What defines a public water supply?

A public water supply is defined by its ability to serve a certain number of connections or individuals on a consistent basis. Specifically, the correct answer indicates that a public water supply is a system that serves at least 15 connections or provides water to at least 25 people daily. This definition is critical because it establishes the basic requirements for a water system to be classified as a public supply under regulatory standards.

The focus on the number of connections or the number of people served ensures that systems meet appropriate safety, quality, and monitoring standards necessary for protecting public health. Public water systems are subjected to regulations that aim to ensure the potability and safety of the water supplied to the community, which can be crucial for larger populations.

In contrast, the other options do not meet the criteria for defining a public water supply; for instance, serving only 10 connections is insufficient to qualify under typical regulatory definitions, operating for a limited period during summer does not ensure consistent monitoring and maintenance, and servicing only industrial facilities does not account for the requirements of residential or mixed-use communities, which are typically included in public water supply definitions.