Cafes, restaurants and food businesses must ensure that they have an approved appropriately sized grease trap to capture any grease, oil and food by-products in the waste. These must be installed by a registered plumber.

A grease trap intercepts fats, oil and grease that have come from kitchen waste water. Without a grease trap, these materials end up in our sewers and can:

  • solidify and reduce how much sewage we can process
  • cause blockages and failures
  • cause overflows into our streams and rivers
  • prevent the network from working properly. This may impact the quality of treatment before effluent is sent back into our natural environment

Our city’s waterways are precious and we’re committed to protecting them.

Grease trap brochure [PDF, 959 KB]

Example of an good grease trap system

Leo's Takeaways have a standard grease trap which takes care of their waste water. They also engage a waste management company to regularly clean and maintain the grease trap.

This system takes Leo's waste water straight from their kitchen to Christchurch's treatment plan, without any problem, leaving Leo to get on with business.

Example of a good grease trap

Selecting and maintaining your grease trap

A strainer type mechanism at the sink hole, like the ones you used at home to catch kitchen waste from going down the pipe, is not adequate enough.

Grease traps are available to purchase from most plumbing suppliers and you will need professional advise as to the type and size for your business needs. The minimum requirement is 500 litres. 

Grease traps need to be emptied and cleaned on a regular basis, and in some cases daily basis. You need to implement a plan for regular emptying, cleaning and disposal of the waste.

It is recommended that you employ the services of a professional and registered service provider that can empty and clean your grease trap as well as collecting and disposing of the actual waste.

We’re here to help

Trade waste requirements are important to follow but can seem complex. That’s where we come in. 

Our specialist Trade Waste Team is available to help you understand and meet your responsibilities as well as improve environmental performance. This free service could include help with consents, pre-treatment, best practice tips or getting the most out of your assets.

If you have any questions or require more information contact the Trade Waste Team on phone 03 941 8999 or email