Nitrate is a naturally occurring chemical compound that is formed in the soil when nitrogen and oxygen combine. Small amounts of nitrate are normal but large amounts can pollute groundwater and cause severe consequences to life.

Sources of nitrate in the soil are chemical fertilizers, septic system discharge and livestock waste. A portion of chemical fertilizer will convert to nitrate in the soil. Ammonia is present in the waste of both humans and animals. It enters the soil from inadequate or poorly managed septic systems. Plants can only absorb so much nitrate from the soil and the excess is then carried down through the soil into the groundwater by the action of rain, snowmelt and irrigation.

The consumption of small amounts of nitrate is not harmful; nitrate is actually apart of a normal diet. Health problems can occur however with ingestion of excessive nitrate. When nitrates enter the body, stomach bacteria converts nitrate to nitrite. Adults have low pH (high acidity) stomach acid that destroys this nitrite producing bacteria.

Infants however (especially those less than three months in age) do not have developed digestive systems that can destroy the stomach bacteria, so infants can develop excess amounts of nitrite in their bodies and develop methemoglobinemia. Methemoglobin is a converted form of hemoglobin, which is found in red blood cells and normally carries oxygen in the body’s bloodstream. In methemoglobin form, these cells are unable to transport oxygen and these infants now become oxygen starved. Because oxygen starvation results in a bluish discoloration of the body, methemoglobinemia has been referred to as “blue baby syndrome”. Once an infant’s system is fully developed (normally three to six months), methemoglobinemia is a rarely a problem. Methemoglobinemia, if recognized by a physician, is relatively easy to treat and babies can make a full recovery.

Livestock are also susceptible to nitrate poisoning however they too, can be treated and fully recover. For more information regarding methemoglobinemia or nitrate ingestion in general, please consult your family doctor.

The United States Environmental Protection Agency (EPA) recommends that well users test their water every one to three years for both total nitrate and biological content. If the taste, odor, or appearance changes, test the water more frequently. Nitrate is either expressed in reports as Nitrate-N (nitrate as nitrogen) or Nitrate as Nitrate. The maximum contaminant level (MCL) for nitrate-N is 10 ppm (also known as milligrams per liter). To express nitrate as nitrate, multiply by 4.4 The MCL for nitrate as nitrate is 44 ppm for instance.

The primary causes for nitrate contamination in groundwater are failed or overloaded or improperly constructed and located septic systems, animal waste and fertilizer. Water that comes in contact with these sources will absorb nitrate and carry it down into the soil eventually ending up in the groundwater.