What is the Maximum Contaminant Level (MCL) for nitrates?

The Maximum Contaminant Level (MCL) for nitrates, specifically in the form of nitrate-nitrogen, is set at 10 mg/L. This limit is established to protect public health, particularly because elevated levels of nitrates in drinking water can lead to methemoglobinemia, or "blue baby syndrome," which can be particularly harmful to infants. The guideline aims to ensure that water supplies remain safe for consumption, especially in areas where agricultural runoff may introduce higher levels of nitrates into groundwater or surface water sources. The established MCL is part of the regulatory framework designed to manage potential health risks associated with contaminant exposure, ensuring a consistent standard across public water systems.