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


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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


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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


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