A Guide to Common Grease Trap Problems

If you run a commercial kitchen, food truck, restaurant or any food service operation in Western Australia, your grease trap is one of the most important and most overlooked pieces of infrastructure on your premises.

When it’s working properly, you won’t think about it at all. When it’s not, you’ll know about it quickly, and so will everyone nearby. At Rogue Works, grease trap servicing is one of the most common callouts we attend across the South West, and in our experience, most problems come down to one thing: the trap not being serviced often enough.

What Does a Grease Trap Actually Do?

A grease trap (also called a grease interceptor) sits between your kitchen drainage and the main wastewater system. Its job is to capture fats, oils and grease (FOG) before they enter the sewer, where they can solidify, cause blockages, and create serious problems for both your property and the wider wastewater network.

Regular maintenance keeps the trap functioning correctly. Neglect it, and problems tend to escalate fast. Our team sees this firsthand on a regular basis, and we can tell you that a small servicing bill is always cheaper than an emergency callout or a compliance issue.

Common Grease Trap Problems

1. Foul Odours

This is usually the first sign something is wrong. A grease trap that hasn’t been serviced recently will begin producing strong, unpleasant smells, typically a rotten or sulphurous odour that can travel through the kitchen and into dining areas.

What causes it: As grease and food waste accumulate, they decompose and produce hydrogen sulphide gas. The smell gets worse the longer the trap goes without being pumped out.

What to do: Get a pump-out booked. At Rogue Works, we’ll have your trap cleaned out and smelling a whole lot better in no time. If odours persist after servicing, there may be a more significant issue such as a damaged seal, cracked housing, or a venting problem. Our team can inspect and advise on the spot.

2. Slow or Blocked Drains

If your kitchen sinks and floor drains are running slowly or backing up, a full or partially blocked grease trap is often the culprit.

What causes it: When a grease trap reaches capacity, wastewater has nowhere to go and begins to back up into the drainage system. In some cases, solidified grease can also cause partial blockages in the pipes leading to or from the trap.

What to do: A pump-out will usually resolve the immediate issue. Where blockages have formed in the lines themselves, our team can clear the pipes using high-pressure water jetting to get everything flowing freely again.

3. Grease Trap Overflow

An overflow is a more serious version of a blockage and a compliance issue. Grease and wastewater can spill onto the floor, into surrounding soil, or directly into the stormwater or sewer system, all of which carry significant health and environmental risks.

What causes it: Overflow almost always comes down to a trap that hasn’t been pumped out often enough. High-volume kitchens can fill a trap surprisingly quickly, particularly if the trap is undersized for the operation.

What to do: Call us. We offer urgent callouts across the South West and our team will get to you as quickly as possible. Once things are under control, we’ll help you review your servicing schedule and assess whether your trap is appropriately sized for your operation.

4. Solid Waste Accumulation

Grease traps are designed to capture FOG, but over time solid food waste also accumulates at the bottom of the trap. This layer, known as the sludge layer, reduces the effective capacity of the trap and causes it to fill faster.

What causes it: Food scraps entering the drainage system, inadequate inlet screening, or infrequent servicing.

What to do: Our pump-out service removes both the grease layer and accumulated solids in one visit. We’ll also take a look at your inlet basket or strainer and let you know if there’s anything that can be done to reduce the amount of solid waste entering the trap in the first place.

5. Damaged or Deteriorating Components

Grease traps take a beating over time. Lids, baffles, inlet and outlet pipes, and the trap housing itself can all deteriorate, particularly in older systems or those exposed to harsh cleaning chemicals.

What causes it: Age, chemical exposure, ground movement, or physical damage. Concrete traps in particular can crack over time, while plastic components can warp or break down.

What to do: During every service, our team does a visual check and will flag anything that looks like it needs attention. We’d rather tell you about a small issue now than have you dealing with a bigger one down the track. In some cases a repair is all that’s needed; in others, replacement is the smarter long-term call, and we’ll give you an honest assessment either way.

6. Non-Compliance with Local Regulations

In Western Australia, grease trap maintenance isn’t optional. It’s a regulatory requirement for most commercial food operations. Failure to maintain your trap adequately can result in fines, licence issues, or being required to upgrade your system entirely.

What causes it: Irregular servicing, lack of documentation, or operating a trap that no longer meets current standards.

What to do: Keep records of all pump-outs and inspections. At Rogue Works, we can help you stay on top of your compliance obligations, and we understand the local requirements that apply to businesses across the South West.

How Often Should a Grease Trap Be Serviced?

There’s no one-size-fits-all answer. It depends on the size of your trap and the volume of your operation. As a general rule, most commercial kitchens in WA should be servicing their grease traps every one to three months, with high-volume operations needing more frequent attention.

In our experience, the best approach is to monitor your trap and build a schedule around how quickly it actually fills. Our team is happy to help you work out the right cadence for your setup, and we’ll always give you a straight answer rather than a one-size-fits-all recommendation.

Need a Grease Trap Service in the South West?

At Rogue Works, we provide professional grease trap cleaning and pump-out services across Western Australia’s South West. Our team knows this work inside and out, and we take pride in showing up on time, doing the job properly, and leaving your kitchen compliant and operational.

Whether it’s a routine service or an urgent callout, we’re ready to help. Get in touch today for a free quote.