You can pour cooking oil down the drain but you will regret it. Cooking oil is a liquid in the fryer at 350 degrees. At 45 to 50 degrees cooking oil begins to solidify. When you pour cooking oil down the drain it lines the pipes and those pipes may be in the walls, below ground (where it’s colder) and that cooking oil quickly turns to a buttery consistency. You might think that running hot water through the pipes chases the cooking oil down to the municipal water system but it does not. It does not carry the grease down because water and grease don’t mix.
As you pour each container of oil down the drain the new oil lines the coating of the previous oil and starts to build up in the pipes. And in time it looks like this:
What happens when the pipe is clogged?
Once the pipe is clogged, wastewater cannot pass through and you have a backup. That backup might include more grease, sewage, food waste or whatever is flowing through the pipes. Soon, your restaurant begins to reek of bad odors. Customers and employees are unhappy and you, the restaurant owner, have a very expensive project to rectify the situation. Should local health and regulatory authorities become aware of this you can receive fines, bills for repairs, orders to shut down, lawsuits and loss of business.
How to prevent backups from cooking oil
First, never pour cooking oil down the drain. Cooking oil should be piped into or transported to a storage tank or deposited safely in an outdoor bin designed to accept used cooking oil. A licensed used cooking oil collector should pump these containers regularly and properly recycle the used oil for use in biodiesel, renewable diesel or animal feed.
As dishes are washed some oil inevitably goes down the drain. The grease trap is the solution here and is required in all restaurants.
How a grease trap prevents backups from used cooking oil
Most grease traps work on a gravity principle. A typical grease trap is a gravity device that separates the fats, oils, grease, and solids (FOGS), preventing them from entering the city sewer lines. It separates grease and solid waste from the kitchen. When waste water from the kitchen enters the trap, the grease settles on the top, the solids in the bottom and waste water in the middle, which separates the grease from the solids.
Grease traps must be pumped and cleaned whenever they approach 25% of capacity. This varies with the volume of business the restaurant does but is typically every 3 months. When the trap is pumped, the walls are scrubbed of solidified grease and then pumped again. Special attention must be paid to the inlet and outlet pipes as well.
Grease traps are what prevent fatbergs, disastrous backups https://pprc.org/2021/pprc/fatbergs-the-growing-menace/ that cost cities millions of dollars.
How should you handle used cooking oil?
Some simple rules to follow for managing your used cooking oil disposal at a restaurant:
- Never pour cooking oil down the drain
- Have a licensed used cooking oil collector such as Rebirth Biofuels collect and recycle your used cooking oil.
- Have Rebirth Biofuels regularly clean and maintain your grease trap. They are licensed
and will properly dispose of the waste from your grease trap at their own plant.
- Train your employees in the do’s and don’ts of handling kitchen grease.