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.
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.
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.
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.