In light of the recent recall of Blue Bell ice cream due to a listeria outbreak, the Food and Drug Administration has revealed past investigations of the facilities, showing that bacteria were found as early as March 2013 in the Oklahoma manufacturing plant. Despite the FDA’s warning regarding the outbreak, Blue Bell continued to produce and make shipments of its product.

The FDA says that since then, Blue Bell has failed to meet adequate standards of health and cleanliness in its facilities. With the recent death toll at three in Kansas affiliated with Blue Bell products, it is a wonder this is coming to light now.

After a Freedom of Information request was made by The Associated Press, the FDA agreed to release the reports on its investigations into Blue Bell’s Oklahoma, Texas, and Alabama plants. Within the Oklahoma plant the FDA found the most extensive violations, getting as many as 16 positive tests for listeria on both ice cream and equipment from March 2013 to January 2015. According to the FDA, most of these positive test results have to do with lack of proper cleaning. Thanks to dirty equipment, improper food storage, employees not washing their hands thoroughly and lack of temperature control, the bacteria were able to grow and contaminate the product.

“We thought our cleaning process took care of any problems, but in hindsight, it was not adequate, which is why we are currently conducting such a comprehensive re-evaluation of all our operations,” said one Blue Bell source to The New York Times.

According to a report by CBS News, both the Texas and Alabama plants featured similar health violations. The FDA stated that in the Alabama plant, they witnessed two employees working directly with the food and wearing soiled clothing. In the Texas plant, condensation was found to drip directly into the food and on surfaces in contact with the food. This is especially dangerous, as listeria is known to be found in water. “The plant is not constructed in such a manner as to prevent drip and condensate from contaminating food, food-contact surfaces, and food-packaging materials,” the FDA noted.

Listeria happens to be very persistent bacteria, and it can be very hard to get rid of once it’s present. Often carried by animals, or found in soil or water, listeria may live up to years in facilities such as Blue Bell’s, where it thrives on refrigeration. “It can hide in the nooks and crannies of machinery, underneath a slime layer, say, and it can be hard to get rid of,” said Dr. Rob Tauxe, of the CDC to The Times.

Listeria is mostly known to affect the elderly, pregnant women, infants, and individuals with compromised immune systems. The most common symptoms are fever, muscle aches, along with gastrointestinal issues. In some cases it can be fatal, in addition to causing miscarriages, premature labor, and stillbirth in pregnant women.