foul water drainage

[Welsh-border]

I have to connect my foul water drainage to the treatment plant.

 

 

What do I need to put in place where the 2 pipes exit the foundations A + B : 

a) to satisfy building regs

b) ease of access.

Can I just join A and B and then a single pipe to the treatment plant or should I take both pipes to a point near the treatment plant?

Thanks

 

[Conor]

Inspection chamber at both and run A in to B then single run to the treatment plant.