Sustainability in the Home: An Oily Mess

At this moment, in kitchens across the country, meals are in the process of being cooked. The ignition for so many of these meals – cooking fats and oils – may be left to pool in the pan, forgotten about until they come to be wiped away in the washing up bowl. What seems like a little grease lost in the vastness of the drains is in fact a congealing, fatty time bomb which poses a genuine threat to the nation’s sewers. In London this summer, sewage workers found a ‘fatberg’ of epic proportions lurking underground. The colossal ball of solidified oil and grease had become fatter and fatter until it blocked 95% of a 2.4 metre sewer pipe, threatening to flood Kingston with sewage. It took a team of sewage workers three weeks to rid the sewer of the mound of fat, using high power water jets.
According to sewage companies, ‘fatbergs’ are becoming more and more a common sight underground, thanks to households and restaurants pouring their used fats and oils down the drain.


However, bottles of olive oil and tubs of margarine have been saved from the status of environmental enemies by a new initiative to transform these waste fats into energy. Boris Johnson is pressing for London buses to be run by the waste fat produced by the capital’s food industry.  Fast food giant McDonalds already powers half of its fleet of lorries with biofuel converted from the waste fat used in its London restaurants. If London could harness the power of its waste oils, Johnson predicts that ‘we could provide 20% of the fuel needed to power London’s entire bus fleet while saving thousands of tonnes of CO2 and creating hundreds of new jobs.’


Though it may be a while before regular homeowners are sending their used fats to the city council for processing, everyone can play their part in reducing the danger of grease-induced sewer blockages. To keep drains clear, it is recommended not to put vegetable or animal fats, cooking oils, margarine, butter, food scraps or dairy products down the drain.


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Post by Action 21 volunteer blog writer  Laura Parkes