The National Ambient Air Quality Standard (NAAQS) for Particulate Matter (PM) is used to determine attainment and nonattainment. EPA requires that the ambient concentration of particles with an aerodynamic equivalent diameter less than or equal to 10 ìm (PM10) be measured with a Federal Reference Method (FRM) PM10 sampler. Furthermore, EPA has issued criteria to be used when locating a FRM sampler for monitoring purposes. According to EPA, a monitoring site must be located in an area inhabited by the public and not affected by any single source. Despite such requirements, EPA and state air pollution regulatory agencies (SAPRAs) maintain that the PM10 NAAQS can be used to regulate a source at the property line. Sources that exceed the PM10 NAAQS at the property line may be required to pay civil penalties and reduce PM emissions. Since PM from agricultural sources is typically larger than PM found in urban environments, measurement inequalities of the FRM PM10 sampler need to be addressed.