Where the back deck meets the house MJ noticed water pooling. Dig hole get sump pump. Waret does not gush, that may be a good thing. Go to store buy colored flouresent dyes. Put yellow die down kitchen sink where we have had clogging issues before. Keep sump pump cleaning up. Yellow die shows up outside.
Sigh, tomorrow go to the last in line sink and put red die in, see if I can pin point the actual source.
A small repair of a tub leak in the slab of my old rental cost the landlord $3k. This is 10 times the level of work if I have to do all of it.

1. jack hammer slab, replace 80 ft of drain, re-concrete and re-floor
2. re-engineer, taking each drop external then bury lines external.
3. see if there is a way to sleeve the drains. If I can engineer it I can sell a solution.
4. Hand the keys to the bank and apologies for the mess.

Sigh