What is the health limit for nitrate/nitrite-N in drinking water?

The health limit for nitrate/nitrite nitrogen (N) in drinking water is set at 10 mg/L. This limit is based on health considerations, particularly for vulnerable populations such as infants and pregnant women. Elevated levels of nitrate in drinking water can lead to methemoglobinemia, or "blue baby syndrome," which prevents oxygen from being effectively transported in the bloodstream, posing serious health risks.

Regulatory agencies, including the Environmental Protection Agency (EPA), have established this threshold to ensure safe drinking water standards. It reflects a balance between potential health risks and the practicality of detecting and treating nitrate contamination in water systems. This limit is part of broader guidelines to maintain public health and safety with regard to water quality.