While spent cooking oil from restaurant fryers is easily disposed of by calling in a cooking oil recycling service, the grease that comes off the dirty dishes in the sink is harder to deal with. If greasy water is simply washed down the drain, the grease can build up in the sewage system over time, congeal in cold weather and cause blockages. When blockages occur, restaurants are at risk of being sued by the city.
Food service establishments, then, need to put together a well-thought-out grease management plan to reduce their consumption of grease and to thoroughly manage whatever grease is released down the sink and into the wastewater stream. Not only is it good business, it is environmentally responsible, too.
Starting at the source
Grease manages to foul up lines wherever it is present. It fouls up the arteries when it’s a regular part of one’s diet just as easily as it fouls up sewage lines when it’s washed down the drain. Many school and hospital food service outlets across the country are changing their menus both to turn healthier and to help with their greasy wastewater management problems. Many have disposed of their fryers and replaced their fried menu items with baked versions. These outlets only offer baked French fries, for instance.
Not only does getting rid of the fryer help a restaurant business avoid the expenses involved in managing grease wastewater, it can help it save on the high costs involved in running fryers and in disposing of spent fat.
Using grease interceptors to manage the grease that does make its way down the drain
According to Green Turtle Commercial Grease Interceptors, a number of different grease management appliances are available for use by the food industry. Restaurants need to install effective interceptors not only in the kitchen sink and the dishwasher waste line but also in the trash compactor and the food pre-wash area.
Most restaurant grease management takes place on passive grease interceptors. These interceptors separate the grease present in kitchen wastewater by running it through a system of standing water chambers to let the grease float to the top where it can be collected from time to time. While simple interceptors are cheap to buy, the costs involved in keeping them clean can add up over time.
Automatic grease interceptors are more sophisticated. They use heated skimmers to mechanically clean wastewater of grease contaminants. The grease that is separated is stored in easy-to-clean containers. While these systems are complex and expensive, they manage to clean wastewater more effectively than passive devices.
Enzyme grease cleaning units take a different approach. They don’t physically separate grease from contaminated wastewater. Instead, they try to chemically treat wastewater with enzymes to render grease harmless. Since enzyme cleaning units aren’t proven to work effectively and can be harmful to the environment in addition, many states prohibit their use.
Recycling kitchen grease
Pizza and other fast food outlets that produce a lot of greasy waste water can regularly produce barrels of grease trap muck. While the usual way to dispose of such waste is to haul it off to the landfill, it’s possible to use it productively. It can be sold to commercial incinerator businesses for use as an incinerator co-fuel.
Spent fryer grease is a more useful substance. Restaurants can convert their delivery trucks to directly run on used up vegetable oil.
Restaurants should train their employees to be responsible about the way they handle grease waste
- Restaurant employees should be trained to use dry clean-up methods to clean grease off pots and pans before placing them in the dishwasher or sink. Cleaning grease off with paper towels and spatulas and throwing grease waste in the trash is environmentally safer than sending it down the drain.
- When spilt oil, greasy kitchen mats and greasy stove hoods are cleaned up, the waste should only be poured down a sink with a grease trap in the line. It shouldn’t be poured down a regular mop sink.
- Acids, solvents and other caustic chemicals shouldn’t be dumped down a kitchen sink drain that goes to a grease trap. These chemicals can temporarily dissolve brown grease deposits and send them into the sewage system. Caustic chemicals should be disposed of in compliance with local codes.
Finally, it’s important for every restaurant to maintain a grease usage supervision code. It should include regular grease handling training and a logbook for the restaurant’s grease trap cleaning schedule.
Alan Rosinski is passionate about practical green living. He enjoys writing for blogs to explain realistic ways for restaurants and businesses to be good stewards of the earth.