Excess nitrogen in drinking water is detrimental to children and livestock
Excess nitrogen, in surface and groundwater systems used for drinking water, is dangerous to the health of certain groups of people and animals. For example, infants less than six months old are particularly susceptible to harm because their stomachs are not acidic enough to prevent certain growth of certain bacteria which convert nitrate to nitrite. High levels of nitrites can oxidize hemoglobin to form methanoglobin which is unable to carry oxygen. Brain damage or death by suffocation can result from this condition known as methemoglobinemia or blue baby syndrome.
Pregnant cows can also suffer from methemoglobinemia, which usually results in the death of a new born calf.
The allowable level of nitrogen in water for children six months or less is 10ppm (10 mg/1) as nitrate nitrogen or 45 ppm (45 mg/1) as nitrate. Adults and older children can probably tolerate higher levels, but the standard is usually set at the more conservative level. Should groundwater become contaminated, nitrate removal at a community treatment plant is presently estimated at a cost about $10 to $15/month for a family of three.