‘What work is it that you’re doing here, and when did it start?’

‘What you see right here is the flood management phase, second phase of the infrastructure plan for the area. We’re putting in water pipes and sewers to serve the new estates planned for the far side of Upper Rissington. We started on it three months ago, and just got up to there, where the body was found, last week.’

‘And what about the first phase?’

‘That was the main sewer modernisation, started nearly a year ago.’ He sucked his teeth. ‘It was designed to stop the storm drain surcharge problems they’ve been having round here.’

‘Did Ozzy Blanchard work on that first phase?’

Collier stared at him. ‘Yeah, he did. Then, as I say, he disappeared, and his company car was found down there in the river in January. It can’t be him, though, can it?’

‘Why not?’

‘The archaeologist said the body is probably years old.’

‘Did he indeed?’ Gillard clenched his teeth.

‘And it’s upriver from the car, so he didn’t get washed up here.’

Gillard made a couple of notes and looked back at Collier. ‘Some in the community say there’s been a lot of pollution over the years.’

Collier sucked his teeth at what was clearly an often-expressed opinion. ‘Yeah, we’ve been having our ears bent about it from all sides. The trouble is it’s not so easy to solve. The original pre-war sewer for all the villages to the north-east of here runs parallel to the storm drains. Normally they run side-by-side, not interfering with each other at all, until they join just prior to the water treatment works five miles that way.’ He pointed west past Gillard, downriver past the flyover. ‘The storm drains are designed to vent rainwater into the river in extreme circumstances. But when you get heavy rain, rainwater gets into the sewer, and it too will vent into the storm drains at certain locations when the water level gets high enough, and certainly when the streets get flooded. And Rissington Common, and the land around, is the lowest point.’

‘So when there is exceptional rain, basically you get shit in the river?’

‘And all the other stuff people flush down the toilet.’

‘Don’t you have gratings to hold that stuff back?’

‘We do, but they get blocked very quickly. It only needs a few nappies for example to inhibit the flow. At a certain pressure, the gratings are designed to lift as an escape valve, which allows everything out.’

‘Why?’

‘Because otherwise we’d flood out the water treatment works and that would take weeks to put right. So we are allowed to vent a certain amount of raw sewage in exceptional circumstances, but the Environment Agency gets upset if there’s too much and we can get fined millions, which has happened.’