Understanding how your grease trap works is the first step to keeping it compliant and your kitchen running without costly emergency callouts. This guide explains the mechanics of grease interception, the signs that a trap needs attention, and the maintenance practices that keep your Dubai Municipality compliance certificate current.
What Is a Grease Trap?
A grease trap — also called a grease interceptor or FOG interceptor — is a plumbing device installed between a commercial kitchen’s drainage outlets and the municipal sewer network. It captures fats, oils, and grease (FOG) before they reach and solidify inside public drainage pipes. Under Dubai Municipality regulations, every commercial kitchen connected to the Dubai drainage network must have a DM-approved grease interceptor installed and professionally cleaned at regulated intervals.
How Does a Grease Trap Work?
The physics are simple: FOG is less dense than water and floats. A grease trap exploits this in three stages:
- Inlet baffle: Wastewater enters through a downward-facing inlet pipe. The direction change reduces flow velocity and allows solids to sink.
- Retention zone: The slow-moving water sits in the trap long enough for grease to rise and accumulate as a floating layer on the surface. Solid food particles sink to the bottom.
- Outlet baffle: Relatively clean water exits through an outlet pipe that draws from the middle column — below the grease layer and above the sediment — before discharging to the municipal sewer.
Efficiency drops sharply once the grease layer and sediment consume more than 25% of the trap’s working volume. At that point FOG carries over into the outlet, bypassing the system entirely — which is why Dubai Municipality mandates cleaning before this threshold is reached.
Regular Cleaning and Maintenance
The most important maintenance task is cleaning at the correct frequency. Dubai Municipality requires:
- High-volume kitchens (200+ meals/day): monthly cleaning minimum
- Medium-volume kitchens (100–200 meals/day): every two months
- Low-volume outlets (under 100 meals/day): quarterly minimum
Cleaning must be performed by a DM-licensed contractor who issues a compliance certificate on the day of service. Self-cleaning is not accepted as evidence of compliance. View our full range of cleaning services for scheduled maintenance options.
7 Warning Signs Your Trap Needs Immediate Attention
- Slow drainage across multiple kitchen sinks simultaneously
- Foul “rotten egg” odour from floor drains or sinks
- Grease or dirty water backing up into the sink
- The trap is more than 25% full at inspection
- Grease layer on the surface exceeds 5cm thickness
- Gurgling sounds from drains after water use
- Your last cleaning certificate is approaching its expiry date
If you notice signs 1–3, stop kitchen operations and call GTC on +971 58 570 7110 immediately — this is an overflow situation that requires emergency cleaning.
Preventative Measures Between Cleaning Visits
- Train kitchen staff to scrape plates and pans before washing — reducing the FOG load reaching the trap extends time between services.
- Avoid pouring hot water or chemical degreasers directly into the trap — these temporarily dissolve grease that then re-solidifies further downstream in the drain line.
- Install a bio-dosing system — these introduce beneficial bacteria that break down FOG between pump-outs, reducing odour and extending effective trap life.
- Inspect the trap lid and baffles after each cleaning service and report any damage to GTC before the next visit.
FOG Disposal: What Happens to the Waste
All FOG removed from a grease trap must be transported to a DM-approved disposal facility by the licensed cleaning contractor. Pouring FOG waste into drains, skips, or general waste is illegal in the UAE and carries significant fines. GTC provides a waste disposal manifest with every service — a document that records the volume removed and the disposal facility used.
How Much Does Professional Grease Trap Cleaning Cost?
GTC cleaning starts from AED 125 per visit for a small under-sink trap, including the DM compliance certificate. Need a new or replacement trap? Browse our supply and installation options. For common questions, check our FAQ page. Call +971 58 570 7110 for a fixed quote.