On Friday May 2, 2008, Lamar Colorado recorded an exceedance of the twenty-four-hour PM10 standard with a concentration of 367 μg/m3 at the Lamar Power Plant. Wind speeds and gust speeds in Lamar exceeded blowing dust criteria, with speeds of 38 to 45 mph and gusts of at 47 to 60 mph for the two-hour period with greatly reduced visibilities during the late morning and early afternoon of May 2.
On Thursday May 22, 2008, Lamar Colorado recorded an exceedance of the twenty-four-hour PM10 standard with a concentration of 227 ug/m3 at the Lamar Power Plant. Sustained winds and gusts in eastern and southeastern Colorado exceeded blowing dust criteria. Winds at Lamar were above the blowing dust thresholds for several hours on May 22, and gusts were as high as 58 mph.
These reports discusses results for ambient air toxics monitoring conducted by the Colorado Department of Public Health and Environment (CDPHE) at the long-term trends site at Grand Junction, Colorado. This site was established as part of the "rural" area component of the EPA National Air Toxics Trends Study. Since that time, the EPA has reconsidered, and decided that the site is more indicative of urban concentrations, and has changed the designation of the site from rural to urban. Most of the compounds detected at Grand Junction are found in urban air nationwide. The majority of compounds can be related to motor vehicle sources. These include formaldehyde, benzene, toluene, ethylbenzene, xylenes, and styrene.
