After the sump pump and pit this is the ideal time to totally remodel the basement into your Dream Basement. A subfloor guitar haven. Totally soundproofed and with fully automated drinks and snacks dispensers.
Seriously though, I really hope you get this all sorted out and fixed up as soon and as inexpensively as possible. We had a similar (though not as serious) problem recently with a leaking water tank in our loft. We didn't know it was leaking until there was water dripping through our bedroom ceiling.
All the best.