This episode is all about fat. From a clogged lift shaft in a nursing home to the sewers under Manchester's city centre - hundreds of litres of this greasy and gross substance is poured down the drains each week in the north west and we see just how messy things can get. Manchester's Waste Water Treatment centre treats 714 million litres of sewage a day, from false teeth to lumps of fat the size of a small car. It can take up to a week removing the leftover grease and fat from the gigantic tanks.
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