A13 road

And so you can see the way that London has used Essex as a kind of colony, sending out vast tracts of shit.

Pitsea was an old Victorian marshland tip off the A13 near Basildon where no one ever knew exactly what was being dumped.

One of the former tip workers I met told me it was later discovered that the soil in some of the places he worked was contaminated with arsenic, strychnine, who knows what.

In 1975, a lorry driver, Thomas Carroll, died after inhaling lethal hydrogen sulphide fumes given off by two toxic loads dumped in Pitsea, which made the press across the UK.

If you'd gone back 150 years, we would have just been looking at a flat marsh, your kind of Charles Dickens Great Expectations salt marsh.

It should have just been completely, completely flat.

Spencer said if you drive out of London on the A13, as you head east, you should be able to see the river as you are driving along the floodplain.

But you can't.