Addressing NO2 Modeling Challenges in New Mexico: Insights from the 2011 WESTAR Meeting
In Spring 2011, the WESTAR business meeting focused on crucial issues regarding 1-hour NO2 modeling for New Mexico. Key takeaways included the necessity for refined methods to demonstrate compliance amid numerous NOx sources. With statutory deadlines for permit issuance looming, discussions highlighted challenges involving model accuracy and USEPA guidance that restricts feasible analyses. AERMOD workgroup strategies included constructing generic scenarios, with the state set to present modeling results and EPA conclusions by Fall 2011. Emphasis was placed on utilizing the Monitored Ratio Method (MRM) to assess NOx and NO2 conversions effectively.
Addressing NO2 Modeling Challenges in New Mexico: Insights from the 2011 WESTAR Meeting
E N D
Presentation Transcript
1-hour NO2 Modeling Issues WESTAR Spring 2011 Business Meeting
The Issues for New Mexico • Many NOx sources in the state • Refined methods needed to demonstrate compliance • Statutory deadlines for permit issuance • Refined model methods not tested for accuracy with refined methods, such as PVMRM • USEPA guidance suggests myriad of analyses not possible to accomplish within deadlines
AERMOD Workgroup • Convened by USEPA • Over 50 participating state and local representatives • Currently constructing generic scenarios • State will model and demonstrate results in June • USEPA to present conclusions Fall 2011
NMED/AQB Modeling Guidelines • Rely on monitor data for 1-hour NO2 in short-term • No modeling required for 1-hour NO2 pending outcome of AERMOD workgroup • Propose and justify use of MRM • Use background monitor concentrations rather than modeled background
What is MRM? • Monitored Ratio Method • Compares NOx concentrations to NO2/NOx ratios to determine upper bound conversion • In-stack ratio determines lower bound conversion • Easily applied as a post-processor to modeling results
