Ozone has not been shown to be a Forest Health concern in the Rocky Mountain Region at this time. The sensitive receptors that receive primary emphasis in the Rocky Mountain Region are lake chemistry, lichens and visibility. Lake chemistry and lichens are the most pollution sensitive and readily measurable component of aquatic and terrestrial ecosystems in the Region. Visibility is very pollution sensitive in this Region because visibility is relatively clean compared to other parts of the nation. This means that it just takes a small addition of pollutants to cause visibility degradation.
Visibility is also readily measureable with a variety of types of monitoring equipment.
Visibility and lake chemistry are the sensitive receptors most commonly emphasized in PSD permits and EIS proposed actions in the Region because future pollution impacts from new sources can be most readily projected to these sensitive receptors using computer models.