A ton of the PNW are resistant to everything from fluoridated water to "unneeded vaccines" which led to a relatively massive Measles outbreak a few years back. Also let me introduce you to "Raw Water"...

Trendy “raw water” source under bird’s nest sparks diarrheal outbreak

Health officials would like to remind you that drinking untreated water is a bad idea.

Oh. My. God. That sounds like a dystopian novel.