The "primary limits" refer to which of the following?

The term "primary limits" specifically refers to chemicals with Maximum Contaminant Levels (MCLs) that cannot be exceeded. MCLs represent legally enforceable standards set by regulatory agencies to ensure public health and safety in drinking water. These limits are established based on health-based criteria and are designed to protect consumers from potential adverse health effects resulting from exposure to specific contaminants.

When a contaminant's concentration exceeds its MCL, it indicates a violation of the standards set to safeguard drinking water quality. In contrast to substances that may have more flexible or discretionary limits, primary limits are stringent and are foundational to maintaining water safety.

Understanding these limits is crucial for water operators, as compliance ensures the provision of safe drinking water and protects public health.