P-1 PREFACE

On 6 July 2005, the U.S. Environmental Protection Agency (EPA) published final amendments to its 1999 Regional Haze Rule in the Federal Regi ster, including Appendix Y, the final guidance for Best Available Retrofit Technology (BART) determ inations (70 FR 39104-39172). ). The BART rule requires the installation of BART on emission sources that fit specific criteria and “may reasonably be anticipated to cause or contribute” to visibility imp airment in any Class I area. Air quality modeling is the preferred method for determin ing which emission sources cause or contribute to visibility impairment.

This document establishes guidelines for perf orming dispersion modeling analyses in support

of BART determinations for sources located within the CENRAP domain. Largely consistent with EPA guidelines, these CENRAP BART Modeling Guid elines cover the many assumptions, data base elements, model configurations an d analytical methods that CENRAP states and/or source operators should consider using in their asse ssments of whether BART eligible sources are indeed ‘subject to BART’, or may be exempted. For those sources dete rmined to be subject to BART, these guidelines provide for a common and consistent methodol ogy for estimating the visibility improvements

associated with BART emissions reductions.

Each state is required to develop a BART Mode ling Protocol setting forth the required steps in assessing the levels of c ontrols needed on sources subject to BA RT. At the same time, the five (5) Regional Planning Organizations (RPO s) are addressing the requirement of the Regional Haze Rule in a generally consistent manner, with some exceptions for how BART is treated. The Midwest RPO for example, is expected to conduct most of the BART modeling for sources within its region. In the VISTAS states, the BART modeling is expected to be a shared exercise between VISTAS and the states. In the central states, the states themse lves will take the lead in the BART modeling, but CENRAP will provide assistance in the form ofmodeling guidance (this document) and readilyavailable modeling data bases (deliver ed separately) that can be used by states and/or source operators to conduct their analyses.

Deferring to the states and RPO’s, EPA has placed the responsibility of preparing modeling protocols with the groups who w ill actually be performing the modeling, rather than developing a prescriptive protocol covering all states and sources. EPA has provided so-called BART modeling guidelines (EPA, 2005) which set for the general fram ework for performing the analyses. It is up to the states and RPO’s to develop the modeling protocols governing the BA RT modeling activities within their jurisdictions.

Several BART modeling protocols have been developed within th e past year prior to and in parallel with these CENRAP BART Modeling Guidelines . In the interest of providing consistency in the selection, use, and interpreta tion of models and analytical methods, we have attempted to synthesize key unifying elements of these protocols and weave them in to a consistent set of modeling procedures for the CENRAP region, paying attention to the unique ch aracteristics of this region and the sources located within. At the same time, EP A guidance on how the BART modeling analyses will be judged has evolved and many prot ocols as well as this guideline do cument have been refined to

reflect EPA’s clarifications.

Several modeling protocols developed by other RPOs and State agencies are particularly

relevant to CENRAP’s effort to develop consistent guidelines for the Central states . Six BART protocols are especially significant:P-2 > “VISTAS Protocol for the Application of the CALPUFF Model for Analyses of Best Available Retrofit Technology (BART)”, (VISTAS, 2005). Prepared by the Visibility Improvement State and Tribal Associati on of the Southeast (VISTAS) Technical Analysis Work Group (TAWG), and Earth Tech, Inc.

> “CALPUFF Modeling Protocol in Support of Best Avail able Retrofit Technology
Determinations”, (Johnson, 2005). Prepared by the Iowa Department of Natural Resources, Air Quality Bu reau, Des Moines, IA.

> “Best Available Retrofit Technology (BART ) Modeling Protocol to Determine Sources Subject to BART in the State of Minnesota”, (MPCA, 2005). Prepared by the Minnesota Pollution Control Agency, St. Paul, MN.

> “Modeling to Support BART”, (Baker, 2005). Prepared by the Midwest Regional Planning Organization and the Lake Michigan Air Directors Consortium, Des Plaines,

IL.

> “CALMET/CALPUFF BART Protocol for Cl ass I Federal Area Individual Source Attribution Visibility Impairment Modeling Analysis” , (CDPHE, 2005). Prepared by the Air Pollution Control Division, Colorado Department of Public Health and Environment, Denver, CO.

> “Screening Analysis of Potentially BART-eligible Sources in Texas”, (ENVIRON, 2005). Prepared for the Texas Commission on Air Quality, Austin, TX.

All of these protocols address a co mmon subject; thus, there is substant ial overlap in the discussions of numerous topics such as Federal require ments, EPA guidance, CALMET/CALPUFF model descriptions, and recommended mode ling procedures and so on. Ther e are differences, of course, due to local meteorology, topography, location of Class I areas, the mix of BART-eligible sources, and established modeling procedures w ithin the state, local and fede ral land manager (FLM) groups.

To promote consistency in BART modeling applications across th e central and eastern U.S., in preparing these CENRAP Guidelines , we have incorporated common elements of existing protocols where possible. The VISTAS protocol deserves sp ecial mention. It was prepared jointly by members of the VISTAS Technical Analysis Work Group (T AWG) led by Ms. Pat Brewer, VISTAS’ Technical Advisor Dr. Ivar Tombach, and Mr . Joe Scire of Earth Tech, Inc. The VISTAS protocol represents

the culmination of several draft ve rsions and considerable public discussion and input. At least two public workshops were convened in the autumn of 2005 to solicit comm ents and suggestions on draft versions and to receive input fr om EPA staff on evolving agency gu idance. Details of these public discussions may be found at: http://www.vistas-sesarm.or g/BART/BARTComments.asp . Because the VISTAS protocol reflects the work of a large number of organizations, we have incorporated a number

of the recommendations set for the therein..

In summary the CENRAP BART Modeling Guidel ines presented in this document represent the integrated writing efforts of many groups, especi ally the modelers and regulatory decision-makers instrumental in developing the VISTAS, MRPO , Iowa, Minnesota, Texas, and Colorado BART Modeling Protocols. The authors are indebted to the contributi ons of these groups, and assumeP-3 responsibility for any misstatements or errors in incorporating written descriptions from the

aforementioned documents.

ACKNOWLEDGMENTS

The authors wish to acknowledge specifically the assi stance and, in several cases, written contributions by the following individuals in the preparation of th is guidance document:

Mr. Chris Arrington, West Virginia Departme nt of Environmental Protection; Mr. Bret
Anderson, U.S. EPA; Dr. Kirk Baker, Lake Michigan Air Directors Consortium; Ms. Pat Brewer, VISTAS Technical Coor dinator; Mr. Chad Daniels, Iowa Department of Natural Resources; Dr. Bright Dor nblaser, Texas Commission on E nvironmental Quality; Mr. Todd Hawes, EPA/OAQPS; Ms. Cyndi Huber, U.S. Forest Service; Mr. Matthew Johnson, Iowa Department of Natural Resour ces; Ms. Margaret Mc Courtney, Minnesota Pollution Control Agency; Mr. Bruce Pol kowsky, National Park Service; Mr. Tom Rodgers, Florida Department of Environmen tal Protection; Ms. Rosalina Rodriguez, North Carolina Department of Natural Resources; Mr. Joe Scire, Earth Tech, Inc.; Dr. Ivar Tombach, VISTAS Technical Advisor; Mr . John Vimont, National Park Service; and Ms. Lee Warden, Oklahoma Department of Environmental Quality.

Particular recognition is due Mr. Ralph Morris of ENVIRON Interna tional Corporation who served as an independent technical reviewer throughout the course of this study and provided many useful suggestions, insightful reco mmendations and key text.