What Is a Commercial Grease Interceptor, and Does Your Kitchen Need One?

A commercial grease interceptor is a tank that catches fat, oil and grease from your kitchen wastewater before it reaches the sewer. In Australia, most people call it a grease trap. The word interceptor usually means a larger unit set in the ground outside, not a small box under the sink. Your trade waste agreement decides what your kitchen needs.

Is a grease interceptor the same as a grease trap?

For the job it does, yes. Both slow the water down so fat floats to the top and heavy solids sink to the bottom. The cleaner water in the middle flows on to the sewer.

The names differ on size and position. Suppliers often say "interceptor" for big in-ground tanks and "trap" for smaller units. Australian water authorities mostly say "grease trap", as you can see on the Sydney Water grease trap page and the Grampians Wimmera Mallee Water grease trap page.

So don't hunt for a legal difference between the two words. Check what your agreement, your last invoice and your quote call the device. If they disagree, sort that out before anyone turns up with a truck.

Does my commercial kitchen need one?

If you cook with oil or fat and wash up on site, expect to need one. That covers restaurants, cafes, pubs, clubs, takeaways and food courts. The exact rule depends on your water authority, your council and your business type. Sydney Water sets its pre-treatment requirements by business type, and your council can add its own conditions. Federation Council is one council that publishes installation, operation and maintenance guidance.

The document that matters most is your trade waste agreement with the water authority. It sets how often the unit must be pumped out. Many operators don't know what theirs says. Most only think about the trap when it smells, backs up or has an inspection due.

For the wider picture for your type of site, see our guide to grease trap cleaning for a commercial kitchen.

What changes when the unit is an interceptor, not an under-sink trap?

Three things change on the day of the clean: access, volume and the cost of disposing of what comes out.

A large in-ground unit needs a truck close to the lid. A parked delivery van, a locked gate or a bin enclosure over the lid can stop the job before it starts. A small under-sink unit needs none of that.

Take a worked example. A cafe owner takes over a site and finds a heavy lid in the back lane. Then a quote arrives that says "interceptor clean". The owner has one question to answer. Is this the right job at a fair price? Run this check:

1. Open the lid, or ask the landlord where the unit sits, and note whether it is in the ground or under a bench. 2. Find the agreement and write down the pump-out frequency it sets. 3. Ask each cleaner to confirm the unit size and that the truck can reach the lid. 4. Ask whether disposal is in the price or added later.

Cleaners quote on trap size, service frequency, access and disposal fees. That is why two kitchens with the same trap can get quite different prices. Without these four answers, you can't compare quotes fairly.

Who cleans a commercial grease interceptor?

A licensed liquid waste contractor pumps out the unit and takes the waste to an approved facility. Your water authority and the NSW EPA set the rules on who can carry and dispose of liquid waste. Ask any cleaner for their licence details before you book.

Keep the paperwork they give you. A dated record of each visit proves to an inspector that the work happened.

If you are a licensed cleaner and want these jobs, you can apply to join GreaseTrapQuotes and check the contractor territory pricing.

What should you do this week?

Start with the simple things.

• Find the unit and note where it is.
• Find your trade waste agreement and read the pump-out frequency.
• Check the date of the last clean.
• Compare quotes on the same four points above.

Grease Trap Quotes sends you three quotes from licensed cleaners by SMS, usually within about a minute of your request. The service covers Sydney today and is expanding to other Australian cities. Read more about GreaseTrapQuotes or see grease trap cleaning for commercial kitchens in Sydney.

Ready to compare? Get 3 grease trap quotes and book the clean before the unit tells you it's full.

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Related reading: Grease Trap Servicing: The Three-Date Check That Tells You What to Do This Month.

Related reading: Grease Trap Interceptor: Make Sure Your Paperwork, Quote and Device All Name the Same Thing.

Related reading: Grease Trap Servicing: Why Two Kitchens With the Same Trap Pay Different Prices.

Related reading: Grease Trap Size: Why a Calculator Answer Is Only the Starting Point.

Related reading: Grease Trap Servicing: What Happens on the Day, and the 48 Hours After the Truck Leaves.

Related reading: Do You Need a Commercial Grease Trap Before You Change Your Menu or Fit-Out?.

Related reading: Grease Trap Servicing for First-Time Bookers: Three Kitchens, Three Decisions.

Related reading: Restaurant FOG Compliance Requirements: An Eight-Step Checklist for Australian Kitchens.

Related reading: Grease Trap Servicing Costs and Waste Disposal: A Reference for Sydney Kitchen Owners.