A fatberg is a mass of congealed fat, oil and grease bound together with wet wipes and other solids that should never have been flushed, forming inside a sewer until it blocks it. They are the visible consequence of the fats, oils and grease that leave kitchens and households, and they are the reason water companies take grease management on catering premises seriously.
How one forms
Warm fats and oils poured down a sink cool in the sewer and solidify on the wall of the pipe. Wipes, sanitary items and other solids catch on that layer, and the mass grows across the flow until it restricts or blocks the sewer entirely.
Who pays for it
The water company clears it, and where a blockage can be traced to a premises, the cost can be recovered from that premises. Businesses discharging significant grease are the first place a company looks.
Why it matters to a kitchen
Enforcement of grease management on catering premises follows directly from this. A trap that is fitted, correctly sized and actually emptied is the evidence a kitchen is not the source, and the transfer notes are what prove the grease went somewhere lawful.
The household half
Domestic cooking oil poured down the sink and wipes flushed down the toilet contribute as much as commercial premises in many areas, which is why water company campaigns address both. It does not reduce what is expected of a business.
Questions people ask about what is a fatberg
What is a fatberg made of?
Congealed fats, oils and grease bound with wet wipes and other solids that were flushed rather than binned.
Can a business be fined for a fatberg?
Discharging matter likely to interfere with the free flow of a sewer is an offence, and water companies also pursue the cost of clearance where a blockage is traced to a premises.
How does a grease trap help?
It holds the fats, oils and grease back at the premises so they can be removed as waste rather than entering the sewer, which is exactly what the enforcement is aimed at.