Private well owners are responsible for the safety of their drinking water. Maintaining a healthy well requires routine testing for possible contaminants, including nitrate and nitrite. To assist in water safety, the EPA has set standards for nitrate levels in public drinking water systems. Although private well owners are not required to meet these standards, they do serve as a reference for safe drinking water. The EPA Maximum Contaminant Level (MCL) nitrate is: 10 ppm (parts per million) or mg/L (milligrams per liter) nitrate-nitrogen or, if expressed as nitrate, 45 ppm. For nitrite, the MCL is: 1 ppm or mg/L nitrite-nitrogen or, 3.28 ppm if expressed as nitrite. Nitrite is not stable in water and rapidly transforms to nitrate fairly easy. Its presence is an indicator of high concentrations of either nitrate or ammonia.
Status and Revision History
Published on Sep 30, 2020