PM(10) SOURCE APPORTIONMENT STUDY IN BULLHEAD CITY, ARIZONA

The Mohave Valley region of southern Nevada/southwestern Arizona has e xperienced elevated particulate concentrations and is classified as a PM(10) nonattainment area. Anthropogenic aerosol sources in the area i nclude the Mohave Power Project (MPP), a 1,580-MW coal-fired power pla nt; motor vehicles; construction activities; and paved and-unpaved roa d dust and disturbed desert soil. Aerosols may also be transported lon g distances from other areas, such as the Los Angeles Basin. Based on the infrequency of plume contact at sites in the valley (as determined by SO2 measurements), it was believed that the contribution of the MP P to primary PM(10) was minimal and that fugitive dust was the primary source of ambient particulate matter. To evaluate the magnitude of so urce contributors, PM(10) measurements were made using a medium-volume sampler along with ancillary meteorological and air quality measureme nts in the Mohave Valley at Bullhead City, Arizona, for a period of lo nger than one year (September 1988 through mid-October 1989). The aero sol filter samples were analyzed for mass, elements, ions, and carbon. Source apportionment using the Chemical Mass Balance (CMB) receptor m odel was performed. On average, geological dust was the major contribu tor to PM(10) (79.5%), followed by primary motor vehicle sources (16.7 %), secondary ammonium sulfate (3.5%), secondary ammonium nitrate (0.1 %), and primary coal-fired power plant emissions (0.1%).