Retail food outlets such as restaurants, cafes and lunch bars produce greasy wastewater from food preparation and cleaning activities.

The grease and fat contained in wastewater can accumulate both in your drains and our wastewater system, resulting in odorous and toxic gases, corrosion, blockages and wastewater overflows. Blockages and overflows impact the community and our ability to provide customers effective wastewater services.

Under the Water Services Act 2012, all businesses involved in the retail food industry must obtain written permission in the form of a trade waste permit before discharging any waste into our wastewater system.

During the trade waste application assessment process our trade waste officers assess if a grease arrestor is required based on the type of activities being undertaken. In general, retail food businesses that prepare and cook on site require a grease arrestor.

How a grease arrestor works

  • Grease arrestors reduce the amount of greasy waste flowing into the wastewater system, by allowing fats, oil and grease to rise to the top and solids to sink to the bottom
  • Your grease arrestor size  must meet current Water Corporation sizing requirements
  • They need to be pumped out according to the frequency shown on your trade waste permit by a licensed liquid waste contractor

The table below show typical pre-treatment requirements for different types of retail food businesses.

Table showing typical pre-treatment requirements for different types of retail food businesses
Minimum pre-treatment required Examples of typical business

Installation of a Water Corporation accepted grease arrestor

  • Cafes and Restaurants
  • Lunch Bar and Deli 
  • Takeaway shops
  • Fish and Chips
  • Kebab Shops
  • Butcher Shops
  • Bakeries (pies, cream cakes etc)
  • Function Centres
  • Taverns/Hotels
  • Quick Service Restaurants
  • Catering Establishments
  • Food Manufacturing
  • School Canteens (cooking)
In-sink and floor strainer units
  • School Canteen (no cooking)
  • Fish Retail (wet processing)
  • Bakery (bread only, no pies or cakes)
  • Takeaway Pizza only (no other type of food)
  • Childcare Centres 
  • Donut Shop

If your business type is not listed here, please contact

Pump out frequencies will depend on the size of the grease arrestor and the nature and volume of wastewater produced by your business.

Pump out frequencies are determined when we assess your trade waste application. The frequency is set as a condition of your trade waste permit.

Your responsibilities are to:

  • Have your grease arrestor pumped out at the frequency shown on your trade waste permit
  • Use a licensed liquid waste contractor (LWC)
  • Report pump outs to us within 7 days
  • Maintain good housekeeping practices

Your frequency can be re-assessed by request, subject to the following conditions:

  • A grease arrestor frequency re-assessment charge will apply
  • Re-assessments may also result in an increase to the pump out frequency
  • The re-assessment process will involve a number of inspections to determine the point of grease arrestor failure
  • To request a re-assessment, please complete our grease arrestor maintenance frequency re-assessment form

Retail food outlets such as restaurants, cafes and lunch bars produce greasy wastewater from food preparation and cleaning activities, and are required to dispose of this waste in a responsible manner.

The grease and fat contained in wastewater can accumulate both in your drains and our wastewater system, resulting in blockages and wastewater overflows. The potential cost to your business associated with a drain or wastewater blockage can be significant, not only in finding and clearing the blockage but also the effect it has on the normal operation of your business. You should be aware that if a wastewater blockage is attributable to your business you may be required to pay the substantial cost for removing the blockage and the associated cleanup.


To limit the amount of greasy wastewater discharged to the wastewater system we require businesses to have some form of wastewater pre-treatment, usually in the form of a grease arrestor. The effectiveness of any pre-treatment depends on good house keeping practices to prevent food solids and excess oil or grease being washed down the drain, and frequent servicing and maintenance of the grease arrestor by a licensed waste contractor.

Some useful tips to best manage greasy wastewater in your business and potentially save you money are:

  • Recycle used fat, oil and grease. Don't pour any oil directly down the drain or into the grease arrestor
  • Scrape or wipe off rather than rinse excess food material or oil and grease from dishes, kitchen utensils and equipment
  • Use quick breakdown detergents
  • Use sink strainers/screens to prevent food solids from going into drains
  • Ensure dish washers and glass washers discharge downstream of the grease arrestor
  • Ensure all grease-bearing drain lines discharge into a grease arrestor
  • Have your grease arrestor pumped out by a licensed contractor as per the frequency stated in your trade waste permit
  • Train your employees in what they can and can't put down sinks and drains. Explain the purpose and function of a grease arrestor
  • Store your used cooking oil in a bunded area so that leaks and spills cannot drain into the sewer or stormwater systems

Correctly sized grease arrestors can be used to serve multiple businesses, such as in shopping centres or other multiple tenancy arrangements.

Who's responsible

A property owner/agent is legally responsible under the Water Services Act 2012 for the operation and maintenance of the shared grease arrestor and must hold a trade waste permit for all shared grease arrestors on the property.

Permits for shared grease arrestors are subject to the standard trade waste fees and charges.

If a property owner/agent is not willing to take responsibility for shared grease arrestors, we will require individual grease arrestors for each business.

To request a shared grease arrestor, please complete our application form.

The requirement to install or upgrade a grease arrestor can be a condition of your trade waste permit.

Protecting our wastewater system and providing effective wastewater services to our customers and the community is important to us. We endeavour to work with our customers to meet the conditions of their trade waste permit.

Customers who do not meet these conditions will be subject to our retail food industry non-compliance process, which may result in additional charges.

Our greasy waste compliance management program is referred to as FOGMan (fats, oils and grease management), it manages our customers’ compliance with their pump out frequency and reporting requirements.

FOGMan liquid waste contractors

A liquid waste contractor licensed by the Department of Environment Regulation is the only person who can pump out a grease arrestor. A FOGMan liquid waste contractor is a licensed contractor who has additionally agreed to comply with our Code of Practice to pump out your grease arrestor and report on your behalf to Water Corporation. We recommend you use a FOGMan liquid waste contractor.

You can use a contractor that isn't part of the FOGMan program. However, these contractors have not agreed to report pump outs to us. Therefore, it is your legal responsibility to ensure a copy of your pump out invoice is provided to us within 7 days to:

Commercial and Industrial Services
Water Corporation
Locked Bag 2
Osborne Park Delivery Centre WA 6916
Fax: 08 6330 669