Grease Trap and Drain Maintenance

A grease trap (grease arrestor) captures fats, oils and grease before they enter the sewer. Australian food businesses generally must have one serviced on a set schedule by a licensed liquid-waste contractor under a trade waste agreement with their water utility or council. Poor maintenance drives blocked drains, foul odours and pests, and can breach both trade waste conditions and the Food Standards Code. Keep every service docket. Key takeaways: A grease arrestor is trade waste infrastructure: your water utility or council sets the pump-out frequency in a written trade waste agreement, and meeting it is a condition of your approval to discharge.. Pump-out intervals vary widely by arrestor size and wastewater volume, commonly from around monthly for busy kitchens to quarterly (or longer) for small, low-grease sites; confirm the exact frequency your provider has set for your premises.. Only a licensed liquid-waste contractor can legally pump out and dispose of grease trap waste, and in some areas (such as Sydney Water's Wastesafe program) the collection is electronically tracked.. Neglected traps and drains are a leading cause of blockages, sewer overflows, foul odours and pest activity, which can breach both trade waste conditions and the Food Standards Code 3.2.3.. Keep pump-out dockets, cleaning logs and your trade waste agreement on file; records are how you prove compliance to a trade waste officer or an environmental health officer.. Typical grease-trap pump-out frequencies: Operation type, Typical interval. High-volume, high-grease kitchen — Around monthly. Medium operation — Every couple of months. Small cafe — Quarterly. Very low-volume site — Longer than quarterly. Why grease trap and drain maintenance matters Every commercial kitchen produces fats, oils and grease (FOG) from cooking, washing up and cleaning. In warm water FOG flows freely, but as it cools in your pipes and the sewer it congeals and hardens. A grease arrestor is designed to slow the wastewater down so the grease floats to the top and heavy food solids settle to the bottom, allowing cleaner water to pass to the sewer. Once the trap fills with accumulated grease and sludge it stops working, and the FOG passes straight into your drains and the public sewer. The consequences are practical and expensive. Internally, an overloaded trap causes slow, smelly floor drains and gully traps, and eventually blockages and backflow into the kitchen. Externally, FOG is a major cause of sewer chokes and overflows across Australia. When a blockage is traced back to a business that has not maintained its trap, the business can generally be held liable for clean-up and repair costs, and can face enforcement action under its trade waste agreement. Check the specific liabilities and penalties that apply with your water authority. FOG that escapes the trap hardens in pipes and causes blockages and sewer overflows.. A full or poorly serviced trap loses its ability to separate grease, so it stops protecting your drains.. Blockages, odours and vermin from a neglected trap create food safety and amenity risks on the premises.. Businesses can generally be held responsible for costs and enforcement when their waste causes sewer problems.. What the law generally requires Two separate but overlapping regimes apply to most food businesses. First, the Australia New Zealand Food Standards Code (Standard 3.2.3, Food Premises and Equipment) requires food premises to have a sewage and waste water disposal system that effectively disposes of all sewage and waste water without ponding or backflow into the building, and in a way that does not jeopardise food safety on-site or off-site. The accompanying FSANZ guidance (Safe Food Australia) treats grease arrestors as part of that disposal system and generally recommends they be located and maintained so they do not contaminate food, attract pests or overflow. Standard 3.2.2 separately requires premises to be kept free of pests. Second, discharging greasy wastewater to the sewer is 'trade waste', which is regulated by your water utility or local council. You generally need a trade waste agreement or approval before you discharge, and that agreement typically specifies the pre-treatment equipment (the grease arrestor), how it must be maintained, and how often it must be pumped out. Requirements vary by jurisdiction and provider, so confirm what applies to you with your water authority or council and your state or territory food regulator. Food Standards Code 3.2.3 requires an effective waste water disposal system with no ponding or backflow into the building.. FSANZ guidance treats grease arrestors as part of that system and expects them to be maintained so they do not contaminate food or attract pests.. Discharging greasy wastewater to sewer is trade waste and generally needs an agreement or approval first.. The trade waste agreement usually sets the required pre-treatment, maintenance and pump-out frequency.. Requirements differ between states, utilities and councils, so always confirm locally.. Who regulates trade waste in Australia There is no single national trade waste authority. In the larger metropolitan areas, the water utility manages trade waste directly. Sydney Water covers greater Sydney; in Melbourne the retail water businesses (such as Yarra Valley Water, South East Water and Greater Western Water) manage it; in South East Queensland, Urban Utilities and the other distributor-retailers apply; in Perth, Water Corporation; and SA Water in South Australia. In many regional and rural areas, the local council acts as the water utility and issues liquid trade waste approvals, often guided at the state level (in NSW, for example, by the state's liquid trade waste regulation guidelines for local water utilities). Because the regulator differs by location, so do the forms, fees, categories and inspection practices. What is consistent is the underlying model: you apply to discharge, your premises and equipment are assessed, and you receive conditions that include a maintenance and pump-out regime. Contact your provider directly to confirm your category, your conditions and your approved list of waste contractors. Metro water utilities (e.g. Sydney Water, the Melbourne retail water businesses, Urban Utilities, Water Corporation, SA Water) regulate trade waste in their areas.. In many regional areas the local council is the water utility and issues the trade waste approval.. Categories, fees and conditions vary by provider; food outlets that generate greasy waste usually sit in a defined food-waste category.. Confirm your specific conditions and approved contractors with your provider.. Setting your cleaning and pump-out schedule There is no single legislated interval that applies everywhere. Your pump-out frequency is set by your water utility or council in your trade waste agreement, and it is based on the size of your arrestor and the volume and greasiness of your wastewater. In practice, intervals commonly range from around monthly for high-volume, high-grease kitchens, to every couple of months for medium operations, to quarterly for smaller cafes; some very low-volume sites may be longer. Treat these as typical ranges only, and follow the frequency your provider has nominated for your premises. A useful rule of thumb used by many operators and regulators is to pump out before the combined grease and solids layer reaches roughly a quarter to a third of the trap's effective depth (Water Corporation, for example, uses a 30% trigger), because beyond that the separation efficiency falls sharply. If your trap is filling faster than your scheduled interval (for example after menu changes or increased trade), ask your provider to reassess the frequency rather than letting it overflow. Critically, a full pump-out is not a job you can do yourself: it must be done by a licensed liquid-waste contractor, and in some areas (such as Sydney Water's Wastesafe program) the collection and disposal are electronically tracked from your site to a licensed treatment facility. Frequency is set individually in your trade waste agreement based on arrestor size and waste volume.. Typical ranges: roughly monthly (busy), every couple of months (medium) or quarterly and beyond (small), but confirm your own interval.. A common trigger is when grease and solids reach about a quarter to a third of the trap's effective depth.. Only a licensed liquid-waste contractor may pump out and dispose of the waste; in some areas it is electronically tracked.. Ask for a reassessment if your trap fills faster than the set schedule.. Daily and weekly drain care in the kitchen Pump-outs deal with what has already reached the trap; good daily habits reduce how much FOG and food solid gets there in the first place, protecting both your drains and your service intervals. The single most effective control is to keep fats, oils and grease out of the drain entirely. Scrape plates, pots and trays into the bin or a used-oil collection drum before washing, and never tip waste cooking oil down a sink or floor drain; use a licensed used-oil collection service instead. Fit and maintain strainers or baskets on all sinks and floor wastes to catch food scraps, and empty them into the general waste. Wipe greasy cookware with paper before it goes into the pot wash. Flush floor drains and gully traps with warm water regularly and clean around them so they do not become odour or pest points. Avoid relying on hot water and chemical degreasers to 'melt' grease down the drain; they simply move solidification further along the pipe, and additives can breach the discharge limits set in your trade waste agreement. Some utilities restrict or prohibit dosing additives into arrestors, so check your conditions first. Scrape and bin food solids before washing up to keep them out of the drains.. Never pour waste cooking oil down any drain; use a licensed used-oil collection drum.. Fit strainers to all sinks and floor wastes and empty them into general waste.. Flush and clean floor drains and gully traps regularly to prevent odour and pests.. Avoid chemical degreasers and hot-water flushing as a way to 'clear' grease into the sewer, and check whether additives are allowed under your agreement.. The pest and odour link A neglected grease trap or drain is one of the most reliable ways to attract pests and generate complaints. Decomposing grease and trapped food solids produce hydrogen sulphide and other gases, which is the classic 'rotten egg' or sour sewer smell that drifts back through floor drains, especially when a trap is overdue for pumping or a gully trap has dried out and lost its water seal. Odour is not just an amenity issue; persistent smells often signal that the system is no longer separating waste effectively. The same conditions feed pests. Cockroaches breed in and travel through drains and grease-laden pipework, rodents are drawn to accumulated food waste, and drain flies (small moth flies) breed in the organic film that lines dirty drains and traps. Under the Food Standards Code, food premises must be kept free of pests and must not provide harbourage for them, so a foul, grease-clogged drainage system can quickly become a food safety finding at inspection. Keeping traps serviced, drains clean and gully trap seals topped up removes the food source and breeding habitat at the same time. Overdue traps and dry gully-trap seals cause hydrogen-sulphide 'sewer' odours through floor drains.. Cockroaches, rodents and drain flies all breed in or are drawn to grease-laden drains and traps.. Persistent drain odour usually signals failing separation, not just a smell to mask.. Clean drainage removes the food source and harbourage that pests rely on, supporting Code compliance.. Records and documentation Maintenance you cannot evidence is, from a regulator's point of view, maintenance that did not happen. Every pump-out by your licensed contractor should generate a docket or receipt showing the date, the site, the volume removed and the disposal destination; keep these on file. In areas with electronic tracking (such as Sydney Water's Wastesafe program), that record is generated in the system, but you should still retain your own copies. Your trade waste agreement or approval, and any correspondence changing your pump-out frequency, should be kept with them. Alongside the pump-out dockets, maintain a simple in-house log for the daily and weekly drain tasks, strainer cleaning, floor drain flushing, degreasing of the pot wash area, and any blockages or issues and how they were resolved. This gives you a defensible trail if a trade waste officer audits your site or an environmental health officer raises drainage as part of a food premises inspection, and it helps you spot when a trap is filling faster than expected. Retain records for at least the period your provider and food regulator require, and check those retention periods locally as they vary. Keep every pump-out docket showing date, volume and disposal destination.. Retain your trade waste agreement and any changes to your pump-out frequency.. Maintain an in-house log of daily/weekly drain cleaning and any blockages or repairs.. Records prove compliance to trade waste officers and environmental health officers, and flag rising fill rates.. Confirm the required retention period with your provider and food regulator.. Worked examples: A trap filling faster than schedule: A busy kitchen finds its grease arrestor reaching about a third of its depth well before the scheduled pump-out after a menu change increased trade. Rather than letting it overflow, the operator asks their water utility to reassess the frequency and books more frequent pump-outs with their licensed liquid-waste contractor. Disposing of waste cooking oil: Instead of tipping used fryer oil down the floor drain, a cafe collects it in a used-oil drum removed by a licensed service. Combined with scraping plates before washing and emptying sink strainers into the bin, this keeps fats, oils and grease out of the trap and protects the scheduled service interval. Checklist: Current trade waste agreement or approval on file with your water utility or council. Grease arrestor sized and installed to your provider's requirements. Pump-out frequency confirmed in writing and diarised. Recurring booking with a licensed (and where required, tracked) liquid-waste contractor. Full pump-out dockets kept for every service. Strainers fitted and emptied on all sinks and floor wastes. Used cooking oil collected in a drum by a licensed service, never poured down drains. Floor drains and gully traps flushed and cleaned regularly, water seals topped up. In-house drain cleaning log maintained and up to date. Grease arrestor maintained so it does not leak, overflow or contaminate food areas. Records retained for the period required by your provider and food regulator. Common mistakes: Treating the grease trap as 'set and forget' and only calling a contractor once it overflows or smells.. Letting an unlicensed contractor, or staff, pump out the trap, which is generally not permitted and can breach trade waste conditions.. Pouring waste cooking oil or fat down sinks and floor drains instead of using a used-oil collection service.. Relying on hot water or chemical degreasers to push grease down the drain, which just moves the blockage further along the sewer.. Not fitting or not emptying sink and floor-waste strainers, so food solids overload the trap.. Discharging greasy wastewater with no trade waste agreement in place at all.. Skimming the surface at a pump-out instead of a full clean-out of grease and settled solids.. Keeping no dockets or cleaning records, so compliance cannot be proven at an audit or inspection.. Ignoring a trap that fills faster than its schedule instead of asking the provider to reassess the frequency.. State and territory notes: NSW: Sydney Water regulates trade w