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

A commercial grease trap catches fat, oil and grease before they reach the sewer. If your kitchen cooks food and washes up on site, your water authority or council almost certainly requires one. A menu or fit-out change can alter the size or type you need, so check before you build.

Most operators only think about the trap when it smells, backs up or an inspection is due. The better time is earlier, while you are still planning the change.

Which fixtures in a commercial kitchen have to drain through the trap?

The trap treats greasy wastewater. So the real question is which of your drains carry it.

The usual candidates are the pre-rinse sink, the pot wash sink, the floor waste under the cooking line and the dishwasher outlet. Hand basins and toilets normally stay off the trap. Your approval documents set the final list, not a rule of thumb.

Try a quick test. Walk the kitchen and list every fixture that sees food scraps, oil or hot detergent. Then check that each one appears on the plumbing plan your trap was approved against. A fixture that drains greasy water but sits outside the plan is a red flag. Our guide to tracing what drains into your trap shows you where to start.

The national plumbing rules sit in the Plumbing Code of Australia, published by the Australian Building Codes Board. Your state and water authority add their own requirements on top.

What changes when you alter the menu or the fit-out?

Most guides skip this question. A trap is approved for the kitchen as it was described at the time. Change the kitchen and that description no longer matches.

Take a worked example. A cafe serves toasties, salads and coffee on an under-bench trap. The new owner adds a fryer, a wok burner and a dishwasher, and starts serving hot meals through lunch and dinner. The trap has not moved, but the load on it has changed completely.

Use this decision rule:

• If you add a cooking appliance that uses oil, ask the water authority whether your approval still covers it.
• If you add or move a sink, floor waste or dishwasher, ask whether the new fixture can connect to the existing trap.
• If you add seats, trading hours or a second service period, expect the cleaning schedule to shift even when the trap stays the same.

The first two need an answer before the work starts. You can sort out the third afterwards with your cleaner. Asking first costs a phone call. Moving a drain later costs a plumber and lost trading days.

What does your trade waste agreement say about the trap?

Your trade waste agreement with the water authority sets the pump-out frequency for a commercial kitchen. Many operators do not know theirs, and that gap causes more trouble than almost anything inside the trap itself.

In Sydney, that authority is Sydney Water. Other cities have their own authority and their own conditions. Your agreement, or the approval attached to it, tells you the required schedule. Your cleaner can then price against a real number instead of a guess.

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. Know your required frequency and trap size before you ask, and the quotes compare cleanly. Our page on grease trap cleaning in Sydney explains what drives those differences.

Who answers for the trap when you lease the space?

The lease usually answers this, but few tenants read that clause. Some landlords keep responsibility for a shared or in-ground trap. Others pass the full cost and the paperwork to the tenant.

Confirm three things in writing:

1. Who owns the trap and where it sits. 2. Who books and pays for the cleans. 3. Where the service records go.

When the council or water authority inspects, they ask the person running the kitchen for evidence. A landlord's promise will not help you on the day. Food businesses also answer to food safety rules, and Food Standards Australia New Zealand is the place to start for those. Grease waste disposal falls to environmental regulators, such as the NSW EPA in New South Wales.

What should you do this week?

Keep it short and practical.

1. Find the trap and note its type and size. 2. Find your trade waste agreement or approval and read the pump-out frequency. 3. List the fixtures that drain to the trap and compare them to the plan. 4. If you are changing the menu or fit-out, ask the water authority before work starts. 5. Learn the early warning signs. Our guide to the signs your grease trap needs cleaning covers them.

Then get the clean priced. 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. Get 3 grease trap quotes and book your clean before the next inspection date catches you out.

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Related reading: Grease Trap Emptying in Sydney: How Often Must Your Kitchen Do It?.

Related reading: Grease Trap Servicing Quotes: How to Compare Three Offers Line by Line.