New Meteorological Data Requirements for Air Quality Modeling

Have you ever performed air quality modeling to support Prevention of Significant Deterioration (PSD) permitting projects or air toxic modeling assessments?  Does your company have any projects in the planning stages that could trigger PSD applicability?  If so, you need to be aware of the United States Environmental Protection Agency’s (U. S. EPA’s) expanded review process for the use of meteorological data in all regulatory air quality modeling analyses.  This expanded review establishes an approach for demonstrating that nearby National Weather Service (NWS) data are representative of your project site.

A possible outcome of this demonstration is a determination that the NWS meteorological data is not representative of your project site and therefore is not suitable for supporting air quality permitting projects.  All4 Inc. (ALL4) recommends that facilities planning to conduct air quality modeling analyses in the near future incorporate sufficient time into their project schedules to evaluate the representativeness of available NWS meteorological data.  As a result of the requirement to provide meteorological data representativeness determinations, ALL4 envisions that some facilities may be forced to collect on-site meteorological data.

The approach for demonstrating the representativeness of meteorological data involves the use of U.S. EPA’s newly developed AERSURFACE program.  AERSURFACE is a preprocessing program that determines values for site specific micro-meteorological surface characteristics for use in air quality modeling evaluations.  AERSURFACE accepts 1992 United States Geological Survey (USGS) land use data to estimate surface characteristics (i.e., surface roughness, albedo, and Bowen ratio) that are required for input into the AERMOD meteorological preprocessor.

ALL4’s Ambient Group meteorologists and scientists have the air quality modeling expertise and the meteorological monitoring experience to help facilities address the issues presented by the promulgation of AERSURFACE.