So, I can try to take it at face value that you were serious in your questions there has been a lot of stuff published in the PDN about the data available in Clallam County on dental needs - The SmileSurvey.  Sadly, the survey does not have a large enough sample size to truly give you comparable data between Sequim, Forks and Port Angeles.   

Filtration systems are being sold on the web for $1500 for whole house.  You would have to do a lot of research on if there is any water lost in the process of filtration - I've not heard that to be the case, but I'm no expert on selling filters.