Kentucky Study Finds High Bacteria Risk in Surface Water

By Blake Jackson

A study by Kentucky State University has revealed that surface water used for irrigation poses a much higher risk of bacterial contamination compared to groundwater. This discovery has major implications for food safety, particularly for small-scale farmers across Kentucky.

The research, led by Dr. Avinash Tope along with John Thomas and Tyler London, involved collecting and analyzing 296 water samples from 90 Kentucky farms over an 18-month period.

Their findings, published in the journal Agriculture under the title "Helping Small-Scale and Socially Disadvantaged Growers in Improving Microbial Quality of Irrigation Water in Kentucky," point to serious concerns for the agricultural community.

Surface water samples often showed E. coli contamination levels ranging from zero to more than 1,000 colony-forming units per 100 milliliters well above federal safety limits. In contrast, groundwater samples were much safer, with most showing no contamination at all.

This research is particularly important given that 77% of Kentucky farmers operate on a small scale, and many sell produce directly to consumers at farmers' markets and other local venues, which collectively generate $24 million in annual sales.

Kentucky's reliance on surface water for 95% of its daily water use makes the findings even more critical. As Dr. Tope noted, “We are grateful to the USDA's Agricultural Marketing Service for funding this project. This initiative has enabled Kentucky State's Land Grant Program to strategically establish four water testing laboratories across the Commonwealth, providing essential services to farmers and stakeholders to ensure produce safety particularly for fresh produce, our most vulnerable food commodity that is typically consumed raw with minimal processing. The outcomes of this project will expand our service capabilities and contribute to making our food supply safer at local, regional, and global levels.”

The project offered free microbial testing at four regional sites to small-scale growers, helping them monitor for coliform bacteria and E. coli common indicators of contamination that can lead to foodborne illness.

The study underscores the need for ongoing education, outreach, and practical tools to help farmers maintain safe and sustainable practices in irrigation and food production.

Photo Credit: istock-laughingmango