Unpaved Road Dust Control in the Piceance Creek Basin in Rio Blanco County, Colorado

Road dust from unpaved roads (dirt roads) is a major source of airborne particulates; the loss of those fines accelerates the deterioration of roads. As a result, road dust emissions are a major concern of the users and managers of dirt roads. Exxon Mobil has been concerned with the dust emissions and rapid road deterioration of the access roads in its natural gas production facility in the Piceance Creek Basin north of Rifle, Colorado. As part of the access road management plan for Exxon Mobil Piceance Creek, a research project was initiated to investigate the effectiveness of several chemical dust suppressants in reducing dust emissions, thus prolonging the intervals between periodic maintenance. Rio Blanco County and the Bureau of Land Management participated in this project. Using the Colorado State University Dustometer and its associated dust measurement protocol, it was found that all chemical suppressants decrease dust emissions and that magnesium chloride (${\mathrm{MgCl}}_2$) was the most effective dust suppressant under the prevailing weather conditions from March through September, 2010. The fugitive dust emissions from the ${\mathrm{MgCl}}_2$ treated sections of the road were more than four times less than those from the untreated control section, generating less than 0.5 g of dust per 0.8 km (0.5 mi) of test section. It was also found that the native soil road surface type performed better than the new gravel road surface type and that emissions were related to speed.