Grease Trap in a Commercial Kitchen: The Five Questions to Ask Before Your First Clean

It is 4:40 on a Friday. Dinner service starts at 5:30. The floor drain behind the pass is holding water a little longer than usual, and a sour smell near the back door was not there on Monday. You open the hatch outside and realise you have never once looked inside it. You do not know who services it, when it was last done, or what the paperwork says.

This is how most operators meet their grease trap. In our experience, most only think about the trap when it smells, backs up, or a council or Sydney Water inspection is due. This guide gives you five questions to answer before that Friday arrives. Answer them in order and the rest of grease trap management gets much easier.

Question 1: What does your trade waste agreement say?

A grease trap in a commercial kitchen is more than a plumbing fixture. It sits inside a legal arrangement with your water authority. In Sydney that is usually a trade waste approval or agreement with Sydney Water, and it sets the pump-out frequency for your site. Many operators do not know theirs.

Fix that first. A cleaner's habit or a neighbour's advice does not override the schedule in your agreement.

Where to find it

Check your lease handover pack, your compliance folder, or the email from when the kitchen was fitted out. If you took over the site, ask the landlord or the previous operator. If nothing turns up, call your water authority and ask what it has on file for the address.

What to write down

Copy three things onto one page: the required pump-out frequency, the trap size and type, and any conditions on how waste must be removed. Pin it where the person who books the service will see it. You do not need our guide on how often to clean a grease trap to get started. Your agreement already answers that question for your site.

Question 2: Which trap do you actually have, and where is it?

Search for "commercial kitchen grease trap" and you mostly get definitions. You need something more specific: where yours is and how someone reaches it.

Most kitchens have one of three setups. A small unit sits under or near the sink inside the kitchen. A larger in-ground trap sits outside, under a heavy lid in a car park, laneway or loading area. Some sites share infrastructure across several tenants. Each setup changes who can reach the trap, how long a visit takes and what the cleaner needs on the day.

The five-minute walk

Walk the kitchen and the exterior with your phone. Photograph every lid or hatch. Note whether a truck can park within hose reach, whether bins or stock block the lid, and whether you need a key or the landlord's permission to get in. Send those photos to anyone who quotes you.

Question 3: What goes down your drains?

The trap catches fats, oils and grease before they reach the sewer. Guidance from the Environment Protection Authority Victoria and other state bodies treats this as the whole point, because grease hardens and blocks pipes.

Two kitchens with the same trap can load it very differently. A wok-heavy takeaway rinsing pans in the sink sends far more grease to the trap than a sandwich bar does. The rule is simple. Scrape plates and pans into the bin first. Collect used cooking oil in a container for a licensed collector, and never pour it down a drain. In New South Wales the NSW Environment Protection Authority regulates waste transport, so check that your collector holds the right authorisation. Do not let hot water and strong detergents flush grease through the trap before it has time to separate.

If your menu or volume has changed since the agreement was written, tell the water authority and rethink your schedule. A schedule set for a quiet cafe will not suit the same room once it runs as a busy pub.

Question 4: Who books the clean, and who checks it happened?

A trap only stays compliant if someone books the service on time and keeps proof. Assign a person, not a team. Put the due date in a shared calendar with a reminder a fortnight ahead, so you never end up booking at the last minute.

Keep the cleaner's docket after each visit. A useful docket lists the date, the site, what was removed and where it went. Inspectors ask for these records, and they show your next cleaner what was done last time. Our post on the warning signs a trap needs cleaning covers what to watch for between visits. What happens if you skip cleaning explains the cost of leaving it.

Question 5: What will the quote actually depend on?

Cleaners price on trap size, service frequency, access and disposal fees. That is why two kitchens with the same trap can get quite different prices. A trap with a blocked lid, a long hose run or a tight time window costs more than the same trap with a clear bay.

A worked example

Take two cafes with identical traps. Cafe A has its lid in an open yard, photos ready and its agreed frequency on hand. Cafe B has its lid under a pallet in a locked shed and does not know its frequency. Cafe A can compare three quotes line by line in minutes. Cafe B gets vague pricing, a call-out fee for access and probably a second visit. Preparation makes the difference, not the trap.

Bring your answers to questions one to four and ask each cleaner to price the same job. Our page on grease trap cleaning for a commercial kitchen covers cost and frequency in more detail, and there is a Sydney version at grease trap cleaning in Sydney.

Get your three quotes

Once you have sorted the agreement, the photos and your drain habits, the quote is the easy part. 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 compare them against your agreement.

Are you a licensed contractor? You can apply to join or see territory pricing.

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*Written by Mario Lucas. Mario runs Grease Trap Quotes, which matches commercial kitchens in Sydney with licensed grease trap cleaners.*

Related reading: Grease Trap Servicing Between Visits: The Checks That Tell You to Book Early.

Related reading: Grease Trap in a Commercial Kitchen: What Happens at the Sink Decides How Often You Pay for a Clean.

Related reading: Grease Trap Servicing: Reactive, Scheduled or Agreement-Led? Pick the Model That Fits Your Kitchen.