What Happens To A Restaurant's Leftover Oil?

If you're a fan of fish and chips for dinner or can't seem to live without some homemade fried chicken, you may be well-versed on how you should be properly disposing of your cooking oil. But if you've made the mistake of pouring it down the drain, you likely had a rude awakening involving long hours of attempted unclogging or inescapable high plumber bills. 

Suppose you haven't yet borne the expensive personal consequences of disposing of oil down your drain. In that case, you should know the practice is illegal, as it can lead to major issues in city sewers and pipelines (via SeQuential). However, have you ever thought about how restaurants choose to get rid of their leftover cooking oil? Huge vats of used oil need to be dealt with on a much bigger scale, and handy tricks wouldn't seem able to cut it. While some don't handle it the best way, others opt for hiring a cooking oil collection company.

While many restaurants may turn to the forbidden down-the-drain method, others hire workers to properly dispose of their cooking oil. Hiring a collection company is likely the most popular and recommended way to remove old cooking oil since restaurants can hire the company on a routine basis to pick it up. 

Typically, the restaurant staff will have a designated place, such as a grease trap, to pour the oil whenever they need to get rid of it. The companies usually come weekly or monthly, depending on a location's size. Most grease collectors have trucks that are equipped with vacuum mechanisms to suck out the liquid oil from the trap. Hardened oil on the sides of the trap will get scraped off. 

Other restaurants have what is known as a grease dumpster. Employees can dump the leftover oil daily into these containers, which are usually located behind their building. Grease collection companies will also handle properly disposing of the oil located in this location as well. 

Just about any method is better than illegally pouring oil in kitchen sinks, storm drains, or other outside locations. When the oil is poured out into pipes, it can cling to the sides and build up over time, becoming a bigger issue. Once the oil reacts with other chemicals already in the sewers, it can harden and become what is known as a fatberg. 

Fatbergs are large, hardened masses that grow over time as they catch pieces of waste, and they can become very damaging in sewer systems. This can easily lead pipelines to burst, which causes issues such as backwashes, flooding, and costly repairs. Such events can be environmentally damaging as toxic waste and debris can wash up, affecting local plants and wildlife.

However, proper collection methods can also have issues. For example, grease dumpsters can occasionally break open, letting the oil flow out. When it rains, this oil can then be washed into the sewers, causing the same environmental issues as mentioned before.

Grease collection companies are likely the best large-scale way to dispose of grease, as the waste usually gets recycled. Depending on the company, the oil can be turned into many things, from fertilizer to biodiesel to makeup and more. If you're an at-home cook looking to reduce your own environmental impact, learning to reuse your old cooking oil may be a great place to start.