So if I'm reading the requirements correctly, to claim Option 2 the project must ensure through the results of computational fuid dynamics modeling, Gaussian dispersion analyses, wind tunnel modeling, or tracer gas modeling that outdoor air contaminant concentrations at outdoor air intakes are below the thresholds listed in Table 1 (or local equivalent for projects outside the U.S., whichever is more stringent). 

Seems onerous/supurflous if there a no notable sources of local contamination and ambient levels are below thresholds listed in the reference standards?

CFD modelling will just show that outdoor air contaminates levels will be more or less whatever the ambient levels are?

Would this requirement not put projects off targeting other initiatives such as increased ventilation and CO2 monitoring?