Waste disposal

While it is inevitable that some fat, oil and grease will go down the sink, it’s important that systems are in place to prevent these contaminants from going any further

Fats, oils and grease - or FOG as they are often referred to - can cause major problems when disposed of in sinks and drains as they congeal and harden as they cool, sticking to the inner lining of drainage pipes and building up to cause blockages.

“Slow draining appliances, localised flooding, foul odours and pest infestation are often signs of the build-up of fats, oils and grease causing problems in your drainage pipework,” says Russell Fraser, MD at specialist grease management business Goodflo. “This can often lead to business interruption to your own and neighbouring properties and can lead to costly water company enforcement including their re-charge for drain clearing and non-compliance fines.”

FOG v UCO It’s important to distinguish FOG from used cooking oil (UCO), which no-one in the industry believes is being tipped into the drains. FOG is the residue left over on plates, cutlery, frying utensils and the such. If you’re serving 300 plus fish and chip meals a day, that’s going to mount up.

Even if you operate a takeaway and the amount of FOG entering the drains is vastly reduced because a lot of the food is going out the door, you’ll still have frying utensils to wash up as well as surfaces, floors and the frying range to clean down all of which will have a certain amount of oil on them. The cloths used will then need to go through a dishwasher, along with staff uniforms quite possibly, which will all contain trace elements of FOG. Whilst you might not think so, these small particles can cause a problem and it’s all to do with what happens at the washing-up stage, as Stephen Williams, network enforcement and protection officer with Southern Water, explains: “Waste food and oil is acidic in nature, so to clean that you need an alkaline cleaner. When you mix the two together in warm water, a process called saponification happens and a greasy soapy substance is formed. This collects in the effluent leaving the premises, mixes with everything else in the sewer and can dry out and that’s what causes the blockages.”

To prevent this from happening, food establishments should have a basic grease management system. In fact, any commercial kitchen built or refitted since the year 2000 requires one to be fitted by law, and it is something that EHOs are now being tasked with inspecting to ensure they are adequate for the needs of the building and that they are being maintained correctly.

So what should you have in place? Firstly, every sink should be fitted with a basic strainer or filter, like those available from drainage solution specialist Aluline, to prevent waste food from going down the drain. And while macerators and bacterial dosing systems have been recommended in the past,

Gareth O’Neill, sales director at grease management company EPAS, has some strong words of warning, commenting: “Macerators should be banned as they merely send mushed food waste and grease to the drain lines. Enzyme dosing systems on their own, meanwhile, do not work and merely emulsify the grease and pass to the drain lines. A correctly sized grease recovery unit or a below ground correctly sized grease interceptor that is maintained are the most effective solutions to ensure that the fats, oils and grease are removed at source.”

Grease traps and recovery units There are many types of grease management systems but they generally fall into two main categories, passive grease traps and grease recovery units. In simple terms, they basically do the same job - attached to the drainage pipes they separate fat, oil and grease from the wastewater, leaving the wastewater free to flow to the sewage works for treatment and the grease retained in the trap. The difference is that with a passive fat trap the grease needs manually skimming and emptying as well as regular cleaning and monitoring - this could be daily, weekly or monthly dependent on how busy your shop is - whereas a grease recover unit skims the fat and grease off into a separate hopper. Although it still needs cleaning and maintaining, it is much less labour intensive. It’s worth bearing in mind the latter often requires a power source to heat the water slightly to keep the oil and grease fluid. The other significant difference is the price, while passive grease traps can cost between £500 and £1,000, grease recovery units can cost from £2,000 upwards.

Before a FOG or grease management system is installed it is important to have a full survey of your kitchen and business as there is no single solution that fits all situations. Goodflo’s Russell Fraser, adds: “With many town and city locations space in the kitchen and wash up area can be at a premium. Initial and ongoing maintenance costs are also key considerations.”

Russell recommends Goodflo’s G-Bag grease trap system, which he says offers an affordable solution with a number of benefits, for example the unit is simple to retro-fit, sized to fit most kitchen space restrictions and provides high levels of health, safety and hygiene. In addition, it requires no daily or weekly cleaning and maintenance and, with all the waste contained in the G-Bag, disposal is simple.

Meanwhile, EPAS’s Gareth O’Neill advises shops look at systems which are certificated to EN1825 and encourages friers ask to see the certification, adding: “Claims by manufacturers that their products are designed in accordance with EN1825 are incorrect and will not be sized correctly to prevent the discharge of grease into the sewer system.”

One of EPAS’s most popular solutions is its GreaseShield grease recovery system, which automatically removes fats, oils and grease with no need for staff to empty or clean it. Unlike many other systems, it doesn’t require a heating element and benefits from low operating costs.

In addition to installing the correct equipment, staff training and good housekeeping will minimise the amount of FOG from food waste that is likely to get into the sewer. So train all staff on why it’s important to keep fats, oils and grease from entering the drains and that failure to do this can lead to expensive costs for your business.


Good practice Plates, pots, trays and utensils should be scraped and dry wiped with a disposable kitchen towel prior to putting them in the sink or dishwasher and the scrapings placed in the bin

TOP TIP Fat and oil taken from your grease traps can go into landfill or your waste collection company may take it away as it is recylable.


Get paid to have used oil taken away

The law insists that takeaways and restaurants dispose of their used cooking oil responsibly or face a hefty fine and, therefore, using a licensed waste oil collector is paramount. But not only will this keep you on the right side of the law but it could also turn you a small profit as there’s value in used cooking oil because it can be recycled and sold on as biodiesel. Companies like Olleco, Proper Oils, Cater Oils and Arrow Oils, as well as most fish and chip wholesalers, will more often than not pay to take your used cooking oil away. Prices vary depending on the volume of oil, how regularly it is collected, whether it’s liquid or solid fat and the market price of oil, but it can be between 2p and 18p a litre. Compare suppliers


There are a few dos and don’ts which should be followed when disposing of used cooking oil:

Do - Use a collector authorised by the Environment Agency who will take your waste to an authorised site for recycling or disposal. Failure to do so could lead to prosecution and a fine. - Use the containers provided by your waste collector to store your used oil in as these are fit for purpose. Most will clean and return these free of charge. - Ensure containers are sealed to prevent spills and store them somewhere secure. Because there’s a return value in used cooking oil, they are prone to theft. - Keep the waste transfer notices (WTN) issued by your collector for two years - this is a legal requirement.

Don’t - Take used cooking oil to household recycling centres as these are not designed for commercial waste. - Pour used cooking oil down drains or sewers as this could lead to blockages, odour and vermin problems. If caught, such action could result in potential prosecution. - Dispose of used cooking oil with general kitchen waste as it may leak, causing odour and pollution problems, plus waste contractors may refuse to take it. - Pour hot oil into containers, wait until it has cooled first or, if using warm oil, use a metal drum not a plastic one.