Federal officials are expected to join state agricultural and health officials on an inspection of a San Luis Valley vegetable farm Wednesday -- on the heels of another food recall.
A bag of Dole's Hearts Delight salad mix that tested positive for E. coli bacteria triggered a lettuce recall in at least nine states on Monday.
The Romaine, green leaf and butter lettuce hearts were grown in Colorado, California and Ohio.
Colorado Deputy Agriculture Commissioner Sheldon Jones told Denver's KMGH-TV that it's unclear where the contamination came from.
He says the FDA will join state health and agriculture inspectors in the San Luis Valley to inspect operations at the farm where the Colorado lettuce was grown.
Officials plan to check the fields, cooling shed, and the packing house.