According to the Centers For Disease Control and Prevention, the deadly bacteria was traced to irrigation canal water in the Yuma, Arizona growing region.
CDC officials are still looking to solve how the bacteria got into the canal water and whether there are other areas of contamination.
The CDC won’t publicly identify the canal’s exact location until it finishes its final report on the incident.
The CDC also declared that the romaine lettuce outbreak is officially over. The last lettuce shipments from the Yuma area were harvested April 16th and the harvest season is over. Contaminated lettuce should no longer be available.
You can read more on the CDC’s findings here.