putting pressure on water companies to stop dumping sewage in them.

I mean, it’s a result of using older combined sewers. The sewer and drains go to the same place, so when there’s enough rain, the system gets overwhelmed and dumps some amount without treating it.

I’m sure that if people are willing to pay what it’d cost to upgrade the sewer system, that upgrading it isn’t a problem, but it’s not free, and one has to weigh the cost against that benefit.

I’ve got one relative living in a city in the US that’s in the process of doing that shift away from a combined sewer system, and the total cost of the rebuild is around $5,000 per resident. That’s a fair bit of money to ask the population to pay.

In their case, it wasn’t driven purely by a desire to convert from a combined sewer system, but because the existing system needed to be fixed, and if you’re going to have to do major repairs anyway, then it’s time to bite the bullet and pay for dealing with the combined sewer. I’m thinking that it may be that British cities might do something like that – kick the can down the road until the system really has to be replaced anyway, and then pay what it costs to move away from the combined sewer.