Stoptap conundrum

[mayfel]

I reckon I'm usually pretty good at figuring this stuff out but I'm completely stumped with this. So here's a water inlet conundrum for anyone who can give me a clue(?)!

I am getting the kitchen prepped for a delivery whenever this lockdown ends. Next to the working stop tap I've found an older seized one. Now I've seen new ones put inline before when an old one has seized open, but this one is teed in. If they put in a new upright pipe teed off underground to make the new feed on the right then I don;t understand why they would tee in the old one on the other side of the tap. The new tap turns off everything in the house.

Any ideas?! I'd like rid of the old line as it comes out from the floor of the new kitchen design rather than behind units. The main outside stop tap in the pavement is full of concrete and Yorkshire Water won't be coming till after the lockdown and even then it'll probably be weeks so I'm loath to do any changes until I know exactly what is happening here!

I don't know whether the old one is seized open or shut by the way.

 

[Burnerman]

Maybe the water enters via the new working stop tap, then goes back down through the old tap heading for a long gone outside provision?
This is exactly the same as on a holiday property of mine, history unknown. I still don't know where the pipe is heading for, but presumably to an outside netty......one day I'll cap it off but at least the water meter assures me its not leaking!
John