This Is AuburnElectronic Theses and Dissertations

Assessment of Microbial Risk Factors Associated with Irrigation Water use on Small Alabama Farms




Chevez, Zoila

Type of Degree

Master's Thesis


Poultry Science


Fresh produce is often associated with foodborne outbreaks as these products easily become contaminated with foodborne pathogens from the environment and poor handling practices. Approximately 46% of foodborne illnesses in the US are attributed to produce contamination according to the CDC. At farm level there are several factors or contamination routes for produce, and water can represent a high risk of contamination. To reduce the food safety issues, The Food Safety Modernization Act (FSMA) Produce Safety Rule (PSR) set regulations to protect the safety of produce during growing, harvesting, packing, and holding produce for human consumption. Some farms are PSR exempt due to their small size and may be at risk of produce contamination, therefore, monitoring and establishing food safety standards for exempt farms is important to guarantee produce safety. The objectives of this study were 1) evaluate the microbial quality of agricultural water used for irrigation in PSR exempt Alabama farms, 2) identify significant differences between three approved generic E. coli enumeration methods and, 3) recognize food safety/handling practices implemented among Alabama produce growers. Agricultural water from 5 locations were evaluated throughout Alabama during 2019-2020 (n = 30). Each location was sampled 3 times per growing season (2 seasons). Generic E. coli were enumerated using the methods EPA 1103.1(mTEC), EPA 1604 (MI) and Hach 10029 (mColiBlue24). The highest population of generic E. coli was 59 CFU/100 mL and there was no detectable generic E. coli in the ground water sources, only in the surface water. No significant difference was found between the three evaluated methods (P > 0.05). Next, a survey with 10 yes- no questions was developed and administered both base paper based and electronically using Qualtrics Software. The survey responses indicated that more awareness on produce safety is needed among small farm growers from Alabama, as well more accessible educational materials and tools.