How Thames is tackling fatbergs

Sewer abuse is a huge problem, with cooking oil and wet wipes being the major problems when it comes to blocking pipes. In fact, we recently covered the extent of the damage caused in our sewers with the discovery of a giant fatberg. A fatberg consists of items such as wet wipes, sanitary products, and cooking oils that get put down the drains. Fatbergs form as a direct result of all these non-biodegradable items being flushed down the drains. We’re tackling this from many angles, with our ‘Bin it – don’t block it’ campaign, to raise awareness of the issue.

We have 350 sewage works, across 85,000 miles of water mains and sewers – enough to wrap around the world 3.5 times! A large proportion of the pipes date back to the Victorian times, when they were first installed and so struggle with the growth of our modern population.

We monitor the network of pipes so we can find the hot-spots for blockages. Wherever possible this means we can get in there early, flush the pipes and prevent sewage flooding into homes and businesses. The scale of the pipe network however, does make this sometimes very difficult.

On average, we unblock 5 house blockages and remove 30 tonnes of ‘unflushable’ material, from just one of our sites each day. This costs us on average £18m per year, but the damage caused by not fixing blockages in customer homes, would cost much more.

Working with wet wipe manufacturers

We’re working with manufacturers to correctly label wet wipes, as we know from experience that the term ‘flushable’ isn’t accurate where sewers are concerned. Items labelled ‘flushable’, are actually very slow to break down, and contribute to the clogging of pipes which can lead to the growth of the infamous fatbergs. We’re also working to influence them to remove the plastics in the wipes, as this makes the materials slow to break down and also harms the environment.

Caring for your environment

We’re collaborating with other water companies as well as environmental organisations to raise awareness of the problems and behaviours that cause damage to the sewers, and ultimately the environment, birds and wildlife.

Influencing the younger generations

We’re working with local schools to ensure the younger generation know what shouldn’t go down the drain. Our fun and interactive sessions are linked to the National Curriculum, and educate children about water and waste.


Prevention is better than a cure and we campaign and persuade individuals and businesses to think about how their behaviour affects the drains. Ultimately if we can stop the wrong things from getting into the system in the first place, then we can focus our attention and energy on other areas.

Help fight the fatberg

You can help by only flushing the 3Ps - pee, poo and paper – as well as disposing of fat and oils in the bin, to keep our sewers flowing free. Why not also try using alternatives to wet wipes which don’t have as bigger impact on the sewers.


This October, we've signed up for Unblocktober. This is the world’s first month-long national campaign and awareness month to improve the health of our drains, sewers, watercourses and seas - driven completely by the British public.