Every day, people in both private homes and catering establishments dispose of various fats and oils by washing them down the sink and into the drains and sewer system. This does not just involve liquid and solid fats such as cooking oil or lard from a frying or chip pan, although this plays a big part. Fats are also present in food such as mayonnaise, salad dressing, gravy, milk, cream and even some soaps, which all tend to be rinsed away.
Unfortunately, unless you have grease traps in place, fats and oils don’t simply disappear for good; instead, they have a terrible effect on our sewer systems. Let’s look at this in more detail.
What happens to fats and oils once they leave your sink?
Initially, anything you rinse down the sink travels through the household waste pipes and then into the shared sewer system; however, they do not necessarily move on very fast. Fats and oils like to mix with chemicals and random debris before clinging to the sewer walls, where they harden until eventually more layers are added. When the pipes block completely, the problem becomes noticeable.
The effect on the sewer system:
– The reduced flow of all contents of the sewer system, which occurs when the space is being compromised. This may well cause unpleasant smells.
– A sudden and very unpleasant overflow of raw sewage caused by the backup of waste that the fat and oil blockage causes.
– Complete blockage of the drain. This is the most serious issue, as raw sewage is likely to reverse and back up into a home or restaurant kitchen because it simply has nowhere else to go. This exposes the spaces affected to potential bacteria, to a hefty bill to repair the issue, and potentially to contaminated water.
How to help avoid these problems
The easiest way is to install grease traps in all restaurant or home sinks that are vulnerable to this problem. As long as they are emptied as required, this should tackle the problem efficiently.
Of course, it makes sense to avoid dumping grease in the sink just because you have a grease trap; instead, try scraping fats into the bin and look for local schemes that recycle vegetable oils from restaurants and cafes into biofuel.