Emission Control Strategy Approach
For developing appropriate emission control strategies for meeting the 8-hour standard, it is important to identify the unique patterns of hourly average concentrations that make up the 8-hour violations and investigate the importance of mid-range concentrations (i.e., 0.06-0.09 ppm) in defining these violations. For those sites whose 8-hour violation is mostly defined by hourly average concentrations below 0.09 ppm, control strategies will have to change from focusing on the higher hourly average concentrations to the mid-level (i.e., 0.06 to 0.09 ppm) hourly average values.