As good as fried food is, if you’ve ever made it at home, you know what a hassle it can be to dispose of leftover oil since pouring oil down the drain is not just bad practice, it’s illegal and can cause major pipeline issues. Luckily home cooks can avoid these problems by simply going out to eat, but for restaurants, the solution isn’t so simple.

For restaurants to properly and legally dispose of their oil, some choose to hire a collection company to regularly come and remove old cooking oil. Typically, the restaurant will have a designated place, such as a grease trap or grease dumpster, to collect old oil that will then be removed weekly or monthly by collection companies.

In terms of the environment, any method aside from pouring oil down drains is best for the environment. When oil is poured into pipes, it can cling to the sides and build up over time, or it can react with other chemicals to harden into a fatberg that can cause burst pipelines, potentially leaking harmful toxins into nearby wildlife.

That said, even proper oil collection methods are not without issue, and grease dumpsters in particular can cause problems by breaking open and letting the oil flow out and drain into nearby sewers. However, if the grease is properly stored and collected, it can be recycled and turned into fertilizer, biodiesel, makeup, and more.