Food Engineering

It may be wet and wild, but is it clean?

August 5, 2004
A close examination of processing plant water systems helps prevent product contamination.

Richard F. Stier
No food plant can operate without water. Besides being used for routine tasks such as hand washing and waste disposal, water often serves as a food ingredient. For this reason, processors need to ensure that the water coming into the facility is free of contamination and pure enough to use as a raw ingredient. It's also imperative that water remains potable upon arriving at and flowing through the facility's own plumbing. While every plant will have different water cleanliness requirements based upon individual processes, there are several steps that should be taken by all food processors to be sure that in-plant water quality is acceptable. These include testing water quality, updating plumbing diagrams, ensuring sufficient capacity and preventing backflow problems.

Water testing

Many processors assume that because they are using water from the local municipality, which should monitor water quality at the water treatment facility, that it is free of contamination. However, the condition of water can change as it flows through the pipes of the city and plant, especially if the piping is aged or in poor condition. For this reason, it is wise for all processors-even those using well water-to test the water as it comes into the plant and at several locations within the facility at least once a year. Sampling should be done at the location that is farthest from where the water enters the plant, and tests may be conducted in house or by a certified water testing laboratory.

Plumbing diagrams

All processors should have updated plumbing diagrams which should show both water and waste water/ sewage lines, clearly indicate that there are no cross-connections, and demonstrate that sewage lines are not connected to the waste water lines at any point in the system.

Plumbing diagrams should also show any dead legs, or areas where water can accumulate. Dead legs can be problematic, because constant flow is what helps keep lines clean and free of debris or contamination.

Adequate capacity

It's important to consider whether the plumbing capacity is sufficient to meet the needs of the process. If water pressure drops during operations, it could indicate that the existing systems are not delivering enough water to meet specifications. This not only reduces operating efficiencies, but it could also have an adverse effect on food safety and quality. Plumbing systems must be designed to deliver enough water for processing, cleanup and other operations. Further, waste water systems must be sufficient. I once worked with a canned food processing facility where the toilets backed up and flooded the restrooms when all retorts were operating. Not only was this unsanitary, but it had an adverse affect on product quality and safety as workers ended up tracking waste to the plant floor.

Backflow prevention

All water lines either leading to or inside the plant need to be protected against backflow. During quality and safety audits inspectors will examine backflow and cross-connection check valves, vacuum breakers and air gaps that protect the system. They will also review how employees handle hoses and other devices used to dispense water. When training your staff about proper plant hygiene, don't forget to include a discussion of handling, use and storage of hoses and water systems. For example, providing hose hangers above floor level, but below the water pipes helps ensure that backflow prevention systems are functional and accessible for maintenance.

Because water is often a food ingredient, it needs to be scrutinized and protected with the same care as any other raw material used in the process. Failure to do so can result in contamination, which can have an enormously negative impact on product quality and safety.