An Environmental Protection Agency study conducted on two farms suggests that the harmful pathogen Escherichia coli O157:H7 can survive in a cow waterer. Contaminated drinking water is one way that experts believe E. coli O157:H7 can be transmitted between cows.

Fresh manure containing E. coli O157:H7 was added to the waterer to mimic a natural contamination event. On one farm the E. coli O157:H7 was present when water temperatures were between 41 F and 59 F for the entire 16-day study. On the second farm, the E. coli O157:H7 remained in the waterer for eight days when the water was 41 F, and for four days when the water temperature was 59 F.

The study, reported in the September 2000 Journal of Dairy Science, reinforces the recommendation to clean cow waterers weekly.