I have a well in my yard and that should be ok, right? Nope....
It's from a limestone aquafer and it is too hard for the CPAP but that's not the only issue.
Nearby are many farms, spray fields and light industry. All the stuff they secrete eventually finds its way into the water.
A few miles away one well turned up with 500% above safe levels for arsenic. Seriously uncool, no?
I don't even drink the tap water though it looks clear and clean.
Even if you are on municipal water you can't be really sure what's in it.
The utilities wont want to talk about is since
...*heavens!*... they might have to fix it!
For me all water for drinking and cooking is run through a reverse osmosis filter with carbon elements.
That gets *almost* everything except chromium-6 & a few other things perhaps.
So, once a month I just pay $2 for a couple gallons of water and for me that's cheap insurance.
It keeps the machine cleaner and ultimately I end up breathing some of the water myself.
(keeps the tissues moist of course.)
When the water is put in your CPAP humidifier it gets warmed up and some turns to gas but some stays in the form of microscopic droplets. If microbes are present they get a free ride right into your lungs.
So..the water MAY be good enough to drink but might not good enough to breathe...
Don't think so? Ask a biologist.
Last point is: whether you know it or not, you ARE paying for your tap water.
I have to pay for the electricity to pump it out of the ground and well maintenance.
In the city you'll find that it is being charged to your utility bill in some place, but we all pay something for it somewhere.
There's no such thing as a free lunch.