We rarely think about our bowels—just like we often overlook drainage in food processing. While focusing on taste and packaging, poor drainage can become a major issue. Hard-to-clean drains raise microbial loads, and undersized ones cause blockages and water stagnation. This threatens food safety and can halt production.
So what are the things that you should be aware of while designing your facility? Here are a few pointers
Type of load
It is important to understand what the drains will be carrying. For example, if it is a dairy plant, the drains would carry only the milk spillage and water from cleaning and these can flow easily. On the other hand, if you are designing a kitchen then the drains would need to carry a slurry of food which is dense and may contain chunks of food. In such scenarios creating adequate traps and interceptors to collect and remove the food waste is critical.
Carrying Capacity
The classic question that always comes is how big should be the drain. You don’t want to make them too big cause it costs money and you never want to make them too small as they would clog. A good way to estimate the carrying capacity is to start with the amount of water you hope to use. After you have estimated the volume, next is the rate. Your SOPs are a good way to estimate what is the maximum flow and the timings when this would happen (typically during cleaning)Direction of Flow
The general rule of thumb while designing a drainage system is that the drains should flow from the high-risk area to the low-risk area. Drains sheath a large number of pathogenic microbes both as free living as well as in the form of biofilms. If not taken care of properly, these microbes can easily become serious food safety hazards.
Plan drainage with proper placement, easy installation, cleaning, and maintenance. Follow local rules on effluent treatment before connecting to public utilities:
EHEDG Principles for Hygienic Drainage Design
The European Hygienic Engineering and Design Group (EHEDG) sets good practice principles for drainage systems. They require fully drainable sumps and a minimum slope of 1% both longitudinally and across all areas. These slopes prevent water stagnation, odors, microbial growth, and chemical hazards.
Additionally, EHEDG prohibits welding lap joints hygienically because welding creates voids that trap bacteria. To ensure easy cleaning and accessibility, drainage should have rounded corners with minimum radii of 3mm to 4mm.
FSSAI Guidelines for Drainage Systems in India
In India, FSSAI mandates drainage designs that prevent contamination of food and potable water. The guidelines specify a minimum gradient of one foot per 100 feet in linear distance. Drains should have smooth surfaces, preferably tiled on three sides.
Furthermore, FSSAI requires drains in food processing areas to be covered with removable grills, filters, or fittings. To block pest entry, cockroach traps must be installed in all trapping areas and at the drain endpoints.
Drainage and cleaning are the pre-requisites of an effective HACCP system and hence it is very important to think about the kind of drainage system required by the facility. Drains, cleaning processes and flooring should always be planned holistically as they all directly impact each other’s performances. Dedicating time and effort to assess the cleaning and sanitation processes will essentially save the time, money and hassles to occur in future.
If you are setting up a new facility and would like to do it right, reach out to us at info@foodsafetyworks.com
