Turning Your Grease Into Green: How to Profit from Used Cooking Oils

In the restaurant industry, disposing of used cooking oils and trap grease can be a messy and expensive business, with the risk of fines for incorrect disposal. Not only will a fat, oil and grease (FOG) recycling program reduce the amount of organic material discharged into the wastewater system, it will also reduce your maintenance costs and could generate significant income from rebates for your business.

Grocery stores and distribution stores can also benefit from implementing a FOG recycling program for their waste oils and greases.

Recycling these organic materials into biofuel is a perfect example of the circular economy in action, turning what was once considered a waste into a valuable resource for another industry. The EPA estimates that producing biofuel from waste grease results in an 86 percent reduction in greenhouse gases, by reducing the consumption of non-renewable fossil fuels. This makes it a great opportunity for businesses to reduce the environmental impact and carbon footprint of their waste operations, while also improving profits.

Capturing the FOG

Several grease-separation devices are available for the food service industry, including:

  • Manual grease traps, the most common devices. These are relatively cheap and simple to maintain but must be regularly cleaned to manually remove the FOG.
  • Automatic grease interceptors, which mechanically separate the FOG from the wastewater, sending it to a designated container. They are more complex and efficient than manual separators and are generally used by large restaurants and foodservice operations.
  • Grease interceptors, which are installed outside of the kitchen, typically in facilities producing large volumes of FOG, and are maintained by professional grease collectors.

Whichever separator you use, a device should be installed at each FOG-producing area in your operations, from prep to fryers to floor drains.

Trap vs. Interceptor – How They Work and How They Differ

National Waste Associates - Waste Trap Diagram

According to the Universal Plumbing Code, “… a grease trap/interceptor is a plumbing device that is installed in a sanitary drainage system to ‘trap’ or ‘intercept’ non-petroleum fats, oil, and greases (FOG) from a wastewater discharge.” Wastewater flows from the sink or drain into a tank. As the wastewater cools, the FOG hardens and the food solids settle. The FOG fills the grease trap from the top down, displacing the wastewater from the middle of the grease trap and into the sanitary sewer or septic system. Inground grease interceptors work in the same method but at a larger scale.

The difference between a grease trap and a grease interceptor is the flow rate of wastewater that the device can handle. Grease traps work well with lower water pressure – less than 50 gallons per minute. Large-scale establishments with a high volume of flow, such as more than 50 gallons per minute, will need a grease interceptor as they are fully equipped to handle the extensive grease that flows through the drains.

FOG that accumulates in food wastewater are hazardous to sewer lines. This is due in part because grease traps were invented in the 1880s and its technology has remained nearly unchanged ever since. That’s why it is important to have a device in place. Whether the unit is a grease trap or grease interceptor, they work the same. FOG floats to the surface, leaving the wastewater to flow into the sewage system.

FOG Best Practices

Here are a few best practice tips for getting the greatest cost savings out of your FOG program:

  • Properly train employees to dispose of solidified grease into a designated container so that it can be transferred to a grease dumpster for recycling.
  • Use sink and floor sink drainers.
  • Direct all drains from FOG producing sources to a properly sized grease interceptor.
  • Don’t dispose of food waste into a garbage disposal unit, which uses an excessive amount of water, contaminates the wastewater, and can cause costly blockages. Food waste should instead be collected separately for composting.
  • Post “No Grease” signs above sinks.

FOG recycling programs will vary depending on your restaurant and should also be tailored by region and municipality. A reputable waste and recycling management company can help you navigate all the specific laws and regulations in your areas of operation and reduce your exposure to improper handling.

Profit from Your Grease

If your restaurant produces a significant amount of yellow grease from a deep fryer or recovers grease from a trap fitted with a grease-recovery device, you can sell this oil to be used in everything from the manufacturing of products to biodiesel.

A recent study showed 30% of yellow grease gets turned into biofuel or about 113 million pounds per month. The demand by refineries for cheap raw materials has caused the price of used cooking oil to increase 230% since 2000. According to the USDA, prices for recycled cooking oil has been trending up with prices ranging from $22.50 to $27.75 ($/cwt), up nearly 10% from a year ago. With the demand for biodiesel from the truck transportation industry expected to continue growing, the trend in used cooking oil prices is likely to continue to rise as well.

NWA Can Help Turn Your Grease into Green

Many restaurant chains with locations spread across multiple regions miss out on significant income opportunities when they manage their own FOG recycling programs. Either they’re unaware of the rebate opportunities at each location, or they undervalue the waste product and so don’t leverage all of the potential opportunities for recovery and recycling.

NWA eliminates all the hassles of managing FOG recycling programs. Since NWA is on site managing waste and recycling solutions, it’s simple to incorporate grease recovery with your core waste program. NWA has an extensive number of vendors in each state and selects the right vendor for each location in order to get the greatest rebates. It then consolidates all the activities into one clean invoice and you receive the rebate; it’s that simple.

Success Story – Turning Used Cooking Oil into Biofuel – And a Profit!

A nationwide chain of 125 restaurants was disposing huge quantities of used cooking oils each year. They realized that this was a potential revenue source and opportunity to ‘green’ their operations.

As they already had a successful core waste and recycling program with NWA, they asked for help in turning this waste product into a revenue stream.

They were able to develop a robust collection program to capture the yellow and brown grease produced by the restaurants (the used cooking oils and grease captured by their grease traps). Over a three-year period, nearly 300 tons of yellow grease was recovered, which was used to generate over 79,000 gallons of biofuel.

This generated rebates for the company in excess of $100,000, and in producing biofuel from their waste, eliminated nearly 700 tons of CO2 emissions from the atmosphere. That’s the equivalent of taking 137 cars off the road for a year!


It is important to remember that any restaurant, food distribution center or grocery store has the potential to turn their FOG from a disposal cost to a revenue stream. By doing so, you’ll not only benefit from cost savings and rebate income, but you’ll also make your waste operations more sustainable, turning a waste product into a valuable feedstock for another industry.

NWA has successfully managed FOG recycling programs that have led to huge cost savings and money-making opportunities. To learn more, talk to us today at 1-888-692-5005 x6 or email sales@nationalwaste.com.

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