There is a long article in this morning's Guardian about a region in France near Basel/Mulhouse where there is government advice not to drink the tap water which is polluted with cancer causing agents PFAS.The problem is not confined to that area. It is said there are 43 other areas so far identified which exceed heath warning levels:
www.theguardian.com
I seems improbable to me that the problem is confined to France.
I have always used bottled water for drinking in my van. You may wish to reconsider if you do otherwise.

‘Even if we stop drinking we will be exposed’: a French region has banned tap water. Is it a warning for the rest of Europe?
Forever chemicals have polluted the water supply of 60,000 people, threatening human health, wildlife and the wider ecosystem. But activists say this is just the tip of the Pfas iceberg
I seems improbable to me that the problem is confined to France.
I have always used bottled water for drinking in my van. You may wish to reconsider if you do otherwise.