Follow CBSDFW.COM: Facebook | Twitter

WASHINGTON (CBSDFW.COM/AP)Listeria bacteria was found in Blue Bell ice cream’s Oklahoma plant as far back as March 2013. That’s according to test results released Thursday by the government.

READ MORE: Tax Refund Delays Grow As Filing Deadline Gets Closer

The company continued to ship ice cream produced in that plant after what the FDA said was inadequate cleaning.

Three deaths are now linked to the ice cream, and the company recalled all of its products last month.

In response to the FDA report Blue Bell spokesman Joe Robertson released the following statement:

“Several swab tests did show the presence of listeria on non-food surfaces in Blue Bell’s Broken Arrow plant in 2013. As is standard procedure for any such positive results, the company would immediately clean the surfaces and swab until the tests were negative. 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.”

After it was learned about the previous contamination, Blue Bell officials also issued an update about their creameries. As of today, the company has collected approximately eight million gallons of ice cream products from retailers, institutions and other outlets.

READ MORE: CDC: Fully Vaccinated People No Longer Need To Wear Masks, Socially Distance In Many Indoor Situations

The Food and Drug Administration released results of investigations into Blue Bell’s plants in Oklahoma, Texas and Alabama. The most extensive violations were found in Oklahoma, where the FDA listed 16 separate positive tests for listeria on equipment and in ice cream from March 2013 through January 2015.

Since Blue Bell stopped production, hundreds of employees have been and are being trained on how to control plant environmental conditions to prevent bacteria, including listeria. Company officials say it’s the first step in an enhanced training program.

Thursday officials said all of the plants are, or will be doing, the following:

  • Evaluating and making facility repairs, including replacing floors, floor tiles and ceiling tiles, as needed.
  • Conducting thorough cleaning and sanitizing, including disassembling and steam cleaning all equipment, and inspecting and sanitizing all HVAC systems.
  • Working with a team of independent microbiologists to review and revise all cleaning and sanitization procedures, and installing new control systems to provide higher hot water temperatures for cleaning and sanitizing.
  • Eliminating possible contamination pathways, including redesigning work spaces to re-route traffic in production areas, placing barriers between work areas, installing additional foot washers at doors into production areas, and discontinuing use of outside materials such as wood pallets in sanitary areas.
  • Establishing revised protocols and quality assurance requirements for environmental and product sample testing, including a more rigorous monitoring program for Listeria.
  • Destroying existing cardboard containers, boxes and product wrappers that could potentially provide a pathway for contamination.  Plants will discontinue the reuse of cardboard shipping sleeves.
  • Continuing employee training in microbiology and detailed cleaning and sanitization methods and systems.

Officials with the company say it “will take longer than we initially anticipated” to resume production. “Unfortunately, we do not yet have a firm timeline for when Blue Bell ice cream will be back in stores, but we believe at this time that it will be several months at a minimum,” said Blue Bell CEO and President Paul Kruse.

Consumers who still have Blue Bell products are being encouraged to dispose of them or return them to a local retailer for a refund.

MORE NEWS: Man Sentenced To Life For Murder Of Sara Hudson, Who Was Found In Burning SUV In Dallas

(©2015 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)