Student or Learner
''The pollution of the municipal well hav-
ing been discovered'', that will be attached with ''the town posted notices urg-
ing people to boil their water''.
It's grammatical, but I think this is better:
Having learned the municpal well was polluted, the town urged residents to boil their water.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.