Governments exist to give everyone a basic set required services. I think even the biggest free market/ small government advocate would agree that access to clean drinking water is one of those services.
I don't think that there is any right level for all countries.
Case in point: my grandparents are on medicare. They pay basically nothing for it. One of them just had bypass surgery and the other a knee replacement. Cost to them: $0.
We pretty much have universal access healthcare in the US before the Obamacare stuff if you go through the system.