about a "50:50 distribution" of funding allocations between "meas urements" and "analysis and interpretation" of monitoring data rather than the (90:10 or 80:20 di stribution) that is typical of many monitoring programs in EPA and other agencies. But please also note that an even better suggestion was made by Mary Barber, former executive leader with the Ecological Society of America who spoke in opposition to the "50:50 distributi on" idea at a recent Whitehouse Conference on monitoring. Mary Barber insisted, and I agree with her, that it would be even more appropriate to distribute the funding into thr ee rather than two categories of investments -- with equal shares going to "measurements," "analysi s and interpretation," and "outre ach and extension of findings" to interested clientele and "customers" for the results of routine field monitoring programs.

This problem is so commonplace -- not only in EPA but in many other agencies in this country and around the world -- that I commend these "lessons that are ava ilable to be learned" (and perhaps even the "15 reasons why this happens" and the " 13 things to do about it") for inclusion among the comments from individua l participants in the CASAC meeting on “Implementation Aspects of the Final Draf t National Ambient Air Monitoring Strategy.”

Point 2) EPA should also guard against the tendency to give undue emphasis to "Data Quality Objectives" in the selection and evaluation of instruments and subseque nt implementation of field monitoring programs to the exclusion of concern about "Science Quality Objectives" and "Policy Relevancy Objectives."

Experience within the Southern Oxidants Study and other large-scale field measurement and monitoring campaigns have demonstrated repeatedly that undue emphasis on "Data Quality Objectives" often leads to: 1) Serious lack of attention to the scientific hypotheses and assumptions that are inherent in any choice of scientific instruments, the appropriateness of the ground-based sites at which the instruments are located, the skills of the instrument operators, the data processing and data-display programs used, and especially the scientific quality of the conclusions and statements of findings that are drawn from an alysis and interpretation of the measurements that are made; and 2) Equally serious lack of atten tion to the policy relevancy of the measurements being made -- relevancy to the general or specific enhan cements of environmental protection that are the real reason behind the public health or public welf are concerns that led to the decision to establish a monitoring program in the first place.

B-6In this latter connection, permit me also to call attention to the attached " Guidelines for the Formulation of Scientific Findin gs to be Used for Policy Purposes. " These guidelines were developed originally by the NAPAP Over sight Review Board led by Milton Russell, former Assistant Administrator for EPA. Please find attached below, an electronic version of these Guidelines which we have adopted and ve ry slightly adapted for use in formulating policy relevant scientific findings in the Southern Oxidants Study.
The original version of these Guidelines wa s published as Appendix III of the April 1999 Report titled " The Experience and Legacy of NAPAP ." This was a Report to the Joint Chairs Council of the Interagency Task Force on Acid ic Deposition of the Oversight Review Board (ORB) of the National Acid Precipitation Asse ssment Program. As indicated in Appendix III: “The following guidelines in the form of checklist questions were developed by the ORB to assist scientists in formulating presen tations of research results to be used in policy decision processes. These guidelines may have broader utility in other programs at the interface of science and pub lic policy and are presented here with that potential use in mind."

Excerpts from: Cowling, E., and J. Nilsson. Acidificati on Research: Lessons from History and Visions of Environmental Futures. Water, Air and Soil Pollution 85:279-292. 1995.

LESSONS LEARNED ABOUT THE SOCIAL DYNAMICS OF MONITORING PROGRAMS AND FIELD RESEARCH CAMPAIGNS

We also observed that there is a social tendenc y among research scientists, to spend more time and energy developing new monitoring networks than in analysis and interpretation of already existing data, especially long time-series measurements. Glen Cass of the California Institute of Technology was one of the first to call this tendency to our attention. But we also have discussed this matter with other scientists and research leaders in Sweden, Norway, Germany, Th e Netherlands, Canada, and the United States. As a result we have come to believe that there are three general reasons and at least 15 specific reasons why this happens and four general things and at least13 specific things that can be done about it.

Three General and Specific Reasons Why this happens Personal/psychological reasons : 1) Some scientists think it is not appropriat e to analyze data collected by other people. 2) Some scientists underestimate the time and creative energy it take s to do thorough analysis and interpretations of field data. 3) Some scientists prefer to concentrate on field measurements rather than the sometimes more demanding intellectual work of data analysis and interpretation. 4) Some instrumentalists and data analysts exaggerate small deficienci es in measurement methods so that they too readily agree to "get out and do it right" rather than "milk the data for all it is worth" before going to the field once again. 5) The tendency to believe that "there is nothing more tragic than a beautiful hypothesis slain by an ugly fact in your own data”. 6) The tendency to "move on to other things" rather th an recognize that “it is a sign of maturity if you finish things and a sign of immaturity if you just start new ones”. 7) Some scientists think analysis and inte rpretation of long term trends is boring.

B-7Social/psychological reasons : 8) The contagious enthusiasm that field campaigns seem to engender in groups of scientists, and which occurs less frequently in the usually more private in tellectual work of data analysis and interpretation. 9) The tendency of some scientists to believe that th ose who collect the data “own” the data and thus can choose (regardless of what organization paid the b ills for the program!) when, where, and under what circumstances of authorship, priority, etc., the data should be validated, archived, analyzed, interpreted, and made available to others. 10) The tendency of research leaders to avoid conflicts about the policy implications of research findings. For example, atmospheric monitoring data usually are not threatening, but data analyses sometimes lead to situations that have policy consequences th at make for uncomfortable disputes. Since noncontroversial portions of research programs proceed to completion more readily than parts of research programs facing opposition, it is not surprising thatthe atmosphere is over-measured and underinterpreted. Budgetary/logistical reasons : 11) The tendency for unreasonable budget optimism. Exaggerated promises ofte n are made to make a project appealing to sponsors -- promises that often cannot be fulfilled with the limited funds that usually are available. Since atmospheric or other field measurements occur at the beginning of a research program, they often are completed at the expense of resources needed later for thorough analysis and interpretation of data. 12) The tendency to buy what is cheap (or what is easy to do) rather than what is really needed (or may be difficult to do). Atmospheric measurements are indivi dually rather cheap. (For example, the elemental composition of a single sample of fine particulate matter can be determined for about $120.) But the same measurement made within the stack of a particular pollution source may cost many thousands of dollars because of logistical difficulties and challenging environmental conditions (e.g., high temperatures). 13) Field measurement campaigns often are planned too soon after each other. 14) Granting agencies often assume that if they fund scientists to make field measurements that these same scientists will find the time and energy for analysis and interpretation whether they are funded to do
so or not. 15) The too dominating role of tradition (what did we do last year?) as the "best guide" to wisdom in budget and personnel decisions.

Four General and Thirteen Specific Things That Can Be Done About It Social/political things : 1) Recognize that monitoring programs cannot be sustained unless there are “customers” who care about the data, use the data often, and are willing to speak- out publicly about the constructive values they derive from analysis and interpretation of the data. Personal/psychological things : 2) Recognize that people want to enjoy the work th ey do. Making atmospheric measurements in the field is both rewarding and fun. By contrast, collecting and tabulating real-world data regarding amounts of emissions can be tedious or even boring. Not su rprisingly, few people want to do the necessary but boring part, and those who are pushed against their will usually do a sloppy job. Solution: Find ways to make data analysis more fun and rewarding! For example, give high praise and other rewards to those who willing to do what is necessary whether it is boring or not! Scientific/intellectual things : 3) Formulate specific science and policy questions that are to be addressed and design measurement systems to answer those specific questions. 4) Use available guidelines for formulation of statemen ts of scientific findings to be used for policy purposes -- See Appendix III in the Oversight Board Report (NAPAP 1991).

B-85) Place heavy emphasis on publication of results not only in peer-reviewed scientific journals, but also in readily accessible professional, environmental, comme rcial, and public-interest publications and electronically accessible information outlets. Budgetary/logistical things : 6) Recognize how many significant scientific discoveries about the phenomena and effects of air pollution have been made by analyzing “old” data. 7) Find and fund those scientists who really enjoy data analysis and interpretation. 8) Buy the research that is really needed, not what is cheap or convenient. 9) Recognize that data archiving, analysis, and interpretation are tedious, time consuming, intellectually demanding, and expensive. An appropriate ratio fo r investment in measurements and investments in analysis and interpretation generally is closer to 50:50 than the customary ratio of only 10:1 or even 20:1. Also, it is valuable to use 2- to 5-year “roll-forw ard” mechanisms to ensure continuity of funding. 10) Recognize large measurement campaigns rarely can be sustained in successive years. 11) Plan research project and programs from the end backward to the start. First, specify the best data analysis procedures necessary to answer important sci ence and policy questions within the available funds and time. Then, make or complete only those measur ements that have a pre-specified place in the dataanalysis plan. 12) Try to balance uncertainties in the time, cost, and performance of research projects so as to keep all three factors approximately on-target. 13) Initiate and maintain measurement programs to determine the effectiveness of environmental management decisions.

GUIDELINES FOR THE FORMULATIO N OF SCIENTIFIC FINDINGS TO BE USED FOR POLICY PURPOSES The following guidelines in the form of checklist qu estions were developed by the NAPAP Oversight Review Board to assist scientists in formulating presentations of research results to be used in policy decision processes. 1) IS THE STATEMENT SOUND? Have the central issues been clearly identified? Does each statement contain the distilled essence of presen t scientific and technical understanding of the phenomenon or process to which it applies ? Is the statement consistent with all relevant evidenceevidence developed either through NAPAP [or SOS] research or through analysis of research conducted outside of NAPAP [or SOS]? Is the st atement contradicted by any important evidence developed through research inside or outside of NAP AP [or SOS]? Have apparent contradictions or interpretations of available evidence been considered in formulating the statement of principal findings? 2) IS THE STATEMENT DIRECTIONAL AND, WHERE APPROPRIATE, QUANTITATIVE? Does the statement correctly quantify both the direction and magnitude of trends and relationships in the phenomenon or process to which the statement is relevant? When possible, is a range of uncertainty given for each quantitative result? Have various sources of uncertainty been identified and quantified, for example, does the statement include or acknowledge errors in actual measurements, standard errors of estimate, possible biases in the av ailability of data, extrapolation of results beyond the mathematical, geographical, or temporal relevancy of available information, etc. In short, are there numbers in the statement? Are the numbers correct? Are the numbers relevant to the general meaning of the statement ? 3) IS THE DEGREE OF CERTAINTY OR UNCERTAINTY OF THE STATEMENT INDICATED CLEARLY? Have appropriate statistical tests been applied to the data used in drawing the conclusion set forth in the statement? If the stat ement is based on a mathematical or novel conceptual model, has the model or concept been validated? Does the statement describe the model or concept on which it is based and the degree of validity of that model or concept?

B-94) IS THE STATEMENT CORRECT WITHOUT QUALIFICATION? Are there limitations of time, space, or other special circumstances in which the statement is true ? If the statement is true only in some circumstances, are these limitations described adequately and briefly? 5) IS THE STATEMENT C LEAR AND UNAMBIGUOUS? Are the words and phrases used in the statement understandable by the decision makers of our society ? Is the statement free of specialized jargon? Will too many people misunderstand its meaning? 6) IS THE STATEMENT AS CONCISE AS IT CAN BE MADE WITHOUT RISK OF MISUNDERSTANDING? Are there any excess words, phrases, or ideas in the statement which are not necessary to communicate the meaning of the st atement? Are there so many caveats in the statement that the statement itself is trivial, confusing, or ambiguous? 7) IS THE STATEMENT FREE OF SCIENTIFIC OR OTHER BIASES OR IMPLICATIONS OF SOCIETAL VALUE JUDGMENTS? Is the statement free of influence by specific schools of scientific thought? Is the statement also free of words, phrases, or concepts that have political, economic, ideological, religious, moral, or other pers onal-, agency-, or organization-specific values, overtones, or implications? Does the choice of how the statement is expressed rather than its specific words suggest underlying biases or value judgments ? Is the tone impartial and free of special pleading? If societal value judgments have been discussed, have these judgments been identified as such and described both clearly and objectively? 8) HAVE SOCIETAL IMPLICATIONS BEEN DESCRIBED OBJECTIVELY? Consideration of alternative courses of action and their consequences inherently involves judgments of their feasibility and the importance of effects. For this reason, it is important to ask if a reasonable range of alternative policies or courses of action have been evaluated? Have societal implications of alternative courses of action been stated in the following general form?: " If this [particular option] were adopted then that [particular outcome] would be expected." 9) HAVE THE PROFESSIONAL BIASES OF AUTHORS AND REVIEWERS BEEN DESCRIBED OPENLY? Acknowledgment of potential sources of bias is important so that readers can judge for themselves the credib ility of reports and assessments.

B-10

### Mr. Rich Poirot

EPA NAAMS Implementation Proposal, Re view Comments, R. Poirot, 12/12/04

Generally, this is a very strong, carefully cons idered, well justified and timely proposal. Many revisions are directly responsive to prev ious CASAC Subcommitt ee review comments. Emphasis on use of continuous methods – for multiple, collocated PM & gaseous precursor species, and de-emphasis on filter-based PM 2.5 a nd speciation is a resour ce-efficient means of supporting multiple monitoring objectives, in cluding compliance determination, improved atmospheric model development & evaluation, and human health, ecological and welfare effects research.

1. The CASAC has expressed its support for the Agency’s proposal to redesign the routine PM monitoring network to supportPM precursor gas measurements (CO, SO 2 , NO/NOy, NH 3 , HNO 3 ) at NCore Level II multiple-pollutant sites, and for air quality management decisions and to obta in relevant exposure data for research programs. Given limited budgetary resou rces, does this represent both an appropriate and adequate balance, as reflected by the relative resource allocations provided in Section 11, “Draft Implementa tion Plan” of the Final Draft NAAMS Document? In addition, are the relative ad justments in the training and guidance approaches proposed in the draft implementation plan consistent with the overall objectives of the Strategy?

The question illustrates what seems to me to be a rather proscriptive emphasis on a specific suite of “precursor gasses” which is difficult to evaluate without additional detail on the specific siting criteria and on the other “require d” or optional measurements at these sites. Regarding siting details, the general Level II formula (1/state, 2/st ate in moderately large states, 3/state in the largest population states, and 12 rural) sounds to me like it will be a very predominantly “urban” network, and that in add ition there would likely be just 1 site per urban area in almost all cases. These many “1 per city” sites have limited valu e for supporting ecological effects research, for enhancing understanding of atmospheric chemical processes, for model development and evaluation, and for some of the proscribed gasses (like NO, CO & NH3) questionable value for characterizing regional spatial patterns. Urban site locations fo r highest human exposures of ozone, PM2.5 and some of the proscribed gasses differ by pollutants. So exactly what kind of “representative” sites are we looking for? On a related point, the inclusion of detailed met instruments is obviously desirable with all this continuous data, but what scale(s) of representation are we looking for in the met measurements, and will or should this further effect the siting criteria?

Regarding the other species measurements, I assume at minimum these include continuous ozone and PM2.5. Will there also be filter-based spec iation measurements, and if so will the new measurements be added at existing STN sites, or will those “trends” sites be moved to the new optimized multi-pollutant sites? How exactly will continuous PM2.5 mass be measured? Ideally a single common method would be employed, rather th an the current mix (all things being equal, I’d suggest the FDMS TEOM, as it provides higher resolution information (separate volatile and non-volatile), and may often capture volatile species partially lost from FRM filters).

B-11Continuous (high sensitivity) SO2 is highly desirable, butthe value of such data would be hugely enhanced if collocated continuous SO4 were also measured. NOy is useful (especially at rural sites), but could be substantially more us eful if accompanied by continuous hydrocarbon analyzers. Aethalometers (especially the dual wa velength – with its potential value as a wood smoke monitor) could provide useful informati on with currently avai lable, field-proven technology, and/or continuous OC/EC (Sunset Labs for example) look promising. Will any of these continues PM species measurements be included, or do we measur e only the precursors?

The proposed monthly integrated NH3 and HNO3 measurements would substantially enhance the status quo (almost no data), but would obviously provide minima l temporal resolution (assuming the technologies work). A possible a lternative or supplemental approach might be through routine extraction of denuders at STN and IMPROVE sites. See additional detail on this under question 3 below.

2. Does the Subcommittee have additional su ggestions for addressing this need for integration and communication to the broader community of “users,” including scientific researchers ( i.e. , human health, atmospheric, ecological) and State, local and Tribal (SLT) Agency representatives? More specifically, what is the most effective manner for EPA both to reach-out to this broad user community and, where appropriate, to incorporate their feedba ck and design input on such issues as monitoring site locations and parameters?

Generally, the above “user communities” (human health, atmospheric, ecological, & SLTs) are very disparate groups who don’t very often inte ract. Also, the most relevant health and ecological effects issues tend to vary on a regional basis, making “centralized” communication awkward. One organizational concep t that might be worth consider ing is to organize periodic workshops on a regional basis, as there tend to be clustered integrated user communities who focus on specific urban health effects or rural ecological effects monitoring/research sites. Examples of the latter from my region include the Vermont Monitori ng Cooperative at Mt. Mansfield/ Underhill, VT, Hubbard Brook, NH, Harvard Forest, MA & Whiteface Mtn, NY (unfortunately none of these is lik ely to become a Level II site, and I’m concerned my Underhill, VT “SIP” IMPROVE site may also be on the NCore chopping block). About 15 years ago, the International Air Quality Advisory Board of the IJC held a series of workshops on “Integrated Transboundary Monitoring” at 5 locations along the US/Canada border, which were very wellattended and productive. Possibly something like this might be considered on an EPA regional basis or through the Regional Pl anning Organizations (RPOs).

3. One of the remaining technical issues relates to harmonizing rural- and urbanbased PM 2.5 chemical speciation networks such that both categories of networks utilize consistent sampling and analysis protocols. For example, EPA is considering converting all of the Speciation Trends Network (STN) speciation sites to Interagency Monitoring of Protected Visual Environments (IMPROVE) samplers and IMPROVE laboratory and sample handling protocols. What are strengths and weaknesses of this approach?

B-12Spatial & urban/rural consistency alone are goo d reasons to consider this, with the added advantages that (I think) IMPR OVE analytical, shipping & site operator costs are lower (though the new equipment costs would be significant and STN “trends” - for some species – would be disrupted).

What exactly is meant by IMPROVE methods? Samp lers, filter media, “identical” copper anode XRF systems, TOR carbon methods – which are curre ntly being revised in IMPROVE, etc? If IMPROVE PESA measurements for H are duplicated by STN, only a very few labs have that capability.

IMPROVE is cited in the EPA Strategy as servin g as a “core rural spec iation trends network: needed network adjustments are handled e ffectively through IMPROVE Steering Committee”. While I generally agree here, it should be cautio ned that being a core rural speciation trends network is serendipitous, but not an objective of IMPROVE, which is intentionally focused on regional haze-related aspects of aer osols in specific class I areas, and in recent years specifically focused on supporting the EPA Regional Haze Ru le – which emphasizes long-term trends. Consequently there is added inertia to change , or for adding supplemental measurements to address non-haze-relevant issues.

Also, given the general tendency for class 1 areas to be locate d in mountainous terrain, the IMPROVE monitoring objectives to measure regiona l rather than local aerosols, and to cover each class I area (with funding c onstraints limiting sites to 1 pe r area), the IMPROVE network tends to provide a “mountaintop” definition of ru ral speciation patterns. Caution is needed in comparing urban sites to nearby rural counterparts (for example Washington DC to Shenandoah NP) since we don’t know how much of the DC “urban excess” (at 16 meters ASL) results from Shenandoah (1100 m ASL) being often above the mixed layer – especially during winter. I emphasize this to point out a need for some rura l low elevation sites – which would also be of benefit to IMPROVE, and might be best managed by adding lowe r elevation IMPROVE sites in a few class 1 areas.

As the number of filter-based speciation site s is reduced, and as methods changes are contemplated, I think it’s possible that we might “think smarter” and squeeze additional information out of the remaining sites. For example, the Canadian NAPS speciation program (see brief summary from Tom Dann pasted at the end of my comments) measures more or less everything we do at IMPROVE and STN sites, and by fairly similar methods to ours. But in addition they denude for HNO3, SO2 and NH3 (S TN does not do NH3 but should) and get (I think) better quality NH4 data than STN does. Then they extract and analyze their denuders to get HNO3, SO2 and NH3, averaged every 3 rd sample day concurrent with the aerosol species. This is less desirable than the ultimate goal of continuous, but way better than monthly means. The Canadians also conduct additional analyses (on Teflon filters) for several organic ions (oxalate, formate, acetate), which in turn have proven extremely valuable for source attribution. Another difference in the Canadianprotocol is that samplers ar e run 8AM to 8AM, rather than midnight to midnight. If loss of volatiles is a co ncern, this seems like a much more intelligent & efficient way of minimizing filter losses (dur ing sampling) compared to the costly STN requirements to ship exposed filters in iced coolers.

B-13Another example of outstanding “v alue added analysis” from exis ting (& expensively collected) filter samples is in the recent molecular car bon analysis Ted Russell’s group at GA Tech has conducted on archived, composited quartz (carbon) filters from selected Eastern US STN and IMPROVE sites – followed by CMB analysis us ing source profiles de veloped with similar analytical methods. I’d like to see something like this conducted routinel y (yearly with seasonal compositing), for at least a subset of remaining STN & IMPROVE sites.

On a related topic, the stated emphasis on da ta analysis in the NAMS proposal is much appreciated – although as usual, the funding leve l is minimal. A novel approach would be to develop a reasonably detailed data analysis plan in advance of conducting new measurements – and use it as a guide to what s hould be measured where, rather th an just assuming “here are some key species and sites from whic h we’re bound to learn something”.

An aside on this, is recent (5 minutes ago) note from our colleague Husar on his latest revisions to the “Combined Aerosol Trajectory tool”, whic h links aerosol data fr om the entire IMPROVE and STN networks (through the end of 2003) to a ssociated back trajectories (ATAD model run by Kristi Gebhart at NPS) and allows all kinds of extremely powerful single and multi-site analyses – and is also really fun! (on ce you get the hang of it). Check it out at: http://webapps.datafed.net/dvoy_ser vices/datafed.aspx?page=KittyC

This RPO-supported (with assistance from EPA) anal ysis tool is I think an excellent example of the kind of data analysis thatshould be routinely funded as a key component of NAMS.

4. As EPA implements the Na tional Ambient Air Monitoring Strategy to address multiple monitoring objectives, it will be looking to spatially optimize the ambient monitoring networks. This may mean that some redundant monitors in adjacent, but separate, geopolitical areas ( e.g. , neighboring counties) are “divested” from a given network. Although technically sound, these divestments could result in data gaps which might, in turn, adversely im pact regulatory decision-making. The Agency is willing to adopt alternative approaches for assessing regulatory issues such as non-attainment designations, so lo ng as such approaches are scientifically justifiable; hence, the rationale for initia ting discussion of these issues with the CASAC. Question: Is it scientifically acce ptable to generate air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regulatory decision-making process?

It has a stronger scientific basis than the current alternative of assuming each political jurisdiction is represented by the single monito r within it. I think much could be learned by efforts to develop and refine this king of “obs ervation-based model”, and at some point it may be appropriate to use such methods to determine co mpliance status. A goal would be to push toward applying such techniques in near-real-time.

B-14Attachment 1: Summary of Canadian PM-2.5 Speciation Sampling (for more details contact Tom.Dann@ec.gc.ca)



### Fine Particle Speciation Program

Sampling Equipment and Field Operation

Sampling sites will be equipped with R&P Partis ol-Plus 2025-D sequential dichot particulate samplers along with R&P Partisol Model 2300 Speciation samplers. These units share common software and data storage systems. The speci ation sampler uses Harvard designed Chemcomb ® cartridges which employ honeycomb glass denuder s and filter packs with Teflon and Nylon media.

Both samplers have sequential sampling features and up to 32 fine and coarse filters (16 sampling days) can be preloaded in the dichot Partisol while up to 12 Chemcomb cartridges (3 sampling days) can be preloaded in the speciation sa mpler. At this time, the protocol will be to operate the samplers once every three days and to visit the sampling sites at least once every six days. Samples will be collected over 24 hours. On e fine and one coarse filter sample will be collected on the dichot Partisol sampler and thr ee Chemcomb cartridge samples will be collected with the speciation sampler as described below. The Chemcomb cartridges are shipped to the field completely assembled and sealed and require only mounting and leak-checking.

Field data sheets will be required but all instrument operating datawill be downloaded to Palm data systems (provided) and the RAM cartridge s will be returned to Ottawa with exposed samples.



### Sample Types and Target Analytes

B-15B-16

### Mr. George Allen

B-17B-18B-19

### Dr. Judith Chow

December 13, 2004

To: Fred Butterfield, Designated Federal Officer, Clean Air Scientific Advisory Committee (CASAC) From: Judith C. Chow, Research Prof essor, Desert Research Institute CC: Phil Hopke, CASAC Ambient Air Monitoring and Methods (AAMM) Subcommittee Chair

Subject: CACAS AAMM Subcommittee Charge on the Evaluation of the Final Draft of the National Ambient Air Monitoring Strategy (NAAMS) document dated April 2004

The staff of the Office of Air Qu ality Planning and Standards did a remarkable job of assembling the final draft National Ambient Air Monitori ng Strategy (NAAMS) document and responses to the 164 comments in the Addendum of the Strate gy document. Conceptually, the NCore strategy represents a major change from what has been do ne over the past 30 years. Its success or failure will depend on building flexibility into, while establishing consistency within, the current monitoring network. EPA is facing ma jor challenges in coming years to assure that data from the restructured NCore network will achieve the objectives for compliance and implementation of air quality standards, air quality forecasting, atmosp heric processes research, and the determination of health, visibility, ecological, and radiative effects. The following review focuses on the four assigned questions, with additional comments on NCore siting, Level 1 sites, and measurement methods.

Question 1. Given limited budgetary resources, does this represent both an appropriate and adequate balance, as reflected by the relative resource allocations pr ovided in Section 11, “Draft Implementation Plan,” of the Final Draft NAAMS Document? In addition, are the relative adjustments in the training a nd guidance approaches proposed in the draft implementation plan consistent with the overall objectives of the Strategy? Table 11-3 listed the proposed re distribution of Federal resources for ambient monitoring. It is difficult to evaluate resource allocation without adequate b ackground on how these estimates were formulated. It would be helpful to document the cost-estimation basis in categories of: 1) initial hardware procurement; 2) initial installati on and shakedown; 3) initi al training; 4) spare parts; 5) repairs; 6) normal operations labor; 7) rent/power/security; 8) quality control and auditing; and 9) data proce ssing and management. Based on my calculation, the allocation is estimated on an average of ~$60,000 per Level 2 NCore site, including capital investments for equipment purchases and associated opera ting expenses, and $50,000 to $100,000 per Level 3 NCore site, depending on whether ~1,000 or 500 sites are planned. (Richard Scheffe’s presentation and Figure 4-1 show >500 Level 3 sites. But Section 4.3.5 [p. 4-10] shows ~1,000 sites.) Even if one factors in the infrastructure of the Level 2 site as being mostly established, resource allocation to the Level 3 sites seems high. This defeats the obj ectives of the Level 3 sites, which focus on a subset of criteria pollutants (e.g., PM and O 3 ).

While the training and guidance approach proposed in the draft implementation plan is consistent with the overall objectives of the Strategy, the resource allocati on seems low. Given a total of

B-20$198.85 million (note that there is an error in the proposed budget sum), the allocations of 1.6% ($3.2 million) to quality assurance (QA) and 0.1% ($200,000) to training are low, even though they are additions to the current budget.

The performance evaluation program (PEP) in Table 7-3 estimates $3.6 million in QA— $0.4 million higher than the Table 11-3 estima te, of which ~60% is allocated to PM 2.5 PEP and speciation. Listings of the curren t State and Tribal Air Grant (STAG) fund ($2.3 million in Table 7-3 and $1.9 million in Table 11-3) are also different. What about QA for existing PM 10 , future PM coarse , newly added HNO 3 and NH 3 , and NO ymeasurements, and audits for meteorological measurements? Even though some of the tr aining and QA needs aris ing from the network modification may be embedded into each pollutant category, the level of effort needed for QA and training (probably at multiple locations) seems to be underestimated, especially for the first 2–5 years, during the transitional period.

The certification program is a good approach for ensuring consistent data quality. More detail is needed on traceability from common primary standard s, to transfer standards, and to in-station QA standards. This is especially important for the non-standard measurements (e.g., PM, NH 3 , NO y ). There is a need for guidance to clearly stat e the corrective action for sites that fail to pass the certification tests. More centraliz ed QA, as recommended by the CASAC NAMS subcommittee, with consistent, clearly stated datavalidation criteria and data formats, is a good target.

It is encouraging to see “data analysis and interp retation” listed as a separate line item, even though it accounts for only 1.1% ($2.2 million) of th e total budget. If funding is available for data analysis, a detailed data analysis plan is needed to specify data analysis objectives that analyze pollution characteristic s and trends, identify episodes, explore seasonal/annual trends and spatial variations, develop control strategies , track progress of control measures, estimate source attribution, as well as evaluate emissions inventory and air qualitymodels (Chow et al., 2002a). These analyses should be th e tools that identify th e needs to further refine the network to meet multiple objectives (U.S. EPA, 1997a).

What Table 11-3 lacks (which may be embedde d in network operations) are resources for different levels of data validation. In the long r un, it is more cost-effective to replace filter-based measurements with in-situ con tinuous monitoring. The initial cost of the switch-over is high, and continuous instruments are more labor-intensi ve in the field for routine calibration and maintenance, and in the office for processing and evaluating short-term average (1- to 5-minute) measurements. Substantial effort is needed for ti mely data validation to resolve data outliers and to take necessary corrective actions to minimize the generation of additional invalid or suspect data. Four levels or categories generally apply to validation of monitoring data (Chow et al., 2002b):

B-21Level 0 Raw data right off the instrument (used for real-time alerts and forecasting).

Level I Routine checks made during the in itial data processing and generation of data, including proper data file identification, re view of unusual events, review of field data sheets and re sult reports, instrument performance checks, and deterministic relationships.

Level II Tests for internal consistency to identify values in the data which appear atypical when compared to values of the entire data set.

Level III Comparison of the current data set w ith historical data to verify consistency over time. Tests for parallel consistency with data sets from the same population (region, air mass, period of time, etc.) to identify systematic bias. This level can be considered as part of the data interpretation or analysis process.

Note that Level III, and possibly Level II, data validation are part of the data analysis and interpretation process and may be grouped to th e data analysis categories and allocated as Research and Development rather than as monitoring funds. While it is desirable to have data available soon after its collecti on—and real-time monito rs permit this on a local basis—current regulations requiring “sub mission to EPA 90 days after the cale ndar quarter in which the sample was collected” are reasonable. This allows state and local agencies to conduct Levels 0 and I data validation and to perform cross-comparisons to re move invalid data and flag suspect data.

The zero sum approach is challe nging during the transi tion period since substantial costs may be incurred for equipment procurement, operator training, and comparabilitytesting (to retain continuity with previous data). I disagree that a datavalidation protocol should be developed by the modeling community (p. 26, response to Comment 127 of the Addendum). For advancement, data validation protocols should benefit from le ssons learned from those who conduct the field measurements; modelers are not necessari ly familiar with these measurements.

Question 2. Does the Subcommittee have additional s uggestions for addressing this need for integration and communication to the broader co mmunity of “users,” including scientific researchers (i.e., human health, atmospheric, ecological) and State, local and Tribal (SLT) Agency representatives? More spec ifically, what is the most effective manner for EPA to both reach out to this broad user community and, wh ere appropriate, to incorporate their feedback and design input on such issues as mon itoring site locations and parameters? The Strategy formulates several good means (i .e., fact sheets, quarterly newsletters, presentations, and brochures) for public outre ach. However, from the public comment process (p. 9-4), it is clear that less than ~10% of the local and state and 30% of the regional offices responded during the comment period, with only two comments each from the public interest groups and industry, and one from the tribes. It appears that it did notcall enough attention to those agencies that would be directly impacted by the proposed Strategy, and the 164 questions raised may not be representative of the gene ral population. More aggressive solicitation of

B-22comments is needed from the research community or data users in the field of atmospheric, health, and ecological sciences. One good approach might be to put a notice on popular real-time web sites (e.g., AIRNow) where people go to make decisions based on air quality data.

The majority of epidemiological studies rely on data from long-term compliance networks for exposure assessment (Vedal, 1997). A need still exis ts to broaden the invo lvement of air quality and health researchers to optimize the restruct ured national network while meeting the current resource constraints.

If additional support can be obtained, the resear ch community can assist in developing data validation protocols, conducting data analysis, and evaluating the representativeness of the NCore sites. As pointed out by Demerjian (2000), there is a need to develop appropriate feedback between the measurement community and da ta analysts to assure data quality and data applicability. This feedback should also cover ad ditional data management issues, such as data and metadata items and report formats to f acilitate data analys is and interpretation.

Question 3. What are the strengths and weaknesses of converting a ll of the Speciation Trends Network (STN) speciation sites to Interagency Monitoring of Protected Visual Environments (IMPROVE) samplers and IMPROVE labor atory and sample handling protocols? The lack of consistency between the IMPROVE and STN networks is a major shortfall, since the two networks use different requirements for samp le archiving, field bl ank collection, shipment, blank subtraction, carbon analysis (Chow et al., 2001, 2004), and uncerta inty estimation (NRC, 2004). Converting all STN sites to IMPROVE sites has the following advantages:

Data consistency: A national approach is needed for field sampling, laboratory analysis, and sample validation to ensure the consistency of data quality. Switching STN over to the IMPROVE protocol would minimize the discrepancies between the two current networks. This will allow model comparison and evaluation between urban and non-urban areas. Archived samples in the IMPROVE network have been shared with the research co mmunity in the United States and foreign countries or to be st ored for special studies.

Cost savings: IMPROVE samplers have b een proven to be robust and easy to operate since 1987-88. Recent modifications have further advanced their utility. With the excepti on of capital investment for IMPROVE samplers, the operati ng cost for STN following the IMPROVE protocol can be substantially reduced. Approximately 80–90% of the current STN network uses Met One speciation samplers (Met One Instruments, Inc., Grants Pass, OR), which are labor intensive for filter load ing and unloading. Shipping costs could also be substantially reduc ed due to the stainless steel housing of the Met One sampling cartridge. The pros and cons of cold shipping requirements in the STN but not the IMPROVE network also warrant further evaluation.

B-23Long-term value: More than 100 publications have used IMPROVE data to evaluate measurement systems, map spatial distributions, develop and apply source apportionment models, and make important control strategy decisions (e.g., Malm et al., 1989; Pitchford et al., 1999). The IMPROVE network is just comple ting the baseline period required by the regional haze rule (U.S. EPA, 1999; Watson, 2002) and cannot experience major changes wi thout substantial comparability testing. The STN has no such requirements.

Question 4. Is it scientifically acceptable to genera te air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regulatory decision-making process? Currently, network assessment starts at the national level. It us es interpolating methods between measurements sites and uses erro r analysis to remove redundant sites. This type of spatial analysis is adequate for flat te rrain with a sufficient number of sites. It also works to evaluate whether one site is redundant w ith other sites. It cannot extrap olate concentrations into areas with insufficient monitoring. A good illustration is the IMPROVE network, where the addition of Midwestern sites in 2001 revealed a large ni trate cloud that was not evident from the earlier network. Integrated predictive/observational fields with adequate uncertainty estimates outweigh any single modeling approach. Relying on modeled results alone may bias the decision-making
process.

As pointed out in a recent National ResearchCouncil (NRC) report (NRC, 2004), the enhanced network should have the following three characte ristics: 1) use continuous measurements of appropriate indicators with real-time access; 2) represent less uniform micro- and middle-scale exposures; and 3) encourage the development and use of continuous monitors for indicators other than mass concentration. Fo r areas that may have concentration gradients between the Level 2 or 3 sites (i.e., not re presentative of micro- or mi ddle-scale exposure), additional monitors may be needed. In these cases, de nse spatial monitoring (e.g., Chow et al., 1999, 2002c) over a short period of time (e.g., 2–4 weeks) is needed to add or remove sites, to assure adequate spatial coverage , or to confirm observational or di agnostic modeling results. The “zone of representation” experiments could be economically executed with portable instruments (e.g., Fujita et al., 2003). Their lower prec ision is still adequate to determine large spatial gradients.

Instrumentation used at Level 3 sites should be required (not “str ongly encouraged”, as stated on
p. 4-10) to be collocated with filter-based measurements for a set period of time to ensure equivalence or comparability. Current requirements for the PM 2.5 Federal Equivalent Method (FEM) are: 1) collocat ed precision of 2 μg/m 3 or 5% (whichever is larg er); 2) linear regression slope of 1 ± 0.05; and 3) linear re gression intercept of 0 ± 1 μg/m 3 and correlation coefficient (r) of 0.97 (U.S. EPA, 1997b). For Regional Equivalent Monitors (REM), the proposed performance criteria are bias (relative to a filter-based Federal Referen ce Method [FRM]) ± 10%, collocated precision (continuous monitors) <10% of coefficient of variance (CV), with r of 0.93. These criteria are too stringent to be met for currently available PM sp eciation monitors. I disagree with relying on vendors to demonstrat e equivalence (p. 20, response to Comment 92 of Addendum ) since comparability between instruments varies by location due to changes in emissions, meteorology, and aerosol composition. There are onl y limited comparisons that can be supported

B-24by vendors. Depending on the complexity of th e surrounding environment at Level 3 sites, equivalence, comparability, or predictability(Watson and Chow, 2002) between the testing instrument and the FRM should be established ateach location for realistic comparison. Methods with acceptable comparability should be allowed to facilitate the network transition. Level 3 sites should also be used to understand the impact from source-oriented location (e.g., Zhu et al., 2002a, 2002b) and concentration gradients between the Level 2 sites.

The Strategy document calls for multi-level netw ork assessment every 5 years (Section 5). It appears that a top-down approach is taken in that the national assessment is conducted prior to regional or state/local assessment. In addition, th e zero-sum approach is at the national level. What will the incentive be for state/local agencies to voluntarily reduce their sites, consequently cutting off their 103 grants and possibly having to reduce staffing? Is the Regional Assessment Guideline Document that is expected to be completed by September 2004 (p. 5-6) available? Were consistent statistical methods used at di fferent levels of assessment? Step 3 in the Statistical Analysis (under S ection 5.4, Guidance for Future Re gional Network Assessment) and examples found at http://www.epa.gov/ttn/amtic/netamap.htm l are helpful, but specific criteria are needed for national consistency.



### Additional Comments

NCore Siting

U.S. EPA Guidance for Network Desi gn and Optimum Site Exposure for PM 2.5 and PM 10 (U.S. EPA, 1997a) defines the following steps for community-oriented core sites and optional community monitoring zones (CMZ ): 1) locate emission sources and populations; 2) identify meteorological patterns; 3) compare PM concen trations; 4) adjust CMZs to jurisdictional boundaries; and 5) locate sites. These criteria should be considered for NCore siting rather than relying on an “NCore design committee” (p. 4-12).

It is not clear how “Nearly 80 ‘re presentative’ air quality region s that group populations based on statistical geographical factors ...” (p. 4-11) were formulated for epidemiological studies, and how “24 rural locations” were selected to support Community Modeli ng Air Quality System (CMAQS) model evaluation. A total of 75 NCore Le vel 2 sites ranging from rural to urban areas across all 50 states appears to be inadequate for human expos ure assessment. In addition to population density, source emissions , terrain features, and meteorol ogical characteristics should be factored in. A drastic reducti on of speciation sites without ade quate analysis of the chemical composition data at the existing sites seems premature. Sites with long-term historical databases and stable infrastructures are valuable for trend analyses and network design.

Level 1 NCore Sites

Much emphasis was given to the importance of Le vel 1 sites, but resources are insufficient. I do not believe that Level 1 sites should be operate d by EPA contractors or academia, or only for short-term durations as suggested in the Strategy document (p. 4-7) . One of their goals should be to demonstrate how new instrumentation might be us ed at Level 2 sites. Investment to be made in Level 1 sites, such as instrument procurement, trained operators, and the establishment of

B-25information technology for data transfers, requi res a long-term commitment. For example, the Fresno Supersite began operating around mid- 1999 and has continued to be operated by the California Air Resources Board (ARB) for more than 5 years. Several vendors, government agencies (e.g., Battelle’s Pacific Northwest Natio nal Laboratory), and academia (e.g., University of California, Davis; Univers ity of California, Berkeley; and Brigham Young University) have benefited from using the Fresno Supersite sampling platform for method testing and for research. Concurrent epidemiological studies (i.e., FA CES, Fresno Asthmatic Children’s Environment Study) have been conducted by taking advantage of 5-minute average continuous measurements and 24-hour integrated chemical composition data acquired at the Supersite. As stated on p. 4-15, Level 1 sites should be an integral long-term ne twork component and opera te with greater intersite consistency. Therefore, Le vel 1 sites should follow the same data validation and data submittal criteria, and should be inclusive of Level 2 site’s measurements.

Measurements at NCore Sites

Inconsistent NO or NO 2 measurements have been listed throughout the Strategy document that need to be clarified. I question th e utility of month-long averaged NH 3 and HNO 3 measurements. What kind of denuders can accommodate such a wide range of concentration levels for NH 3 and HNO 3 without breakthrough? HNO 3 is a very unstable gas and mi ght shift its equilibrium state with particles under high temperatures. What will a month-long measurement or 12 samples per year at 75 locations represent? Ideally, these m easurements should be an integral part of the speciation sampler. Or, at a minimum, they s hould be collected on a 24- hour basis corresponding to one or several of the 24-hour speciation sample s to understand the gas-to-particle relationship. In fact, shorter averaging intervals (~1 to 3 hours) are desired for pr ecursor gases to better understand the gas-to-particle equilibrium under di fferent temperatures and relative humidities. These measurements may be considered as part of short-termspecial studies.

To facilitate the transition from filter-based speciation measurements to in-situ continuous mass

= and chemical measurements (e.g., SO 4 = , NO 3 , carbon) requires a collocated comparison to ensure the equivalence or comp arability between the measuremen ts (Fehsenfeld et al., 2003). Recent comparisons (e.g., Drewnick et al., 2003; Fine et al., 2003; Weber et al., 2003; Harrison et al., 2004) show that commercia lly available instruments still need to be modified to demonstrate equivalence or comparability.



### References

Chow, J.C.; Watson, J.G. Guideline on speciated particulate monitoring; pr epared for U.S. EPA, Research Triangle Park, NC, by Desert Research Institute: Reno, NV, 1998. www.dri.edu.

Chow, J.C.; Watson, J.G.; Green, M.C.; Lowentha l, D.H.; DuBois, D.W.; Kohl, S.D.; Egami, R.T.; Gillies, J.A.; Rogers, C.F.; Frazier, C.A.; Cates, W. Middle- and neighborhoodscale variations of PM 10 source contributions in Las Vegas, Nevada; JAWMA 1999, 49(6), 641-654.

B-26Chow, J.C.; Engelbrecht, J.P. ; Watson, J.G.; Wilson, W.E.; Frank, N.H.; Zhu, T. Designing monitoring networks to repr esent outdoor human exposure; Chemosphere 2002a, 49(9), 961-978.

Chow, J.C.; Engelbrecht, J.P.; Freeman, N.C.G.; Hashim, J.H.; Jantunen, M.; Michaud, J.P.; de Tejada, S.S.; Watson, J.G.; Wei, F.S.; Wils on, W.E.; Yasuno, M.; Zhu, T. Chapter one: exposure measurements; Chemosphere 2002b, 49(9), 873-901.

Chow, J.C.; Watson, J.G.; Edgerton, S.A.; Vega, E. ; Ortiz, E. Spatial differences in outdoor PM 10 mass and aerosol composition in Me xico City; JAWMA 2002c, 52(4), 423-434.

Chow, J.C.; Watson, J.G.; Chen, L.-W.A.; Arnott, W.P.; Moosmüller, H.; Fung, K.K. Equivalence of elemental carbon by thermal/op tical reflectance and transmittance with different temperature pr otocols; Environ. Sci. Technol. 2004, 38(16), 4414-4422.

Demerjian, K.L. A review of national monitoring networks in North America; Atmos. Environ. 2000, 34(12-14), 1861-1884.

Drewnick, F.; Schwab, J.J.; Hogrefe, O.; Pe ters, S.; Husain, L.; Diamond, D.; Weber, R.; Demerjian, K.L. Intercomparison and evaluation of four semi-continuous PM 2.5 sulfate instruments; Atmos. Environ. 2003, 37, 3335-3350.

Fehsenfeld, F.C.; Hastie, D.R.; Solomon, P.A.; Chow, J.C. Chapter 5: Gas and particle measurements, in Particulate Matter Scie nce for Policy Makers, A NARSTO Assessment, Part 2; NARSTO: Pasc o, WA, 2003, pp. 5-1-5-37.

Fine, P.M.; Jaques, P.A.; Hering, S.V.; Sioutas , C. Performance evaluation and use of a continuous monitor for meas uring size-fractionated PM 2.5 nitrate; Aerosol Sci. Technol. 2003, 37(4), 342-354.

Fujita, E.M.; Watson, J.G.; Chow, J.C.; Zielinska, B.; Islam, M. Demonstration PM Study Plan for Pune, Maharastra, India; prepared for U. S. Environmental Prot ection Agency Office of International Affairs; DesertResearch Institute: Reno, NV, 2003.

Harrison, D.; Park, S.S.; Ondov, J.; Buckley, T.; Kim, S.R.; Jayanty, R.K.M. Highly time resolved fine particle nitrate measurements at the Baltimore Supersite; Atmos. Environ. 2004, 38(31), 5321-5332.

Malm, W.C.; Pitchford, M.L.; Iyer, H.K. De sign and implementation of the Winter Haze Intensive Tracer Experiment – WHITEX, in Transactions, Receptor Models in Air Resources Management, Watson, J.G., Ed.; Air & Waste Management Association: Pittsburgh, PA, 1989, pp. 432-458.

National Research Council of the National Academies. Research priorities for airborne particulate matter: IV. Continuing resear ch progress; The National Academy Press: Washington, DC, 2004. www.nap.edu.

B-27Pitchford, M.L.; Green, M.C.; Kuhns, H.D.; Tomb ach, I.H.; Malm, W.C.; Scruggs, M.; Farber, R.J.; Mirabella, V.A.; White, W.H.; McDade , C.; Watson, J.G.; Koracin, D.; Hoffer, T.E.; Lowenthal, D.H.; Vimont, J.C.; Gebhart, D.H.; Molenar, J.V.; Henry, R.C.; Eatough, D.A.; Karamchandani, P.K.; Yang, Z.; Se igneur, C.; Eldred, R.A.; Cahill, T.A.; Saxena, P.; Allan, M.A.; Yamada, T.; Lu, D. Project MOHAVE, Final Report; U.S. Environmental Protection Agency, Re gion IX: San Francisco, CA, 1999.

U.S. EPA. Guidance for network de sign and optimum site exposure for PM 2.5 and PM 10 ; EPA454/R-99-022; US EPA, 1997a.

U.S. EPA. Revised requirements for designatio n of reference and equivalent methods for PM 2.5 and ambient air surveillance for particulate matter – final rule; Fe deral Register 1997b, 62(138), 38763-38854.

U.S. EPA. 40 CFR Part 51 – Regional haze re gulations: Final rule; Federal Register 1999, 64(126), 35714-35774.

Vedal, S. Critical review – Ambient particles and health: Lines that divide; JAWMA 1997, 47(5), 551-581.

Watson, J.G. Visibility: Science an d regulation; JAWM A 2002, 52(6), 628-713.

Watson, J.G.; Chow, J.C. Comparison and evalua tion of in-situ and filter carbon measurements at the Fresno Supersite; J. Geophys . Res. 2002, 107(D21), ICC 3-1-ICC 3-15.

Weber, R.; Orsini, D.; Duan, Y.; Baumann, K. ; Kiang, C.S.; Chameides, W.; Lee, Y.N.; Brechtel, F.; Klotz, P.; Jongejan, P.; ten Bri nk, H.; Slanina, J.; Boring, C.B.; Genfa, Z.; Dasgupta, P.; Hering, S.; Stolzenburg, M.; Du tcher, D.D.; Edgerton, E.; Hartsell, B.; Solomon, P.A.; Tanner, R. Intercompari son of near real time monitors of PM 2.5 nitrate and sulfate at the U.S. Environmental Protec tion Agency Atlanta S upersite; J. Geophys. Res. 2003, 108(D7), SOS 9-1-SOS 9-13.

Zhu, Y.F.; Hinds, W.C.; Kim, S.; Shen, S.; Sioutas, C. Study of ultrafine particles near a major highway with heavy-duty diesel traffic; Atmos. Environ. 2002a, 36(27), 4323-4335.

Zhu, Y.F.; Hinds, W.C.; Kim, S.; Sioutas, C. C oncentration and size dist ribution of ultrafine particles near a major highw ay; JAWMA 2002b, 52(9), 1032-1042.

B-28

## Mr. Bart Croes

U.S. EPA’s National Ambient Air Monitoring Strategy Implementation
December 15, 2004 Consultation Meeting

CASAC AAMM Subcommittee Review Comments, Bart Croes

Overall, the Strategy document represents a we lcome initiative by U.S. EPA to rethink the nation’s approach to ambient air quality monitoring in partnership with state, local and tribal (SLT) agencies. The document provides a thorough de scription of the ad hoc process that led to the current national air monitoring networks, e xplains why the networks need to be more integrated and adaptable to changing needs, and provides a reasonable rationale for the many proposed changes. I appreciate the degree to wh ich U.S. EPA has responded to comments from the CASAC NAAMS Subcommittee a nd others. My comments address the four charge questions posed by Rich Scheffe in his N ovember 19, 2004 memo to Fred Butterfield.

Question 1: Given limited budgetary resources, does the network redesign represent both an appropriate and adequate balance, as reflected by the relative resource allocations provided in Section 11, “Draft Implementation Plan,” of the Final Draft NAAMS Document? In additi on, are the relative adjustments in the training and guidance approaches proposed in the draft implementation plan consistent with the overall objectives of the Strategy?

My comments are based on the premise that public health (and welfare) considerations should inform the priority and funding allocation for what is measured, and that all measurements must have clients that will use the data for their intended purpose.

The proposed future resource allocation (Table 11-3) has the right order in terms of the relative priority of PM, ozone, and TACs. In Californi a, we estimate 400 annual Statewide cancer cases attributable to all TACs (primarily diesel PM , benzene, and 1,3-butadie ne) versus 6,500 deaths per year related to PM2.5 and 640 deaths per year for ozone. PM2.5 and PM10 are responsible for the majority of the morbidity effects. The TAC mortality estimate is an overestimate since it uses the 95% upper confidence limit while the PM2.5 mortality estimate could be up to three times higher because there may not be a threshol d. Thus, PM represents 80-90% of the known health risk attributable to ambient air pollution and rightly deserves the majority of resources.

I recommend that U.S. EPA drop the PAMS VOC m onitoring requirements entirely, as the vast amounts of data collected each summer do not appear to have a client. Data collected in California has had very little utility for trend analyses, emi ssion inventory reconciliati on, or air quality model input and evaluation. A strategy of continuous NMVOC mass measurements (for trends to check on the success of control programs and ozone data an alysis), and VOC speciati on during special studies of ozone episodes likely to be used in SIP modeling, is sufficient. This would save at least $10 M

B-29that can be devoted to data analysis and inte rpretation (proposed for onl y $2.2 M), baseline funding of the Level 1 sites, enhancem ent of the Level 2 sites, and environmental justice-oriented monitoring.

Perhaps the resources ($10 M) devoted to PMc monitoring can be minimized. U.S. EPA and SLT agencies have already invested huge resour ces into the current PM10 and PM2.5 monitoring networks. Several states (i.e., California) have State ambient air qualitystandards for PM10 and do not plan to follow U.S. EPA in adopting a coarse particle standar d. Surely if a site meets the PMc standard with PM10 monitoring data (uncorre cted), then there is no need to deploy a PMcspecific monitor at the site. While U.S. EPA ha s not yet promulgated a coarse particle NAAQS, it has released a Staff Paper with a proposed rang e of possible standards for PM2.5 and PMc. As a first-order estimate, data from the existing PM 10 monitoring network should be compared to the proposed lower and upper ranges of the coarse particle recommendations to determine if the potential scope of a PMc monitoring network would be national in scale or restricted to a few states. In these likely non-attainment areas, PM10 would primar ily consist of the coarse fraction. Sites that have collocated PM2.5 and PM10 monitors or SLT agenci es that have operated dichot samplers (e.g., California) provide more re levant data for this screening analysis.

The revised Strategy places importance on the Level 1 sites, but needs to devote resources to the effort (with perhaps matching funds from SLT agen cies and industry). Leve l 1 sites can serve as a test bed for Level 2 instrumentation, and can appropriately by operate d by highly trained SLT agency personnel. This approach has worked ex tremely well at the Fresno PM Supersite, with operations by the California Air Resources Boar d and funding from U.S. EPA. Major yearlong air quality field studie s (CRPAQS, CCOS), atmospheric re searchers (BYU, DRI, UCB, UCD, UCSD), government agencies (PNNL, U.S. EPA) , and a major $7 M health study (i.e., Fresno Asthmatic Children’s Environment Study) have benefited from the Supersite.

The Level 2 sites should include continuous NMVOC (for trends to check on the success of control programs and ozone data analysis) and CO 2 (for fuel-based emission inventories that are a good check on MOBILE and EMFAC). Sites coordi nated with health studies should include particle counts or surface area to check health hypotheses and because they do not necessarily correlate with PM mass like so many PM compon ents. Some of the Level 2 sites should be located for special purposes. These include road way or tunnel sites (t o measure the success of the motor vehicle control program), sites to document Asian and Saharan dust events, global O 3 trends, and conditions aloft (instrumented buildings).

Environmental justice concerns ne ed some funding. Screening methods (i.e., low-cost, easy-to-use monitoring technologies) should be developed and deployed to asse ss near-source exposures in lowincome communities and communities of color. Relatively low-cost passive monitoring technologies exist for O 3 , NO 2 , BTEX, and HCHO, and portable samp lers are available for CO and PM. These are not FRM-equivalent devices, but should be suitable for screening purposes.

Question 2: Does the Subcommittee have addi tional suggestions for addressing the need for integration and communication of the NCore Level 2 network to the broader community of “users,” including scientific researchers (i.e., human health, atmospheric, ecological) a nd State, local and Tribal Agency

B-30representatives? More specifically, what is the most e ffective manner for EPA to both reach-out to this broad user co mmunity and, where appropriate, to incorporate their feedback and design in put on such issues as monitoring site locations and parameters?

It is disappointing to read that only 29 co mment letters were submitted on the September 2002 draft Strategy document, although that does not necessarily reflect poorly on U.S. EPA public outreach process. However, as an active memb er of NARSTO and an attendee at the annual conferences of the Health Eff ects Institute, I am not aware th at NAAMS was presented to these broad stakeholder communities. Perhaps a more activ e effort is needed to identify organizations, conferences, journals, and other publications wh ere U.S. EPA staff can present the Strategy.

If it has not already b een done, an email list-se rve should be developed and advertised on U.S. EPA’s monitoring-related website s. I know that Region 9 ha s a distribution list of SLT representatives, and other regions likely do as we ll, that can serve as a starting point. The listserve can be used to release the final Strategy and periodic guidance documents, and to solicit reviews.

A useful product to circulate widely is the maps and summaries of existing networks contained in Chapter 3. A recent effort by epidemiologists at New York University to do national source apportionment maps only found one California STN s ite in AIRS. There are many more sites as part of STN, IMPROVE, and other networks, an d easy-to-access network summaries with points of contact will increase the use of network data.

Question 3: EPA is considering converting a ll of the Speciation Trends Network (STN) sites to Interagency Monitoring of Protected Visual Environments (IMPROVE) samplers and IMPROVE laboratory and sample handling protocols. What are strengths and weaknesses of this approach?

There would be clear benefits from consistent sampling, analysis, data handling, and quality assurance protocols for the STN and IMPROVE networks. My group is a major user of speciation data for PM SIPs, Asian transport evaluations, determinations of the impacts of shipping emissions, atmospheric de position estimates for Lake Tahoe, etc., and the difficulty of combining the two datasets constrains our analyses . I will leave it to my colleagues to advise U.S. EPA whether the STN protocols, IMPROV E, or a hybrid should be employed by both networks. Whatever the choice, an effort should also be ma de to develop source speciation profiles consistent with the ambient data.

Question 4: Is it scientifically acceptable to generate air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty fo r use in the regulatory decision-making process?

Model results are not a substitute for measuremen ts as they rely on highly uncertain emission inventories. In general, model acceptability criter ia allow much greater errors (on the order of

B-3130% for ozone) than is acceptable for ambient ai r monitoring (less than 15%). I doubt the public would accept any substitute for observational data to determine non-attainment status because of the risk for “gaming” the model. Ambient air qua lity standards link back to monitoring data, not model results used in epidemiological studies. Could satellite data possibly be an alternative approach?

B-32

### Dr. Kenneth L. Demerjian

B-33B-34B-35

### Dr. Delbert Eatough

B-36B-37B-38B-39B-40

### Mr. Eric Edgerton

Response to CASAC AAMM Subcommittee Charge Questions on Implementation of National Ambient Air Monitoring Strategy

Question 1: Given limited budgetary resources, does this represent both an appropriate and adequate balance, as reflected by the rel ative resource allocations provided in Section 11, “Draft Implementation Plan,” of the Fina l Draft NAAMS Document? In addition, are the relative adjustments in the training a nd guidance approaches proposed in the draft implementation plan consistent with the overall objectives of the Strategy?

It is difficult to answer the first question without: 1) knowing the fungibility of 103 and 105 grant dollars; 2) having the criteria pollutant network assessments from the Regions; and 3) having an analysis of th e PAMS network. The working assumption in Chapter 11 appears to be that PM2.5 funds (2nd largest pool) are fair game for redistribution, criteria pollutant funds (by far the largest pool) are not and PAMS funds (3rd largest pool ) are somewhere in between. Given this scenario, except for the inability to fund Level 1 sites, resource allocations seem reasonable and adequate.

The PAMS network is a continuing enigma. On the one hand, it represents a tremendous investment and a game attempt to collect high time resolution data for ozone assessments. By my tally, the average operating cost for a PA MS site is nearly 375K. Many of the PAMS measurements are analogous to what is needed fo r PM assessment. For example, the experience of measuring 50-60 organic specie s by GC might come in handy when we want to measure 4-5 ions via IC. On the other hand, there is little evidence the data have ever been used or even scrutinized. My recommendation would be to conduct a forward-l ooking analysis of PAMS with the following questions in mind: 1) Can the ne twork be redesigned to serve needs for ozone, PM and toxics assessments? and 2) Can a subset of PAMS sites serve as Level 1 NCORE sites? Infrastructure at PAMS sites should provide considerable leveraging. Although PAMS is not geographically positioned to provide all Level 1 sites, might it not underwrite 3 or 4, if the total number of PAMS sites were reduced to 50 or 60? If the answers to these questions is "no", then much deeper cuts in the curre nt PAMS funding are warranted.

Regarding the second question, the QA compon ent will need substantial funding for development of standard reference materials in addition to lab and fiel d audits. The training component will need substantial funding to ensure the entire chain of data collection/management understands the measurement objectives. For the Level 2 sites, a key objective will be detection of secular trends, and this will require very careful attention to analyzer response in the botto m 10% of the measurement range (5-20 ppb for SO2 and NOy; 100-300 ppb for CO).

B-41Question 2: Does the Subcommittee have additi onal suggestions for a ddressing this need for integration and communication to the broader community of “users,” including scientific researchers ( i.e. , human health, atmospheric, ecological) and State, local and Tribal (SLT) Agency representatives? More speci fically, what is the most effective manner for EPA both to reach-out to this broad user community and, where appropriate, to incorporate their feedback and design input on such issues as monitoring site locations and parameters?

As a long-term solution, analysis of data for Le vel 1, Level 2 and PAMS sites and publication of results in peer-reviewed journals is hard to be at. It might also be worthwhile to convene symposia or panel discussions at ISEEpi (International Society of Environmental Epidemiologists, not to be confused with Intern ational Society of Explos ive Engineers). There could be a panel discussion at annual SLT m onitoring workshops. The panel would include recognized experts in the relevant fields and would discuss future monitoring needs and opportunities. In the near-term, all data users should be alerted to the NCORE Strategy and impending changes, and encourag ed to provide feedback.

Question 3: What are strengths and weaknesses of converting all of the Speciation Trends Network (STN) speciation sites to Inter agency Monitoring of Protected Visual Environments (IMPROVE) samplers and IM PROVE laboratory and sample handling protocols?

Harmonization is seductive; however, I would recommend a thorough analysis of network protocols before making a wholesale move to IM PROVE. Clearly, something needs to be done about carbon and a switch to the IMPROVE protocol (TOR) make s sense in terms of current operational definitions of OC/EC. Not so clear is whether STN measurement technologies and sample handling protocols should be replaced. Does either netw ork offer advantages in flow control or Dp 50 or sample preservation? For vari ous reasons, IMPROVE does not measure ammonium ion, an important component of PM 2.5 mass, a nutrient species and an important counter-ion to nitrate and sulfate. Instead, IMPROVE incorrectly a ssumes that nitrate is always associated with ammonium and that sulfate is always fully neutrali zed by ammonium (molar ratio = 2). We have to do better than this if we are ever going to understand dynamics of particle formation, etc. STN, on the other hand, does me asure ammonium and does have protocols in place to ensure a certain level of data quality. If a change is in the cards, it will be important to ensure it doesn't impair current data quality.

Question 4: Is it scientifically acceptabl e to generate air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regulatory decision-making process?

From a scientific standpoint, you want to bring all information to bear. The key will be in understanding uncertainties and prop erly factoring them into the decision-making process. If this can be done, then there are significant advantages to the concept, including better definition of attainment/non-attainment areas and potentially accelerated designation/re-designation. While

B-42the scientific advantages are obvious, using combined surfaces for regulatory decision-making may be a very tough sell to stakeholders.

Eric S. Edgerton 12/19/04 Cary, NC 27513

B-43

### Mr. Henry (Dirk) Felton

Responses: Dirk Felton, NY SDEC (Submitted 12/14/04) Charge to the CASAC AAMM Subcommittee Dec 15 th 

### 2004 Meeting

General Comments follow the four questions to the committee:

1. The CASAC has expressed its support for the Agency’s proposal to re design the routine PM monitoring network to support PM pr ecursor gas measurements (CO, SO 2 , NO/NOy, NH 3 , HNO 3 ) at NCore Level II multiple-pollutant sites, and for air quality management decisions and to obtain relevant exposure data for research programs.

Questions: Given limited budgetary resources, does th is represent both an appropriate and adequate balance, as reflected by the relative resource allo cations provided in Section 11, “Draft Implementation Plan,” of th e Final Draft NAAMS Document? In addition, are the relative adjustments in the training and guidance approaches proposed in the draft implementation plan consistent with th e overall objectives of the Strategy?

No, the proposed extensive PM-2.5 non-attainment areas demonstrate that PM monitoring and particularly PM-2.5 specia tion cannot be reduced in many areas. Additionally, it may be that the PM-2.5 annual and daily NAAQS will be lowered which could require additional monitoring res ources. This was evidenced after the implementation of the 8-Hr Ozone NAAQS. More borderline attainment areas required additional monitors and non-attainment ar eas required additional up and downwind monitors. Establishing sites is difficult and expensive and it does not make sense to close a site that may be needed a short time later for ozone, enhanced PM-2.5 or PM-coarse monitoring. Many of the NCore principles are important and should be gradually incorporated into the existing NAMS and SLAMS requirements.

The training and guidance approaches may be co nsistent with the stra tegy, however, it is not generally helpful for the monitoring agency staff who need it most. Many of the staff who will be operating the newer technologies ar e located in remote offices without the ability to travel or to access many of these information resources.

2. The implementation plan proposes a series of communication actions to advance the NCore Level 2 network, in order to more directly support long-term health effects research and provide better support to ecosystem assessments through an increased level of coordination.

Questions: Does the Subcommittee have additional s uggestions for addressing this need for integration and communication to the broader community of “users,” including scientific researchers ( i.e. , human health, atmospheric, ecological ) and State, local and Tribal (SLT) Agency representatives? More sp ecifically, what is the most effective manner for EPA both to reach-out to this broad user community and, where appropriate, to incorporate their feedback and design input on such issues as monito ring site locations and parameters?

B-44State agencies that have non-attainment concerns must be able to select site locations based on how they believe they will be able to demonstrate the effectiv eness of their SIP. This monitoring, which is already aimed at pr otecting human health must take priority over other research monitoring priorities. Hea lth oriented researchers may be interested in urban hotspot monitoring while a modeler may be interested in a boundary site or even a monitoring location chosen at random. The monitoring objectives and operational procedures may be too different for some of these groups to reconcile in one monitoring location or in a comparable dataset.

State and Local Agencies face the very difficult task of operating quality-assured monitoring networks consisten tly for long periods of time. Many research oriented monitoring programs are designed to examine a particular issue and then publish results. Some of these Science oriented mon itoring programs such as CASTNET have demonstrated problems in the long term ope ration of criteria in strumentation. One CASTNET site in the lower Hudson Valley expanded to Ozone monitoring. Over time, the operation of the instrument was not pr operly quality assured and the Regional EPA office attempted to make the surrounding area non-attainment for ozone because of this data.

It is advantageous for the various monitoring agency, health agency and research groups to meet regularly to discuss instrument se lection and limitations, data comparability, multi-media pollutants public awareness and other issues.

3. One of the remaining technical issues re lates to harmonizing rural- and urban-based PM 2.5 chemical speciation networks such that bothcategories of networks utilize consistent sampling and analysis protocols. For example, EPA is considering converting all of the Speciation Trends Network (STN) speciation sites to In teragency Monitoring of Protected Visual Environments (IMPROVE) samplers and IMPROVE laboratory and sample handling protocols.

Question: What are strengths and w eaknesses of this approach?

The urban IMPROVE study has not been comple ted and it is not apparent that the IMPROVE protocols would be entirely successf ul in urban environments. For example, inlets on IMPROVE sampler are cleaned annually while the STN inlets are cleaned either Monthly or after each sample depending on th e type of sampler. A better approach would be to select the strengths of each ne twork and design a new Na tion-wide program. Carbon sampling techniques can be drastically improved by minor changes in flow rates, filter shipping containers and field procedures. Since the cost of analysis is so high for this program, it makes sense to optimize the sampling equipment in an effort to raise the quality of the data.

4. As EPA implements the National Ambient Air Monitoring Strategy to address multiple monitoring objectives, it will be looking to spatially optimize the ambient monitoring networks. This may mean that some redundant monitors in adjacent, but separate , geopolitical areas ( e.g. , neighboring counties) are “dives ted” from a given network. Although technically sound, these divestments could result in data gaps which might, in turn, advers ely impact regulatory decision

B-45making. The Agency is willing to adopt alternativ e approaches for assessing regulatory issues such as non-attainment designations, so long as su ch approaches are scientifically justifiable; hence, the rationale for initiating discu ssion of these issues with the CASAC.

Question: Is it scientifically acceptable to generate air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the re gulatory decision-making process?

No, ambient data must be used in the regulat ory decision making proce ss. This is clear from all of the recent cases where ambient data has been used to refute poor model performance. Models are developed to wo rk in a majority of usually simplified applications. It is difficult enough to veri fy a model’s overall pr edictive accuracy but impossible to prove that it accurately covers all areas of a domain. Many areas of a State or Territory may not fit into the acceptable range of a model and this could not be known without actual data. Recent experiences have shown that the EPA is willing to use models that are not accurate or verifiable.

For example, the EPA’s accepted model for use in PM-10 SIP development calculates road dust concentration based on the mass emitted from vehicle tailpipes. This model was developed for older cars on roads with fe wer vehicles than those of today. The model substantially over-predicts the amount of vehicle generated PM-10 in dense urban areas such as NYC. What is disappointing is the EPA’s lack of concern or attention to poor model performance even when it prev ents State Agencies from meeting their requirements.

Another example is the EPA’s use of the Urban Excess model which has been inappropriately applied in the urban Northeast. The EPA is currently using this model to determine the extent of the PM-2.5 non-attainment areas. This model has been applied without taking into account actual ambient data , transport, secondary particle formation, meteorology or differences among monitoring programs.

General Comments on the National Air Monitoring Strategy:

The majority of people on the AAMM board work in the research field and most likely will be in favor of the overall NCore strategy. Many of the NCore objectives are worthwhile such as trace gas monitoring, a greater emphasis on data and pr ogram analysis and a better integration with health and multimedia communities. There is mo re disagreement towards the overall objectives of NCore from State and Local monitoring Agen cies and perhaps even from the Regional EPA offices. I see a greater loss from what is left out of NCore than what may be gained from its adoption in its present form. I think the lack of enthusiastic support from some of the EPA regional offices stems from their concern that when the spatial covera ge of monitoring is reduced, they will have a more difficult time res ponding to public issues and complaints.

My concerns with NCore include the melding of networks with different design principles such as PM-2.5, Ozone and Toxics, the lack of emph asis on sources, characterization, controls and

B-46permits and the reduction in State Agency flex ibility due to the tightening of SPM (Special Purpose Monitor) regulation. The NCore fundi ng strategy was determined by examining Nationwide statistics from AQS Criteria Data. The value of individual St ate networks or even individual sites cannot be examined in this way. What is the value of a PM-10 instrument if it is the only one downwind of a permitted facility? What will happen when the PM-10 standard is rescinded before suitable PMc stack testing met hods are developed. Data from many State and Local Agency’s monitoring sites are put into th e AQS system even thoug h these sites are not Federally-supported SLAMs or NAMs monitors. InNY, for instance, almost one third of the Ozone monitoring network operates at State funded Acid Rain sites. Closing these sites would not create the funding opportuni ty that the NCore strategy indicates.

Many of the positive attributes of NCore can be implemented with less disruption to State and Local agencies’ existing monitori ng and permit programs. Currently, State and Local monitoring programs are evaluated by their respective EPA Regi onal offices annually. This network review should be expanded to include representatives fr om the National OAQPS offi ce, health officials and if the case warrants; scientific specialti es, such as atmospheric modelers, deposition researchers, the Forest Service, the Park Serv ice, NOAA, etc. The NC ore monitoring objectives, sampling technologies and operational experience should be available as a resource to the stakeholders at these network design meetings.

Other goals of NCore may be achieved or at least improved upon thr ough simple procedural changes. Some State Agencies still upload 1⁄2 of their MDL (Minimum Detection Limit) to AQS in place of their concentrations for parameters such as NO 2 and toxics. This convention prohibits modelers, risk assessors and data analysts from using low concentration data in their analysis. Other low cost opportunities to improve low concentration data include lowering span concentrations where appropriate , setting up dual range analog outputs, and through the use of digital data logging.

The benefit to the State and Local monitoring agencies from the implementation of NCore is supposed to be the flexibility that results from the reduction in criteria monitoring. The NCore strategy suggests that 1000 may be an appropria te number of NCore Leve l III sites operating Nationally. When this number is examined as re presenting the majority of the spatial component of monitoring including PM-2.5, PM-10, PMc, Lea d, Ozone, NO2 and Toxics, it is apparent that there will not be any “surplus” Level III sites available for State and Local Agency specific needs. The resources needed to establish m onitoring for SIP development, control strategy verification, toxics hot spot inve stigations or investigations of environmental justice are not clearly defined in the Air Monito ring Strategy Document.

B-47

### Dr. Rudolf Husar



## Response to the NAAMS Implementation Plan

Rudolf Husar , CASAC AAMM Meeting, Updated December 17, 2004

Overall, the NAAMS implementation plan is as good as its parent conceptual plan. It has been developed through the same responsive participatory process and it shows. The freshness of the implementation plan s ounds almost too good. What’s the ketch? Actual Implementation?

Question 0: Is the plan consistent with the NAAMS strategy? To a large degree yes. A key implementation issu e concerns the realization of the multi-tier, monitoring strategy represented by th e 3-level pyramid. Implicit in the strategy is that the levels will be mutually supportive entities for the charac terization of air quality. How will the tiers be linked to form a coherent monito ring unit that provides useful, integrated data from the new integrated network?

Question 4: Is it scientifically acceptable to ex trapolate observations by physical or statistical models? Not only acceptable, but a necessity for integrating the multi-tier data. Thus, spatial data extrapolation (say from L2 to L3 and below) should be an integral part of NAAMS strategy implementation. It should be part of the monito ring process. ‘Smart’ ex trapolation schemes can now be used to constrain the estimates by the data as well as by physical laws. The derived pollution ‘surfaces’ resulting from the monitoring pr ocess could then be used for regulatory as well as for many other purposes.

Question 1: Is this implementation plan an appr opriate reallocation of monitoring resources? The bulk of the reallocation makes sense. Howe ver, routine network assessment and level 2-3 data integration need specific implementation pl an and line item in the budget. The $$ for these

B-48network operation activities could be fr om reduced PAMS and from the dubious $10M PMc monitoring allocation.

Question 2: How to improve communication with us er communities (health, atmospheric, ecological)

By a more open NAAMS process (glasnost) and by closing communication feedback loops.

Question 3: Should the STN sites be converted to the IMPROVE protocol? IF (Since) the STN approach does not show distinct advantag es, it would make sense to adopt the IMPROVE protocol for all routine speciated monitoring, so urban-rural differences can be reliably quantified.

The implementation plan takes a very defe nsive posture toward linking with non-NCore networks. There are several readily available real -time datasets that could significantly augment the NCore aerosol characterization, e.g. ASOS and Satellites. As shown below, the spatial coverage of real-time AIRNOWPM25 (~300 stations) and ASOS li ght scattering networks (1200 stations) operated by NWS, FAA and DoD would enrich the spatial texture AND the in situ characterization

B-49B-50Satellites add spatial texture (MODIS, 250m), source identification (s moke, dust) and some vertical information. The example shows a supe rposition of ASOS Bext and 1 km resolution SeaWiFS reflectance and Aerosol Optical Thickness during the July 2002 Quebec Smoke event. The augmenting the NCore 3-tier pyramid with such data should be encouraged and made explicit in the implementation plan.

B-51B-52

### Dr. Kazuhiko Ito

Revised comments on the NAAMS final draft.

Kaz Ito, 12/20/04

General comments :

I came into this review process rather late (thi s Final Draft was the first draft I read regarding NAAMS). Since most of the decisions regardin g the network design have been already made, some of my comments may be too late. I will nevertheless provide th ese comments hoping that they may still be useful in the remaining period of implementation as well as in the future revision of the Strategy.

The difficulty of balancing the budget with the most reasonable scientific decisions to redesign the ambient monitoring network is overwhe lming, but I was impressed with the level of effort and progress made so far. The proposed NCore network is appealing. Its plan to collect multi-pollutant data at each monitor accommodates the need of health effects research community (such data were often lacking in the past network monitors ). I understand that the priorities of the state and local agencies are the most important fact ors in designing the new network, but I also hope that the Strategy will take a closer look at the issues and the needs of the health effects research community. In the pa st ten years, many observational epidemiological studies utilized the data from these routine m onitors, producing valuable inputs into the process of setting the NAAQS. It is in teresting to note that, while th e main motivation to reduce the number of monitors for CO, SO 2 , and NO 2 comes from the observation that most of these monitors measure levels well below the NAAQS, ma ny of the PM studies in the past ten years reported associations with mortality and morbid ity at levels well belo w the NAAQS. I am not implying that I am against reducing redundant monito rs (I am all for it). I am just suggesting that we should do this carefu lly. I assume that determining the “redundancy” for CO, SO 2 , and NO 2 monitors would be much more complicated th an for more regional pollutants such as O 3
. Also, it seems that the decisions about the speci ation monitors are being made without detailed analyses of the new speciation network data(collected so far, 2001-2004). Some specific comments related to these issues are given below.

Question 1 : Given limited budgetary resources, does th is represent both an appropriate and adequate balance, as reflected by the relative re source allocations provide d in Section 11, “Draft Implementation Plan,” of the Final Draft NAAMS Document? In addi tion, are the relative adjustments in the training and guidance appro aches proposed in the draft implementation plan consistent with the overall objectives of the Strategy?

It is not easy for me to a ssess the adequacy of the balan ce without knowing the details of the process to eliminate a certain fraction of mon itors (for example, what reasoning was used to reduce non-trend PM 2.5 speciation sites from 160 to 80?). Given my limited knowledge on this process, the general distributi on of budget seems ok to me.

B-53Question 2 : Does the Subcommittee have additional s uggestions for addressing this need for integration and communication to the broader community of “users,” including scientific researchers ( i.e. , human health, atmospheric, ecological ) and State, local and Tribal (SLT) Agency representatives? More sp ecifically, what is the most effective manner for EPA both to reach-out to this broad user community and, where appropriate, to incorporate their feedback and design input on such issues as monito ring site locations and parameters?

The Strategy should obtain feedback from the epidemiology/public health researchers who have been using the data from these rout ine monitors as well as those who have been involved in setting up their own monitors for epidemiological st udies. I do understand that the existing and future air monitoring network is not necessarily for epidemiological studies but mostly for regulatory and compliance purposes, and the budget and capacity of the SLT agencies would determine the type and extent of the change in the network design. However, input from the health effects research community should still be useful, especially because so many of the observational epidemiological studies relied on the use of data fr om these routine air monitors that were not developed for epidemiological stu dy designs. Monitor site location needs for both short- and long-term health eff ects study designs should be consid ered. I speculate that many of the epidemiologists and public health scientists who have used the rou tine air quality network data are unaware of the changes that are taki ng place through the Strategy. I would suggest a workshop to identify and discuss the issues among the health effects/exposure community. Federal Register is certainly not the medium th at these researchers regularly seek information from. At the NAAMS subcommittee meeting, Dr. Sche ffe suggested that Heal th Effects Institute may be a good place to have sucha forum, but I think we need to reach a broader list of researchers who should be informed on this issue. I know that some of us are even writing grant applications (without knowing the changes in the network design) that rely on these air quality data. Aside from getting feedback, at minimum, all the current and recent EPA grantees, as well as those who have been involved in this type of research should be notified of the proposed changes.

Question 3 : What are strengths and weaknesses of converting all of the Speciation Trends Network (STN) speciation sites to Interagency Monitoring of Protected Visual Environments (IMPROVE) samplers and IMPROVE laborat ory and sample ha ndling protocols?

I think it would be easier to answer this question if we had a good summary of the STN data that have been collected so far (2000-2004) so that we coul d compare various aspects of the data with those for the IMPROVE database . The IMPROVE web site has a very good descriptive analysis of their data. I haven’t seen a similar analysis for the STN (I am sure many of us, including myself, are tryi ng to do this now). So, it is so mewhat frustrating to make a judgment without sufficient knowledge. With th is limitation in mind, the strength of switching to IMPROVE protocol would be th at we would have one larger database that is measured in a consistent way. At the 12/14/04 NAAMM meeting, I learned that they are collecting data using co-located monitors with the STN and IMPROVE protocols. We should probably wait for these data to be analyzed before we make decisions.

B-54Question 4 : Is it scientifically acceptable to generate air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regul atory decision-making process?

This question is rather general. However, fo r a specific situation, I th ink there is always a “scientifically acceptable” (the best available, anyway) way to use the modeled data. I assume that EPA is referring to the surface depiction of some smoothed data such as Figure 5-1 on page 5-1 of the NAAMS final draft. In this case, the objective appears to be to identify areas where removing existing monitors does not affect the predic tive power of some stat istics, in this case, the 4 thhighest 8-hr daily maximum average O 3 value. The approach taken for the objective here seems reasonable. The remaining question would be the model uncertainty associated with the interpolation methods. For example, if we us ed another available method (e.g., kriging) to estimate the surface, how much difference doe s it make? Also, how do you decide on the acceptable (tolerance?) level of error?

At the 12/14/04 NAAMM meeting, I learned thatthese modeled surfaces were not being used for determining monitoring “redundancy” to remove monitors, so I take back my initial concern about the application of these models for SO 2 and NO 2 monitors. I maintain my concern regarding the applicability of th ese models for non-regional pollu tants. For regional pollutants (e.g., O 3 and sulfate), we can generally assume sm oothness in spatial vari ability (except high density traffic areas where NO may quench O 3 ). Determining concentration surfaces for PM 2.5 monitors may also be relatively less problem atic in areas where spatially homogeneous secondary sulfate dominates PM 2.5 . Estimating concentration surfaces for CO, SO 2 , and NO 2 as well as some of the PM 2.5 species would be more difficult because they are more strongly influenced by primary emissions from local s ources, and the monitor-to -monitor correlations are much poorer both in terms of temporal correla tion and mean levels. The problem with the locally impacted pollutants that, if separation di stance of two monitors is relatively far (> 20 miles), then the two monitors having similar av erage concentrations (o r any annual statistics) does not necessarily imply that a point betw een the two monitors would have a similar concentration because they may simply reflect separate local sources that do not reach or influence concentrations at the mid-point. Thus , the prediction error woul d be greater for these pollutants than O 3 or PM 2.5 in many of urban areas. I looke d at monitor-to-monitor temporal correlation for PM 10 and the gaseous pollutants in the nati onwide data, and found that the overall rankings in monitor-to-monitor correlation within the same Air Quality Control Region to be: O 3 , NO 2 , and PM 10 , (r ~ 0.6 to 0.8) > CO (r < 0.6) > SO 2 (r < 0.5), confirming the larger prediction errors for locally impacted pollutants. We will have to deal with this issue for the PM 2.5 speciation data. Some of the PM 2.5 species are more locally impacted than others. The implication is that differential errors across the PM 2.5 species from differ ent source types (e.g., regional vs. local pollution sources) will affect source apportionment results and associated prediction errors. This issue n eeds to be investigated using the current trend and non-trend PM 2.5 speciation monitors’ data. Ideal ly, such information should influence the decision as to which non-trend monitors should (can) be removed (for the planned reduction of non- trend monitors).

B-55

### Dr. Donna Kenski

Response to CASAC AAMM Subcommittee Charge Questions on Implementation of National Ambient Air Monitoring Strategy

Donna Kenski Lake Michigan Air Directors Consortium December 14, 2004

Question 1: Are the relative resource allocations appropriate and balanced? The allocations presented in Table 11-3 seem mostly reasonable. However, the continuing inability to confirm a funding m echanism for Level 1 sites is dist urbing. These are an integral part of the strategy and must be allotted adequate long-term funding. It is greatly encouraging to see a line item for data analysis (two line items, in fact). The da ta analysis funding for the toxics program has been a terrific investment that has and will continue to yield benefits for years to come. That said, the strategy’s funds for data analysis and interpretation seem a bit puny for the size of the program – even the least generous estimates suggest that a minimum of 10% of project funds should be spent on data analysis . Although some analysis will be undertaken by SLTs or others, the costs are considerable to pl an, perform, and integrat e various analyses and then make the results web-accessible. Inadequate funding will only leave us with unanswered questions and broken or unsatisfactory public access to important data.

While the decrease in gravimetri c PM measurements is justifie d, and moving to continuous PM is advisable, the document doesn’t discuss allocations to continuous speciation measurements, except the modest bump-up in CASTNET funds fo r their 3 pilot sites. These continuous speciation measurements are ultimately the most revealing about the nature of PM2.5, and more investment on EPA’s part is absolutely critical. These measurements are perhaps best left to the Level 1 sites for now, but EPA needs a stronger commitment (financial and political) to advancing the state of science of these measurements so that they can eventually be rolled out to more sites. Since ORD isn’t supporting this development, perhaps the strategy could take a stronger stand.

Training and guidance adjustments were consiste nt with objectives; th e emphasis on webcasts and DVDs should be well received by states. It’s nice of EPA to acknowledge the travel restrictions that so many SLTs are subject to. I’m a little skeptical that these types of training can really be adequate for some of the more complicated measurements – e.g., NOy. In general, while the strategy’s objectives were clear, I have some doubts that the existing technology (and the states’ willingness to operate it) are really ready for this broad dissemination. Here again, as the strategy notes, EPA/ORD has failed to keep up with the needs of th e monitoring community, leaving a very large gap be tween our measurement needs and the technology available (commercial or research) to meet those needs.

Question 2: How can EPA best reach the user community and incorporate their feedback? Well...why not just ask them? EPA knows the user community. It’s not that complicated or expensive to put together a list of people likely to have some thing to say on these issues. Put

B-56together a short, focused set of questions, or evena draft proposal that gives EPA’s rationale for site selection, then get on the phone or email. You are much more likely to get meaningful responses if you ask people directly. And don’ t forget to ask the stakeholders, too.

Question 3: What are the strengths and weaknesses of converting STN to IMPROVE? From a data analysis standpoi nt, harmonizing these networks would be a huge improvement. The urban/rural signals we’re so anxious to teas e apart are hopelessly obscured by these network protocol differences. But so many issues are yet to be resolved! Blank correction – to do or not to do? What’s the right way? What role do i norganics and the various organic species play? What’s the effect of higher mass loadings on sample rs designed for clean rural environments? Is there a ‘machine’ effect at DRI or RTI – do diffe rent instruments yield different results for the same protocol? This is not my area of expertise, but since both IM PROVE and STN protocols are just that, and the EC/OC measurements are operationally defined, it seems silly to have the two major networks be incompatible. We s hould choose one and be consistent. Even though there are many outstanding questions (some of wh ich should be answered by Supersite data and other current studies), IMPROVE’s very long and very reliable record make it the obvious choice. EPA should make this switch part of the strategy, and get a plan for the transition in place ASAP.

Question 4: Is it scientifically acceptable to generate air quality surfaces through modeled observations or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regulatory decision-making process? Of course it is scientifically acceptable to generate surfaces fr om modeled or observed data. Defining ‘appropriate uncertainty ’ is more difficult. Our inte rpolations should be based on a fundamental knowledge of spatial variability of a given pollutant. In some cases we have a very good understanding of pollutant emissions, disper sion, transport, and the resulting spatial variability. But there are serious gaps in our knowledge of other pollutants. We don’t have any good idea of NH3 or HNO3 spatial variability across an urban area, so how can we have a realistic estimate of modeled uncertainty for such pollutant s? And if our modeled PM2.5 estimates depend on these precursor concentrations , then this uncertainty will propagate through a model and perhaps lead to unacceptable uncertainty for decision making. This lack of data on spatial variability (particularly on a microscale or in complex terrain) is a data gap that the strategy doesn’t really address. There really ought to be some provision for determining spatial variability via short term saturation monitoring.

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### Dr. Thomas Lumley

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### Dr. Peter McMurry

Peter H. McMurry University of Minnesota December 18, 2004

Comments on EPA’s plan for Implementing the National Ambient Air Monitoring Strategy

General Comments:

a. I compliment the EPA Staff who developed this strategy. They have been responsive to previous recommendations by this committee, and have taken the initiative to create a coherent vision that extends well beyond specific reco mmendations of the committee. NAAMS represents a clear vision for a measurement strategy that is suitable for the 21 st Century. NAAMS will lead to more efficient use of the Agency’s resour ces for carrying out measurements and providing access to data. This strategy will play an important role in protecting the public’s health and welfare. It has been a pleasure to serve on this committee.

b. My primary concern with the NAAMS proposal is the lack of a plan for funding Level I sites

. My arguments in support of Le vel I sites are listed below:

• I have been involved in studies of atmospheric aerosols for more than 30 years. During this period, the need for instrumentation that woul d measure, in real time, the composition of aerosol particles was clearly understood. With funding from the EPA Supersites program (and other programs that focused on airborne particles) in the 1990s, several different instruments were developed to enable such m easurements. This is terrific progress. However, while several such systems are nowcommercially available, the technologies have not yet grown to maturity. Level I s ites would enable conti nued testing of such instrumentation. I have no doubt that within th e next decade, instruments that can routinely and automatic measure the composition of atmospheric aerosols will be available. Level I sites will play an enormous role in ensuring that this occurs.

• State and local agencies prefer to use instrume nts that operate continuou sly rather than filter

samplers, which are more expensive to operate and provide less useful data. Level I sites will provide platforms for evaluating the performance of such instruments.

• Real-time measurements of composition offer the potential to provide much more useful

information on aerosol compositi on and at a much lower cost than can be achieved with filter samplers. Real-time data is required to evaluate chemical transport models, to assess human exposures, and to understand processes thataffect size-resolved aerosol composition. I am convinced that such data are needed to significantly advance our understanding of the effects of atmospheric aerosols (especially thei r health effects). Leve l I sites would play a substantial role in advancing measur ement technology “to the next level.”

B-61• Virtually all of the basic research and development on real-time instrumentation for measuring the composition of atmospheric aerosol s has been carried out in the U.S. Level I sites will help to enable this industry sector to grow to world leadership.

• The measurements that are proposed for Level II and III sites do not include any measurements of ultrafine particles (<100 nm) despite the fact that (1) concern has been expressed about possible health effects of sub-100 nm partic les, (2) planned changes in emissions control (especially for diesel-powered vehicles) are likely to lead to significant changes in concentrations of ultrafine partic les, and (3) recent work has shown that such particles can be measured well on a routine basis. Such meas urements have been conducted for extended periods (more than a decade, in se veral cases) in other c ountries, and these longterm measurements are providing extremel y valuable information on trends and “climatology.” Again, this is a case where the basic R&D was carried out in the U.S., but the benefits of that work are larg ely being realized abroad.

• One of the greatest scientific challenges is understanding semi-volatile species (i.e., species that are present in both ga s and particle phases). Important among these are ammonium nitrate, and many organic compounds. We cannot currently measure all semi-volatile compounds on a routine basis (although techniques for measuring the gas and particle phases or inorganics in real time ar e available.) Organics are an especially challenging problem. Level I sites would enable continued work on this problem, which is likely to play a significant role in potential health impacts of air pollutants, and which will require more work before gas/particle distributions can be accurately represented in chemical transport models.

c. Based on the discussion at our meeting I conc luded that realizing the full benefits of NAAMS will be hampered by EPA’s organizational structure. As was pointed out by Professors Husar and Hopke, it is important that NAAMS data (1) be available in real time, and (2) be easily accessed by the public. The presentation by repres entatives in the Information Transfer and Program Implementation Division made it clear that th ey do not currently plan to establish a data access strategy that meets these needs. It appears that the Monitoring and Quality Assurance Group is hampered because the Information Tran sfer and Program Implementation Division is not responsive to their needs. This needs to be changed.

d. Recent studies provide growing evidence th at those who live immediately downwind of highways are especially likely to experience adve rse health effects from air pollutants. The NAAMS strategy does not explicitly deal with this i ssue. Some consideration should be given to citing some of the NAAMS sampling stations in lo cations that would enable long-term studies of such effects.

e. I served as one of three co-chairs on th e NARSTO PM Assessment, and I wrote Chapter 11 of that Assessment, which addressed needs for further research. I am delighted to note that many of NARSTO’s recommendations are include d in the NAAMS program. NARSTO recommendations that are not explicitly discussed include:

• The NAAMS proposal makes no mention of any consultations or discussions with monitoring agencies in Mexico or Canada. One of the NARSTO reco mmendations is that networks across North America should be “h armonized” to enable the integration of

B-62knowledge from ambient measurements, receptor models, chemical transport models as bases for air quality management. I re cognize that the U.S. cannot dictate to Canada and Mexico how they should carry out air qua lity measurements. However, if they were informed about U.S. plans, they would have an opportunity to work in parallel to develop measurement programs that are reasonably compatible.

• NARSTO recommends that we aim to deve lop methods to assess benefits of emission controls to air quality and the linkage to human health and welfare. NAAMS focuses primarily on measurement, without explicit consideration given to the use that will be given to such data.

• NARSTO recommends that ASOS and AWOS data be integrated into national air quality monitoring programs. Such data are acquired routinely, but not by EPA. The public would benefit substantially if such data were included in NAAMS.

My responses to questions given by Richard Sc heffe in his November 19 memorandum are given below:

Q1. Given limited budgetary resources, does this represent both an appropriate and adequate balance, as reflected by the relative res ource allocations provided in Section 11?

My primary concern is the lack of a specific pl an to fund Level I sites, as explained above. Other committee members have expressed other concerns that should be reviewed by EPA.

Q2. Does the Subcommittee have additional suggestions for addressing the need for integration and communication to the broa der community of “users.”

Meet with Mexicans and Canadians to inform th em of our plans, in hopes that they would establish compatible measurement strate gies and data distribution policies.

Q3. What are the strengths and weaknesses of converting STN to IMPROVE.

I will defer to others on the committee who are more knowledgeable than I about sampling and analysis strategies for these networks.

Q4. Is it appropriate for EPA to use “mode ls” for identifying non- attainment areas.

First, it is important to clarify what is meant by a “model.” Is this a full-blown chemical transport model (CTM) that includes everythi ng that is known about meteorology, sources, transport and transformations of air pollutants? If so, than it would be appropriate that such models be used for regulatory purposes. CTMs w ould also provide useful information on diurnal variations, etc., which is typi cally not obtained from sampling networks used for attainment studies. Of course, different models will produce different results, so the choice of models that are used for this purpose w ould be highly controversial.

B-63More empirical models that interpolate among data from sparse measurements would need to be used with greater care. Such an approach woul d probably work reasonably well for species that are distributed relatively uniformly. However, when species are emitted locally, then such interpolations would likely lead to significant errors.

So, in summary, the use of “models” is neede d, but implementing them for regulatory purposes will not be straightforward.

B-64

### Dr. Armistead (Ted) Russell

Review of EPA’s Final Draft National Ambien t Air Monitoring Strategy and responses to Charge Questions

Armistead (Ted) Russell Georgia Institute of Technology Atlanta, GA 30332-0512

Having read through the new Draf t Implementation Plan section of the Final Draft National Ambient Air Monitoring Strategy in detail, followe d by the whole report, as well as attending the AAMM meeting and presentations by EPA, my firs t comment is that I was pleased to note the extent to which the strategy has evolved since our last review, and how they have addressed many of the comments provided in the last round. In particular, they have increased their focus on monitoring to address issues dealing with environmental endpoi nts, e.g., health and ecosystem impacts. As noted below, there are lingering issu es in this regard. Al so, I note that they are planning on adding more sensitive CO monitors: another plus. There is also increased emphasis on analysis.

In this review, first, the four questions we have been charged are addressed. This is followed by a more global discussion and summary.

Question 1 . Given the limited budgetary resources, doe s this (the redesign ) represent both an appropriate and adequate balance? Are the adjustments in the training and guidance approaches consistent?

As noted above, I am pleased to see that more sensitive CO measurements will be pursued as part of the NCore Level II monitori ng as this is important both for understanding of PM sources, but also as a marker for the potentia l presence of elevated concentrations of other automotive emission related species. In our recent source apportionment work, we found that having SO2, NO/NOy and CO measurements availabl e led to more stable and reliable results when conducting PM source apportionment. The ga s phase species act to constrain the solution space. Further, these measurements can be made at a temporally finer scale than is currently being used for the PM speciation.

In the preamble to this charge, the emphasi s was on gas phase measurements. In regards to PM measurements, the reduced emphasis (and resource allocation) on FRM PM mass measurements is applauded as they help rela tively little with unders tanding the sources and solutions of the PM in a region. Continuous meas urements help somewhat. However, it was not apparent if the continuous measurements are pr imarily mass or speciated mass measurements. Continuous mass measurements still fall short of providing the type of information needed to really understand the sources impacting a region and for evaluating source apportionment study results. Greater emphasis on semi-continuous speciated measurements by the emerging techniques is suggested. Even if this does not cover the full range of species needed to conduct CMB-type source apportionment, they will support other approaches, plus provide more

B-65information on the atmospheric dynamics. Further, along with the continuous gas-phase measurements, one can utilize additional methods for assessing source impacts. Thus, if the increased emphasis on continuous methods does not include continuous (or semi-continuous) speciated measurements, I would re think the resource allocation to include this important set of measurements, at least in a limited, critical area, a pproach. This will also lead to identifying the appropriate technologies to use elsewhere.

I would, in fact, go a bit further, and suggest that resour ces for non-continuous, speciated measurements be reduced and those put in to continuous speciated measurements. One could still, at a very reduced frequency, still conduct a full suite of speciated, integrated (filter-based) measurements for use with CMB-type analyses, and also seasonal detailed OC analysis. I would suggest that this source apportionment, along with the continuous gas and PM speciated measurements will provide ample information to understand, even better, the sources impacting a receptor, and provide much more information to those who might use the data later (e.g., the health community).

The adjustment in training and guidance seems reasonable, though I do not have a good feel for the level of resources it takes to effectively address this task.

Question 2 : Does the Subcommittee have additiona l suggestions for addressing this need (communication and coordination with health effects and ecosystem assessment communities ), including scientific and SLT representatives? What is th e most effective manner for EPA to reach-out, obtain and incorporate feedback?

Again, EPA is to be applauded for recognizi ng this need. However, the document was rather vague in how this would be accomplished. I would be more proactive, identifying which cities have been the basis for many of the recent health studies, as well as the researchers. Ask them, specifically, what they would recomme nd. (A possible workgroup?) Likewise for ecosystem researchers. Also, EPA should address the issue of site representativeness again. The Supersite data, and that for othe r special studies and routine mon itoring provides a wealth of data to address the questions: How representative is a single site being used for health/ecosystem assessments? What determines the representative ness of a site? How should one identify a site that is a balance between having an historical record and is most representative of the exposures (human/ecosystem) of concern? The issue of site representativeness for use in different purposes has not been well addressed, particul arly with attention to uncertainti es. This is explored further in the response to Charge 4.

Question 3 : What are the strengths and weaknesses of this (harmonizing rural and urban-based PM2.5 chemical speciation networks, e.g., us ing the IMPROVE EC/OC method) approach?

There is no easy answer here. Ingeneral, there are a variety of benefits to using consistent methods, which usually outweigh some minor reas ons for maintaining different approaches for different applications. Data analysis is typically much more straightforward with less uncertainties (note the word uncertainties, no t uncertainty... one deals with the number of uncertainties, the other with th e total amount of uncertainty in troduced) when the measurements are conducted in a consistent fashion. On the other hand, there is some value in having two (or

B-66more) competing approaches in terms of more readily identifying weaknesses in the other approaches, and if there is a known weakness in the approach that is to be adopted. In the case of the IMPROVE vs. NIOSH method debate, both have weaknesses. My read is that the case is very much open as to which one has greater wea knesses, in particular the consistency of results for conducting source tests and the ensuing source apportionments. It would be a mistake to adopt one method now if it makes if introduces a greater uncertainty in the analysis of the measurements, e.g., if the diesel pm profile is mo re consistent using one method over the other. Thus, it may be premature to switch right now. I have heard that the argument for choosing IMPROVE over NIOSH is that IMPROVE has been around longer, and is not willing to change. This is the wrong reason to switch the STN approach. EPA should show, and the community agree, that IMPROVE has fundamental advantag es over NIOSH. Without this, we should not switch as that will close, possibly very adversely for future analyses, an important debate. If one can develop better source profile s using NIOSH, then NIOSH shoul d be used and vice versa. Again, this is an area where the measurement community at large should discuss which method, ultimately, is preferred and for what reasons. Abse nt from this debate should be that one method or the other has been around for longer. That should come second.

In summary, I support harmonization of the me thods used, but as an evolution to using the best techniques, not as a convenience.

Question 4 : Is it scientifically accepta ble to generate air quality surfaces through modeled observations and/or integrated predictive/observationa l fields that would be of appropriate uncertainty for use in the regul atory decision making process?

Great setof issues arising from this one quest ion! First, however, I would not use “modeled” observations in this process. Use si mulated concentrations. That will upset fewer people. Next, should one use purely simulated concentr ations? Surely not with today’s level of modeling accuracy/reliability. That was an easy answer. However, one could also answer is that any worse than relying on a singl e observation in determining a ttainment/non-attainment and to identify sources viewed as contributing to PM in a region. The measurements are representative of a very limited region. This gets back to Question/Charge 2. While an observation showing non-attainment very, very strongly suggests that the PM levels in a region are out of attainment with the standards, it is less strong for dete rmining attainment! The degree to which the observation is below the standard is suggestive as to how confident one is that the region is fully in attainment, but it has a limited spatial applic ation to demonstrating that the region is in attainment. A number of observations in a si ngle region does provide further evidence to determining attainment, but the observations al l have limited spatial application and further analysis is necessary to support their regional representativeness.

Thus, this leads to the use of integrated predictive/observational fields as being the preferred approach. While there is much work to be done here, this approach will help tackle multiple issues. First, it is probably the be st way to extend an observation (or set of observations) both spatially and te mporally, if necessary. Second, it can be used in the process of source apportionment (or vice-versa-: source a pportionment can be used in extending the use of observations). Third, it will help identify uncertainties in the representativeness of the

B-67observations at a monitoring location. Fourth, it will produce the type of information that can be used by groups identified in Question 2. Thus, this is, in some ways, the silver bullet. However, we still do not have the best approach laid ou t, and the enabling tec hnologies developed (e.g., software/hardware environments to provide this information). However, this can probably be tackled within three or for years. Such a pr ocess should utilize the observations available, both in situ and remote (e.g., satellite) and PM modeling (with data assimilation). There should be a feed-back loop where the information provided bythe integrated system utilizes additional approaches to assess the quality of the fields de veloped (e.g., data withhold ing, etc.). While this may seem lofty, but EPA should set, as a goa l, to have a field of source apportioned daily/monthly/yearly PM for the U.S. by 2010 (e.g., target PM2.5 and coarse for 2008, with the apportioned fields developed by 2010). The work s hould also include fields of the uncertainties in the integrated daily PM levels and, at least, in th e annual source apportionments. This should be updated on an on-going basis. (Once it is done once, the second time is relatively easy.) If the resources were currently available, I susp ect this could actually be achieved by 2008 (using 2006 data).

I like what was presented at the meeting in this regard. EPA is going the right direction, i.e., by developing surfaces using an integration of observations and modeling. They must take it one step further, and that is to also calculate uncertainties. Folks who are against using modeled concentrations for attainment/non- attainment decisions must realiz e that at present, we are not even being so sophisticated. A number of coun ties are designated non-attainment without even such information, and some are being designated non-attainment even with observations suggesting attainment. Let’s put so me more rigor in the process, then struggle with the issue of whether one should be 95% confident that a county is in/out of attainment to make determinations.

General Discussion . As noted in previous discussion, I am generally please d with the Draft Implementation Plan and their responsiveness to prior recommendations. I am concerned about the motivation to move to the IMPROVE appr oach without further discussion about the disadvantages and advantages of the variety of methods. Given that I strongly recommend going to more semi-continuous speciated measurements , this may be somewhat moot... instead of discussing IMPROVE vs. NIOSH, lets discuss how to do the measurements semi-continuously (if that is at all feas ible), and the NIOSH vs. IMPROVE attri butes as part of that discussion. Given that the reason for conducti ng speciated measurements is to do source apportionment, the question to address is which one is best suited to that task. This requir es asking (and answering) the question which method will provide the most consistent source profiles within a source category and is least sensitive to interferences from atmospheric processing. (Difficult question... ask the real experts.)

We were not directly charged with addressi ng the reduction in the funding for PAMS and the allocation of resources directly for analysis of PAMS observations. PAMS data has been plagued by both issues of quality and timeliness, a nd has been badly underutilized. To this end, I would devote greater resources to the analysis of PAMS data, at the expense of other aspect of PAMS, possibly reducing the covera ge (spatially and temporally) of the PAMS network until we milk the current PAMS data and understand what the network can really tell us. This will help identify the future role of PAMS, and how res ources should be allocated down the road. Until

B-68we really start using the PAMS data for wh at it was intended, let’s spend some additional resources to do more analysis of what we have with the concurrent reduction in resources allocated for producing more unused data from monitoring.

Question 4 is a very important question in re gards to policy and the need to develop the appropriate techniques to achieve EPA’s objectives in a scientifically defensible fashion. With satellite observations, a much mo re powerful information technology infrastructure and new, but not “reference method” measuremen t technologies coming on line, there is the pos sibility of being able to estimate air pollutant fields, expos ures, and source impacts, much better than can be achieved from individual monitoring site s. This includes better identification of “exceedences” defined more broadly as not specif ically measured, but sufficiently likely given the full range of information available. (Determining sufficiently likely will be fun.) Use of the full range of sources can reduce the needed re sources for pure monitoring, but this requires developing the foundation that can undergo scientific and legal scrutiny. This activity will also provide a foundation for better fore casting and control decisions. Don’t be shy about tackling the set of problems associated w ith blending observations (of what ever type), model results, and other inputs.

Finally, the NCore Level 1 sites should get funds from sources other than Science and Technology as part of the mission of these sites is regulatory, and their operation should not be viewed as something that has li ttle relevance to to day’s issues. Planning requires knowledge of sources, which can come from NCore level 1 sites, as will attainment/non-attainment decisions. Using the process EPA has developed to decide high- priority Level 2 sites, one could also locate high-priority Level 1 sites, wh ich then would be used, along with more detailed modeling, to identify the regional sources.

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### Dr. Jay Turner

B-70B-71B-72

### Dr. Warren H. White

Initial responses to the AAMM charge Warren H. White, 12/8/04

Question 1: Given limited budgetary resources, does this represent both an appropriate and adequate balance, as reflected by the relative resource allocations ...?

I think it serves as a model for how to extract maximum utility from given resources. It is a thoughtful initiative that has been carefully deliberated, and is well crafted to align the Agency’s air monitoring activities with th e needs of the coming years.

Question 2: Does the Subcommittee have additional suggestions for ... communication to the broader community of “users,” including scientific researchers ( i.e. , human health, atmospheric, ecological) ... to incorporate their feedback and design input on such issues as monitoring site locations and parameters?

The Agency is already doing very well in this regard, but I might suggest adding measurement qualityto the list of issues on which inputs are explic itly solicited. I have inmind here such uses as epidemiology, where critical information is carried by variations in concentration rather than by concentration itself, or source apportionment, where it may be carried by small shifts in concentration ratios, or by inter-s pecies correlations. The real da ta needs of such uses can be tricky to express in terms of the accuracy and pr ecision of individual measurements. Of course, every researcher you ask will just say “more is be tter!” And you will have to disappoint them. What you learn by asking, though, is what kind of “more” they want; which aspects of measurement quality are critical in their contemplated applications.

Question 3: EPA is considering converting all of the STN speciation sites to IMPROVE samplers and IMPROVE laboratory and sample handling protocols. What are strengths and weaknesses of this approach?

“If you want an exact answer, make just one measurement.” That’s the strength and weakness of this approach. The core problem is that partic ulate matter has so many degrees of freedom. EPA can simply define one particular measurement as truth, as it did in the PM 2.5 FRM, but this doesn’t mean that important information won’t late r be found in the rejected alternatives, as the existence of the speciation samplers acknowledges.

Any benefit of preserving dual networks would come from understandin g their differences, and that would require extensive overlap (collocated sampling), laboratory expe rimentation, and data analysis. You have to sort out how often-subtle differences in sampling and analysis interact in practice with the varieties of aerosols actually fo und in different environments. And this has to be a sustained effort, if you are interested in trends over time; materials and practices inevitably evolve through the years, and the differences can be expected to compound. I think there are better uses for the Agency’s limited resources. And absent the considerable resources to do it right, running dual networks will yield nothi ng but problems; you will always be wondering whether your differences arise in the atmosphere or the measurements.

B-73So I think the strengths of moving soon to the IMPROVE mode l substantially outweigh the weaknesses. With that bottom line, here are some thoughts on specific strengths and weaknesses. Strengths of IMPROVE sampler: converti ng would clearly bring more consistency to sampling, not just between the networks but also within STN. Moreover, the IMPROVE sampler is field-proven and operator-friendly. Weakness of IMPROVE sampler: it employs a critical orifice rather than active flow control. While flows are measured accurately, they are allowed to depart from the nominal rate that yields a 2.5 μ m cut-point in aerodynamic particle diam eter. Average cut-points lie outside the 2-3 μ m range in about 1 of 10 samples. Strengths of IMPROVE prot ocols: there is no good reason for maintaining two noncomparable systems for analyzing and reporting carbon measurements when both use the same basic principle, thermal analysis. DRI (the carbon laboratory used by IMPROVE) has invested a lot of research into the underlying method, and I trust their fundamental understanding of it.

Point of clarification: Would “ all of the STN speciation sites” in clude those oriented to SIPs rather than trends? If it incl udes SIP sites, what sort of dataquality objectives does the Agency have for such trace XRF elements as Lanthanum, Yttrium, Cerium, Samarium, Niobium, Europium, Terbium, Hafnium, Tantalum, Ga llium, Indium, Tungsten, Iridium, Scandium, Antimony, Gold, Cesium, Mercury, and Barium, all of which are currently reported by STN* but not by IMPROVE? That is, how will it specify data quality for elements that are rarely/barely detectable? * Standard Operating Procedures for PM2.5 XRF Analysis, Revision 2, 1/20/2004.

Question 4: Is it scientifically acceptable to generate air quality surfaces through modeled observations and/or integrated predictive/observational fields that would be of appropriate uncertainty for use in the regulatory decision-making process?

Given that both satisfy the relevant data quality objectives, I don’t s ee any scientifically meaningful difference between modeled and meas ured data. I can’t believe I said that!

B-74

### Dr. Yousheng Zeng

December 15, 2004 AAMM Subcommi ttee Advisory Meeting Comments on the EPA NAAMS Implementation Plan

By Yousheng Zeng (AAMM Subcommittee Member)

Initial comments: December 14, 2004 Revised: December 20, 2004

Response to Charge Question 1:

Based on the NCore Level 2 parameter list in Table 4-1, if these PM precursor gas measurements are not required for NCor e Level 2 sites, it will leave only PM 2.5 , PM 2.5 speciation, PMc, and ozone. This will almost downgrade Level 2 to Level 3. Considering the usefulness of these measur ements co-located with other Level 2 instruments and only 75 Level 2 sites nationall y, I certainly consider it appropriate to include these gaseous PM precursors at Level 2 sites. This seems barely adequate, if at all.

By comparing Table 4-1 and Table 4-3, there se em to be some mismatch. Table 4-1 does not include air toxic measurements as core parameters for Level 2 sites. However, according to Table 4-3, air toxic trends are one of the objectives for Level 2 sites. How can air toxic trends be asse ssed through Level 2 monitor ne twork if air toxics are not measured at Level 2 sites? How the measurem ents for air toxic trends be implemented?

Response to Charge Question 2:

My comment for this question is about pres entation for communicati on purposes. I feel that the representation of the big picture of the nation’s ambient air quality monitoring systems (before and after NCore) is still somewh at confusing. I think it will be helpful to describe the landscape of the nation’s monitori ng systems before and after NCore, similar to the approach used in the EPA presentation dated July 2003 ( http://www.epa.gov/ttn/amtic/file s/ambient/pm25/casac/jul03pre.pd f ), page 27 (slide 27) with further clarifications. Specifically, af ter NCore, what networks will still be in existence? It may be helpful to reader s if the nomenclature in the presentation corresponds to the names of networks rather than “Core+PM Spec”, “Core Spec”, etc. Does everything on the “Future Directions” side of the slide belongs to NCore and there are other networks that will be coexist but not shown?

Response to Charge Question 3:

It sounds like a good idea.

B-75Response to Charge Question 4:

The context of this question is about dive sting “redundant monitors in adjacent, but separate, geopolitical areas”. I think this appr oach is valid in princi ple; but there may be some practical issues to be worked out. M odeled pollutant concentrations are used in various regulatory processes from SIP dem onstrations to permitting. Particularly in permitting, modeled concentrations are used heav ily as the basis for regulatory decisions regardless of the geopolitical boundary. Some of these permitting decisions bear important economical, political, and legal im plications. In my opinion, air quality surfaces generated based on a network of well pl aced monitors are not only scientifically acceptable, they are better than using obser ved data from individual monitor(s) to represent the air quality of the geopolitical area in which the monitor(s) are located.

There may be some practical issues to consider:

• How close should the monitors be to each other to be considered “adjacent” and therefore a candidate for divestment? EPA may establish some general guidelines to address this issue. This is also a func tion of uncertainty and reliability/confidence level of the model to be used in place of the actual monitors.

• If a monitor is to be divested, which side of the boundary should maintain the other monitor? How will that affect funding? Should the divesting si de still contribute some financially if they rely on the other si de to provide the data for their regulatory needs?

Additional General Comments:

Data Integration

There are significant ambient monitoring activiti es outside of the networks discussed in the Strategy. They include special studies funded by State or local agencies and ambient air monitoring programs funded by private industr ies as part of Bene ficial Environmental Projects (BEP). For example, the Louisian a DEQ recently ordered sixteen facilities in the Baton Rouge ozone non-attainment area to monitor Total Non-Methane Organic Compounds (TNMOC) and speciated ozone precurs ors. The initial order requires each of the sixteen facilities to install four monitors, i.e. , 64 monitors. Although the final number of monitors may be less as a result of on- going negotiations, it w ill still represent a significant increase in spatial resolution in the area and the monitoring will go on for at least multiple years.

The data collected by these monitoring activ ities can be a very good complement to the NCore and other monitoring networks covered by the Strategy. The data from many of these monitoring programs are not captured in the EPA monitoring data system. The EPA should consider developing some mechanis m to bring the monitoring data into the system. This will be a very cost effectiv e way to improve the spatial and temporal coverage. The quality control of these monito ring systems may or may not be as rigorous as NCore network. This concern can be addr essed by having code flag s to indicate data

B-76quality confidence level (e.g., a code for NCor e, codes for certain types of privately funded monitors). In a data analysis, having a mixture of high and low quality data with high density spatial coverage is often bette r than having accurate but sparsely populated data.

Funding for Level 1 Sites

I agree with many AAMM Subcommittee me mbers concerning the importance and funding of Level 1 sites. Reducing PAMS site s in some east and west coastal areas (but not in the Gulf Mexico coastal region where ozone problems require high spatial resolution PAMS data) to fund Level 1 sites seems to be a good idea. There may be another funding source (although I don’t know how to make it wo rk at this time). Based on my observations and experience, some m onitoring programs required as BEP are not well thought-out. Sometimes the pollutants se lected for monitoring are not critical. Companies implement the monitoring program almost just for the sake of spending money required by BEP elements of the settlement without too much concern as what will be monitored. As a result, the monitoring data have very low value. It will be interesting to investigate if there is anadministrative mechanism to channel and aggregate this type of BEP funds to support Level sites.

Atmospheric Processes That Were Previously Ma sked by High Pollutant Concentrations

Another comment I have is also related to spatial resolution. As the ozone situation improves in some industrialized regions of the country, some previously less known factors that have impact in a small area beco me more salient (i.e., as the overall ozone level drops, some previously “buried” peaks will become visible. The ozone formation due to highly reactive VOC (HRVOC) in Houst on and Baton Rouge in recent years is an example of such a condition. My concern is that the network spatial resolution may not be high enough if we don’t take thes e factors into th e consideration.

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### NOTICE

This report has been written as part of the activities of the Environmental Protection Agency’s (EPA) Clean Air Scie ntific Advisory Committee (CASAC), a Federal advisory committee administratively located under the EP A Science Advisory Board Staff that is chartered to provide extr amural scientific information and advice to the Administrator and other officials of the EPA. The CASAC is structured to provide balanced, expert assessment of scientific matters related to issue and problems facing the Agency. This report has not been reviewed for approval by the Agency and, hence, the contents of this report do not necessarily re present the views and policies of the EPA, nor of other agencies in the Executive Branch of the Federal government, nor does mention of trade names or commercial products c onstitute a recommendation for use. CASAC reports are posted on the SAB Web site at: http://www.epa.gov/sab

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