How does Hayek justify government regulation for sanitation and clean drinking water?

Hayek mentions “sanitation” only ONCE in four of his books: Constitution of Liberty, Law, legislation and Liberty, Road to Serfdom, Fatal Conceit. My annotations in blue. Highlights mine.

CONSTITUTION OF LIBERTY

The rules of property and contract are required to delimit the individual’s private sphere wherever the resources or services needed for the pursuit of his aims are scarce and must, in consequence, be under the control of some man or another. But if this is true of most of the benefits we derive from men’s efforts, it is not true of all. [Sanjeev: This is a major statement, and requires a highly systematic justification of such exceptions, which Hayek doesn’t provide] There are some kinds of services, such as sanitation or roads, which, once they are provided, are normally sufficient for all who want to use them. The provision of such services has long been a recognized field of public effort, and the right to share in them is an important part of the protected sphere of the individual. We need only remember the role that the assured “access to the King’s highway” has played in history to see how important such rights may be for individual liberty.

Sanjeev:

1. “Once they are provided” is NOT a good reason to distinguish the private sphere and shared sphere.
2. Niether roads nor sanitation come up magically on their own. Each has a historical justification and someone HAD to pay. Hayek is also factually wrong to suggest that roads are a field of public (government) effort. Not. Many (if not most) roads in the past were privately built. So also for drinking water supplies.
3. There is no “right to share” in private roads or private drinking water supply. Where does such a “right” come from? Who is paying for it?