Sewer showing signs of fat, oil and grease. A build-up of this type of residue is indirectly responsible for many cases of flooding and pollution incidents.

Emergency work being carried out following a pollution incident. Sewage back-ups, caused by blockages, can pollute our environment and homes.

Effects of disposing of fat down the sewer are seen in this picture of a blocked sewer manhole. About £15 million is spent annually on clearing sewer blockages nationwide.

Fat, oil and grease build-up. Over time, fat builds up and hardens to form a concrete-like material that can eventually block the sewer system.

Effects of food residues in a sewer. Blockages account for 55 per cent of sewer flooding incidents.

There are approximately 200,000 sewer blockages throughout the UK every year of which 75 per cent are caused by fat. This picture shows a drain clogged with fat.