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Kitty Thompson: Don't wake up to a fatberg on boxing day

Kitty Thompson (Nature Programme Manager at CEN)

Roast turkey, brussel sprouts with crispy bacon lardons, roast parsnips and potatoes, pigs in blankets. Christmas Day is fast approaching, and I am very excited to eat my dinner and all the festive accoutrements that are piled on my plate for this one day a year.

But with a great dinner comes great responsibility. Water companies regularly see an increase in sewer blockages around Christmas time. The culprit, they believe, is the incorrect disposal of fats, oils and greases.

This is because fats and oils, although liquid when heated for roasting, will turn solid when they have cooled. If put down the sink, the fat will turn solid in your pipes and build up over time.

At best, this will lead to a small blockage that you need to sort out, at worst, you will be contributing to your local fatberg that will cost bill payer money to deal with.

There are approximately 300,000 sewage blockages annually in the UK, costing the country £100 million to clear. Incorrect disposal of our Christmas cooking waste can pose massive problems to our already strained sewer system.

So, if you flash forward to the moment you carry your empty dishes back into the kitchen, and the washing up tasks are assigned, here is what you can do…

Just as you would scrape your leftovers into tupperware and your scraps into the (compost or food waste) bin, scrape the oils that remain in your cooking trays and dishes into a separate container.

Fortunately, you do not need to buy a purpose-made container to do this, any upcycled old yoghurt pot, Gu pot or jam jar will do. Leave the contents to cool and harden and, when ready, put it into the bin.

Turning to my favourite part of the dinner, gravy, whilst not a fat, oil or grease, is a liquid. This does not mean, however, that it can go down the sink and should be redirected to the bin instead.

To avoid any messy accidents that a burst bin bag combined with gravy could create, use some old kitchen roll, napkin or other paper that is unable to be recycled to absorb the liquid and then put it in the bin bag.

If you revert to autopilot and accidentally pour something down the sink that you shouldn’t, don’t reach for the washing-up liquid and kettle. Contrary to popular belief, soap will not necessarily break down the fat and could even actually harden it, contributing to the blockage.

Hot water alone is unlikely to work either, but adding vinegar and baking soda beforehand just might do the trick. The main thing to do is to tell your sink you are sorry and promise not to do it again.

As everyone starts to dust off their gravy boats and roasting tins ahead of their Christmas cooking, remember to put a handy container nearby to collect your fats, oils and greases. It may not be the most exciting of Christmas tasks, but you’ll regret not doing it as you dial for an emergency plumber on Boxing Day!


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