|CAS Number: 14797-55-8|
|Contaminant Type: Chemical|
Nitrate (NO3-), combined with various organic and inorganic compounds, is a widespread groundwater contaminant and a major water quality concern in drinking water supplies .
Primary sources of organic nitrates include human sewage and livestock manure . Livestock feedlots, wastewater treatment discharge, and faulty septic systems can result in the release of organic nitrates into the environment . Fertilizers containing potassium nitrate and ammonium nitrate compounds are the major source of inorganic nitrate . In 2005, over 291 million pounds of inorganic nitrate compounds associated with fertilizer application were reportedly released .
In natural waters, most nitrogenous materials are converted to nitrate. All sources of combined nitrogen, particularly nitrogen and ammonia, are potential sources of nitrate . Nitrates are very mobile in soil and have a high potential to migrate to ground water due to weak soil retention and high water solubility . Nitrates do not volatilize and therefore are likely to remain soluble in water until consumed by plants or other organisms .
Excessive levels of nitrate in drinking water supplies can cause serious illness and possibly death, with infants and children among the highest at risk . The major health concern associated with nitrate consumption is methemoglobinemia, also known as “blue baby syndrome” . In infants, nitrate is reduced to nitrite which combines with hemoglobin in the blood to form methemoglobin . The presence of methemoglobin decreases the oxygen-carrying capacity of the blood resulting in acute symptoms, such as shortness of breath and blue coloration of the skin . Reduced oxygenation of the tissues can have numerous adverse implications, the most severe of which are coma and death .
The maximum contaminant level (MCL) for nitrate is 10 mg per L as nitrogen (N) or 45 mg per L as Nitrate. EPA has identified ion exchange, reverse osmosis, and electrodialysis as the best available technologies for nitrate removal from drinking water.
Date of Literature Search: July 2014
Jensen, V., Darby, J., Seidel, C., and Gorman, G. ;
Nitrate in potable water supplies: alternative management strategies;
Envir. Sci. & Tech.;
2268 USEPA; 2007; Nitrates and nitrites toxicity and exposure assessment for children’s health chemical summary; http://www.epa.gov/teach/chem_summ/Nitrates_summary.pdf; As posted on November 20, 2014. EPA TEACH databases, Washington, DC.
2269 USEPA; 2014; Technical factsheet on: nitrate/nitrite; http://www.epa.gov/ogwdw/pdfs/factsheets/ioc/tech/nitrates.pdf; As posted on November 20, 2014. EPA Office of Ground Water and Drinking Water, Washington, DC.