Commercial disposal of fats, oils, grease, and solids (FOGS)

When fats, oils, grease, and solids go down the drain, they cool, solidify, and build up in pipes. Over time, this buildup can lead to clogs, unpleasant odours, and sewer backups, resulting in costly repairs and disruptions for businesses across the city.

An inspector and someone at a commercial kitchen having a discussion after a grease trap inspection.

On this page

Common sources of fats, oils, grease, and solids
Essential equipment for commercial kitchens
Protect the pipes in your business
Questions about fats, oils, grease, and solids
Fats, oils, grease and solids resources
Best management practices

Common sources of fats, oils, grease, and solids

Fats, oils, grease, and solids come from everyday food preparation in commercial kitchens. They are commonly found in:

Meat drippings and lard
Cooking oil, butter and margarine
Sauces, spreads and salad dressings
Milk, yogurt and other dairy products
Food scraps
Soup

Facilities like restaurants, cafes, lunch counters, cafeterias, bars, hotels, food processing and bakeries all generate fats, oils, grease, and solids as part of their operations.

Essential equipment for commercial kitchens

If food preparation is taking place in your business, a grease trap or interceptor will need to be installed on all fixtures that may release fats, oils, grease, and solids, in a location that is easy to access for routine maintenance and inspection.

These devices are necessary in any commercial kitchen. They capture fats, oils, grease, and solids - including cooking oil, fryer grease, butter and other food-related fats - before they enter the plumbing system. This helps prevent clogged pipes, blockages, sewer backups, and costly plumbing repairs.

Protect the pipes in your business

The best way to safeguard your plumbing is to ensure all kitchen staff are trained to properly dispose of fats, oils, grease, and solids:

Scrape food scraps into the garbage before washing.
Wipe cooking oils and all other food-related fats from pots and pans with a paper towel or spatula and throw into the garbage.
Collect used fryer grease and place it directly into your designated outdoor grease bin.
Use strainers in sinks to reduce the buildup of food solids in your grease interceptor.

Questions about fats, oils, grease, and solids

Fats, oils, grease, and solids create major issues in wastewater systems:

Poor solubility: Cooking oil and fryer grease separates from water and sticks to pipes and equipment.
Pipe blockages: Build-up reduces capacity, leading to backups and overflows.
Treatment disruption: As cooking oil and fryer grease cools, it congeals into mats that hinder plant operations and can cause shutdowns.
Regulatory concern: Waste from restaurants and other sources has led to requirements for grease interceptors to control discharges of fats, oils, grease, and solids.

Grease traps (also called grease interceptors) capture fats, oils, grease, and solids before they enter your pipes. Made from metal or plastic, they can be installed above grade or in-floor and connected to single or multiple fixtures. Grease traps help prevent blockages in your private plumbing, and protect the wastewater collection system.

Grease traps are:

Typically installed in the kitchen area, near grease-producing fixtures.
Appropriately sized for the fixtures that drain into them, where wastewater flows into the trap and internal baffles slow the flow to allow fats, oils, and grease to cool, congeal, and rise to the surface. Solids settle at the bottom and remaining wastewater flows out. The remaining fats, oils, grease, and solids are removed during routine maintenance.
Metal grease traps are better suited to high-heat applications, such as the discharge from a wok range. However, they are more prone to corrosion and require more frequent repair or replacement.
Much larger tanks, usually installed underground and outside of the building, are sometimes required for large-scale operations. These tanks typically receive discharge from multiple fixtures that are releasing fats, oils, and grease. Due to their size, these tanks must be professionally cleaned at regular intervals.

An EPCOR employee inspecting a commercial kitchen's grease trap.

The choice depends on your facility’s size and output, must be installed in an accessible location and cleaned regularly per the Code of Practice for Fats, Oil, Grease & Solids Interceptor Installation & Maintenance Requirements.

Grease traps should be cleaned at least once a month, or whenever fats, oils, grease, and solids reach 25% of the grease trap’s total capacity. If the trap or interceptor is consistently exceeding this 25% threshold, you’ll need to increase the cleaning frequency to maintain proper function and compliance.

All grease interceptors must be cleaned regularly and properly disposed of, and cleaning logs must be maintained for a period of two years.

Fats, oils, grease and solids resources

Best management practices

Small steps make a big difference in keeping your plumbing system efficient and avoiding costly repairs. Implementing best management practices helps reduce the:

Amount of fats, oils, grease, and solids that go down the drain.
Cleaning frequency of grease traps and interceptors.
Risk of clogged pipes and sewer backups.

Caustics, acids, solvents and emulsifying agents may seem like a quick fix, but they only push the problem downstream. Grease dissolved by these agents can re-solidify later, causing bigger blockages.

Clean your grease trap monthly, or whenever fats, oils, and grease reach 25% of the trap’s capacity.
If cleaning costs are too high, consider installing a larger grease trap or multiple grease traps in series. This can reduce costs and save time over the long term.
Once fats, oils, grease, and solids reach 25% of the grease traps capacity, they lose efficiency and allow grease to pass into the sewer.

Always ensure cleaning is done properly. Inspect interceptors after service and observe staff during grease trap cleaning.
Keep a maintenance log with dates, amounts of fats, oils and grease removed and who performed the cleaning. Logs are required for all businesses with grease retention devices.

Train kitchen staff to avoid pouring cooking oil and fryer grease down drains and dispose of food scraps in the garbage.
Post “No Grease” signs above sinks as gentle reminders to your staff.
Share the “why”: less grease in the system means fewer blockages, lower costs and smoother operations.

Avoid discharging water hotter than 140°F as it liquefies grease, which re-solidifies further downstream.
Wipe pots, pans and dishware with paper towels or scrapers before washing.
Use disposable high-temperature pan liners to reduce the discharge of grease and food when cleaning pots and pans.
Always dispose of food waste in the trash, not the drain.
Install drain screens in sinks and train staff to empty them into the garbage.

Collect waste fryer grease, grill grease and cooking oils for recycling. Partnering with a grease recycler can even save money and reduce garbage hauling costs.
Don’t overfill outdoor grease bins - outdoor storm catch basins release directly to the environment without treatment.

If a spill occurs, report it to EPCOR at (780) 412‑4500.
Store grease away from storm drain catch basins to prevent spills from reaching the environment.
Use absorbent pads or similar materials to clean spills and dispose of them in the garbage.
Scrape and sweep spills before using water. Dry cleaning keeps fats, oils and grease out of drains.

Clean kitchen exhaust filters regularly in a sink connected to the grease trap or interceptor.
If using harsh chemicals to clean filters, first remove excess grease and dispose of it in the garbage. This prevents the chemicals from dissolving grease inside your grease trap.
Never clean filters outside. Chemicals and greases are not allowed to enter a catch basin.

Dishwashers are not allowed to discharge to a grease trap unless they have their own dedicated trap. High water temperatures and detergents can flush fats, oils, grease, and solids further downstream.