What distinguishes primary standards from secondary standards?

The distinction between primary and secondary standards is primarily based on their impact on health and safety. Primary standards are linked to health and are designed to protect public health by limiting contaminants in drinking water that could pose immediate or long-term health risks. These standards are established with the understanding that certain contaminants may lead to serious health issues if present above specified levels.

In contrast, secondary standards are focused on non-health-related aspects of water quality, such as taste, odor, color, and other aesthetic factors. While they address various characteristics of drinking water that could affect consumer acceptability, they do not impose mandatory requirements for health protection like primary standards do.

This clarification highlights the critical nature of primary standards in ensuring that water remains safe for consumption and underscores why those standards are considered mandatory by regulatory agencies, whereas secondary standards serve as guidelines that can improve the overall quality and enjoyment of drinking water but do not directly safeguard health.