In message , at 19:09:25 on
Wed, 2 Apr 2014, Aurora remarked:
How easy is it to provide loos in deep tube stations? I'm thinking of issues
like being below the sewers.

It would be difficult, there would be ventilation issues. Moreover,
waste would need to be pumped up to the sewers. In the event of a
failure the WCs would become a health hazard very quickly.

I know that architects and designers like to do their very best to prove
me wrong, but surely the hydraulics involved are very well understood
technology (for example one-way valves on the pumps). As for
ventilation, the whole station needs ventilating anyway.
--
Roland Perry