(NIOSH 2006-2011) This two-year exploratory project investigated a probable cause of Yakima County’s high rates of diarrheal illness – bacterial pathogens from livestock, taken home or in well water. It is hypothesized that occupational and environmental exposure pathways from livestock operations pose a significant risk of exposure to zoonotic bacterial contamination for farmworkers and their families. This study demonstrates the effectiveness of currently available methods for recovery of example bacteria from various surfaces. These methods are available to exposure science researchers. Additionally this study examines the roles of organism die-off and the experimental design of validation studies in the reported efficacy for surface sampling methods.