Which types of contaminants does the primary MCL regulation address?

The primary Maximum Contaminant Level (MCL) regulation specifically addresses health-threatening contaminants. These regulations are established to protect public health by setting limits on the concentration of specific harmful substances in drinking water. The focus is on contaminants that can pose significant health risks to consumers if present at certain levels.

This is crucial because the overarching goal of water quality regulation is to ensure that drinking water is safe for the public. The MCLs are derived from health studies indicating the potential adverse effects these contaminants can have, leading to illnesses or chronic health issues when consumed over time.

In contrast, aesthetic effects like taste and odor do not fall under the primary MCLs, as they are classified differently and are described by secondary MCLs aimed at improving the sensory quality of water rather than directly assessing health risks. Physical contaminants and non-toxic contaminants are also not the focus, as the regulation primarily aims to address substances that can threaten human health rather than those that may cause physical changes or are deemed non-toxic.