What is defined as a public water system under the SDWA?

The definition of a public water system under the Safe Drinking Water Act (SDWA) stipulates that a system must have at least 15 service connections or serve 25 or more individuals for a duration of 60 days or more within a given year. This criteria is put in place to ensure that any water system which meets these parameters is subject to the regulations and standards necessary to protect public health through safe drinking water.

Option A correctly identifies these key thresholds, emphasizing that both the number of service connections and the population served over a certain period are critical for classification as a public water system. This definition aims to encompass water systems that provide consistent and sustained service to a community, thereby ensuring accountability and regulatory oversight.

In contrast, the other options either state insufficient thresholds for service connections or population size or fail to acknowledge the critical time frame needed for classification. Therefore, option A is the most accurate and aligns precisely with the SDWA's criteria for defining a public water system.