Grease Trap Cleaning and Tips for Grease Management

With increased awareness of fatbergs, the importance of grease traps in commercial kitchens and the food service industry is clear. These devices prevent fats, oils, and grease (FOG) from entering sewer systems, protecting drainage infrastructure and the environment. Understanding grease trap basics and taking grease prevention seriously safeguards the environment and your business from fines. Investigators can trace FOG back to its source, holding businesses accountable.

You've chosen the right grease trap for your business, considering factors like sink number and flow rate, and it's correctly installed. However, ongoing maintenance is crucial. Neglected grease traps are ineffective, and simply having one installed doesn't prevent fines. Ineffective traps, due to improper installation or cleaning, still incur liability, highlighting the importance of proper cleaning and maintenance.

Both passive and automatic grease traps require cleaning. Cleaning can be a messy job, so hiring a certified specialist is recommended. Larger, typically external grease traps require pumping equipment and trained specialists. 

Smaller units can be cleaned in-house, but disposal must always be handled by a licensed waste contractor, whether you clean yourself or hire a specialist. Professional service is strongly advised to minimise the risk of prosecution due to incorrect procedures.

• FOG Removal: Skim and remove the top layer of FOG daily. Staff must use Personal Protective Equipment (PPE) during this process. The collected FOG must be stored appropriately and disposed of by a licensed contractor.
• Inspection: Check daily for any obvious faults or issues with the actual grease trap and ensure couplings are still achieving a tight seal.
• Solid Waste Management: Remove and empty the solids container or filter.
• External Cleanliness: Ensure the external parts of the trap are clean.
• Scrape Plates/Pans: This helps reduce the amount of FOG that enters the trap.
• Log Maintenance: Update the cleaning and maintenance log after every cleaning or maintenance.*

• FOG Container Management: Remove and empty the FOG container. Ensure it's appropriately stored in sealed containers and disposal is handled by a licensed contractor.
• Inspection: Check daily for any obvious faults or issues with the actual grease trap and ensure couplings are still achieving a tight seal.
• Solid Waste Management: Remove and empty the solids container or filter..
• External Cleanliness: Ensure the external parts of the trap are clean.
• Scrape Plates/Pans: This helps reduce the amount of FOG that enters the trap.
• Log Maintenance: Update the cleaning and maintenance log after every cleaning or maintenance.*

*Read more about the importance of filling out cleaning and maintenance logs and What Information Should Be Recorded in Grease Trap Management Records.

These tasks should be completed by a third-party company and are crucial for both passive and automatic grease traps:

• Deep Clean: A thorough cleaning of the entire system.
• Electrical and Mechanical Service: Regular servicing ensures that automatic grease traps function optimally.

Daily attention and maintenance is necessary, however the type of grease trap, usage, and water flow will all contribute to required frequency. 

Manual epoxy steel grease traps and stainless steel passive grease traps require more frequent, in-depth cleaning. Opening these traps can release bacteria, so a deep clean is recommended afterwards, adding to the expense with the closing of the kitchen.

Automatic grease traps/grease recovery units (GRUs) require less frequent in-depth cleaning. The grease collection container or cassette is visible and so traps don’t need to be opened to check on levels. The ease of removing, cleaning and maintaining GRU’s means they are often preferred by water companies. 

Top Tip: Clean traps when they are about 25% full, never waiting for overflow. 

The '25% Rule' is a common sense guideline stating that once 25% of a grease trap's capacity is filled with FOG and solid waste, it should be cleaned. This rule is vital because:

• Efficiency: A grease trap filled beyond 25% of its capacity cannot effectively separate FOG from wastewater.
• Compliance: Many local regulations mandate adherence to this rule to prevent sewer blockages and environmental hazards.
• Longevity: Regular maintenance extends the life of the grease trap and prevents costly repairs or replacements.

Adhering to a cleaning schedule is vital for hygiene, environmental protection, and regulatory compliance. Follow the 25% rule and employ daily/quarterly tasks, and consult your local water authority.

All traps need regular cleaning, maintenance, and servicing. If cleaning is required too frequently, consider upgrading your installation.

Proactive FOG management is better than reactive. After installing a grease trap, implement these best practices:

• Clean food solids and FOG products regularly from the grease trap; frequency will depend on the size and capacity of the grease trap. Store fats, oils and grease in a suitable container until collection is arranged.
• Only use a licensed grease contractor to dispose of FOG. Contact your local authority for information on specialist cleaning contractors.
• Regularly check grease traps to assess the integrity of the structure. Note any damages to internal and external walls, fixing or replacing as necessary.
• Always keep a complete record of cleaning, maintenance and disposal on site and ready for inspection.
• Make sure the lid fits firmly to prevent pests getting in and unpleasant odours getting out.
• Always follow manufacturer's guidelines for cleaning and maintenance.
• Keep grease traps cleaner for longer by using a liquid fat digester to break down grease and fats and reduce manual cleaning.
• Consider an automatic dosing pump to deliver regular quantities of fat digester. Bio-dosing systems such as GreasePak, can be used with passive traps to break down FOG, potentially reducing cleaning frequency. Read more about bio-dosing systems.
• Keep detailed records of cleaning and disposal, along with FOG quantities

• Scrape food residue and wipe items before rinsing.
• Use sink strainers.
• Clean strainers and standpipes.
• Collect used oil for removal by a registered contractor.
• Train staff on proper procedures and FOG handling.

DO NOT

• Flush sinks with boiling water.
• Use a grease trap with a high-temperature dishwasher.
• Connect garbage disposals to grease traps.
• Use chemicals or bleach in grease traps.

Regular review is crucial for health and safety, and it's a legal requirement under HACCP.  Effective cleaning of equipment that uses or produces oil such as commercial deep fryers, chargrills and commercial griddles reduces fire risk.  A Grease Management Procedure is advised for catering kitchens and staff should be familiar with it. This procedure outlines cleaning schedules, substances, and oil disposal for several areas of a commercial kitchen, including grease traps.

Regular cleaning of kitchens is essential for a number of reasons:

• To eliminate the risk of fire from grease and oil near cooking equipment.
• To ensure no contaminants are left on surfaces
• To prevent the build-up of bacteria
• To stop any fats, oils and grease (FOG) from entering drains

The cleaning schedule needs to take into account all areas of the kitchen where oil or grease may collect including:

• Fans, cooking hoods and kitchen canopies
• Walls
• Floors
• Under cookers and storage units
• Ovens and fryers
• Grease traps

The Water Industry Act 1991 stipulates that it is a criminal offence to permit anything to enter the drainage system that may impede the natural flow of the water. These blockages are also an offence under the Food Safety Act 1990. Are your grease traps still sufficient for the water flow and usage of your kitchen?

Keep oil from food out of grease traps and drains as much as possible by wiping plates before swilling. Dispose of large amounts of oil in food waste bins before washing.

Change fryer oil regularly and dispose of it via commercial recycling companies. Store used oil in sealed containers until collection.

Scrape food into bins or compost containers. Wipe plates with paper towels before rinsing and use drain covers in sinks.

Staff training is critical. Train staff on food safety, equipment use, personal hygiene, cleaning procedures, and grease management. Review and refresh training regularly.