What distinguishes primary drinking water from secondary drinking water?

The distinction between primary and secondary drinking water standards lies primarily in their purposes and regulatory requirements. Primary drinking water standards are enforceable regulations established by the Environmental Protection Agency (EPA) that set maximum contaminant levels for specific pollutants in drinking water. These standards are designed to protect public health by reducing exposure to harmful substances that can lead to illness or adverse health effects.

In contrast, secondary drinking water standards are not enforceable and primarily address aesthetic considerations such as taste, odor, and color of the water. They provide guidance on non-health-related aspects of drinking water quality.

While the other options might touch on various aspects of drinking water quality, they do not accurately represent the enforceability and health-focused nature of primary drinking water standards compared to the aesthetic focus of secondary standards. This foundational understanding of primary standards as enforceable regulations directly correlates to public health protection, making it clear why that distinction is essential.