1. ITV Report

Another massive 'fatberg' forms, costing a million pounds a month

By Martin Stew: ITV London Presenter

Under this central London manhole is a sewer in one of the worst states Thames Water has ever seen.

Credit: ITV London

Why I agreed to go down there I'm not sure. The smell coming off the guys who were down there wasn't great.

What I found at the bottom of the ladder 10 metres below Whitehall is even worse than feared.

Credit: ITV News

A fatberg is when people put fat and oil down the sink. It all congeals into these big huge rocks like this that block up all the sewage system. It's like concrete.

Sewers are used these days literally like rubbish ground. Not just fat it's everyday rubbish toiletry items, waste items, I mean we've got a plank of wood here that's never going to go down a main sewer.

– Dave Dennis, Thames Water
Credit: ITV News

Much like a clogged artery, the fat and rubbish reduces the flow which can pass through the sewer.

To remove it requires hug machines to suck the muck.

Credit: ITV News

It costs about £12 million a year - a million pounds a month it's costing us as a business. We pay for it but the customers pay for it too. They pay for it through their bills they also pay for it through their bills and also the misery because its not nice if you get internal flooding.

– Dave Dennis, Thames Water

So after my trip to the sewer, I have the message 'bin it don't block it' ringing in my ears and a foul stench burning my nostrils.