Who needs a grease trap / fat trap?

Other than buildings used as a single residential dwelling, all buildings that are likely to discharge fat i.e. engaged in the cooking and preparation of food for other persons (for instance restaurants, takeaways with deep fryers, hospitals, hotels, bakeries, butcheries, and supermarkets) are required to install and regularly maintain an adequately sized grease trap.
Grease traps are necessary to prevent sewer blockages, pump failure in sewer pumping stations and reduce levels of fat occurring at the City's Sewage Treatment Plant.

Pre-treatment and grease traps

The main type of pre-treatment used in dealing with greasy waste is the grease trap. Only wastewater from food preparation areas, floor wastes, kitchen sinks and dishwashers should be discharged to the wastewater system through the grease trap. Wastewater from toilets, showers and other processes must not be directed through the grease trap.

There are three basic types of grease trap:

• Gravity separation
• Enzyme digestion
• Mechanical separation.

Grease traps are sized according to the daily volume of wastewater discharged and the seating capacity of the restaurant or café.

Maintaining your grease trap

All grease traps require maintenance to ensure they operate effectively and efficiently. It is important to know what type of grease trap you have, where it is located, how it operates and what maintenance is required.

Lack of maintenance will cause the grease trap to become inefficient, due to grease accumulation on the surface, preventing circulation of air and reducing cooling efficiency. This will lead to blockages, offensive odours and pose a health hazard.

Grease trap cleaning must be undertaken by a recognised contractor. Do not attempt to clean the grease trap yourself.

Recycling your cooking oil

• Collect used cooking oil so that it can be recycled.
• Never pour fat, oil or grease down any sink or drain. It is an offence under the Trade Waste Bylaw to pour any waste into a stormwater drain.

Water savings

• Avoid running the tap continuously during rinsing.
• Use dry or waterless cleaning methods such as wiping or sweeping up spills first.
• Ensure the dishwasher is full each time it is used.

Reducing solid waste

• Scrape and wipe leftover food from plates and cooking utensils before washing.
• Install sink strainers or screens.
• Other solid materials must not be put down the sink.

Use appropriate cleaning products

• Detergents dissolve grease, allowing it to pass through the grease trap, which can cause blockages in the wastewater collection system. Avoid using products such as caustic soda. Cleaning products should be used according to the supplier’s recommendation.
• Do not use solvents or products that can re-dissolve the grease in the grease trap that can lead to blockages in the system.