Masticator ducks in and out of culverts, threading its way through the city. We got into the culvert and straight away side pipes beckoned further inspection, one home to a CSO chamber with the processing gear annoyingly up near the ceiling.

The infall stands proud and makes little effort to conceal itself, it's grille reduced to lying in the water creating a mini dam.

A culvert that travels under much of St Helens with a dirty big sewer overflow at one end.

A set of stairs drops down from a small dry RCP and joins after the outfall, the whole setup looking like a 'Y' from above.

STD starts off with a long old stoop through Corrugated Metal Pipe.

A balancer between the A and B Outfall sewers with penstocks to enable throttling between pipes.