About Nitrates And Nitrites In Drinking Water

Nitrates & Nitrites Occur Naturally

There are many questions about whether or not nitrates and nitrites are dangerous to human beings. Nitrates and nitrites naturally exist within the environment at relatively low levels. In these instances, neither substance causes any harm. It is only when the levels are increased that problems arise. Increased levels of nitrates and nitrites can cause serious health issues, especially for pregnant women and infants.


What Are Nitrates & Nitrites?

Plants make nitrates and obtain nourishment from nitrates in the soil. Nitrate-rich fertilizers are used to enrich the soil for growing plants.  Nitrates are also used to create explosives, and potassium nitrate is used to make glass.

Nitrites are commonly found in fertilizers and are sometimes used to cure meats and preserve food. Nitrites also come from human and animal waste and septic tanks. When introduced into a water supply, nitrites can increase the growth of algae and bacteria.

Both nitrates and nitrites are polyatomic ions that occur naturally and occasionally appear in water sources. As the nitrates and nitrites from fertilizers work their way into the soil, they can contaminate drinking supplies.  They can also enter groundwater and surface water from water treatment plants.  Shallow and poorly constructed wells are highly susceptible to these particular contaminants.


EPA Recommendations

The EPA recommends nitrate levels under ten parts per million for safe drinking water.  Nitrite levels should not exceed 1 part per million for safe drinking water.  Excess nitrates and nitrites in the water can cause developmental issues, blood disorders, and possibly cancer.

These are the accepted levels for nitrates and nitrites based on current research:

10 mg/L (measured as nitrogen) Standard limit for nitrate
45 mg/L (expressed as nitrate)Causes adverse health effects
Above 10 mg/L (measured as nitrogen) Causes adverse health effects
1 ppm nitriteStandard limit
Above 10 mg/L Consult a health professional


How to Test for Nitrates and Nitrites in Water

The EPA strongly suggests that you test for nitrates and nitrites in your well water every year. Home testing water analysis kits often include tests for nitrates and nitrites. TestAssured includes a test strip for these two contaminants in the Complete Water Analysis Test Kit as well as the Well Water Testing Kit.

To perform the nitrate and nitrite test:

  1. Remove the test strip from the packet labeled CL/CO/NA/NI.
  2. Pick up the strip at the end with no pads.
  3. Dip the strip in the sample three times and remove without shaking off excess water.
  4. Hold the test strip level for 2 seconds.
  5. Place the strip on the results color chart and wait 45 seconds before reading the results for nitrate and nitrite.


Health Effects of Nitrates & Nitrites in Water

High levels of nitrates and nitrites can impact the hemoglobin in your blood. Hemoglobin transports oxygen from one cell to another. When these ions are present at excessive levels, they change hemoglobin into methemoglobin, which reduces the blood’s ability to transfer oxygen throughout the body. Normally, your body contains methemoglobin at a rate of 2.5 percent, but the rate is increased when nitrates are present.  This oxygen deprivation can cause respiratory illnesses, heart problems, and in extreme cases, death.

Nitrate and nitrite water contamination is particularly dangerous for pregnant women because pregnancy increases their levels of methemoglobin. Babies are also highly vulnerable to this type of water contamination because they have exceptionally high pH levels in their stomachs. Infants under six months old who drink nitrate/nitrite contaminated water can become dangerously ill and, if untreated, may die.

If you are pregnant or have an infant at home, it’s important to know whether you have nitrates and nitrites in your water system. These contaminants pose serious health risks that can be deadly if ignored.