Technical Factsheet on: NITRATE/NITRITE List of Contaminants As part of the Drinking Water and Health pages, this fact sheet is part of a larger publication: National Primary Drinking Water Regulations Drinking Water Standards (in mg/L) Nitrate- MCLG: 10; MCL: 10; 10-day HAL: 10 Nitrite- MCLG: 1; MCL: 1; 10-day HAL: 1 Total (Nitrate+Nitrite)- MCLG: 10; MCL: 10; 10-day HAL: 10 Health Effects Summary Acute: Excessive levels of nitrate in drinking water have caused serious illness and sometimes death. The serious illness in infants is due to the conversion of nitrate to nitrite by the body, which can interfere with the oxygen-carrying capacity of the child's blood. This can be an acute condition in which health deteriorates rapidly over a period of days. Symptoms include shortness of breath and blueness of the skin. Drinking water levels which are considered "safe" for short-term exposures: For a 10-kg (22 lb.) child consuming 1 liter of water per day, a ten-day exposure to 10 mg/L total nitrate/nitrite. Chronic: Effects of chronic exposure to high levels of nitrate/nitrite include diuresis, increased starchy deposits and hemorrhaging of the spleen. Cancer: There is inadequate evidence to state whether or not nitrates or nitrites have the potential to cause cancer from lifetime exposures in drinking water. Usage Patterns Most nitrogenous materials in natural waters tend to be converted to nitrate, so all sources of combined nitrogen, particularly organic nitrogen and ammonia, should be considered as potential nitrate sources. Primary sources of organic nitrates include human sewage and livestock manure, especially from feedlots. The primary inorganic nitrates which may contaminate drinking water are potassium nitrate and ammonium nitrate. Potassium nitrates are used mainly as fertilizers (85%), with the remainder in heat transfer salts, glass and ceramics, and in matches and fireworks. Ammonium nitrates are used as fertilizers (84%) and in explosives and blasting agents (16%). Release Patterns The major environmental releases of inorganic sources of nitrates are due to the use of fertilizers. According to the Toxics Release Inventory, releases to water and land totalled over 112 million pounds from 1991 through 1993. The largest releases of inorganic nitrates occurred in Georgia and California. Environmental Fate Due to its high solubility and weak retention by soil, nitrates are very mobile in soil, moving at approximately the same rate as water, and has a high potential to migrate to ground water. Because it ------- does not volatilize, nitrate/nitrite is likely to remain in water until consumed by plants or other organisms. Ammonium nitrate will be taken up by bacteria. Nitrate is more persistent in water than the ammonium ion. Nitrate degradation is fastest in anaerobic conditions. Chemical/Physical Properties CAS Number: Nitrate ion: 14797-55-8; Nitrite ion: 14797-65-0 Color/ Form/Odor: Domestic fertilizer grade ammonium or potassium nitrates are in prilled (beaded) or crystalline forms, usually coated with an anti-caking agent and adsorbed fuel oil. Solubilities: Nitrates and nitrites are highly soluble in water Soil sorption coefficient: N/A Bioconcentration Factor: N/A Trade Names/Synonyms: Potassium salt: Potnit, Hitec, Niter, Nitrate of potash, Saltpeter. Ammonium salt: German or Norway saltpeter, Varioform I, Merco or Herco prills, Nitram. Other Regulatory Information Monitoring: - For Ground Water Sources: Initial Frequency-Nitrate: 1 sample annually Nitrite: 1 sample during first 3-year compliance period Repeat Frequency-Nitrate: 1 sample annually Nitrite: determined by State -- For Surface Water Sources: Initial Frequency-Nitrate: 1 sample each quarter Nitrite: 1 sample during first 3-year compliance period Repeat Frequency-Nitrate: 1 sample annually Nitrite: determined by State -Triggers - If detect at > 5 mg/L nitrate, sample quarterly. If detect at > 0.5 mg/L nitrite, sample quarterly. If detect total nitrate + nitrite > 5 mg/L, sample quarterly EPA 600/4-79-020 353.1; 353.2; 353.3; 300.0; 354.1 Standard Methods 418C; 418F ASTM D3867-85A; D3867-85B Treatment/Best Available Technologies: Ion exchange; Reverse osmosis; Electrodialysis (nitrate only) Toxic Release Inventory - Releases to Water and Land, 1987 to 1993 (in pounds): Analysis Reference Source Method Number TOTALS Top Fifteen States* Water 59,014,378 Land 53,134,805 GA CA AL 12,114,253 0 3,463,097 12,028,585 21,840,999 6,014,674 ------- LA MO MS KS VA NV FL AR MD IA OK UT 8,778,237 6,985,890 6,952,387 5,140,000 5,091,764 0 0 1,056,560 1,206,610 1,802,219 1,500,340 1,436,348 0 2,250 206,181 0 877,095 4,977,482 1,835,736 1,058,294 138,819 132,042 14,199 1,045,400 Major Industries* Nitrogenous fertilizer Misc. Ind. inorganics Misc. Metal ores Misc. Ind. organics Fertilizer mixing Explosives Paper mills Pulp mills Canned foods Phosphate fertilizers 41,584,611 4,113,312 0 5,091,764 480,000 850,921 1,727,061 1,321,500 0 1,000,000 8,607,376 29,676,919 5,764,976 0 4,554,916 1,297,590 0 3,350 1,056,794 0 * State/Industry totals only include facilities with releases greater than 10,000 lbs. For Additional Information: EPA can provide further regulatory and other general information: EPA Safe Drinking Water Hotline - 800/426-4791 Other sources of toxicological and environmental fate data include: Toxic Substance Control Act Information Line - 202/554-1404 Toxics Release Inventory, National Library of Medicine - 301/496-6531 Agency for Toxic Substances and Disease Registry - 404/639-6000 ------- |