What is the Secondary MCL for Iron?

The Secondary Maximum Contaminant Level (MCL) for iron is set at 0.3 mg/L. This guideline focuses on aesthetic considerations rather than health risks, primarily addressing the taste, odor, and color of drinking water rather than direct health effects. High levels of iron can result in water that has a metallic taste and can cause staining of laundry and plumbing fixtures. Maintaining levels at or below 0.3 mg/L helps ensure that water remains pleasing for consumers and minimizes these aesthetic issues.

Understanding this benchmark is crucial, especially for water treatment professionals, as it guides the treatment processes needed to reduce iron concentrations to acceptable levels before the water reaches consumers.