Grease Trap Sizing FAQs
Grease trap sizing is usually determined by the type of food business you operate, the amount of wastewater your kitchen produces, and local trade waste requirements. Restaurants, cafés, bakeries, takeaway shops, and commercial kitchens commonly require grease traps to help prevent fats, oils and grease from entering the sewer system.
What determines grease trap size?
Grease trap size may depend on:
- kitchen size
- wastewater volume
- number of sinks and fixtures
- food preparation activities
- peak kitchen usage
- local water authority requirements
Sizing is commonly determined by your plumber, hydraulic consultant, or water authority.
What is the minimum grease trap size?
In many WA applications, Water Corporation requires a minimum grease arrestor size of 500 litres for food businesses.
Larger kitchens and high-volume food sites may require significantly larger grease traps.
How often should grease traps be serviced?
Servicing frequency depends on:
- grease trap size
- business type
- wastewater volume
- trade waste permit conditions
Many businesses require grease trap cleaning every:
- 1 month
- 2 months
- 3 months
Your servicing schedule may be determined by your local water authority.
Why is grease trap sizing important?
Incorrect grease trap sizing can increase the risk of:
- blocked drains
- bad odours
- sewer overflows
- plumbing damage
- trade waste compliance issues
Proper sizing helps grease traps operate effectively and maintain compliance requirements.
How does Water Corporation affect grease trap requirements?
Water Corporation and other Australian water authorities may require businesses to:
- install approved grease traps
- maintain minimum grease trap sizes
- follow scheduled pump-out frequencies
- comply with trade waste requirements
Requirements can vary depending on the type of business and wastewater produced.
FAQs
Who determines grease trap sizing?
Grease trap sizing is typically determined by your plumber, hydraulic consultant, or local water authority.
Do all food businesses need grease traps?
Many commercial kitchens and food preparation businesses require grease traps or similar pre-treatment systems.
Can grease traps be too small?
Yes. Undersized grease traps may fill too quickly and operate inefficiently.
How often should grease traps be cleaned?
Many businesses require servicing every 1–3 months depending on usage and permit conditions.
Can businesses clean grease traps themselves?
Grease trap cleaning is generally completed by licensed liquid waste contractors.