What is the MCL for nitrate in mg/l?

The maximum contaminant level (MCL) for nitrate in drinking water is established at 10 mg/l. This regulation is in place because elevated levels of nitrate can pose serious health risks, particularly for vulnerable populations such as infants. Nitrate can interfere with the ability of blood to carry oxygen, leading to conditions such as methemoglobinemia, also known as "blue baby syndrome." The 10 mg/l standard helps ensure that drinking water remains safe and protects public health.

In assessing the other choices, 1 mg/l, 4 mg/l, and 0.1 mg/l are significantly lower than the established MCL, and while these values might be safe in terms of nitrate levels, they do not represent the regulatory limit set to protect against potential health risks associated with higher concentrations. Therefore, understanding the MCL of 10 mg/l is crucial for operators and safety managers involved in drinking water quality.