The paper analyzes a 17-year data base consisting of CRSTER outputs. Only the high and the high second-high (HSH) concentrations for two typical sources for the 17 years of CRSTER air quality output were investigated. Resampling techniques are used to assign probabilities of choosing the highest second-high concentration from the 17-year record assuming that one through five years of meteorological data were measured. It is not the intent of the paper to suggest that the exact probabilities estimated from this data base are universal to every city or site location. The important issue is to indicate the shortcomings in accepting as little as one year of on-site data for regulatory applications and to suggest a method that will better ensure that maximum concentrations are properly estimated.