Waste Disposal

Kitchen waste has a double hit on kitchen costs. Food not sold and thrown away immediately hits the bottom line of profit, but the second hit is the charge for removal of kitchen and plate waste.

Most local authorities will charge for packaging and food waste removal, and waste cooking oil often carries a removal and recycling cost from specialist companies.

Although it's not always illegal, tipping old cooking oil into the sewerage system causes serious pollution, and if it causes a drain blockage leading from a kitchen, the restaurant could be charged by the local authority for cleaning and repairs.

Plastic sacks are adequate for non-food waste in small premises, but they should never be used to store waste food, as vermin could easily tear them open. The most practical means of holding all waste not destined for recycling is in heavy-duty wheelie bins with lids too heavy for vermin, feral cats, dogs, and foxes to lift.

Since collection is charged by the wheelie bin, it makes economic sense for premises which produce a lot of waste to invest in a compacter, which can compress bulky items such as packaging waste to a quarter of the space. The cost can be recouped by a busy operation in less than a year.

A feature of most local authority building regulations for commercial food premises is that a grease-separation system must be fitted in all new or refurbished kitchens, but the legislation is not retrospective.

Blocked kitchen drains caused by food waste and fats washed off dirty plates can mean a very expensive service call, and can be avoided through fitting a fat-separation unit or grease trap to the water outflow system.

A grease trap works by slowing down the flow of warm or hot greasy water coming out of a dishwasher and allowing it to cool. As the water cools, the grease and oil separate and float to the top of the grease trap. The cooler water containing less grease continues to flow down the pipe to the sewer. The grease is trapped by baffles, which cover the inlet and outlet of the tank, preventing grease from flowing out of the trap. The baffles are regularly removed for cleaning and the grease put into general waste.

Local authorities have different views on the siting of a grease trap. Some say it must be outside the kitchen, others are happy for it to be in the kitchen. Where a grease trap is taking water from a dishwashing system, it has to be sited sufficiently far away from the dishwasher to allow the emulsified fat to cool and split out from the water.

The amount of food waste going into wheelie bins can be reduced by fitting a waste disposal unit. The waste is pulverised and discharged into the sewerage system, reducing the cost of waste management. Some local authorities don't allow food waste that has been pulverised in an under-sink waste disposal unit to be discharged into the sewers, and the usual way of complying with this regulation is through a dewatering system. This quite simply separates the water from suspended solids. The water goes into the drains and the slurry is disposed of through other means.