Define a Public Water System (PWS).

A Public Water System (PWS) is defined as a system that provides water for human consumption and meets specific criteria regarding the number of service connections or the population served. The correct answer states that a PWS must have at least fifteen service connections or serve an average of twenty-five individuals daily. This definition is significant because it establishes a baseline for the scale of water supply involved, ensuring that adequate safety and health standards are applied for systems that cater to both small and large populations.

This definition is rooted in public health regulations that govern water quality and access, reflecting the importance of consistent and safe water supply for communities. By identifying systems based on their connections and populations, regulatory frameworks can effectively monitor and ensure compliance with safety guidelines, thus protecting public health.

In contrast, the other options provide definitions that do not meet the established criteria for a PWS. Systems solely for industrial use don't represent the public health focus relevant to community water supplies. Systems that supply water to more than 1,000 residents may exceed the minimum requirements but do not encompass smaller systems that are also classified as PWS. Finally, emergency water supply systems are limited in scope and do not operate under the same regulatory framework aimed at ongoing, routine water delivery for human consumption.