Water Reuse and Pathogen Reduction Part of the Solution or Part of the Problem?
The Role of Process Water in Pathogen Reduction
The USDA’s Pathogen Reduction/Hazard Analysis and Critical Control Point (HACCP) rule in July of 1996 required all meat and poultry slaughter plants to adopt a system of process controls to prevent food safety hazards. It contained four components: standard operating procedures (SOPs) for sanitation, HACCP plans, generic E. coli testing and Salmonella performance standards. With the implementation of this new rule, poultry processors quickly recognized that compliance would mean using more water, a lot more water.
Under the new HACCP rule, establishments were required to conduct generic E. coli testing to verify that process control systems are working as intended to prevent fecal contamination. Prior to the new rule the immersion chiller had been considered the primary means of pathogen reduction in the slaughter process. Afterwards, the pre-chill rinse cabinets were found to be an important key to compliance. Processors discovered very quickly that high volumes of pressurized water could physically rinse contaminants off the surface of the birds. At that point, the challenge became one of how to balance food safety with water conservation and still stay in business.
Also as part of the new rule FSIS set Salmonella performance standards to verify whether or not HACCP systems are effective in controlling contamination. These standards are based on post chiller sampling. Suddenly it was essential that the microbial load entering the chiller system be reduced as much as possible pre-chiller to provide a better opportunity for antimicrobials in the chiller to perform. The water used in the birdwashers, potable water with no chlorine demand, proved to be an excellent medium for the delivery of these antimicrobial agents.
As more fresh, chlorinated water came into contact with carcasses the contact time for antimicrobial agents such as chlorine, which require balanced CT values (concentration x time) for maximized disinfection, could be enhanced to improve disinfection levels. The down side was that water usage increased in some poultry plants by more than 50%, which immediately taxed, and in some cases overwhelmed, the existing water utility infrastructure.
USDA/FSIS acknowledged that more water was indeed a valid response to Zero Tolerance and began to consider extensive water reuse in the poultry industry for the first time. On October 20, 1999 the USDA released the Sanitation Performance Standards in the form of CFR 416.2. As a part of that document water reuse was addressed. Section (g)(3) states, “Water, ice, and solutions used to chill or wash raw product may be reused for the same purpose provided that measures are taken to reduce physical, chemical, and microbiological contamination so as to prevent contamination or adulteration of product.”
This statement was considered to be ambiguous and created a tremendous number of questions from the poultry industry. In an effort to answer those questions the FSIS Technical Center issued the Water, Ice and Solutions Reuse Guidelines in January of 2000. The main intent was to create a set of guidelines that allowed for safe water reuse by providing a guideline to treatment with a published, measurable, repeatable standard. The guidelines relied upon a specific set of parameters and a series of “failsafe” mechanisms that are based on the National Primary Drinking Water Regulations of the Safe Drinking Act.