Ground-level ozone (the primary constituent of smog) is the most complex, difficult to control, and pervasive of the six principal air pollutants. Unlike other pollutants, ozone is not usually emitted directly into the air, but at ground-level is formed via photochemical reactions among NOx and volatile organic compounds (VOCs) in the presence of sunlight. Scientific evidence indicates that ground-level ozone not only affects people with impaired...

In general, the Air Pollution Control Division (APCD) recommends following U.S. Environmental Protection Agency (EPA) procedures to assemble emission inventories and estimate Prevention of Significant Deterioration (PSD) increment (the maximum allowable increase in concentration that is allowed to occur above a baseline concentration for a pollutant. The baseline concentration is defined for each pollutant).

The Quality Assurance Project Plan (QAPP) provides a clear description of the activities of a project in the acquisition of environmental data or information from direct measurement activities, existing data, or generated by models.

On Thursday October 30, 2003, Delta, Crested Butte, Mount Crested Butte, and Grand Junction recorded exceedances of the twenty-four-hour PM10 standard with readings of 215 ug/m3 at Delta, 177 ug/m3 at Crested Butte, 165 ug/m3 at Mount Crested Butte, and 234 ug/m3 at Grand Junction. The exceedances were caused by a combination of dense smoke transported from the massive wildfires in Southern California and blowing dust from the desert Southwest and...

The primary goals of this study are to: Develop comprehensive inventories of Prevention of Significant Deterioration (PSD) increment consuming emissions for nitrogen oxides (NOx) in southwest Colorado; Develop meteorological fields as necessary for input to the Industrial Source Complex (ISC3) and CALPUFF models; Setup and run the ISC3 and CALPUFF models for appropriate near-field and far-field receptors, respectively; Compare modeled concentration...