Grease is certainly the word for municipal workers involved in clearing blocked drains and sewers. According to the US Environmental Protection Agency (EPA) there are around 10 billion gallons of annual sewerage spills and the primary cause of blockages is grease. More specifically, FOG (fats, oils and grease) are the collective cause for blocked drains and sewers. The sources of this contamination are kitchens; domestic and commercial kitchens alike are the usual suspects. Grease, like many teenagers, is hydrophobic (or averse to water). It floats on top of water rather than mixing with it. Grease, oils and fats also clings to the interior of pipes, water outlets and drains, and over time this build-up of fatty substances can block these drainage pipes. The result can be blocked drainage and sewerage systems which can affect an individual property or several properties. As the build-up continues it also presents further problems at public wastewater treatment facilities and can cause serious disruption at sewerage treatment facilities. For both domestic and commercial properties, the need to keep waste water free from grease and oils is essential.
The Usual and Unusual Suspects
One common misconception, even in the commercial kitchen, is that grease is the by-product of cooking with oil. Many foods contain natural fats and oils (meat and fish in particular, but also dairy products, baking supplies and all manner of sauces). As the remains of food are washed away down the drains they contribute to the build-up grease in drains and sewers. Garbage disposal units are sometimes considered effective at solving the problem but these units only shred food waste and still allow FOG to enter the water system. The biggest risk from a build-up of grease is that it will block the sewerage system from your premises, causing sewage to flow back into the building; this is a serious problem for commercial restaurants as not only will the odour be unpleasant, it’s likely to shut you down for a period of time due to the potential health risk. The blockages may not, of course, just affect your premises but can also affect the street and neighbouring businesses or residential properties. The majority of problems with FOG related blockages are down to poor precautions and bad housekeeping. Expensive to rectify when they occur, blockages also have cost implications for businesses in terms of lost income. Grease traps should be fitted in commercial premises serving and preparing food and they are not only simple to install (in most cases), but reduce the problem (or potential for problems) significantly.
Thanks to its hydrophobic qualities grease is actually very simple to trap; grease traps have been used for at least two centuries to resolve the problems presented by FOG. In commercial premises most properties have two systems to remove waste water from their buildings; the first is connected to the toilets and sinks (some also connect floor drains to this part of the system). The second system is connected to the sinks, kitchen and dishwashing areas/machines. Legally a requirement to have grease traps fitted to this part of the system is common in many countries across the world and in the US each state has similar regulations. The grease trap is a simple piece of technology to understand; on a simple level the trap is a tank that allows waste water in and out but traps FOG products on the top of the water. More sophisticated traps employ a series of filters and ‘baffles’ which separate oil and grease. Waste water then continues out of the trap into the rest of the drainage system and on to the sewer, minus the contaminating FOG. Traps come in a range of sizes and complexity to suit different sized businesses (a small restaurant will not need a massive trap, while a hotel or hospital may suit a larger model). In the case of smaller firms a single trap fitted in the kitchen itself is usually suitable, while large premises sometimes favour tanks fitted underground outside of the premises. Grease traps need periodic cleaning to remove food waste (usually found at the bottom of the tank and referred to as ‘sludge’) along with the grease and oil itself. The majority of commercial carriers removing waste FOG substances currently dispose of this at landfill sites, although technology is being developed to recycle this type of material. In order to help protect the environment, and your business, fitting grease traps is a simple, but effective step.
Alan Rosinski is a freelance writer who has experience on both sides of the counter in the restaurant and hospitality industry. In this blog he looks at the problems created by waste cooking oils, grease and fats, in both environmental and business terms.