**CALPUFF: Status and Update Tyler Fox** **9 th** **Conference on Air Quality Modeling October 9, 2008** **CALPUFF History • CALPUFF modeling system:** **– CALPUFF, a non-steady-state Lagrangian puff model – CALMET, a diagnostic 3-D wind field model** **• CALPUFF was promulgated April 2003 as EPA’s prefer red** **model for long-range transport (LRT) applications, beyond** **50 km, primarily for Class I increments • CALPUFF developer (Earth Tech) arranged to maintai** **n control of code development and distribution and** **copyrighted code • CALPUFF also identified in Appendix W for near-fie** **ld applications involving “complex winds” on a case-by-** **case basis (more on this later)** **• CALPUFF also used for Class I AQRV analyses, not u nder** **Appendix W purview Scorecard of CALPUFF** **Versions - 5.7 April 2003 (promulgated version)** **- 5.711a July 2004 (previous regulatory) - 5.711b December 2005** **- 5.754 February 2006 (original VISTAS) - 5.756 August 2006 (latest VISTAS)** **-**5.8 June 2007 (current regulatory)**- 6.112 April 2006 (MMS)**April, 2003July, 2004Dec., 2005Feb., 2006April, 2006August, 20065.7 5.711a 5.711b5.7545.7566.112**FEDs Discussions on CALPUFF: Spring 2006** **• Reason: Earth Tech sells CALPUFF rights to TRC (A pril** **2006) and EPA experiences difficulties in assessing /** **updating to VISTAS version 5.754 • Representatives from Federal Agencies discussed** **current situation with CALPUFF (status and regulato ry** **updates) – EPA** **– FLM – MMS** **• Discussed the following issues: – lack of adequate documentation** **– responsiveness to issues by developer – need for funding to address any issues from Federal** **community, despite regulatory classification of the model** **EPA contacts TRC: June 30, 2006** **• CALPUFF must meet Appendix W requirements for regulatory models,** **Section 3.1.1(b)-(d):****– *.exe to run on a common platform****– current model documentation – input/output test data w/model** **– users can operate model from available documentation** **– documentation must include comparison w/tracer data** **– model/code cannot be proprietary TRC to EPA response:** **July 11, 2006 • TRC provides copy of Use Agreement** **• States that ... “Permission to modify the Fortran computer codes is granted to** **users with the provision that modified versions of the model codes must be** **provided promptly to TRC, along with appropriate written documentation and** **instructions for use” TRC to EPA response:** **July 11, 2006 • Use Agreement also states...** **“It is the user's responsibility to determine if the CALPUFF modeling system is** **appropriate for any particular application, and the user assumes all responsibility** **and liability for its use.”**AnalysisToolSourcesMeteorologyTerrainDifferences?Resolve DocumentBETABASE**CALPUFF Update Tool CALPUFF Regulatory Update:** **Version 5.7 to 5.711a • Model Change Bulletin-A provided** **description of changes – Only minor changes in coding** **• Application of Update Tool showed minimal differences/impacts on** **concentrations – Clearly attributed differences to bug fixes** **• Approved 5.711a - June 15, 2006 CALPUFF Regulatory Update** **• Began update process with v5.754 in June, 2006** **• Engaged with TRC in discussions to understand 5.711a vs. 5.754 differences** **• August 15, 2006—Received e-mail from TRC indicating a new VISTAS v5.756 would be** **released • OAQPS decided to focus on update for new** **VISTAS v5.756 – newest features, latest corrections, etc. for user** **community (including MMS updates for over water) CALPUFF Regulatory Update:** **5.711a -> 5.756 • Found large ‘unresolved’ differences** **between 5.711a/5.756 – CALMET versions (5.53a vs. 5.726)—up to** **83% for scenarios 2, 3, (Pacific NW), 5 (deep valley)** **– CALPUFF versions (5.711a vs. 5.756)— up to 7% for scenario 5 (deep valley)** **• PROBLEM = incomplete documentation – Missing Model Change Bulletins (MCBs)** **– No in-code comparisons – Inadequate model documentation** **While we wait for response . . . • BART usage** **– “Good faith” effort to use “best” available model version** **– Attempt to be “consistent” with App W and ‘wall off’ any potential bad precedents** **• OAQPS becomes increasingly concerned about NSR/PSD permit modeling** **– Appendix W provides “rules of the game” Clearing the Air on CALPUFF** **• OAQPS makes clear position statement at monthly call with RO modelers (January 2007)** **• Region 4 communicates with VISTAS so Pat Brewer contacts OAQPS and facilitates** **discussion with TRC (Feb 2007) • Request for documentation from TRC via** **VISTAS (Feb. 2007) • Received documentation from TRC on March** **15, 2007 CALPUFF Modeling System:** **Update on Recent Activities • OAQPS updated regulatory version to 5.8 in June 20** **07 – CALMET, CALPUFF, CALPOST** **• OAQPS has multiple concerns on science and code implementation and has undertaken evaluations** **– Currently completing performance evaluations, both near-field and** **LRT, and preparing documentation for release prior to 9** **th Modeling** **Conference • Pending assessment of v5.8’n’ and v6 updates** **– Currently “on hold” due to broader issues • Goal = Get firm handle on science and its implemen** **tation so use of model with confidence in regulatory appli** **cations; engage with community at 9** **th Modeling Conference** **Game Plan & Next Steps • Post v5.8 update documentation on SCRAM** **• Issue near-field “Clarification Memo” • Post additional documentation of technical** **issues/concerns with near-field applications • Complete CALPUFF performance evaluations and** **document • Compile list of issues and recommendations** **– June workshop in Denver w/ R/S/L modelers – Communicate issues & recommendations to TRC/Scire** **– Discuss with FED users group (short-term and long- term** **implications) • Engage community at 9** **th Modeling Conference, Oct 2008** **– Update on status, issues, and applications – Performance evaluation & findings** **– Science and implementation issues • OAQPS expects to fund thorough and fully informed** **peer review of CALPUFF modeling system**