Grease Trap Installation and Repair in Sydney

Prepare your business for long term success with a compliant grease trap installation

If you own and operate a restaurant, bar, or café in Sydney, you could risk damage, loss, or even fines without a compliant grease trap installation. When fat, oils, and grease (FOG) are washed down the pipes in your kitchen plumbing or main drainage, they can cause serious plumbing issues. They can solidify on the walls of pipes, causing them to become hardened, blocked, and finally breakdown. This can result in costly repairs and disruption of business operations. 

Grease can also overwhelm wastewater treatment plants, damage them, and lead to the release of raw sewage into the environment, leading to the pollution of water sources such as beaches and rivers. Also, damage caused by fats, oils, and grease cost councils millions of dollars in repairs. 

A recent grease trap installation.

To help avoid costly damage and pollution that can cause severe damage to the environment, Sydney Water requires grease trap installation for all food establishments. These local and state grease regulations are heavily enforced, and any foodservice operators’ noncompliance can be met with hefty fines or even closure. 

Read along to learn more about grease traps. 

What is a grease trap?

A grease trap is a receptacle that collects and reduces fats, oils, and grease (FOG) in trade wastewater before it flows into the main sewer. Food establishments such as hotels, bars, cafes, and restaurants are required to have grease traps. If trade wastewater is discharged directly to the drainage system, it can block pipes, overload water treatment plants and pollute natural water sources. Pipe blockages on your premises can result in backflows, bad odours, and disruption of business operation. This can lead to expensive plumbing problems in your business and attract hefty fines from Sydney Water.

A grease trap works in a pretty simple way. Animal fats and vegetable oils are referred to as grease. Grease is less dense than water, and both do not mix. Therefore, grease floats to the top of water. When the wastewater enters the grease trap, its flow rate is reduced enough to give it time to cool and separate into layers. Grease floats at the top and is trapped with a system of baffles; the relatively grease-free water flows through an outlet to the sewer line, and the solid debris settles at the bottom where they can be collected with strainers. The receptacle must be cleaned regularly to prevent a build-up of grease and solid waste to the point where they begin to back up through the inlet or escape through the outlet. 

Businesses that produce trade wastewater must have a grease trap installation, and trade waste agreement with Sydney water. Examples of businesses which require a grease trap  include:

  • Bakeries
  • Restaurants
  • Hotels
  • Schools and colleges
  • Cafes
  • Pubs, bars, and inns
  • Conference centers
  • Takeaways
  • Food manufacturers

Grease trap installation

There are several considerations any business operating in Sydney needs to make when planning for a grease trap installation. They include:

  • Get approval. Before installing your grease trap, you must seek approval from Sydney Water.
  • Use a licensed plumber. You need a licensed plumber to install your grease trap according to the manufacturer’s instructions, Sydney Water requirements, and the Plumbing Code of Australia, 2012. After the work is complete, you should ask for a certificate of compliance from your plumber.
  • Use authorised grease traps only. Sydney Water permits installation of only authorised grease traps. One of our qualified plumbers can help you select an authorised grease trap.
  • Select the right size grease trap. The size of your grease trap should meet your present and future maximum flow rate to ensure that it treats your trade wastewater. If you install an undersized grease trap, you may be asked to install additional pre-treatment. A grease trap must be at least 1,000 litres.
  • Must be close to the source. You should consider installing your grease trap as close to your kitchen area as possible. This will help you avoid using long pipe runs, where grease can solidify, clog the pipes, and cause overflows in your premises.
  • Ability to drain by gravity. A pumped system is more expensive to install and maintain than a gravity system. In case the pump fails, there can be an overflow in your premises.
  • Unrestricted access. Sydney water representatives need safe and unrestricted access when checking the grease trap’s performance.

A certified plumbing team from Absolute Plumbing Solutions will install and repair your grease traps according to the manufacturers’ instructions, and all requirements from Sydney Water. They will determine the size of your grease trap, figure out the best place to install it, and clean out any debris. They will then excavate the site, supply all the required material, and connect the holding tank, the source of wastewater, and the sewage system. After the installation, they will backfill and clean the area, arrange for a plumbing and drainage inspection, and provide an updated sewer service diagram to the department of Fair Trading. Finally, they will issue you with a certificate of compliance so that you will have no issues with local authorities.

What size grease trap do I need?

Grease traps come in different sizes because not all commercial food businesses are equal. The size of the grease trap you need will be determined by your business activities based on the rate of flow in litres. The rate of flow in your commercial kitchen will depend on the number of sink outlets and equipment, such as dishwashers or glasswashers. To help capture grease efficiently and ease pump outs and cleanouts, Sydney Water requires grease traps to be a minimum size of 1,000 litres and a maximum size of 5,000 litres. That means the higher the rate of flow in your kitchen, the bigger your grease trap will be.

Common grease trap repairs

Over its lifetime, a grease trap may have some common issues that may call for repairs. These include:

  • A clog in the crossover. This occurs when solid debris or grease builds up in the crossover line between compartments. This causes the level of water in the first compartment to rise while remaining normal in the second compartment.
  • Clogged incoming and outgoing line. A clogged incoming line leads to a backup, while a clogged outgoing line results in an overflow.
  • Full grease trap. This occurs when grease is not pumped out as required.
  • Rotten egg smell. This occurs when you don’t clean your grease trap regularly or when the kitchen plumbing gets filled by heavy sludge.
  • Grease trap leak. This can result from cracks, shifting, collapsed flow diverters, or broken elbow fittings.

A qualified plumber from the Absolute Plumbing Solution will inspect your grease trap to identify any issues and get to work to rectify the fault. They will remove any clogs in the crossover, ingoing or outgoing lines, and remove any sludge in your kitchen plumbing using specialized tools like hydro-jetting machines. They will also perform necessary spot repairs, install new diamond plate lids, replace missing baffles, perform an epoxy coating restoration to coat your old grease trap, or an acrylic insert restoration to add an extra layer and give your grease trap reliable protection. If your grease trap is old and difficult to repair, our plumbers can organise a replacement. 

How often should grease traps be cleaned?

The interval within which your grease trap should be cleaned is determined by Sydney Water and is based on the size of your grease trap, and the quality and volume of greasy wastewater your business generates. Sydney Water uses an electronic tracking system called Wastesafe to monitor the generation and disposal of grease trap waste. To prevent wastewater from entering the sewer system, prevent overflows, and odours, your grease trap must be serviced by an authorised Wastesafe transporter who pumps out the wastewater and cleans its internal surfaces during servicing. 

How much does it cost to get a grease trap installed in Sydney?

When it comes to determining the cost of installing a grease trap, there is no one-size-fits-all because several factors come to play. Here are the factors that influence the cost of grease trap installation:

  • The size of the grease trap. It is more expensive to install a 5,000 litre grease trap than to install a 1,000 litre grease trap.
  • The position of the installation. Installing an underground grease trap is more expensive.
  • Size of property/businesses. The size of the business or property will determine your grease trap installation requirements, and whether you need a grease trap pump station. This will influence the installation cost. 
  • Sitting capacity. Sydney Water relies on your restaurant or café sitting capacity to determine your flow per hour or per day and decide the size of the grease trap installation.

All these factors will influence your grease installation cost, making it difficult to have a generic cost because different businesses will have varying requirements. Roughly, it may cost you anywhere between $5000 – $30,000 to have your grease trap installed, with complicated jobs e.g larger tanks in difficult areas costing significantly more. Each job is different, and grease trap installation jobs vary, so give us a call to talk about your specific job.

Frequently asked questions about grease trap installation and repairs

Does a commercial dishwasher need a grease trap?

Yes. Sydney Water requires any commercial kitchen wastewater, such as water from dishwashers containing fats, oils and grease, to pass through a grease trap.

Can I clean my own grease trap?

No. Sydney Water sets the intervals at which your grease trap must be serviced by an authorised Wastesafe transporter who pumps out the wastewater and cleans its internal surfaces during servicing.

Do homes have grease traps?

Grease traps are mandatory in food businesses such as cafés and restaurants but rarely required in residential homes.


If you operate any of the businesses mentioned above, a grease trap installation can save you a lot of trouble down the line by ensuring that you are running your business in compliance with Sydney Water regulations. This will also help you prevent costly repairs and potential operation disruptions in your business. Absolute Plumbing Solutions is here to help you with all of your grease trap installation and maintenance needs. Call us on 0421 714 322 or get a quote today.

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