Listeria sp. counts in fiberglass, open-trench floor drain 6, which was located near a poultry meat packing area and was typically filled to 5 to 20% of capacity during operation. ▪, bottom side of cover; ▨, right side of drain; ▤, left side of drain; ▩, inside of drain; □, floor within ca. 30 cm of the drain. (T), CE treatment applied.